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12 | https://en.wikipedia.org/wiki/Anarchism | Anarchism | Anarchism is a political philosophy and movement that is against all forms of authority and seeks to abolish the institutions it claims maintain unnecessary coercion and hierarchy, typically including the state and capitalism. Anarchism advocates for the replacement of the state with stateless societies and voluntary free associations. As a historically left-wing movement, this reading of anarchism is placed on the farthest left of the political spectrum, usually described as the libertarian wing of the socialist movement (libertarian socialism).
Although traces of anarchist ideas are found all throughout history, modern anarchism emerged from the Enlightenment. During the latter half of the 19th and the first decades of the 20th century, the anarchist movement flourished in most parts of the world and had a significant role in workers' struggles for emancipation. Various anarchist schools of thought formed during this period. Anarchists have taken part in several revolutions, most notably in the Paris Commune, the Russian Civil War and the Spanish Civil War, whose end marked the end of the classical era of anarchism. In the last decades of the 20th and into the 21st century, the anarchist movement has been resurgent once more, growing in popularity and influence within anti-capitalist, anti-war and anti-globalisation movements.
Anarchists employ diverse approaches, which may be generally divided into revolutionary and evolutionary strategies; there is significant overlap between the two. Evolutionary methods try to simulate what an anarchist society might be like, but revolutionary tactics, which have historically taken a violent turn, aim to overthrow authority and the state. Many facets of human civilization have been influenced by anarchist theory, critique, and praxis.
Etymology, terminology, and definition
The etymological origin of anarchism is from the Ancient Greek anarkhia (ἀναρχία), meaning "without a ruler", composed of the prefix an- ("without") and the word arkhos ("leader" or "ruler"). The suffix -ism denotes the ideological current that favours anarchy. Anarchism appears in English from 1642 as anarchisme and anarchy from 1539; early English usages emphasised a sense of disorder. Various factions within the French Revolution labelled their opponents as anarchists, although few such accused shared many views with later anarchists. Many revolutionaries of the 19th century such as William Godwin (1756–1836) and Wilhelm Weitling (1808–1871) would contribute to the anarchist doctrines of the next generation but did not use anarchist or anarchism in describing themselves or their beliefs.
The first political philosopher to call himself an anarchist () was Pierre-Joseph Proudhon (1809–1865), marking the formal birth of anarchism in the mid-19th century. Since the 1890s and beginning in France, libertarianism has often been used as a synonym for anarchism and its use as a synonym is still common outside the United States. Some usages of libertarianism refer to individualistic free-market philosophy only, and free-market anarchism in particular is termed libertarian anarchism.
While the term libertarian has been largely synonymous with anarchism, its meaning has more recently been diluted by wider adoption from ideologically disparate groups, including both the New Left and libertarian Marxists, who do not associate themselves with authoritarian socialists or a vanguard party, and extreme cultural liberals, who are primarily concerned with civil liberties. Additionally, some anarchists use libertarian socialist to avoid anarchism's negative connotations and emphasise its connections with socialism. Anarchism is broadly used to describe the anti-authoritarian wing of the socialist movement. Anarchism is contrasted to socialist forms which are state-oriented or from above. Scholars of anarchism generally highlight anarchism's socialist credentials and criticise attempts at creating dichotomies between the two. Some scholars describe anarchism as having many influences from liberalism, and being both liberal and socialist but more so. Many scholars reject anarcho-capitalism as a misunderstanding of anarchist principles.
While opposition to the state is central to anarchist thought, defining anarchism is not an easy task for scholars, as there is a lot of discussion among scholars and anarchists on the matter, and various currents perceive anarchism slightly differently. Major definitional elements include the will for a non-coercive society, the rejection of the state apparatus, the belief that human nature allows humans to exist in or progress toward such a non-coercive society, and a suggestion on how to act to pursue the ideal of anarchy.
History
Pre-modern era
The most notable precursors to anarchism in the ancient world were in China and Greece. In China, philosophical anarchism (the discussion on the legitimacy of the state) was delineated by Taoist philosophers Zhuang Zhou and Laozi. Alongside Stoicism, Taoism has been said to have had "significant anticipations" of anarchism.
Anarchic attitudes were also articulated by tragedians and philosophers in Greece. Aeschylus and Sophocles used the myth of Antigone to illustrate the conflict between laws imposed by the state and personal autonomy. Socrates questioned Athenian authorities constantly and insisted on the right of individual freedom of conscience. Cynics dismissed human law (nomos) and associated authorities while trying to live according to nature (physis). Stoics were supportive of a society based on unofficial and friendly relations among its citizens without the presence of a state.
In medieval Europe, there was no anarchistic activity except some ascetic religious movements. These, and other Muslim movements, later gave birth to religious anarchism. In the Sasanian Empire, Mazdak called for an egalitarian society and the abolition of monarchy, only to be soon executed by Emperor Kavad I.
In Basra, religious sects preached against the state. In Europe, various sects developed anti-state and libertarian tendencies. Renewed interest in antiquity during the Renaissance and in private judgment during the Reformation restored elements of anti-authoritarian secularism, particularly in France. Enlightenment challenges to intellectual authority (secular and religious) and the revolutions of the 1790s and 1848 all spurred the ideological development of what became the era of classical anarchism.
Modern era
During the French Revolution, partisan groups such as the Enragés and the saw a turning point in the fermentation of anti-state and federalist sentiments. The first anarchist currents developed throughout the 18th century as William Godwin espoused philosophical anarchism in England, morally delegitimising the state, Max Stirner's thinking paved the way to individualism and Pierre-Joseph Proudhon's theory of mutualism found fertile soil in France. By the late 1870s, various anarchist schools of thought had become well-defined and a wave of then unprecedented globalisation occurred from 1880 to 1914. This era of classical anarchism lasted until the end of the Spanish Civil War and is considered the golden age of anarchism.
Drawing from mutualism, Mikhail Bakunin founded collectivist anarchism and entered the International Workingmen's Association, a class worker union later known as the First International that formed in 1864 to unite diverse revolutionary currents. The International became a significant political force, with Karl Marx being a leading figure and a member of its General Council. Bakunin's faction (the Jura Federation) and Proudhon's followers (the mutualists) opposed state socialism, advocating political abstentionism and small property holdings. After bitter disputes, the Bakuninists were expelled from the International by the Marxists at the 1872 Hague Congress. Anarchists were treated similarly in the Second International, being ultimately expelled in 1896. Bakunin famously predicted that if revolutionaries gained power by Marx's terms, they would end up the new tyrants of workers. In response to their expulsion from the First International, anarchists formed the St. Imier International. Under the influence of Peter Kropotkin, a Russian philosopher and scientist, anarcho-communism overlapped with collectivism. Anarcho-communists, who drew inspiration from the 1871 Paris Commune, advocated for free federation and for the distribution of goods according to one's needs.
By the turn of the 20th century, anarchism had spread all over the world. It was a notable feature of the international syndicalist movement. In China, small groups of students imported the humanistic pro-science version of anarcho-communism. Tokyo was a hotspot for rebellious youth from East Asian countries, who moved to the Japanese capital to study. In Latin America, Argentina was a stronghold for anarcho-syndicalism, where it became the most prominent left-wing ideology. During this time, a minority of anarchists adopted tactics of revolutionary political violence, known as propaganda of the deed. The dismemberment of the French socialist movement into many groups and the execution and exile of many Communards to penal colonies following the suppression of the Paris Commune favoured individualist political expression and acts. Even though many anarchists distanced themselves from these terrorist acts, infamy came upon the movement and attempts were made to prevent anarchists immigrating to the US, including the Immigration Act of 1903, also called the Anarchist Exclusion Act. Illegalism was another strategy which some anarchists adopted during this period.
Despite concerns, anarchists enthusiastically participated in the Russian Revolution in opposition to the White movement, especially in the Makhnovshchina; however, they met harsh suppression after the Bolshevik government had stabilised, including during the Kronstadt rebellion. Several anarchists from Petrograd and Moscow fled to Ukraine, before the Bolsheviks crushed the anarchist movement there too. With the anarchists being repressed in Russia, two new antithetical currents emerged, namely platformism and synthesis anarchism. The former sought to create a coherent group that would push for revolution while the latter were against anything that would resemble a political party. Seeing the victories of the Bolsheviks in the October Revolution and the resulting Russian Civil War, many workers and activists turned to communist parties which grew at the expense of anarchism and other socialist movements. In France and the United States, members of major syndicalist movements such as the General Confederation of Labour and the Industrial Workers of the World left their organisations and joined the Communist International.
In the Spanish Civil War of 1936–39, anarchists and syndicalists (CNT and FAI) once again allied themselves with various currents of leftists. A long tradition of Spanish anarchism led to anarchists playing a pivotal role in the war, and particularly in the Spanish Revolution of 1936. In response to the army rebellion, an anarchist-inspired movement of peasants and workers, supported by armed militias, took control of Barcelona and of large areas of rural Spain, where they collectivised the land. The Soviet Union provided some limited assistance at the beginning of the war, but the result was a bitter fight between communists and other leftists in a series of events known as the May Days, as Joseph Stalin asserted Soviet control of the Republican government, ending in another defeat of anarchists at the hands of the communists.
Post-WWII
By the end of World War II, the anarchist movement had been severely weakened. The 1960s witnessed a revival of anarchism, likely caused by a perceived failure of Marxism–Leninism and tensions built by the Cold War. During this time, anarchism found a presence in other movements critical towards both capitalism and the state such as the anti-nuclear, environmental, and peace movements, the counterculture of the 1960s, and the New Left. It also saw a transition from its previous revolutionary nature to provocative anti-capitalist reformism. Anarchism became associated with punk subculture as exemplified by bands such as Crass and the Sex Pistols. The established feminist tendencies of anarcha-feminism returned with vigour during the second wave of feminism. Black anarchism began to take form at this time and influenced anarchism's move from a Eurocentric demographic. This coincided with its failure to gain traction in Northern Europe and its unprecedented height in Latin America.
Around the turn of the 21st century, anarchism grew in popularity and influence within anti-capitalist, anti-war and anti-globalisation movements. Anarchists became known for their involvement in protests against the World Trade Organization (WTO), the Group of Eight and the World Economic Forum. During the protests, ad hoc leaderless anonymous cadres known as black blocs engaged in rioting, property destruction and violent confrontations with the police. Other organisational tactics pioneered at this time include affinity groups, security culture and the use of decentralised technologies such as the Internet. A significant event of this period was the confrontations at the 1999 Seattle WTO conference. Anarchist ideas have been influential in the development of the Zapatistas in Mexico and the Democratic Federation of Northern Syria, more commonly known as Rojava, a de facto autonomous region in northern Syria.
While having revolutionary aspirations, many forms of anarchism are not confrontational nowadays. Instead, they are trying to build an alternative way of social organization, based on mutual interdependence and voluntary cooperation. Scholar Carissa Honeywell takes the example of Food not Bombs group of collectives, to highlight some features of how anarchist groups work: direct action, working together and in solidarity with those left behind. While doing so, they inform about the rising rates of world hunger suggest a policy to tackle hunger, ranging from de-funding the arms industry to addressing Monsanto seed-saving policies and patents, helping farmers and commodification of food and housing. Honeywell also emphasizes that contemporary anarchists are interested in the flourishing not only of humans, but non-humans and the environment as well. Honeywell argues that escalation of problems such as continuous wars and world poverty show that the current framework not only cannot solve those pressing problems for humanity, but are causal factors as well, resulting in the rejection of representative democracy and the state as a whole.
Thought
Anarchist schools of thought have been generally grouped into two main historical traditions, social anarchism and individualist anarchism, owing to their different origins, values and evolution. The individualist current emphasises negative liberty in opposing restraints upon the free individual, while the social current emphasises positive liberty in aiming to achieve the free potential of society through equality and social ownership. In a chronological sense, anarchism can be segmented by the classical currents of the late 19th century and the post-classical currents (anarcha-feminism, green anarchism, and post-anarchism) developed thereafter.
Beyond the specific factions of anarchist movements which constitute political anarchism lies philosophical anarchism which holds that the state lacks moral legitimacy, without necessarily accepting the imperative of revolution to eliminate it. A component especially of individualist anarchism, philosophical anarchism may tolerate the existence of a minimal state but claims that citizens have no moral obligation to obey government when it conflicts with individual autonomy. Anarchism pays significant attention to moral arguments since ethics have a central role in anarchist philosophy. Anarchism's emphasis on anti-capitalism, egalitarianism, and for the extension of community and individuality sets it apart from anarcho-capitalism and other types of economic libertarianism.
Anarchism is usually placed on the far-left of the political spectrum. Much of its economics and legal philosophy reflect anti-authoritarian, anti-statist, libertarian, and radical interpretations of left-wing and socialist politics such as collectivism, communism, individualism, mutualism, and syndicalism, among other libertarian socialist economic theories. As anarchism does not offer a fixed body of doctrine from a single particular worldview, many anarchist types and traditions exist and varieties of anarchy diverge widely. One reaction against sectarianism within the anarchist milieu was anarchism without adjectives, a call for toleration and unity among anarchists first adopted by Fernando Tarrida del Mármol in 1889 in response to the bitter debates of anarchist theory at the time. Belief in political nihilism has been espoused by anarchists. Despite separation, the various anarchist schools of thought are not seen as distinct entities but rather as tendencies that intermingle and are connected through a set of shared principles such as autonomy, mutual aid, anti-authoritarianism and decentralisation.
Classical
Inceptive currents among classical anarchist currents were mutualism and individualism. They were followed by the major currents of social anarchism (collectivist, communist and syndicalist). They differ on organisational and economic aspects of their ideal society.
Mutualism is an 18th-century economic theory that was developed into anarchist theory by Pierre-Joseph Proudhon. Its aims include "abolishing the state", reciprocity, free association, voluntary contract, federation and monetary reform of both credit and currency that would be regulated by a bank of the people. Mutualism has been retrospectively characterised as ideologically situated between individualist and collectivist forms of anarchism. In What Is Property? (1840), Proudhon first characterised his goal as a "third form of society, the synthesis of communism and property." Collectivist anarchism is a revolutionary socialist form of anarchism commonly associated with Mikhail Bakunin. Collectivist anarchists advocate collective ownership of the means of production which is theorised to be achieved through violent revolution and that workers be paid according to time worked, rather than goods being distributed according to need as in communism. Collectivist anarchism arose alongside Marxism but rejected the dictatorship of the proletariat despite the stated Marxist goal of a collectivist stateless society.
Anarcho-communism is a theory of anarchism that advocates a communist society with common ownership of the means of production, held by a federal network of voluntary associations, with production and consumption based on the guiding principle "From each according to his ability, to each according to his need." Anarcho-communism developed from radical socialist currents after the French Revolution but was first formulated as such in the Italian section of the First International. It was later expanded upon in the theoretical work of Peter Kropotkin, whose specific style would go onto become the dominating view of anarchists by the late 19th century. Anarcho-syndicalism is a branch of anarchism that views labour syndicates as a potential force for revolutionary social change, replacing capitalism and the state with a new society democratically self-managed by workers. The basic principles of anarcho-syndicalism are direct action, workers' solidarity and workers' self-management.
Individualist anarchism is a set of several traditions of thought within the anarchist movement that emphasise the individual and their will over any kinds of external determinants. Early influences on individualist forms of anarchism include William Godwin, Max Stirner, and Henry David Thoreau. Through many countries, individualist anarchism attracted a small yet diverse following of Bohemian artists and intellectuals as well as young anarchist outlaws in what became known as illegalism and individual reclamation.
Post-classical and contemporary
Anarchist principles undergird contemporary radical social movements of the left. Interest in the anarchist movement developed alongside momentum in the anti-globalisation movement, whose leading activist networks were anarchist in orientation. As the movement shaped 21st century radicalism, wider embrace of anarchist principles signaled a revival of interest. Anarchism has continued to generate many philosophies and movements, at times eclectic, drawing upon various sources and combining disparate concepts to create new philosophical approaches. The anti-capitalist tradition of classical anarchism has remained prominent within contemporary currents.
Contemporary news coverage which emphasizes black bloc demonstrations has reinforced anarchism's historical association with chaos and violence. Its publicity has also led more scholars in fields such as anthropology and history to engage with the anarchist movement, although contemporary anarchism favours actions over academic theory. Various anarchist groups, tendencies, and schools of thought exist today, making it difficult to describe the contemporary anarchist movement. While theorists and activists have established "relatively stable constellations of anarchist principles", there is no consensus on which principles are core and commentators describe multiple anarchisms, rather than a singular anarchism, in which common principles are shared between schools of anarchism while each group prioritizes those principles differently. Gender equality can be a common principle, although it ranks as a higher priority to anarcha-feminists than anarcho-communists.
Anarchists are generally committed against coercive authority in all forms, namely "all centralized and hierarchical forms of government (e.g., monarchy, representative democracy, state socialism, etc.), economic class systems (e.g., capitalism, Bolshevism, feudalism, slavery, etc.), autocratic religions (e.g., fundamentalist Islam, Roman Catholicism, etc.), patriarchy, heterosexism, white supremacy, and imperialism." Anarchist schools disagree on the methods by which these forms should be opposed. The principle of equal liberty is closer to anarchist political ethics in that it transcends both the liberal and socialist traditions. This entails that liberty and equality cannot be implemented within the state, resulting in the questioning of all forms of domination and hierarchy.
Tactics
Anarchists' tactics take various forms but in general serve two major goals, namely, to first oppose the Establishment and secondly to promote anarchist ethics and reflect an anarchist vision of society, illustrating the unity of means and ends. A broad categorisation can be made between aims to destroy oppressive states and institutions by revolutionary means on one hand and aims to change society through evolutionary means on the other. Evolutionary tactics embrace nonviolence, reject violence and take a gradual approach to anarchist aims, although there is significant overlap between the two.
Anarchist tactics have shifted during the course of the last century. Anarchists during the early 20th century focused more on strikes and militancy while contemporary anarchists use a broader array of approaches.
Classical era
During the classical era, anarchists had a militant tendency. Not only did they confront state armed forces, as in Spain and Ukraine, but some of them also employed terrorism as propaganda of the deed. Assassination attempts were carried out against heads of state, some of which were successful. Anarchists also took part in revolutions. Many anarchists, especially the Galleanists, believed that these attempts would be the impetus for a revolution against capitalism and the state. Many of these attacks were done by individual assailants and the majority took place in the late 1870s, the early 1880s and the 1890s, with some still occurring in the early 1900s. Their decrease in prevalence was the result of further judicial power and targeting and cataloging by state institutions.
Anarchist perspectives towards violence have always been controversial. Anarcho-pacifists advocate for non-violence means to achieve their stateless, nonviolent ends. Other anarchist groups advocate direct action, a tactic which can include acts of sabotage or terrorism. This attitude was quite prominent a century ago when seeing the state as a tyrant and some anarchists believing that they had every right to oppose its oppression by any means possible. Emma Goldman and Errico Malatesta, who were proponents of limited use of violence, stated that violence is merely a reaction to state violence as a necessary evil.
Anarchists took an active role in strike actions, although they tended to be antipathetic to formal syndicalism, seeing it as reformist. They saw it as a part of the movement which sought to overthrow the state and capitalism. Anarchists also reinforced their propaganda within the arts, some of whom practiced naturism and nudism. Those anarchists also built communities which were based on friendship and were involved in the news media.
Revolutionary
In the current era, Italian anarchist Alfredo Bonanno, a proponent of insurrectionary anarchism, has reinstated the debate on violence by rejecting the nonviolence tactic adopted since the late 19th century by Kropotkin and other prominent anarchists afterwards. Both Bonanno and the French group The Invisible Committee advocate for small, informal affiliation groups, where each member is responsible for their own actions but works together to bring down oppression utilizing sabotage and other violent means against state, capitalism, and other enemies. Members of The Invisible Committee were arrested in 2008 on various charges, terrorism included.
Overall, contemporary anarchists are much less violent and militant than their ideological ancestors. They mostly engage in confronting the police during demonstrations and riots, especially in countries such as Canada, Greece, and Mexico. Militant black bloc protest groups are known for clashing with the police; however, anarchists not only clash with state operators, they also engage in the struggle against fascists and racists, taking anti-fascist action and mobilizing to prevent hate rallies from happening.
Evolutionary
Anarchists commonly employ direct action. This can take the form of disrupting and protesting against unjust hierarchy, or the form of self-managing their lives through the creation of counter-institutions such as communes and non-hierarchical collectives. Decision-making is often handled in an anti-authoritarian way, with everyone having equal say in each decision, an approach known as horizontalism. Contemporary-era anarchists have been engaging with various grassroots movements that are more or less based on horizontalism, although not explicitly anarchist, respecting personal autonomy and participating in mass activism such as strikes and demonstrations. In contrast with the big-A anarchism of the classical era, the newly coined term small-a anarchism signals their tendency not to base their thoughts and actions on classical-era anarchism or to refer to classical anarchists such as Peter Kropotkin and Pierre-Joseph Proudhon to justify their opinions. Those anarchists would rather base their thought and praxis on their own experience which they will later theorize.
The decision-making process of small anarchist affinity groups plays a significant tactical role. Anarchists have employed various methods in order to build a rough consensus among members of their group without the need of a leader or a leading group. One way is for an individual from the group to play the role of facilitator to help achieve a consensus without taking part in the discussion themselves or promoting a specific point. Minorities usually accept rough consensus, except when they feel the proposal contradicts anarchist ethics, goals and values. Anarchists usually form small groups (5–20 individuals) to enhance autonomy and friendships among their members. These kinds of groups more often than not interconnect with each other, forming larger networks. Anarchists still support and participate in strikes, especially wildcat strikes as these are leaderless strikes not organised centrally by a syndicate.
As in the past, newspapers and journals are used, and anarchists have gone online in the World Wide Web to spread their message. Anarchists have found it easier to create websites because of distributional and other difficulties, hosting electronic libraries and other portals. Anarchists were also involved in developing various software that are available for free. The way these hacktivists work to develop and distribute resembles the anarchist ideals, especially when it comes to preserving users' privacy from state surveillance.
Anarchists organize themselves to squat and reclaim public spaces. During important events such as protests and when spaces are being occupied, they are often called Temporary Autonomous Zones (TAZ), spaces where art, poetry, and surrealism are blended to display the anarchist ideal. As seen by anarchists, squatting is a way to regain urban space from the capitalist market, serving pragmatical needs and also being an exemplary direct action. Acquiring space enables anarchists to experiment with their ideas and build social bonds. Adding up these tactics while having in mind that not all anarchists share the same attitudes towards them, along with various forms of protesting at highly symbolic events, make up a carnivalesque atmosphere that is part of contemporary anarchist vividity.
Key issues
As anarchism is a philosophy that embodies many diverse attitudes, tendencies, and schools of thought, disagreement over questions of values, ideology, and tactics is common. Its diversity has led to widely different uses of identical terms among different anarchist traditions which has created a number of definitional concerns in anarchist theory. The compatibility of capitalism, nationalism, and religion with anarchism is widely disputed, and anarchism enjoys complex relationships with ideologies such as communism, collectivism, Marxism, and trade unionism. Anarchists may be motivated by humanism, divine authority, enlightened self-interest, veganism, or any number of alternative ethical doctrines. Phenomena such as civilisation, technology (e.g. within anarcho-primitivism), and the democratic process may be sharply criticised within some anarchist tendencies and simultaneously lauded in others.
The state
Objection to the state and its institutions is a sine qua non of anarchism. Anarchists consider the state as a tool of domination and believe it to be illegitimate regardless of its political tendencies. Instead of people being able to control the aspects of their life, major decisions are taken by a small elite. Authority ultimately rests solely on power, regardless of whether that power is open or transparent, as it still has the ability to coerce people. Another anarchist argument against states is that the people constituting a government, even the most altruistic among officials, will unavoidably seek to gain more power, leading to corruption. Anarchists consider the idea that the state is the collective will of the people to be an unachievable fiction due to the fact that the ruling class is distinct from the rest of society.
Specific anarchist attitudes towards the state vary. Robert Paul Wolff believed that the tension between authority and autonomy would mean the state could never be legitimate. Bakunin saw the state as meaning "coercion, domination by means of coercion, camouflaged if possible but unceremonious and overt if need be." A. John Simmons and Leslie Green, who leaned toward philosophical anarchism, believed that the state could be legitimate if it is governed by consensus, although they saw this as highly unlikely. Beliefs on how to abolish the state also differ.
Gender, sexuality, and free love
As gender and sexuality carry along them dynamics of hierarchy, many anarchists address, analyse, and oppose the suppression of one's autonomy imposed by gender roles.
Sexuality was not often discussed by classical anarchists but the few that did felt that an anarchist society would lead to sexuality naturally developing. Sexual violence was a concern for anarchists such as Benjamin Tucker, who opposed age of consent laws, believing they would benefit predatory men. A historical current that arose and flourished during 1890 and 1920 within anarchism was free love. In contemporary anarchism, this current survives as a tendency to support polyamory, relationship anarchy, and queer anarchism. Free love advocates were against marriage, which they saw as a way of men imposing authority over women, largely because marriage law greatly favoured the power of men. The notion of free love was much broader and included a critique of the established order that limited women's sexual freedom and pleasure. Those free love movements contributed to the establishment of communal houses, where large groups of travelers, anarchists and other activists slept in beds together. Free love had roots both in Europe and the United States; however, some anarchists struggled with the jealousy that arose from free love. Anarchist feminists were advocates of free love, against marriage, and pro-choice (utilising a contemporary term), and had a similar agenda. Anarchist and non-anarchist feminists differed on suffrage but were supportive of one another.
During the second half of the 20th century, anarchism intermingled with the second wave of feminism, radicalising some currents of the feminist movement and being influenced as well. By the latest decades of the 20th century, anarchists and feminists were advocating for the rights and autonomy of women, gays, queers and other marginalised groups, with some feminist thinkers suggesting a fusion of the two currents. With the third wave of feminism, sexual identity and compulsory heterosexuality became a subject of study for anarchists, yielding a post-structuralist critique of sexual normality. Some anarchists distanced themselves from this line of thinking, suggesting that it leaned towards an individualism that was dropping the cause of social liberation.
Education
The interest of anarchists in education stretches back to the first emergence of classical anarchism. Anarchists consider proper education, one which sets the foundations of the future autonomy of the individual and the society, to be an act of mutual aid. Anarchist writers such as William Godwin (Political Justice) and Max Stirner ("The False Principle of Our Education") attacked both state education and private education as another means by which the ruling class replicate their privileges.
In 1901, Catalan anarchist and free thinker Francisco Ferrer established the Escuela Moderna in Barcelona as an opposition to the established education system which was dictated largely by the Catholic Church. Ferrer's approach was secular, rejecting both state and church involvement in the educational process whilst giving pupils large amounts of autonomy in planning their work and attendance. Ferrer aimed to educate the working class and explicitly sought to foster class consciousness among students. The school closed after constant harassment by the state and Ferrer was later arrested. Nonetheless, his ideas formed the inspiration for a series of modern schools around the world. Christian anarchist Leo Tolstoy, who published the essay Education and Culture, also established a similar school with its founding principle being that "for education to be effective it had to be free." In a similar token, A. S. Neill founded what became the Summerhill School in 1921, also declaring being free from coercion.
Anarchist education is based largely on the idea that a child's right to develop freely and without manipulation ought to be respected and that rationality would lead children to morally good conclusions; however, there has been little consensus among anarchist figures as to what constitutes manipulation. Ferrer believed that moral indoctrination was necessary and explicitly taught pupils that equality, liberty and social justice were not possible under capitalism, along with other critiques of government and nationalism.
Late 20th century and contemporary anarchist writers (Paul Goodman, Herbert Read, and Colin Ward) intensified and expanded the anarchist critique of state education, largely focusing on the need for a system that focuses on children's creativity rather than on their ability to attain a career or participate in consumerism as part of a consumer society. Contemporary anarchists such as Ward claim that state education serves to perpetuate socioeconomic inequality.
While few anarchist education institutions have survived to the modern-day, major tenets of anarchist schools, among them respect for child autonomy and relying on reasoning rather than indoctrination as a teaching method, have spread among mainstream educational institutions. Judith Suissa names three schools as explicitly anarchists' schools, namely the Free Skool Santa Cruz in the United States which is part of a wider American-Canadian network of schools, the Self-Managed Learning College in Brighton, England, and the Paideia School in Spain.
The arts
The connection between anarchism and art was quite profound during the classical era of anarchism, especially among artistic currents that were developing during that era such as futurists, surrealists and others. In literature, anarchism was mostly associated with the New Apocalyptics and the neo-romanticism movement. In music, anarchism has been associated with music scenes such as punk. Anarchists such as Leo Tolstoy and Herbert Read stated that the border between the artist and the non-artist, what separates art from a daily act, is a construct produced by the alienation caused by capitalism and it prevents humans from living a joyful life.
Other anarchists advocated for or used art as a means to achieve anarchist ends. In his book Breaking the Spell: A History of Anarchist Filmmakers, Videotape Guerrillas, and Digital Ninjas, Chris Robé claims that "anarchist-inflected practices have increasingly structured movement-based video activism." Throughout the 20th century, many prominent anarchists (Peter Kropotkin, Emma Goldman, Gustav Landauer and Camillo Berneri) and publications such as Anarchy wrote about matters pertaining to the arts.
Three overlapping properties made art useful to anarchists. It could depict a critique of existing society and hierarchies, serve as a prefigurative tool to reflect the anarchist ideal society and even turn into a means of direct action such as in protests. As it appeals to both emotion and reason, art could appeal to the whole human and have a powerful effect. The 19th-century neo-impressionist movement had an ecological aesthetic and offered an example of an anarchist perception of the road towards socialism. In Les chataigniers a Osny by anarchist painter Camille Pissarro, the blending of aesthetic and social harmony is prefiguring an ideal anarchistic agrarian community.
Criticism
The most common critique of anarchism is the assertion that humans cannot self-govern and so a state is necessary for human survival. Philosopher Bertrand Russell supported this critique, stating that "[p]eace and war, tariffs, regulations of sanitary conditions and the sale of noxious drugs, the preservation of a just system of distribution: these, among others, are functions which could hardly be performed in a community in which there was no central government." Another common criticism of anarchism is that it fits a world of isolation in which only the small enough entities can be self-governing; a response would be that major anarchist thinkers advocated anarchist federalism.
Another criticism of anarchism is the belief that it is inherently unstable: that an anarchist society would inevitably evolve back into a state. Thomas Hobbes and other early social contract theorists argued that the state emerges in response to natural anarchy in order to protect the people's interests and keep order. Philosopher Robert Nozick argued that a "night-watchman state", or minarchy, would emerge from anarchy through the process of an invisible hand, in which people would exercise their liberty and buy protection from protection agencies, evolving into a minimal state. Anarchists reject these criticisms by arguing that humans in a state of nature would not just be in a state of war. Anarcho-primitivists in particular argue that humans were better off in a state of nature in small tribes living close to the land, while anarchists in general argue that the negatives of state organization, such as hierarchies, monopolies and inequality, outweigh the benefits.
Philosophy lecturer Andrew G. Fiala composed a list of common arguments against anarchism which includes critiques such as that anarchism is innately related to violence and destruction, not only in the pragmatic world, such as at protests, but in the world of ethics as well. Secondly, anarchism is evaluated as unfeasible or utopian since the state cannot be defeated practically. This line of arguments most often calls for political action within the system to reform it. The third argument is that anarchism is self-contradictory as a ruling theory that has no ruling theory. Anarchism also calls for collective action whilst endorsing the autonomy of the individual, hence no collective action can be taken. Lastly, Fiala mentions a critique towards philosophical anarchism of being ineffective (all talk and thoughts) and in the meantime capitalism and bourgeois class remains strong.
Philosophical anarchism has met the criticism of members of academia following the release of pro-anarchist books such as A. John Simmons' Moral Principles and Political Obligations. Law professor William A. Edmundson authored an essay to argue against three major philosophical anarchist principles which he finds fallacious. Edmundson says that while the individual does not owe the state a duty of obedience, this does not imply that anarchism is the inevitable conclusion and the state is still morally legitimate. In The Problem of Political Authority, Michael Huemer defends philosophical anarchism, claiming that "political authority is a moral illusion."
One of the earliest criticisms is that anarchism defies and fails to understand the biological inclination to authority. Joseph Raz states that the acceptance of authority implies the belief that following their instructions will afford more success. Raz believes that this argument is true in following both authorities' successful and mistaken instruction. Anarchists reject this criticism because challenging or disobeying authority does not entail the disappearance of its advantages by acknowledging authority such as doctors or lawyers as reliable, nor does it involve a complete surrender of independent judgment. Anarchist perception of human nature, rejection of the state, and commitment to social revolution has been criticised by academics as naive, overly simplistic, and unrealistic, respectively. Classical anarchism has been criticised for relying too heavily on the belief that the abolition of the state will lead to human cooperation prospering.
Friedrich Engels, considered to be one of the principal founders of Marxism, criticised anarchism's anti-authoritarianism as inherently counter-revolutionary because in his view a revolution is by itself authoritarian. Academic John Molyneux writes in his book Anarchism: A Marxist Criticism that "anarchism cannot win", believing that it lacks the ability to properly implement its ideas. The Marxist criticism of anarchism is that it has a utopian character because all individuals should have anarchist views and values. According to the Marxist view, that a social idea would follow directly from this human ideal and out of the free will of every individual formed its essence. Marxists state that this contradiction was responsible for their inability to act. In the anarchist vision, the conflict between liberty and equality was resolved through coexistence and intertwining.
See also
Anarchism by country
Governance without government
List of anarchist political ideologies
List of books about anarchism
Anarchist communities
List of stateless societies
List of intentional communities
List of self-managed social centers
References
Explanatory notes
Citations
General and cited sources
Primary sources
Secondary sources
Tertiary sources
Further reading
Criticism of philosophical anarchism.
A defence of philosophical anarchism, stating that "both kinds of 'anarchism' [i.e. philosophical and political anarchism] are philosophical and political claims." (p. 137)
Anarchistic popular fiction novel.
An argument for philosophical anarchism.
External links
Anarchy Archives – an online research center on the history and theory of anarchism.
Anti-capitalism
Anti-fascism
Economic ideologies
Far-left politics
Left-wing politics
Libertarian socialism
Libertarianism
Political culture
Political ideologies
Political movements
Social theories
Socialism |
308 | https://en.wikipedia.org/wiki/Aristotle | Aristotle | Aristotle ( Aristotélēs, ; 384–322 BC) was an Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, and the arts. As the founder of the Peripatetic school of philosophy in the Lyceum in Athens, he began the wider Aristotelian tradition that followed, which set the groundwork for the development of modern science.
Little is known about Aristotle's life. He was born in the city of Stagira in northern Greece during the Classical period. His father, Nicomachus, died when Aristotle was a child, and he was brought up by a guardian. At 17 or 18, he joined Plato's Academy in Athens and remained there until the age of 37 (). Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, tutored his son Alexander the Great beginning in 343 BC. He established a library in the Lyceum, which helped him to produce many of his hundreds of books on papyrus scrolls.
Though Aristotle wrote many elegant treatises and dialogues for publication, only around a third of his original output has survived, none of it intended for publication. Aristotle provided a complex synthesis of the various philosophies existing prior to him. His teachings and methods of inquiry have had a significant impact across the world, and remain a subject of contemporary philosophical discussion.
Aristotle's views profoundly shaped medieval scholarship. The influence of his physical science extended from late antiquity and the Early Middle Ages into the Renaissance, and was not replaced systematically until the Enlightenment and theories such as classical mechanics were developed. He influenced Judeo-Islamic philosophies during the Middle Ages, as well as Christian theology, especially the Neoplatonism of the Early Church and the scholastic tradition of the Catholic Church.
Aristotle was revered among medieval Muslim scholars as "The First Teacher", and among medieval Christians like Thomas Aquinas as simply "The Philosopher", while the poet Dante called him "the master of those who know". His works contain the earliest known formal study of logic, and were studied by medieval scholars such as Peter Abelard and Jean Buridan. Aristotle's influence on logic continued well into the 19th century. In addition, his ethics, although always influential, gained renewed interest with the modern advent of virtue ethics.
Life
In general, the details of Aristotle's life are not well-established. The biographies written in ancient times are often speculative and historians only agree on a few salient points.
Aristotle was born in 384 BC in Stagira, Chalcidice, about 55 km (34 miles) east of modern-day Thessaloniki. His father, Nicomachus, was the personal physician to King Amyntas of Macedon. While he was young, Aristotle learned about biology and medical information, which was taught by his father. Both of Aristotle's parents died when he was about thirteen, and Proxenus of Atarneus became his guardian. Although little information about Aristotle's childhood has survived, he probably spent some time within the Macedonian palace, making his first connections with the Macedonian monarchy.
At the age of seventeen or eighteen, Aristotle moved to Athens to continue his education at Plato's Academy. He probably experienced the Eleusinian Mysteries as he wrote when describing the sights one viewed at the Eleusinian Mysteries, "to experience is to learn" [παθείν μαθεĩν]. Aristotle remained in Athens for nearly twenty years before leaving in 348/47 BC. The traditional story about his departure records that he was disappointed with the Academy's direction after control passed to Plato's nephew Speusippus, although it is possible that he feared the anti-Macedonian sentiments in Athens at that time and left before Plato died. Aristotle then accompanied Xenocrates to the court of his friend Hermias of Atarneus in Asia Minor. After the death of Hermias, Aristotle travelled with his pupil Theophrastus to the island of Lesbos, where together they researched the botany and zoology of the island and its sheltered lagoon. While in Lesbos, Aristotle married Pythias, either Hermias's adoptive daughter or niece. They had a daughter, whom they also named Pythias. In 343 BC, Aristotle was invited by Philip II of Macedon to become the tutor to his son Alexander.
Aristotle was appointed as the head of the royal Academy of Macedon. During Aristotle's time in the Macedonian court, he gave lessons not only to Alexander but also to two other future kings: Ptolemy and Cassander. Aristotle encouraged Alexander toward eastern conquest, and Aristotle's own attitude towards Persia was unabashedly ethnocentric. In one famous example, he counsels Alexander to be "a leader to the Greeks and a despot to the barbarians, to look after the former as after friends and relatives, and to deal with the latter as with beasts or plants". By 335 BC, Aristotle had returned to Athens, establishing his own school there known as the Lyceum. Aristotle conducted courses at the school for the next twelve years. While in Athens, his wife Pythias died and Aristotle became involved with Herpyllis of Stagira. They had a son whom Aristotle named after his father, Nicomachus. If the Suda an uncritical compilation from the Middle Ages is accurate, he may also have had an erômenos, Palaephatus of Abydus.
This period in Athens, between 335 and 323 BC, is when Aristotle is believed to have composed many of his works. He wrote many dialogues, of which only fragments have survived. Those works that have survived are in treatise form and were not, for the most part, intended for widespread publication; they are generally thought to be lecture aids for his students. His most important treatises include Physics, Metaphysics, Nicomachean Ethics, Politics, On the Soul and Poetics. Aristotle studied and made significant contributions to "logic, metaphysics, mathematics, physics, biology, botany, ethics, politics, agriculture, medicine, dance, and theatre."
Near the end of his life, Alexander and Aristotle became estranged over Alexander's relationship with Persia and Persians. A widespread tradition in antiquity suspected Aristotle of playing a role in Alexander's death, but the only evidence of this is an unlikely claim made some six years after the death. Following Alexander's death, anti-Macedonian sentiment in Athens was rekindled. In 322 BC, Demophilus and Eurymedon the Hierophant reportedly denounced Aristotle for impiety, prompting him to flee to his mother's family estate in Chalcis, on Euboea, at which occasion he was said to have stated: "I will not allow the Athenians to sin twice against philosophy" – a reference to Athens's trial and execution of Socrates. He died in Chalcis, Euboea of natural causes later that same year, having named his student Antipater as his chief executor and leaving a will in which he asked to be buried next to his wife.
Theoretical philosophy
Logic
With the Prior Analytics, Aristotle is credited with the earliest study of formal logic, and his conception of it was the dominant form of Western logic until 19th-century advances in mathematical logic. Kant stated in the Critique of Pure Reason that with Aristotle, logic reached its completion.
Organon
Most of Aristotle's work is probably not in its original form, because it was most likely edited by students and later lecturers. The logical works of Aristotle were compiled into a set of six books called the Organon around 40 BC by Andronicus of Rhodes or others among his followers. The books are:
Categories
On Interpretation
Prior Analytics
Posterior Analytics
Topics
On Sophistical Refutations
The order of the books (or the teachings from which they are composed) is not certain, but this list was derived from analysis of Aristotle's writings. It goes from the basics, the analysis of simple terms in the Categories, the analysis of propositions and their elementary relations in On Interpretation, to the study of more complex forms, namely, syllogisms (in the Analytics) and dialectics (in the Topics and Sophistical Refutations). The first three treatises form the core of the logical theory stricto sensu: the grammar of the language of logic and the correct rules of reasoning. The Rhetoric is not conventionally included, but it states that it relies on the Topics.
What is today called Aristotelian logic with its types of syllogism (methods of logical argument), Aristotle himself would have labelled "analytics". The term "logic" he reserved to mean dialectics.
Metaphysics
The word "metaphysics" appears to have been coined by the first century AD editor who assembled various small selections of Aristotle's works to the treatise we know by the name Metaphysics. Aristotle called it "first philosophy", and distinguished it from mathematics and natural science (physics) as the contemplative (theoretikē) philosophy which is "theological" and studies the divine. He wrote in his Metaphysics (1026a16):
Substance
Aristotle examines the concepts of substance (ousia) and essence (to ti ên einai, "the what it was to be") in his Metaphysics (Book VII), and he concludes that a particular substance is a combination of both matter and form, a philosophical theory called hylomorphism. In Book VIII, he distinguishes the matter of the substance as the substratum, or the stuff of which it is composed. For example, the matter of a house is the bricks, stones, timbers, etc., or whatever constitutes the potential house, while the form of the substance is the actual house, namely 'covering for bodies and chattels' or any other differentia that let us define something as a house. The formula that gives the components is the account of the matter, and the formula that gives the differentia is the account of the form.
Immanent realism
Like his teacher Plato, Aristotle's philosophy aims at the universal. Aristotle's ontology places the universal (katholou) in particulars (kath' hekaston), things in the world, whereas for Plato the universal is a separately existing form which actual things imitate. For Aristotle, "form" is still what phenomena are based on, but is "instantiated" in a particular substance.
Plato argued that all things have a universal form, which could be either a property or a relation to other things. When one looks at an apple, for example, one sees an apple, and one can also analyse a form of an apple. In this distinction, there is a particular apple and a universal form of an apple. Moreover, one can place an apple next to a book, so that one can speak of both the book and apple as being next to each other. Plato argued that there are some universal forms that are not a part of particular things. For example, it is possible that there is no particular good in existence, but "good" is still a proper universal form. Aristotle disagreed with Plato on this point, arguing that all universals are instantiated at some period of time, and that there are no universals that are unattached to existing things. In addition, Aristotle disagreed with Plato about the location of universals. Where Plato spoke of the forms as existing separately from the things that participate in them, Aristotle maintained that universals exist within each thing on which each universal is predicated. So, according to Aristotle, the form of apple exists within each apple, rather than in the world of the forms.
Potentiality and actuality
Concerning the nature of change (kinesis) and its causes, as he outlines in his Physics and On Generation and Corruption (319b–320a), he distinguishes coming-to-be (genesis, also translated as 'generation') from:
growth and diminution, which is change in quantity;
locomotion, which is change in space; and
alteration, which is change in quality.
Coming-to-be is a change where the substrate of the thing that has undergone the change has itself changed. In that particular change he introduces the concept of potentiality (dynamis) and actuality (entelecheia) in association with the matter and the form. Referring to potentiality, this is what a thing is capable of doing or being acted upon if the conditions are right and it is not prevented by something else. For example, the seed of a plant in the soil is potentially (dynamei) a plant, and if it is not prevented by something, it will become a plant. Potentially, beings can either 'act' (poiein) or 'be acted upon' (paschein), which can be either innate or learned. For example, the eyes possess the potentiality of sight (innate – being acted upon), while the capability of playing the flute can be possessed by learning (exercise – acting). Actuality is the fulfilment of the end of the potentiality. Because the end (telos) is the principle of every change, and potentiality exists for the sake of the end, actuality, accordingly, is the end. Referring then to the previous example, it can be said that an actuality is when a plant does one of the activities that plants do.
In summary, the matter used to make a house has potentiality to be a house and both the activity of building and the form of the final house are actualities, which is also a final cause or end. Then Aristotle proceeds and concludes that the actuality is prior to potentiality in formula, in time and in substantiality. With this definition of the particular substance (i.e., matter and form), Aristotle tries to solve the problem of the unity of the beings, for example, "what is it that makes a man one"? Since, according to Plato there are two Ideas: animal and biped, how then is man a unity? However, according to Aristotle, the potential being (matter) and the actual one (form) are one and the same.
Epistemology
Aristotle's immanent realism means his epistemology is based on the study of things that exist or happen in the world, and rises to knowledge of the universal, whereas for Plato epistemology begins with knowledge of universal Forms (or ideas) and descends to knowledge of particular imitations of these. Aristotle uses induction from examples alongside deduction, whereas Plato relies on deduction from a priori principles.
Natural philosophy
Aristotle's "natural philosophy" spans a wide range of natural phenomena including those now covered by physics, biology and other natural sciences. In Aristotle's terminology, "natural philosophy" is a branch of philosophy examining the phenomena of the natural world, and includes fields that would be regarded today as physics, biology and other natural sciences. Aristotle's work encompassed virtually all facets of intellectual inquiry. Aristotle makes philosophy in the broad sense coextensive with reasoning, which he also would describe as "science". However, his use of the term science carries a different meaning than that covered by the term "scientific method". For Aristotle, "all science (dianoia) is either practical, poetical or theoretical" (Metaphysics 1025b25). His practical science includes ethics and politics; his poetical science means the study of fine arts including poetry; his theoretical science covers physics, mathematics and metaphysics.
Physics
Five elements
In his On Generation and Corruption, Aristotle related each of the four elements proposed earlier by Empedocles, earth, water, air, and fire, to two of the four sensible qualities, hot, cold, wet, and dry. In the Empedoclean scheme, all matter was made of the four elements, in differing proportions. Aristotle's scheme added the heavenly aether, the divine substance of the heavenly spheres, stars and planets.
Motion
Aristotle describes two kinds of motion: "violent" or "unnatural motion", such as that of a thrown stone, in the Physics (254b10), and "natural motion", such as of a falling object, in On the Heavens (300a20). In violent motion, as soon as the agent stops causing it, the motion stops also: in other words, the natural state of an object is to be at rest, since Aristotle does not address friction. With this understanding, it can be observed that, as Aristotle stated, heavy objects (on the ground, say) require more force to make them move; and objects pushed with greater force move faster. This would imply the equation
,
incorrect in modern physics.
Natural motion depends on the element concerned: the aether naturally moves in a circle around the heavens, while the 4 Empedoclean elements move vertically up (like fire, as is observed) or down (like earth) towards their natural resting places.
In the Physics (215a25), Aristotle effectively states a quantitative law, that the speed, v, of a falling body is proportional (say, with constant c) to its weight, W, and inversely proportional to the density, ρ, of the fluid in which it is falling:;
Aristotle implies that in a vacuum the speed of fall would become infinite, and concludes from this apparent absurdity that a vacuum is not possible. Opinions have varied on whether Aristotle intended to state quantitative laws. Henri Carteron held the "extreme view" that Aristotle's concept of force was basically qualitative, but other authors reject this.
Archimedes corrected Aristotle's theory that bodies move towards their natural resting places; metal boats can float if they displace enough water; floating depends in Archimedes' scheme on the mass and volume of the object, not, as Aristotle thought, its elementary composition.
Aristotle's writings on motion remained influential until the Early Modern period. John Philoponus (in Late antiquity) and Galileo (in Early modern period) are said to have shown by experiment that Aristotle's claim that a heavier object falls faster than a lighter object is incorrect. A contrary opinion is given by Carlo Rovelli, who argues that Aristotle's physics of motion is correct within its domain of validity, that of objects in the Earth's gravitational field immersed in a fluid such as air. In this system, heavy bodies in steady fall indeed travel faster than light ones (whether friction is ignored, or not), and they do fall more slowly in a denser medium.
Newton's "forced" motion corresponds to Aristotle's "violent" motion with its external agent, but Aristotle's assumption that the agent's effect stops immediately it stops acting (e.g., the ball leaves the thrower's hand) has awkward consequences: he has to suppose that surrounding fluid helps to push the ball along to make it continue to rise even though the hand is no longer acting on it, resulting in the Medieval theory of impetus.
Four causes
Aristotle suggested that the reason for anything coming about can be attributed to four different types of simultaneously active factors. His term aitia is traditionally translated as "cause", but it does not always refer to temporal sequence; it might be better translated as "explanation", but the traditional rendering will be employed here.
Material cause describes the material out of which something is composed. Thus the material cause of a table is wood. It is not about action. It does not mean that one domino knocks over another domino.
The formal cause is its form, i.e., the arrangement of that matter. It tells one what a thing is, that a thing is determined by the definition, form, pattern, essence, whole, synthesis or archetype. It embraces the account of causes in terms of fundamental principles or general laws, as the whole (i.e., macrostructure) is the cause of its parts, a relationship known as the whole-part causation. Plainly put, the formal cause is the idea in the mind of the sculptor that brings the sculpture into being. A simple example of the formal cause is the mental image or idea that allows an artist, architect, or engineer to create a drawing.
The efficient cause is "the primary source", or that from which the change under consideration proceeds. It identifies 'what makes of what is made and what causes change of what is changed' and so suggests all sorts of agents, non-living or living, acting as the sources of change or movement or rest. Representing the current understanding of causality as the relation of cause and effect, this covers the modern definitions of "cause" as either the agent or agency or particular events or states of affairs. In the case of two dominoes, when the first is knocked over it causes the second also to fall over. In the case of animals, this agency is a combination of how it develops from the egg, and how its body functions.
The final cause (telos) is its purpose, the reason why a thing exists or is done, including both purposeful and instrumental actions and activities. The final cause is the purpose or function that something is supposed to serve. This covers modern ideas of motivating causes, such as volition. In the case of living things, it implies adaptation to a particular way of life.
Optics
Aristotle describes experiments in optics using a camera obscura in Problems, book 15. The apparatus consisted of a dark chamber with a small aperture that let light in. With it, he saw that whatever shape he made the hole, the sun's image always remained circular. He also noted that increasing the distance between the aperture and the image surface magnified the image.
Chance and spontaneity
According to Aristotle, spontaneity and chance are causes of some things, distinguishable from other types of cause such as simple necessity. Chance as an incidental cause lies in the realm of accidental things, "from what is spontaneous". There is also more a specific kind of chance, which Aristotle names "luck", that only applies to people's moral choices.
Astronomy
In astronomy, Aristotle refuted Democritus's claim that the Milky Way was made up of "those stars which are shaded by the earth from the sun's rays," pointing out partly correctly that if "the size of the sun is greater than that of the earth and the distance of the stars from the earth many times greater than that of the sun, then... the sun shines on all the stars and the earth screens none of them." He also wrote descriptions of comets, including the Great Comet of 371 BC.
Geology and natural sciences
Aristotle was one of the first people to record any geological observations. He stated that geological change was too slow to be observed in one person's lifetime.
The geologist Charles Lyell noted that Aristotle described such change, including "lakes that had dried up" and "deserts that had become watered by rivers", giving as examples the growth of the Nile delta since the time of Homer, and "the upheaving of one of the Aeolian islands, previous to a volcanic eruption."'
Meteorologica lends its name to the modern study of meteorology, but its modern usage diverges from the content of Aristotle's ancient treatise on meteors. The ancient Greeks did use the term for a range of atmospheric phenomena, but also for earthquakes and volcanic eruptions. Aristotle proposed that the cause of earthquakes was a gas or vapor (anathymiaseis) that was trapped inside the earth and trying to escape, following other Greek authors Anaxagoras, Empedocles and Democritus.
Aristotle also made many observations about the hydrologic cycle. For example, he made some of the earliest observations about desalination: he observed early – and correctly – that when seawater is heated, freshwater evaporates and that the oceans are then replenished by the cycle of rainfall and river runoff ("I have proved by experiment that salt water evaporated forms fresh and the vapor does not when it condenses condense into sea water again.")
Biology
Empirical research
Aristotle was the first person to study biology systematically, and biology forms a large part of his writings. He spent two years observing and describing the zoology of Lesbos and the surrounding seas, including in particular the Pyrrha lagoon in the centre of Lesbos. His data in History of Animals, Generation of Animals, Movement of Animals, and Parts of Animals are assembled from his own observations, statements given by people with specialized knowledge, such as beekeepers and fishermen, and less accurate accounts provided by travellers from overseas. His apparent emphasis on animals rather than plants is a historical accident: his works on botany have been lost, but two books on plants by his pupil Theophrastus have survived.
Aristotle reports on the sea-life visible from observation on Lesbos and the catches of fishermen. He describes the catfish, electric ray, and frogfish in detail, as well as cephalopods such as the octopus and paper nautilus. His description of the hectocotyl arm of cephalopods, used in sexual reproduction, was widely disbelieved until the 19th century. He gives accurate descriptions of the four-chambered fore-stomachs of ruminants, and of the ovoviviparous embryological development of the hound shark.
He notes that an animal's structure is well matched to function so birds like the heron (which live in marshes with soft mud and live by catching fish) have a long neck, long legs, and a sharp spear-like beak, whereas ducks that swim have short legs and webbed feet. Darwin, too, noted these sorts of differences between similar kinds of animal, but unlike Aristotle used the data to come to the theory of evolution. Aristotle's writings can seem to modern readers close to implying evolution, but while Aristotle was aware that new mutations or hybridizations could occur, he saw these as rare accidents. For Aristotle, accidents, like heat waves in winter, must be considered distinct from natural causes. He was thus critical of Empedocles's materialist theory of a "survival of the fittest" origin of living things and their organs, and ridiculed the idea that accidents could lead to orderly results. To put his views into modern terms, he nowhere says that different species can have a common ancestor, or that one kind can change into another, or that kinds can become extinct.
Scientific style
Aristotle did not do experiments in the modern sense. He used the ancient Greek term pepeiramenoi to mean observations, or at most investigative procedures like dissection. In Generation of Animals, he finds a fertilized hen's egg of a suitable stage and opens it to see the embryo's heart beating inside.
Instead, he practiced a different style of science: systematically gathering data, discovering patterns common to whole groups of animals, and inferring possible causal explanations from these. This style is common in modern biology when large amounts of data become available in a new field, such as genomics. It does not result in the same certainty as experimental science, but it sets out testable hypotheses and constructs a narrative explanation of what is observed. In this sense, Aristotle's biology is scientific.
From the data he collected and documented, Aristotle inferred quite a number of rules relating the life-history features of the live-bearing tetrapods (terrestrial placental mammals) that he studied. Among these correct predictions are the following. Brood size decreases with (adult) body mass, so that an elephant has fewer young (usually just one) per brood than a mouse. Lifespan increases with gestation period, and also with body mass, so that elephants live longer than mice, have a longer period of gestation, and are heavier. As a final example, fecundity decreases with lifespan, so long-lived kinds like elephants have fewer young in total than short-lived kinds like mice.
Classification of living things
Aristotle distinguished about 500 species of animals, arranging these in the History of Animals in a graded scale of perfection, a nonreligious version of the scala naturae, with man at the top. His system had eleven grades of animal, from highest potential to lowest, expressed in their form at birth: the highest gave live birth to hot and wet creatures, the lowest laid cold, dry mineral-like eggs. Animals came above plants, and these in turn were above minerals. He grouped what the modern zoologist would call vertebrates as the hotter "animals with blood", and below them the colder invertebrates as "animals without blood". Those with blood were divided into the live-bearing (mammals), and the egg-laying (birds, reptiles, fish). Those without blood were insects, crustacea (non-shelled – cephalopods, and shelled) and the hard-shelled molluscs (bivalves and gastropods). He recognised that animals did not exactly fit into a linear scale, and noted various exceptions, such as that sharks had a placenta like the tetrapods. To a modern biologist, the explanation, not available to Aristotle, is convergent evolution. Philosophers of science have generally concluded that Aristotle was not interested in taxonomy, but zoologists who studied this question in the early 21st century think otherwise. He believed that purposive final causes guided all natural processes; this teleological view justified his observed data as an expression of formal design.
Psychology
Soul
Aristotle's psychology, given in his treatise On the Soul (peri psychēs), posits three kinds of soul ("psyches"): the vegetative soul, the sensitive soul, and the rational soul. Humans have all three. The vegetative soul is concerned with growth and nourishment. The sensitive soul experiences sensations and movement. The unique part of the human, rational soul is its ability to receive forms of other things and to compare them using the nous (intellect) and logos (reason).
For Aristotle, the soul is the form of a living being. Because all beings are composites of form and matter, the form of living beings is that which endows them with what is specific to living beings, e.g. the ability to initiate movement (or in the case of plants, growth and transformations, which Aristotle considers types of movement). In contrast to earlier philosophers, but in accordance with the Egyptians, he placed the rational soul in the heart, rather than the brain. Notable is Aristotle's division of sensation and thought, which generally differed from the concepts of previous philosophers, with the exception of Alcmaeon.
In On the Soul, Aristotle famously criticizes Plato's theory of the soul and develops his own in response. The first criticism is against Plato's view of the soul in the Timaeus that the soul takes up space and is able to come into physical contact with bodies. 20th-century scholarship overwhelmingly opposed Aristotle's interpretation of Plato and maintained that he had misunderstood him. Today's scholars have tended to re-assess Aristotle's interpretation and been more positive about it. Aristotle's other criticism is that Plato's view of reincarnation entails that it is possible for a soul and its body to be mis-matched; in principle, Aristotle alleges, any soul can go with any body, according to Plato's theory. Aristotle's claim that the soul is the form of a living being eliminates that possibility and thus rules out reincarnation.
Memory
According to Aristotle in On the Soul, memory is the ability to hold a perceived experience in the mind and to distinguish between the internal "appearance" and an occurrence in the past. In other words, a memory is a mental picture (phantasm) that can be recovered. Aristotle believed an impression is left on a semi-fluid bodily organ that undergoes several changes in order to make a memory. A memory occurs when stimuli such as sights or sounds are so complex that the nervous system cannot receive all the impressions at once. These changes are the same as those involved in the operations of sensation, Aristotelian , and thinking.
Aristotle uses the term 'memory' for the actual retaining of an experience in the impression that can develop from sensation, and for the intellectual anxiety that comes with the impression because it is formed at a particular time and processing specific contents. Memory is of the past, prediction is of the future, and sensation is of the present. Retrieval of impressions cannot be performed suddenly. A transitional channel is needed and located in past experiences, both for previous experience and present experience.
Because Aristotle believes people receive all kinds of sense perceptions and perceive them as impressions, people are continually weaving together new impressions of experiences. To search for these impressions, people search the memory itself. Within the memory, if one experience is offered instead of a specific memory, that person will reject this experience until they find what they are looking for. Recollection occurs when one retrieved experience naturally follows another. If the chain of "images" is needed, one memory will stimulate the next. When people recall experiences, they stimulate certain previous experiences until they reach the one that is needed. Recollection is thus the self-directed activity of retrieving the information stored in a memory impression. Only humans can remember impressions of intellectual activity, such as numbers and words. Animals that have perception of time can retrieve memories of their past observations. Remembering involves only perception of the things remembered and of the time passed.
Aristotle believed the chain of thought, which ends in recollection of certain impressions, was connected systematically in relationships such as similarity, contrast, and contiguity, described in his laws of association. Aristotle believed that past experiences are hidden within the mind. A force operates to awaken the hidden material to bring up the actual experience. According to Aristotle, association is the power innate in a mental state, which operates upon the unexpressed remains of former experiences, allowing them to rise and be recalled.
Dreams
Aristotle describes sleep in On Sleep and Wakefulness. Sleep takes place as a result of overuse of the senses or of digestion, so it is vital to the body. While a person is asleep, the critical activities, which include thinking, sensing, recalling and remembering, do not function as they do during wakefulness. Since a person cannot sense during sleep, they cannot have desire, which is the result of sensation. However, the senses are able to work during sleep, albeit differently, unless they are weary.
Dreams do not involve actually sensing a stimulus. In dreams, sensation is still involved, but in an altered manner. Aristotle explains that when a person stares at a moving stimulus such as the waves in a body of water, and then looks away, the next thing they look at appears to have a wavelike motion. When a person perceives a stimulus and the stimulus is no longer the focus of their attention, it leaves an impression. When the body is awake and the senses are functioning properly, a person constantly encounters new stimuli to sense and so the impressions of previously perceived stimuli are ignored. However, during sleep the impressions made throughout the day are noticed as there are no new distracting sensory experiences. So, dreams result from these lasting impressions. Since impressions are all that are left and not the exact stimuli, dreams do not resemble the actual waking experience. During sleep, a person is in an altered state of mind. Aristotle compares a sleeping person to a person who is overtaken by strong feelings toward a stimulus. For example, a person who has a strong infatuation with someone may begin to think they see that person everywhere because they are so overtaken by their feelings. Since a person sleeping is in a suggestible state and unable to make judgements, they become easily deceived by what appears in their dreams, like the infatuated person. This leads the person to believe the dream is real, even when the dreams are absurd in nature. In De Anima iii 3, Aristotle ascribes the ability to create, to store, and to recall images in the absence of perception to the faculty of imagination, phantasia.
One component of Aristotle's theory of dreams disagrees with previously held beliefs. He claimed that dreams are not foretelling and not sent by a divine being. Aristotle reasoned naturalistically that instances in which dreams do resemble future events are simply coincidences. Aristotle claimed that a dream is first established by the fact that the person is asleep when they experience it. If a person had an image appear for a moment after waking up or if they see something in the dark it is not considered a dream because they were awake when it occurred. Secondly, any sensory experience that is perceived while a person is asleep does not qualify as part of a dream. For example, if, while a person is sleeping, a door shuts and in their dream they hear a door is shut, this sensory experience is not part of the dream. Lastly, the images of dreams must be a result of lasting impressions of waking sensory experiences.
Practical philosophy
Aristotle's practical philosophy covers areas such as ethics, politics, economics, and rhetoric.
Ethics
Aristotle considered ethics to be a practical rather than theoretical study, i.e., one aimed at becoming good and doing good rather than knowing for its own sake. He wrote several treatises on ethics, most notably including the Nicomachean Ethics.
Aristotle taught that virtue has to do with the proper function (ergon) of a thing. An eye is only a good eye in so much as it can see, because the proper function of an eye is sight. Aristotle reasoned that humans must have a function specific to humans, and that this function must be an activity of the psuchē (soul) in accordance with reason (logos). Aristotle identified such an optimum activity (the virtuous mean, between the accompanying vices of excess or deficiency) of the soul as the aim of all human deliberate action, eudaimonia, generally translated as "happiness" or sometimes "well-being". To have the potential of ever being happy in this way necessarily requires a good character (ēthikē aretē), often translated as moral or ethical virtue or excellence.
Aristotle taught that to achieve a virtuous and potentially happy character requires a first stage of having the fortune to be habituated not deliberately, but by teachers, and experience, leading to a later stage in which one consciously chooses to do the best things. When the best people come to live life this way their practical wisdom (phronesis) and their intellect (nous) can develop with each other towards the highest possible human virtue, the wisdom of an accomplished theoretical or speculative thinker, or in other words, a philosopher.
Politics
In addition to his works on ethics, which address the individual, Aristotle addressed the city in his work titled Politics. Aristotle considered the city to be a natural community. Moreover, he considered the city to be prior in importance to the family, which in turn is prior to the individual, "for the whole must of necessity be prior to the part". He famously stated that "man is by nature a political animal" and argued that humanity's defining factor among others in the animal kingdom is its rationality. Aristotle conceived of politics as being like an organism rather than like a machine, and as a collection of parts none of which can exist without the others. Aristotle's conception of the city is organic, and he is considered one of the first to conceive of the city in this manner.
The common modern understanding of a political community as a modern state is quite different from Aristotle's understanding. Although he was aware of the existence and potential of larger empires, the natural community according to Aristotle was the city (polis) which functions as a political "community" or "partnership" (koinōnia). The aim of the city is not just to avoid injustice or for economic stability, but rather to allow at least some citizens the possibility to live a good life, and to perform beautiful acts: "The political partnership must be regarded, therefore, as being for the sake of noble actions, not for the sake of living together." This is distinguished from modern approaches, beginning with social contract theory, according to which individuals leave the state of nature because of "fear of violent death" or its "inconveniences".
In Protrepticus, the character 'Aristotle' states:
As Plato's disciple Aristotle was rather critical concerning democracy and, following the outline of certain ideas from Plato's Statesman, he developed a coherent theory of integrating various forms of power into a so-called mixed state:
Aristotle's views on women influenced later Western philosophers, who quoted him as an authority until the end of the Middle Ages, but these views have been controversial in modern times. Aristotle's analysis of procreation describes an active, ensouling masculine element bringing life to an inert, passive female element. The biological differences are a result of the fact that the female body is well-suited for reproduction, which changes her body temperature, which in turn makes her, in Aristotle's view, incapable of participating in political life. On this ground, proponents of feminist metaphysics have accused Aristotle of misogyny and sexism. However, Aristotle gave equal weight to women's happiness as he did to men's, and commented in his Rhetoric that the things that lead to happiness need to be in women as well as men.
Economics
Aristotle made substantial contributions to economic thought, especially to thought in the Middle Ages. In Politics, Aristotle addresses the city, property, and trade. His response to criticisms of private property, in Lionel Robbins's view, anticipated later proponents of private property among philosophers and economists, as it related to the overall utility of social arrangements. Aristotle believed that although communal arrangements may seem beneficial to society, and that although private property is often blamed for social strife, such evils in fact come from human nature. In Politics, Aristotle offers one of the earliest accounts of the origin of money. Money came into use because people became dependent on one another, importing what they needed and exporting the surplus. For the sake of convenience, people then agreed to deal in something that is intrinsically useful and easily applicable, such as iron or silver.
Aristotle's discussions on retail and interest was a major influence on economic thought in the Middle Ages. He had a low opinion of retail, believing that contrary to using money to procure things one needs in managing the household, retail trade seeks to make a profit. It thus uses goods as a means to an end, rather than as an end unto itself. He believed that retail trade was in this way unnatural. Similarly, Aristotle considered making a profit through interest unnatural, as it makes a gain out of the money itself, and not from its use.
Aristotle gave a summary of the function of money that was perhaps remarkably precocious for his time. He wrote that because it is impossible to determine the value of every good through a count of the number of other goods it is worth, the necessity arises of a single universal standard of measurement. Money thus allows for the association of different goods and makes them "commensurable". He goes on to state that money is also useful for future exchange, making it a sort of security. That is, "if we do not want a thing now, we shall be able to get it when we do want it".
Rhetoric
Aristotle's Rhetoric proposes that a speaker can use three basic kinds of appeals to persuade his audience: ethos (an appeal to the speaker's character), pathos (an appeal to the audience's emotion), and logos (an appeal to logical reasoning). He also categorizes rhetoric into three genres: epideictic (ceremonial speeches dealing with praise or blame), forensic (judicial speeches over guilt or innocence), and deliberative (speeches calling on an audience to make a decision on an issue). Aristotle also outlines two kinds of rhetorical proofs: enthymeme (proof by syllogism) and paradeigma (proof by example).
Poetics
Aristotle writes in his Poetics that epic poetry, tragedy, comedy, dithyrambic poetry, painting, sculpture, music, and dance are all fundamentally acts of mimesis ("imitation"), each varying in imitation by medium, object, and manner. He applies the term mimesis both as a property of a work of art and also as the product of the artist's intention and contends that the audience's realisation of the mimesis is vital to understanding the work itself. Aristotle states that mimesis is a natural instinct of humanity that separates humans from animals and that all human artistry "follows the pattern of nature". Because of this, Aristotle believed that each of the mimetic arts possesses what Stephen Halliwell calls "highly structured procedures for the achievement of their purposes." For example, music imitates with the media of rhythm and harmony, whereas dance imitates with rhythm alone, and poetry with language. The forms also differ in their object of imitation. Comedy, for instance, is a dramatic imitation of men worse than average; whereas tragedy imitates men slightly better than average. Lastly, the forms differ in their manner of imitation – through narrative or character, through change or no change, and through drama or no drama.
While it is believed that Aristotle's Poetics originally comprised two books – one on comedy and one on tragedy – only the portion that focuses on tragedy has survived. Aristotle taught that tragedy is composed of six elements: plot-structure, character, style, thought, spectacle, and lyric poetry. The characters in a tragedy are merely a means of driving the story; and the plot, not the characters, is the chief focus of tragedy. Tragedy is the imitation of action arousing pity and fear, and is meant to effect the catharsis of those same emotions. Aristotle concludes Poetics with a discussion on which, if either, is superior: epic or tragic mimesis. He suggests that because tragedy possesses all the attributes of an epic, possibly possesses additional attributes such as spectacle and music, is more unified, and achieves the aim of its mimesis in shorter scope, it can be considered superior to epic. Aristotle was a keen systematic collector of riddles, folklore, and proverbs; he and his school had a special interest in the riddles of the Delphic Oracle and studied the fables of Aesop.
Transmission
More than 2300 years after his death, Aristotle remains one of the most influential people who ever lived. He contributed to almost every field of human knowledge then in existence, and he was the founder of many new fields. According to the philosopher Bryan Magee, "it is doubtful whether any human being has ever known as much as he did".
Among countless other achievements, Aristotle was the founder of formal logic, pioneered the study of zoology, and left every future scientist and philosopher in his debt through his contributions to the scientific method. Taneli Kukkonen, observes that his achievement in founding two sciences is unmatched, and his reach in influencing "every branch of intellectual enterprise" including Western ethical and political theory, theology, rhetoric, and literary analysis is equally long. As a result, Kukkonen argues, any analysis of reality today "will almost certainly carry Aristotelian overtones ... evidence of an exceptionally forceful mind." Jonathan Barnes wrote that "an account of Aristotle's intellectual afterlife would be little less than a history of European thought".
Aristotle has been called the father of logic, biology, political science, zoology, embryology, natural law, scientific method, rhetoric, psychology, realism, criticism, individualism, teleology, and meteorology.
The scholar Taneli Kukkonen notes that "in the best 20th-century scholarship Aristotle comes alive as a thinker wrestling with the full weight of the Greek philosophical tradition." What follows is an overview of the transmission and influence of his texts and ideas into the modern era.
His successor, Theophrastus
Aristotle's pupil and successor, Theophrastus, wrote the History of Plants, a pioneering work in botany. Some of his technical terms remain in use, such as carpel from carpos, fruit, and pericarp, from pericarpion, seed chamber.
Theophrastus was much less concerned with formal causes than Aristotle was, instead pragmatically describing how plants functioned.
Later Greek philosophy
The immediate influence of Aristotle's work was felt as the Lyceum grew into the Peripatetic school. Aristotle's students included Aristoxenus, Dicaearchus, Demetrius of Phalerum, Eudemos of Rhodes, Harpalus, Hephaestion, Mnason of Phocis, Nicomachus, and Theophrastus. Aristotle's influence over Alexander the Great is seen in the latter's bringing with him on his expedition a host of zoologists, botanists, and researchers. He had also learned a great deal about Persian customs and traditions from his teacher. Although his respect for Aristotle was diminished as his travels made it clear that much of Aristotle's geography was clearly wrong, when the old philosopher released his works to the public, Alexander complained "Thou hast not done well to publish thy acroamatic doctrines; for in what shall I surpass other men if those doctrines wherein I have been trained are to be all men's common property?"
Hellenistic science
After Theophrastus, the Lyceum failed to produce any original work. Though interest in Aristotle's ideas survived, they were generally taken unquestioningly. It is not until the age of Alexandria under the Ptolemies that advances in biology can be again found.
The first medical teacher at Alexandria, Herophilus of Chalcedon, corrected Aristotle, placing intelligence in the brain, and connected the nervous system to motion and sensation. Herophilus also distinguished between veins and arteries, noting that the latter pulse while the former do not. Though a few ancient atomists such as Lucretius challenged the teleological viewpoint of Aristotelian ideas about life, teleology (and after the rise of Christianity, natural theology) would remain central to biological thought essentially until the 18th and 19th centuries. Ernst Mayr states that there was "nothing of any real consequence in biology after Lucretius and Galen until the Renaissance."
Revival
In the slumbering centuries following the decline of the Roman Empire, Aristotle's vast philosophical and scientific corpus lay largely dormant in the West. But in the burgeoning intellectual heartland of the Abbasid Caliphate, his works underwent a remarkable revival. Translated into Arabic alongside other Greek classics, Aristotle's logic, ethics, and natural philosophy ignited the minds of early Islamic scholars.
Through meticulous commentaries and critical engagements, figures like Al-Farabi and Ibn Sina (Avicenna) breathed new life into Aristotle's ideas. They harmonized his logic with Islamic theology, employed his scientific methodologies to explore the natural world, and even reinterpreted his ethics within the framework of Islamic morality. This revival was not mere imitation. Islamic thinkers embraced Aristotle's rigorous methods while simultaneously challenging his conclusions where they diverged from their own religious beliefs.
Byzantine scholars
Greek Christian scribes played a crucial role in the preservation of Aristotle by copying all the extant Greek language manuscripts of the corpus. The first Greek Christians to comment extensively on Aristotle were Philoponus, Elias, and David in the sixth century, and Stephen of Alexandria in the early seventh century. John Philoponus stands out for having attempted a fundamental critique of Aristotle's views on the eternity of the world, movement, and other elements of Aristotelian thought. Philoponus questioned Aristotle's teaching of physics, noting its flaws and introducing the theory of impetus to explain his observations.
After a hiatus of several centuries, formal commentary by Eustratius and Michael of Ephesus reappeared in the late eleventh and early twelfth centuries, apparently sponsored by Anna Comnena.
Medieval Islamic world
Aristotle was one of the most revered Western thinkers in early Islamic theology. Most of the still extant works of Aristotle, as well as a number of the original Greek commentaries, were translated into Arabic and studied by Muslim philosophers, scientists and scholars. Averroes, Avicenna and Alpharabius, who wrote on Aristotle in great depth, also influenced Thomas Aquinas and other Western Christian scholastic philosophers. Alkindus greatly admired Aristotle's philosophy, and Averroes spoke of Aristotle as the "exemplar" for all future philosophers. Medieval Muslim scholars regularly described Aristotle as the "First Teacher". The title was later used by Western philosophers (as in the famous poem of Dante) who were influenced by the tradition of Islamic philosophy.
Medieval Europe
With the loss of the study of ancient Greek in the early medieval Latin West, Aristotle was practically unknown there from to except through the Latin translation of the Organon made by Boethius. In the twelfth and thirteenth centuries, interest in Aristotle revived and Latin Christians had translations made, both from Arabic translations, such as those by Gerard of Cremona, and from the original Greek, such as those by James of Venice and William of Moerbeke.
After the Scholastic Thomas Aquinas wrote his Summa Theologica, working from Moerbeke's translations and calling Aristotle "The Philosopher", the demand for Aristotle's writings grew, and the Greek manuscripts returned to the West, stimulating a revival of Aristotelianism in Europe that continued into the Renaissance. These thinkers blended Aristotelian philosophy with Christianity, bringing the thought of Ancient Greece into the Middle Ages. Scholars such as Boethius, Peter Abelard, and John Buridan worked on Aristotelian logic.
According to scholar Roger Theodore Lafferty, Dante built up the philosophy of the Comedy with the works of Aristotle as a foundation, just as the scholastics used Aristotle as the basis for their thinking. Dante knew Aristotle directly from Latin translations of his works and indirectly through quotations in the works of Albert Magnus. Dante even acknowledges Aristotle's influence explicitly in the poem, specifically when Virgil justifies the Inferno's structure by citing the Nicomachean Ethics. Dante famously refers to him as "he / Who is acknowledged Master of those who know".
Medieval Judaism
Moses Maimonides (considered to be the foremost intellectual figure of medieval Judaism) adopted Aristotelianism from the Islamic scholars and based his Guide for the Perplexed on it and that became the basis of Jewish scholastic philosophy. Maimonides also considered Aristotle to be the greatest philosopher that ever lived, and styled him as the "chief of the philosophers". Also, in his letter to Samuel ibn Tibbon, Maimonides observes that there is no need for Samuel to study the writings of philosophers who preceded Aristotle because the works of the latter are "sufficient by themselves and [superior] to all that were written before them. His intellect, Aristotle's is the extreme limit of human intellect, apart from him upon whom the divine emanation has flowed forth to such an extent that they reach the level of prophecy, there being no level higher".
Early Modern science
In the Early Modern period, scientists such as William Harvey in England and Galileo Galilei in Italy reacted against the theories of Aristotle and other classical era thinkers like Galen, establishing new theories based to some degree on observation and experiment. Harvey demonstrated the circulation of the blood, establishing that the heart functioned as a pump rather than being the seat of the soul and the controller of the body's heat, as Aristotle thought. Galileo used more doubtful arguments to displace Aristotle's physics, proposing that bodies all fall at the same speed whatever their weight.
18th and 19th-century science
The English mathematician George Boole fully accepted Aristotle's logic, but decided "to go under, over, and beyond" it with his system of algebraic logic in his 1854 book The Laws of Thought. This gives logic a mathematical foundation with equations, enables it to solve equations as well as check validity, and allows it to handle a wider class of problems by expanding propositions of any number of terms, not just two.
Charles Darwin regarded Aristotle as the most important contributor to the subject of biology. In an 1882 letter he wrote that "Linnaeus and Cuvier have been my two gods, though in very different ways, but they were mere schoolboys to old Aristotle". Also, in later editions of the book "On the Origin of Species', Darwin traced evolutionary ideas as far back as Aristotle; the text he cites is a summary by Aristotle of the ideas of the earlier Greek philosopher Empedocles.
Present science
The philosopher Bertrand Russell claims that "almost every serious intellectual advance has had to begin with an attack on some Aristotelian doctrine". Russell calls Aristotle's ethics "repulsive", and labelled his logic "as definitely antiquated as Ptolemaic astronomy". Russell states that these errors make it difficult to do historical justice to Aristotle, until one remembers what an advance he made upon all of his predecessors.
The Dutch historian of science Eduard Jan Dijksterhuis writes that Aristotle and his predecessors showed the difficulty of science by "proceed[ing] so readily to frame a theory of such a general character" on limited evidence from their senses. In 1985, the biologist Peter Medawar could still state in "pure seventeenth century" tones that Aristotle had assembled "a strange and generally speaking rather tiresome farrago of hearsay, imperfect observation, wishful thinking and credulity amounting to downright gullibility".
Zoologists have frequently mocked Aristotle for errors and unverified secondhand reports. However, modern observation has confirmed several of his more surprising claims. Aristotle's work remains largely unknown to modern scientists, though zoologists sometimes mention him as the father of biology or in particular of marine biology. Practising zoologists are unlikely to adhere to Aristotle's chain of being, but its influence is still perceptible in the use of the terms "lower" and "upper" to designate taxa such as groups of plants. The evolutionary biologist Armand Marie Leroi has reconstructed Aristotle's biology, while Niko Tinbergen's four questions, based on Aristotle's four causes, are used to analyse animal behaviour; they examine function, phylogeny, mechanism, and ontogeny. The concept of homology began with Aristotle; the evolutionary developmental biologist Lewis I. Held commented that he would be interested in the concept of deep homology.
Surviving works
Corpus Aristotelicum
The works of Aristotle that have survived from antiquity through medieval manuscript transmission are collected in the Corpus Aristotelicum. These texts, as opposed to Aristotle's lost works, are technical philosophical treatises from within Aristotle's school. Reference to them is made according to the organization of Immanuel Bekker's Royal Prussian Academy edition (Aristotelis Opera edidit Academia Regia Borussica, Berlin, 1831–1870), which in turn is based on ancient classifications of these works.
Loss and preservation
Aristotle wrote his works on papyrus scrolls, the common writing medium of that era. His writings are divisible into two groups: the "exoteric", intended for the public, and the "esoteric", for use within the Lyceum school. Aristotle's "lost" works stray considerably in characterization from the surviving Aristotelian corpus. Whereas the lost works appear to have been originally written with a view to subsequent publication, the surviving works mostly resemble lecture notes not intended for publication. Cicero's description of Aristotle's literary style as "a river of gold" must have applied to the published works, not the surviving notes. A major question in the history of Aristotle's works is how the exoteric writings were all lost, and how the ones now possessed came to be found. The consensus is that Andronicus of Rhodes collected the esoteric works of Aristotle's school which existed in the form of smaller, separate works, distinguished them from those of Theophrastus and other Peripatetics, edited them, and finally compiled them into the more cohesive, larger works as they are known today.
According to Strabo and Plutarch, after Aristotle's death, his library and writings went to Theophrastus (Aristotle's successor as head of the Lycaeum and the Peripatetic school). After the death of Theophrastus, the peripatetic library went to Neleus of Scepsis.
Some time later, the Kingdom of Pergamon began conscripting books for a royal library, and the heirs of Neleus hid their collection in a cellar to prevent it from being seized for that purpose. The library was stored there for about a century and a half, in conditions that were not ideal for document preservation. On the death of Attalus III, which also ended the royal library ambitions, the existence of Aristotelian library was disclosed, and it was purchased by Apellicon and returned to Athens in about 100 BC.
Apellicon sought to recover the texts, many of which were seriously degraded at this point due to the conditions in which they were stored. He had them copied out into new manuscripts, and used his best guesswork to fill in the gaps where the originals were unreadable.
When Sulla seized Athens in 86 BC, he seized the library and transferred it to Rome. There, Andronicus of Rhodes organized the texts into the first complete edition of Aristotle's works (and works attributed to him). The Aristotelian texts we have today are based on these.
Depictions in art
Paintings
Aristotle has been depicted by major artists including Lucas Cranach the Elder, Justus van Gent, Raphael, Paolo Veronese, Jusepe de Ribera, Rembrandt, and Francesco Hayez over the centuries. Among the best-known depictions is Raphael's fresco The School of Athens, in the Vatican's Apostolic Palace, where the figures of Plato and Aristotle are central to the image, at the architectural vanishing point, reflecting their importance. Rembrandt's Aristotle with a Bust of Homer, too, is a celebrated work, showing the knowing philosopher and the blind Homer from an earlier age: as the art critic Jonathan Jones writes, "this painting will remain one of the greatest and most mysterious in the world, ensnaring us in its musty, glowing, pitch-black, terrible knowledge of time."
Sculptures
Eponyms
The Aristotle Mountains in Antarctica are named after Aristotle. He was the first person known to conjecture, in his book Meteorology, the existence of a landmass in the southern high-latitude region, which he called Antarctica. Aristoteles is a crater on the Moon bearing the classical form of Aristotle's name.
See also
Aristotelian Society
Conimbricenses
Perfectionism
References
Notes
Citations
Sources
Further reading
The secondary literature on Aristotle is vast. The following is only a small selection.
Ackrill, J. L. (1997). Essays on Plato and Aristotle, Oxford University Press.
These translations are available in several places online; see External links.
Bakalis, Nikolaos. (2005). Handbook of Greek Philosophy: From Thales to the Stoics Analysis and Fragments, Trafford Publishing, .
Bolotin, David (1998). An Approach to Aristotle's Physics: With Particular Attention to the Role of His Manner of Writing. Albany: SUNY Press. A contribution to our understanding of how to read Aristotle's scientific works.
Burnyeat, Myles F. et al. (1979). Notes on Book Zeta of Aristotle's Metaphysics. Oxford: Sub-faculty of Philosophy.
Code, Alan (1995). Potentiality in Aristotle's Science and Metaphysics, Pacific Philosophical Quarterly 76.
De Groot, Jean (2014). Aristotle's Empiricism: Experience and Mechanics in the 4th century BC, Parmenides Publishing, .
Frede, Michael (1987). Essays in Ancient Philosophy. Minneapolis: University of Minnesota Press.
Gendlin, Eugene T. (2012). Line by Line Commentary on Aristotle's De Anima , Volume 1: Books I & II; Volume 2: Book III. The Focusing Institute.
Gill, Mary Louise (1989). Aristotle on Substance: The Paradox of Unity. Princeton University Press.
Jori, Alberto (2003). Aristotele, Bruno Mondadori (Prize 2003 of the "International Academy of the History of Science"), .
Knight, Kelvin (2007). Aristotelian Philosophy: Ethics and Politics from Aristotle to MacIntyre, Polity Press.
Lewis, Frank A. (1991). Substance and Predication in Aristotle. Cambridge University Press.
Lord, Carnes (1984). Introduction to The Politics, by Aristotle. Chicago University Press.
Loux, Michael J. (1991). Primary Ousia: An Essay on Aristotle's Metaphysics Ζ and Η. Ithaca, NY: Cornell University Press.
Maso, Stefano (Ed.), Natali, Carlo (Ed.), Seel, Gerhard (Ed.) (2012) Reading Aristotle: Physics VII. 3: What is Alteration? Proceedings of the International ESAP-HYELE Conference, Parmenides Publishing. .
[Reprinted in J. Barnes, M. Schofield, and R.R.K. Sorabji, eds.(1975). Articles on Aristotle Vol 1. Science. London: Duckworth 14–34.]
Reeve, C. D. C. (2000). Substantial Knowledge: Aristotle's Metaphysics. Hackett.
Scaltsas, T. (1994). Substances and Universals in Aristotle's Metaphysics. Cornell University Press.
Strauss, Leo (1964). "On Aristotle's Politics", in The City and Man, Rand McNally.
External links
At the Internet Encyclopedia of Philosophy:
At the Internet Classics Archive
From the Stanford Encyclopedia of Philosophy:
Collections of works
At Massachusetts Institute of Technology
Perseus Project at Tufts University
At the University of Adelaide
P. Remacle
The 11-volume 1837 Bekker edition of Aristotle's Works in Greek (PDFDJVU)
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309 | https://en.wikipedia.org/wiki/An%20American%20in%20Paris | An American in Paris | An American in Paris is a jazz-influenced symphonic poem (or tone poem) for orchestra by American composer George Gershwin first performed in 1928. It was inspired by the time that Gershwin had spent in Paris and evokes the sights and energy of the French capital during the .
Gershwin scored the piece for the standard instruments of the symphony orchestra plus celesta, saxophones, and automobile horns. He brought back four Parisian taxi horns for the New York premiere of the composition, which took place on December 13, 1928, in Carnegie Hall, with Walter Damrosch conducting the New York Philharmonic. It was Damrosch who had commissioned Gershwin to write his Concerto in F following the earlier success of Rhapsody in Blue (1924). He completed the orchestration on November 18, less than four weeks before the work's premiere. He collaborated on the original program notes with critic and composer Deems Taylor.
Background
Although the story is likely apocryphal, Gershwin is said to have been attracted by Maurice Ravel's unusual chords, and Gershwin went on his first trip to Paris in 1926 ready to study with Ravel. After his initial student audition with Ravel turned into a sharing of musical theories, Ravel said he could not teach him, saying, "Why be a second-rate Ravel when you can be a first-rate Gershwin?"
Gershwin strongly encouraged Ravel to come to the United States for a tour. To this end, upon his return to New York, Gershwin joined the efforts of Ravel's friend Robert Schmitz, a pianist Ravel had met during the war, to urge Ravel to tour the U.S. Schmitz was the head of Pro Musica, promoting Franco-American musical relations, and was able to offer Ravel a $10,000 fee for the tour, an enticement Gershwin knew would be important to Ravel.
Gershwin greeted Ravel in New York in March 1928 during a party held for Ravel's birthday by Éva Gauthier. Ravel's tour reignited Gershwin's desire to return to Paris, which he and his brother Ira did after meeting Ravel. Ravel's high praise of Gershwin in an introductory letter to Nadia Boulanger caused Gershwin to seriously consider taking much more time to study abroad in Paris. Yet after he played for her, she told him she could not teach him. Boulanger gave Gershwin basically the same advice she gave all her accomplished master students: "What could I give you that you haven't already got?" This did not set Gershwin back, as his real intent abroad was to complete a new work based on Paris and perhaps a second rhapsody for piano and orchestra to follow his Rhapsody in Blue. Paris at this time hosted many expatriate writers, among them Ezra Pound, W. B. Yeats, Ernest Hemingway, F. Scott Fitzgerald and artist Pablo Picasso.
Composition
Gershwin based An American in Paris on a melodic fragment called "Very Parisienne", written in 1926 on his first visit to Paris as a gift to his hosts, Robert and Mabel Schirmer. Gershwin called it "a rhapsodic ballet"; it is written freely and in a much more modern idiom than his prior works.
Gershwin explained in Musical America, "My purpose here is to portray the impressions of an American visitor in Paris as he strolls about the city, listens to the various street noises, and absorbs the French atmosphere."
The piece is structured into five sections, which culminate in a loose A–B–A format. Gershwin's first A episode introduces the two main "walking" themes in the "Allegretto grazioso" and develops a third theme in the "Subito con brio". The style of this A section is written in the typical French style of composers Claude Debussy and Les Six. This A section featured duple meter, singsong rhythms, and diatonic melodies with the sounds of oboe, English horn, and taxi horns. The B section's "Andante ma con ritmo deciso" introduces the American Blues and spasms of homesickness. The "Allegro" that follows continues to express homesickness in a faster twelve-bar blues. In the B section, Gershwin uses common time, syncopated rhythms, and bluesy melodies with the sounds of trumpet, saxophone, and snare drum. "Moderato con grazia" is the last A section that returns to the themes set in A. After recapitulating the "walking" themes, Gershwin overlays the slow blues theme from section B in the final "Grandioso".
Response
Gershwin did not particularly like Walter Damrosch's interpretation at the world premiere of An American in Paris. He stated that Damrosch's sluggish, dragging tempo caused him to walk out of the hall during a matinee performance of this work. The audience, according to Edward Cushing, responded with "a demonstration of enthusiasm impressively genuine in contrast to the conventional applause which new music, good and bad, ordinarily arouses."
Critics believed that An American in Paris was better crafted than Gershwin's Concerto in F. Evening Post did not think it belonged in a program with classical composers César Franck, Richard Wagner, or Guillaume Lekeu on its premiere. Gershwin responded to the critics:
Instrumentation
An American in Paris was originally scored for 3 flutes (3rd doubling on piccolo), 2 oboes, English horn, 2 clarinets in B-flat, bass clarinet in B-flat, 2 bassoons, 4 horns in F, 3 trumpets in B-flat, 3 trombones, tuba, timpani, snare drum, bass drum, triangle, wood block, ratchet, cymbals, low and high tom-toms, xylophone, glockenspiel, celesta, 4 taxi horns labeled as A, B, C, and D with circles around them, alto saxophone, tenor saxophone, baritone saxophone (all doubling soprano and alto saxophones), and strings. Although most modern audiences have heard the taxi horns using the notes A, B, C, and D, it had been Gershwin's intention to use the notes A4, B4, D5, and A3. It is likely that in labeling the taxi horns as A, B, C, and D with circles, he was referring to the four horns, and not the notes that they played.
A major revision of the work by composer and arranger F. Campbell-Watson simplified the instrumentation by reducing the saxophones to only three instruments: alto, tenor and baritone; the soprano and alto saxophone doublings were eliminated to avoid changing instruments. This became the standard performing edition until 2000, when Gershwin specialist Jack Gibbons made his own restoration of the original orchestration of An American in Paris, working directly from Gershwin's original manuscript, including the restoration of Gershwin's soprano saxophone parts removed in Campbell-Watson's revision. Gibbons' restored orchestration of An American in Paris was performed at London's Queen Elizabeth Hall on July 9, 2000, by the City of Oxford Orchestra conducted by Levon Parikian.
William Daly arranged the score for piano solo; this was published by New World Music in 1929.
Preservation status
On September 22, 2013, it was announced that a musicological critical edition of the full orchestral score would be eventually released. The Gershwin family, working in conjunction with the Library of Congress and the University of Michigan, were working to make scores available to the public that represent Gershwin's true intent. It was unknown whether the critical score would include the four minutes of material Gershwin later deleted from the work (such as the restatement of the blues theme after the faster 12 bar blues section), or if the score would document changes in the orchestration during Gershwin's composition process.
The score to An American in Paris was scheduled to be issued first in a series of scores to be released. The entire project was expected to take 30 to 40 years to complete, but An American in Paris was planned to be an early volume in the series.
Two urtext editions of the work were published by the German publisher B-Note Music in 2015. The changes made by Campbell-Watson were withdrawn in both editions. In the extended urtext, 120 bars of music were re-integrated. Conductor Walter Damrosch had cut them shortly before the first performance.
On September 9, 2017, The Cincinnati Symphony Orchestra gave the world premiere of the long-awaited critical edition of the piece prepared by Mark Clague, director of the Gershwin initiative at the University of Michigan. This performance was of the original 1928 orchestration.
Recordings
An American in Paris has been frequently recorded. The first recording was made for the Victor Talking Machine Company in 1929 with Nathaniel Shilkret conducting the Victor Symphony Orchestra, drawn from members of the Philadelphia Orchestra. Gershwin was on hand to "supervise" the recording; however, Shilkret was reported to be in charge and eventually asked the composer to leave the recording studio. Then, a little later, Shilkret discovered there was no one to play the brief celesta solo during the slow section, so he hastily asked Gershwin if he might play the solo; Gershwin said he could and so he briefly participated in the actual recording. This recording is believed to use the taxi horns in the way that Gershwin had intended using the notes A-flat, B-flat, a higher D, and a lower A.
The radio broadcast of the September 8, 1937, Hollywood Bowl George Gershwin Memorial Concert, in which An American in Paris, also conducted by Shilkret, was second on the program, was recorded and was released in 1998 in a two-CD set.
Arthur Fiedler and the Boston Pops Orchestra recorded the work for RCA Victor, including one of the first stereo recordings of the music.
In 1945, Arturo Toscanini conducting the NBC Symphony Orchestra recorded the piece for RCA Victor, one of the few commercial recordings Toscanini made of music by an American composer.
The Seattle Symphony also recorded a version in 1990 of Gershwin's original score, before numerous edits were made resulting in the score as we hear it today.
The blues section of An American in Paris has been recorded separately by a number of artists; Ralph Flanagan & His Orchestra released it as a single in 1951 which reached No. 15 on the Billboard chart. Harry James released a version of the blues section on his 1953 album One Night Stand, recorded live at the Aragon Ballroom in Chicago (Columbia GL 522 and CL 522).
Use in film
In 1951, Metro-Goldwyn-Mayer released the musical film An American in Paris, featuring Gene Kelly and Leslie Caron and directed by Vincente Minnelli. Winning the 1951 Best Picture Oscar and numerous other awards, the film featured many tunes of Gershwin and concluded with an extensive, elaborate dance sequence built around the symphonic poem An American in Paris (arranged for the film by Johnny Green), which at the time was the most expensive musical number ever filmed, costing $500,000 .
Notes and references
Further reading
External links
Scores, marked by Leonard Bernstein, Andre Kostelanetz, Erich Leinsdorf; New York Philharmonic archives
1944 recording by the New York Philharmonic conducted by Artur Rodziński
, New York Philharmonic, Leonard Bernstein, 1959.
1928 compositions
Compositions by George Gershwin
Grammy Hall of Fame Award recipients
Music about Paris
Music commissioned by the New York Philharmonic
Symphonic poems |
316 | https://en.wikipedia.org/wiki/Academy%20Award%20for%20Best%20Production%20Design | Academy Award for Best Production Design | The Academy Award for Best Production Design recognizes achievement for art direction in film. The category's original name was Best Art Direction, but was changed to its current name in 2012 for the 85th Academy Awards. This change resulted from the Art Directors' branch of the Academy of Motion Picture Arts and Sciences (AMPAS) being renamed the Designers' branch. Since 1947, the award is shared with the set decorators. It is awarded to the best interior design in a film.
The films below are listed with their production year (for example, the 2000 Academy Award for Best Art Direction is given to a film from 1999). In the lists below, the winner of the award for each year is shown first, followed by the other nominees in alphabetical order.
Superlatives
Winners and nominees
1920s
1930s
1940s
1950s
1960s
1970s
1980s
1990s
2000s
2010s
2020s
See also
BAFTA Award for Best Production Design
Critics' Choice Movie Award for Best Production Design
Individuals with multiple wins
11 wins
Cedric Gibbons
8 wins
Edwin B. Willis
7 wins
Richard Day
6 wins
Thomas Little
Walter M. Scott
5 wins
Lyle R. Wheeler
4 wins
John Box
Samuel M. Comer
F. Keogh Gleason
George James Hopkins
3 wins
Edward Carfagno
Stuart Craig
William S. Darling
John DeCuir
Vernon Dixon
Hans Dreier
Dante Ferretti
Paul S. Fox
Alexander Golitzen
Paul Groesse
John Meehan
Ray Moyer
Francesca Lo Schiavo
Jack Martin Smith
2 wins
Ken Adam
E. Preston Ames
Herman A. Blumenthal
Henry Bumstead
Donald Graham Burt
Gene Callahan
Rick Carter
George Davis
Leslie Dilley
Michael D. Ford
George Gaines
Russell A. Gausman
Nancy Haigh
Harry Horner
William A. Horning
Hugh Hunt
Wiard Ihnen
Emile Kuri
Terence Marsh
Catherine Martin
William Cameron Menzies
Urie McCleary
John Myhre
Gil Parrondo
Robert Priestley
Stuart A. Reiss
Norman Reynolds
Dario Simoni
Robert Stromberg
Richard Sylbert
Joseph C. Wright
Peter Young
Notes
References
Best Production Design
Awards for best art direction |
332 | https://en.wikipedia.org/wiki/Animalia%20%28book%29 | Animalia (book) | Animalia is an illustrated children's book by Graeme Base. It was originally published in 1986, followed by a tenth anniversary edition in 1996, and a 25th anniversary edition in 2012. Over four million copies have been sold worldwide. A special numbered and signed anniversary edition was also published in 1996, with an embossed gold jacket.
Synopsis
Animalia is an alliterative alphabet book and contains twenty-six illustrations, one for each letter of the alphabet. Each illustration features an animal from the animal kingdom (A is for alligator and armadillo, B is for butterfly, etc.) along with a short poem utilizing the letter of the page for many of the words. The illustrations contain many other objects beginning with that letter that the reader can try to identify (however, there are not necessarily "a thousand things, or maybe more", as the author states). As an additional challenge, the author has hidden a picture of himself as a child in every picture.
Related products
Julia MacRae Books published an Animalia colouring book in 2008. H. N. Abrams also published a wall calendar colouring book version for children the same year.
H. N. Abrams published The Animalia Wall Frieze, a fold-out over 26 feet in length, in which the author created new riddles for each letter.
The Great American Puzzle Factory created a 300-piece jigsaw puzzle based on the book's cover.
Adaptations
A television series was also created, based on the book, which airs in Canada. The Australian Children's Television Foundation released a teaching resource DVD-ROM in 2011 to accompany the TV series with teaching aids for classroom use.
In 2010, The Base Factory and AppBooks released Animalia as an application for iPad and iPhone/iPod Touch.
Awards
Animalia won the Young Australian's Best Book Award in 1987 for Best Picture Story Book.
The Children's Book Council of Australia designated Animalia a 1987 Picture Book of the Year: Honour Book.
Kid's Own Australian Literature Awards named Animalia the 1988 Picture Book Winner.
References
External links
Graeme Base's official website
A Learning Time activity guide for Animalia created by The Little Big Book Club
1986 children's books
Alphabet books
Australian children's books
Children's books about animals
Picture books by Graeme Base
Puffin Books books
Puzzle books |
334 | https://en.wikipedia.org/wiki/International%20Atomic%20Time | International Atomic Time | International Atomic Time (abbreviated TAI, from its French name ) is a high-precision atomic coordinate time standard based on the notional passage of proper time on Earth's geoid. TAI is a weighted average of the time kept by over 450 atomic clocks in over 80 national laboratories worldwide. It is a continuous scale of time, without leap seconds, and it is the principal realisation of Terrestrial Time (with a fixed offset of epoch). It is the basis for Coordinated Universal Time (UTC), which is used for civil timekeeping all over the Earth's surface and which has leap seconds.
UTC deviates from TAI by a number of whole seconds. , when another leap second was put into effect, UTC is currently exactly 37 seconds behind TAI. The 37 seconds result from the initial difference of 10 seconds at the start of 1972, plus 27 leap seconds in UTC since 1972.
TAI may be reported using traditional means of specifying days, carried over from non-uniform time standards based on the rotation of the Earth. Specifically, both Julian days and the Gregorian calendar are used. TAI in this form was synchronised with Universal Time at the beginning of 1958, and the two have drifted apart ever since, due primarily to the slowing rotation of the Earth.
Operation
TAI is a weighted average of the time kept by over 450 atomic clocks in over 80 national laboratories worldwide. The majority of the clocks involved are caesium clocks; the International System of Units (SI) definition of the second is based on caesium. The clocks are compared using GPS signals and two-way satellite time and frequency transfer. Due to the signal averaging TAI is an order of magnitude more stable than its best constituent clock.
The participating institutions each broadcast, in real time, a frequency signal with timecodes, which is their estimate of TAI. Time codes are usually published in the form of UTC, which differs from TAI by a well-known integer number of seconds. These time scales are denoted in the form UTC(NPL) in the UTC form, where NPL here identifies the National Physical Laboratory, UK. The TAI form may be denoted TAI(NPL). The latter is not to be confused with TA(NPL), which denotes an independent atomic time scale, not synchronised to TAI or to anything else.
The clocks at different institutions are regularly compared against each other. The International Bureau of Weights and Measures (BIPM, France), combines these measurements to retrospectively calculate the weighted average that forms the most stable time scale possible. This combined time scale is published monthly in "Circular T", and is the canonical TAI. This time scale is expressed in the form of tables of differences UTC − UTC(k) (equal to TAI − TAI(k)) for each participating institution k. The same circular also gives tables of TAI − TA(k), for the various unsynchronised atomic time scales.
Errors in publication may be corrected by issuing a revision of the faulty Circular T or by errata in a subsequent Circular T. Aside from this, once published in Circular T, the TAI scale is not revised. In hindsight, it is possible to discover errors in TAI and to make better estimates of the true proper time scale. Since the published circulars are definitive, better estimates do not create another version of TAI; it is instead considered to be creating a better realisation of Terrestrial Time (TT).
History
Early atomic time scales consisted of quartz clocks with frequencies calibrated by a single atomic clock; the atomic clocks were not operated continuously. Atomic timekeeping services started experimentally in 1955, using the first caesium atomic clock at the National Physical Laboratory, UK (NPL). It was used as a basis for calibrating the quartz clocks at the Royal Greenwich Observatory and to establish a time scale, called Greenwich Atomic (GA). The United States Naval Observatory began the A.1 scale on 13 September 1956, using an Atomichron commercial atomic clock, followed by the NBS-A scale at the National Bureau of Standards, Boulder, Colorado on 9 October 1957.
The International Time Bureau (BIH) began a time scale, Tm or AM, in July 1955, using both local caesium clocks and comparisons to distant clocks using the phase of VLF radio signals. The BIH scale, A.1, and NBS-A were defined by an epoch at the beginning of 1958 The procedures used by the BIH evolved, and the name for the time scale changed: A3 in 1964 and TA(BIH) in 1969.
The SI second was defined in terms of the caesium atom in 1967. From 1971 to 1975 the General Conference on Weights and Measures and the International Committee for Weights and Measures made a series of decisions that designated the BIPM time scale International Atomic Time (TAI).
In the 1970s, it became clear that the clocks participating in TAI were ticking at different rates due to gravitational time dilation, and the combined TAI scale, therefore, corresponded to an average of the altitudes of the various clocks. Starting from the Julian Date 2443144.5 (1 January 1977 00:00:00 TAI), corrections were applied to the output of all participating clocks, so that TAI would correspond to proper time at the geoid (mean sea level). Because the clocks were, on average, well above sea level, this meant that TAI slowed by about one part in a trillion. The former uncorrected time scale continues to be published under the name EAL (Échelle Atomique Libre, meaning Free Atomic Scale).
The instant that the gravitational correction started to be applied serves as the epoch for Barycentric Coordinate Time (TCB), Geocentric Coordinate Time (TCG), and Terrestrial Time (TT), which represent three fundamental time scales in the solar system. All three of these time scales were defined to read JD 2443144.5003725 (1 January 1977 00:00:32.184) exactly at that instant. TAI was henceforth a realisation of TT, with the equation TT(TAI) = TAI + 32.184 s.
The continued existence of TAI was questioned in a 2007 letter from the BIPM to the ITU-R which stated, "In the case of a redefinition of UTC without leap seconds, the CCTF would consider discussing the possibility of suppressing TAI, as it would remain parallel to the continuous UTC."
Relation to UTC
Contrary to TAI, UTC is a discontinuous time scale. It is occasionally adjusted by leap seconds. Between these adjustments, it is composed of segments that are mapped to atomic time by a constant offset. From its beginning in 1961 through December 1971, the adjustments were made regularly in fractional leap seconds so that UTC approximated UT2. Afterward, these adjustments were made only in whole seconds to approximate UT1. This was a compromise arrangement in order to enable a publicly broadcast time scale. The less frequent whole-second adjustments meant that the time scale would be more stable and easier to synchronize internationally. The fact that it continues to approximate UT1 means that tasks such as navigation which require a source of Universal Time continue to be well served by the public broadcast of UTC.
See also
Clock synchronization
Time and frequency transfer
Notes
References
Footnotes
Bibliography
External links
BIPM technical services: Time Metrology
Time and Frequency Section - National Physical Laboratory, UK
IERS website
NIST Web Clock FAQs
History of time scales
NIST-F1 Cesium Fountain Atomic Clock
Japan Standard Time Project, NICT, Japan
Standard of time definition: UTC, GPS, LORAN and TAI
Time scales |
359 | https://en.wikipedia.org/wiki/List%20of%20Atlas%20Shrugged%20characters | List of Atlas Shrugged characters | This is a list of characters in Ayn Rand's 1957 novel Atlas Shrugged.
Major characters
The following are major characters from the novel.
Protagonists
Dagny Taggart
Dagny Taggart is the protagonist of the novel. She is vice president in charge of operations for Taggart Transcontinental, under her brother, James Taggart. Given James' incompetence, Dagny is responsible for all the workings of the railroad.
Francisco d'Anconia
Francisco d'Anconia is one of the central characters in Atlas Shrugged, an owner by inheritance of the world's largest copper mining operation. He is a childhood friend, and the first love, of Dagny Taggart. A child prodigy of exceptional talents, Francisco was dubbed the "climax" of the d'Anconia line, an already prestigious Argentine family of skilled industrialists. He was a classmate of John Galt and Ragnar Danneskjöld and student of both Hugh Akston and Robert Stadler. He began working while still in school to show that he could have been successful without the aid of his family's wealth. Later, Francisco bankrupts the d'Anconia business to put it out of others' reach. His full name is given as "Francisco Domingo Carlos Andres Sebastián d'Anconia".
John Galt
John Galt is the primary male hero of Atlas Shrugged. He initially appears as an unnamed menial worker for Taggart Transcontinental, who often dines with Eddie Willers in the employees' cafeteria, and leads Eddie to reveal important information about Dagny Taggart and Taggart Transcontinental. Only Eddie's side of their conversations is given in the novel. Later in the novel, the reader discovers this worker's true identity.
Before working for Taggart Transcontinental, Galt worked as an engineer for the Twentieth Century Motor Company, where he secretly invented a generator of usable electric energy from ambient static electricity, but abandoned his prototype, and his employment, when dissatisfied by an easily corrupted novel system of payment. This prototype was found by Dagny Taggart and Hank Rearden. Galt himself remains concealed throughout much of the novel, working a job and living by himself, where he unites the most skillful inventors and business leaders under his leadership. He delivers a lengthy broadcast speech that presents the author's philosophy of Objectivism.
Henry "Hank" Rearden
Henry (known as "Hank") Rearden is one of the central characters in Atlas Shrugged. He owns the most important steel company in the United States, and invents Rearden Metal, an alloy stronger, lighter, cheaper and tougher than steel. He lives in Philadelphia with his wife Lillian, his brother Philip, and his elderly mother. Rearden represents a type of self-made man and eventually divorces Lillian, abandons his steel mills following a bloody assault by government-planted workers, and joins John Galt's strike.
Eddie Willers
Edwin "Eddie" Willers is the Special Assistant to the Vice-President in Charge of Operations at Taggart Transcontinental. His father and grandfather worked for the Taggarts, and himself likewise. He is completely loyal to Dagny and to Taggart Transcontinental. Willers does not possess the creative ability of Galt's associates, but matches them in moral courage and is capable of appreciating and making use of their creations. After Dagny shifts her attention and loyalty to saving the captive Galt, Willers maintains the railroad until its collapse.
Ragnar Danneskjöld
One of Galt's first followers, and world-famous as a pirate, who seizes relief ships sent from the United States to the People's States of Europe. He works to ensure that once those espousing Galt's philosophy are restored to their rightful place in society, they have enough capital to rebuild the world. Kept in the background for much of the book, Danneskjöld makes a personal appearance to encourage Rearden to persevere in his increasingly difficult situation, and gives him a bar of gold as compensation for the income taxes he has paid over the last several years. Danneskjöld is married to the actress Kay Ludlow; their relationship is kept hidden from the outside world, which only knows of Ludlow as a retired film star. Considered a misfit by Galt's other adherents, he views his actions as a means to speed the world along in understanding Galt's perspective.
According to Barbara Branden, who was closely associated with Rand at the time the book was written, there were sections written describing Danneskjöld's adventures at sea, cut from the final published text. In a 1974 comment at a lecture, Rand said that Danneskjöld's name was a tribute to Victor Hugo's novel Hans of Iceland, wherein the hero becomes the first of the Counts of Danneskjöld. In the published book, Danneskjöld is always seen through the eyes of others (Dagny Taggart or Hank Rearden), except for a brief paragraph in the very last chapter.
Antagonists
James Taggart
The President of Taggart Transcontinental and the book's most important antagonist. Taggart is an expert influence peddler but incapable of making operational decisions on his own. He relies on his sister, Dagny Taggart, to actually run the railroad, but nonetheless opposes her in almost every endeavor because of his various anti-capitalist moral and political beliefs. In a sense, he is the antithesis of Dagny. This contradiction leads to the recurring absurdity of his life: the desire to overcome those on whom his life depends, and the horror that he will succeed at this. In the final chapters of the novel, he suffers a complete mental breakdown upon realizing that he can no longer deceive himself in this respect.
Lillian Rearden
The unsupportive wife of Hank Rearden, who dislikes his habits and (secretly at first) seeks to ruin Rearden to prove her own value. Lillian achieves this, when she passes information to James Taggart about her husband's affair with his sister. This information is used to blackmail Rearden to sign a Gift Certificate which delivers all the property rights of Rearden Metal to others. Lillian thereafter uses James Taggart for sexual satisfaction, until Hank abandons her.
Dr. Floyd Ferris
Ferris is a biologist who works as "co-ordinator" at the State Science Institute. He uses his position there to deride reason and productive achievement, and publishes a book entitled Why Do You Think You Think? He clashes on several occasions with Hank Rearden, and twice attempts to blackmail Rearden into giving up Rearden Metal. He is also one of the group of looters who tries to get Rearden to agree to the Steel Unification Plan. Ferris hosts the demonstration of the Project X weapon, and is the creator of the Ferris Persuader, a torture machine. When John Galt is captured by the looters, Ferris uses the device on Galt, but it breaks down before extracting the information Ferris wants from Galt. Ferris represents the group which uses brute force on the heroes to achieve the ends of the looters.
Dr. Robert Stadler
A former professor at Patrick Henry University, and along with colleague Hugh Akston, mentor to Francisco d'Anconia, John Galt and Ragnar Danneskjöld. He has since become a sell-out, one who had great promise but squandered it for social approval, to the detriment of the free. He works at the State Science Institute where all his inventions are perverted for use by the military, including a sound-based weapon known as Project X (Xylophone). He is killed when Cuffy Meigs (see below) drunkenly overloads the circuits of Project X, causing it to destroy itself and every structure and living thing in a 100-mile radius. The character was, in part, modeled on J. Robert Oppenheimer, whom Rand had interviewed for an earlier project, and his part in the creation of nuclear weapons. To his former student Galt, Stadler represents the epitome of human evil, as the "man who knew better" but chose not to act for the good.
Wesley Mouch
The incompetent and treacherous lobbyist whom Hank Rearden reluctantly employs in Washington, who rises to prominence and authority throughout the novel through trading favours and disloyalty. In return for betraying Hank by helping broker the Equalization of Opportunity Bill (which, by restricting the number of businesses each person may own to one, forces Hank to divest most of his companies), he is given a senior position at the Bureau of Economic Planning and National Resources. Later in the novel he becomes its Top Co-ordinator, a position that eventually becomes Economic Dictator of the country. Mouch's mantra, whenever a problem arises from his prior policy, is to say, "I can't help it. I need wider powers."
Secondary characters
The following secondary characters also appear in the novel.
Hugh Akston is identified as "One of the last great advocates of reason." He was a renowned philosopher and the head of the Department of Philosophy at Patrick Henry University, where he taught Francisco d'Anconia, John Galt, and Ragnar Danneskjöld. He was, along with Robert Stadler, a father figure to these three. Akston's name is so hallowed that a young lady, on hearing that Francisco had studied under him, is shocked. She thought he must have been one of those great names from an earlier century. He now works as a cook in a roadside diner, and proves extremely skillful at the job. When Dagny tracks him down, and before she discovers his true identity, he rejects her enthusiastic offer to manage the dining car services for Taggart Transcontinental. He is based on Aristotle.
Jeff Allen is a tramp who stows away on a Taggart train during one of Dagny's cross-country trips. Instead of throwing him out, she allows him to ride as her guest. It is from Allen that she learns the full story behind the collapse of the Twentieth Century Motor Company (Rand's extensive metaphor for the inherent flaws of communism), as well as a hint of John Galt's true background.
Calvin Atwood is owner of Atwood Light and Power Company and joins Galt's strike.
Mayor Bascom is the mayor of Rome, Wisconsin, who reveals part of the history of the Twentieth Century Motor Company.
Dr. Blodgett is the scientist who pulls the lever to demonstrate Project X.
Orren Boyle is the head of Associated Steel, antithesis of Hank Rearden and a friend of James Taggart. He is an investor in the San Sebastián Mines. He disappears from the story after having a nervous breakdown following the failed 'unification' of the steel industry.
Laura Bradford is an actress and Kip Chalmers' mistress. She is one of the passengers on his train, and dies in the Taggart Tunnel disaster.
Bill Brent is the chief dispatcher for the Colorado Division of Taggart Transcontinental, who tries to prevent the Taggart Tunnel disaster.
Cherryl Brooks is a dime store shopgirl who marries James Taggart after a chance encounter in her store the night the John Galt Line was falsely deemed his greatest success. She marries him thinking he is the heroic person behind Taggart Transcontinental. Cherryl is at first harsh towards Dagny, having believed Jim Taggart's descriptions of his sister, until she questions employees of the railroad. Upon learning that her scorn had been misdirected, Cherryl puts off apologizing to Dagny out of shame, but eventually admits to Dagny that when she married Jim, she thought he had the heroic qualities that she had looked up to - she thought she was marrying someone like Dagny. Shortly after making this admission, she commits suicide by jumping over a stone parapet and into the river, unable to live with her evil husband and seeing no way to escape him.
Emma Chalmers, Kip Chalmers' mother, gains some influence after his death. Known as "Kip's Ma," she starts a soybean-growing project in Louisiana and commandeers thousands of railroad freight cars to move the harvest. As a result, the year's wheat crop from Minnesota never reaches the rest of the country, but instead rots in storage; also, the soybean crop is lost, having been reaped too early.
Kip Chalmers is a Washington man who has decided to run for election as Legislator from California. On the way to a campaign rally, the Taggart Transcontinental train that is carrying him encounters a split rail, resulting in the destruction of its diesel engine. His demands lead to a coal-burning steam engine being attached to his train in its stead and used to pull it through an eight-mile tunnel. The result is the suffocation of all passengers and the destruction of the tunnel, caused when a train hauling military ordnance crashes into Chalmers' train and explodes.
Tom Colby is the head of the Rearden Steel Workers Union.
Dan Conway is the middle-aged president of the Phoenix-Durango railroad. Running a railroad is just about the only thing he knows. When the Anti-dog-eat-dog Rule is used to drive his business out of Colorado, he loses the will to fight, and resigns himself to a quiet life of books and fishing. He is not one of those who joined John Galt's strike, his resignation being a personal choice of his own.
Ken Danagger owns Danagger Coal in Pennsylvania. He helps Hank Rearden illegally make Rearden Metal, then later decides to quit and join Galt's strike moments before Dagny arrives to try to persuade him otherwise.
Quentin Daniels is an enterprising engineer hired by Dagny Taggart to reconstruct John Galt's motor. Partway through this process, Quentin withdraws his effort for the same reasons John Galt himself had. Dagny's pursuit of Quentin leads her to Galt's Gulch. Galt recognizes in him a younger version of himself, having emulated both Galt's achievements in physics and Galt's social reasoning.
Balph Eubank is called "the literary leader of the age", despite the fact that no book he has written has sold more than 3,000 copies. He complains that it is disgraceful that artists are treated as peddlers, and that there should be a law limiting the sales of books to 10,000 copies. He is a misogynist who thinks it disgusting that Dagny Taggart is a railroad vice-president.
The Fishwife is one of the strikers, who earns her living by providing the fish for Hammond's grocery market; she is described as having "dark, disheveled hair and large eyes", and is a writer. Galt says she "wouldn't be published outside. She believes that when one deals with words, one deals with the mind." This character represents Rand herself; it is her cameo appearance in her own novel.
Richard Halley is Dagny Taggart's favorite composer, who mysteriously disappeared after the evening of his greatest triumph. Halley spent years as a struggling and unappreciated composer. At age 24, his opera Phaethon was performed for the first time, to an audience who booed and heckled it. After 19 years, Phaethon was performed again, but this time it was received to the greatest ovation the opera house had ever heard. The following day, Halley retired, sold the rights to his music, and disappeared. It is later revealed that he has joined the strike and settled in Galt's Gulch.
Lawrence Hammond runs Hammond Cars in Colorado, one of the few companies in existence that still produces top-quality vehicles. He eventually quits and joins the strike.
Mrs. William Hastings is the widow of the chief engineer at the Twentieth Century Motor Company. Her husband quit shortly after Galt did and joined the strike some years later. Her lead allows Dagny to find Hugh Akston.
Dr. Thomas Hendricks is a famous brain surgeon who developed a new method of preventing strokes. He joined Galt's strike when the American medical system was put under government control.
Tinky Holloway is one of the "looters" and is frequently referred to and quoted by other characters in the story, but he has only one major appearance: during the Washington meeting with Hank Rearden.
Lee Hunsacker is in charge of a company called Amalgamated Service that takes over the Twentieth Century Motor Company. He files a lawsuit that eventually leads to Midas Mulligan and Judge Narragansett joining the strike. A failed businessman, he laments constantly that no-one ever gave him a chance.
Gwen Ives is Hank Rearden's secretary, described as being in her late twenties and remaining calm and professional despite the chaos that threatens his business. When Rearden abandons his mills and joins Galt's strike, she and many other employees do the same.
Gilbert Keith-Worthing is a British novelist of erstwhile fame, now neglected but still considered a "walking classic," and a proponent of the idea that freedom is an illusion. Kip Chalmers brings him along on the train to California, "for no reason that either of them could discover"; he dies in the Taggart Tunnel disaster.
Owen Kellogg is Assistant to the Manager of the Taggart Terminal in New York. He catches Dagny Taggart's eye as one of the few competent men on staff. After seeing the sorry state of the Ohio Division, she decides to make him its new Superintendent. However, as soon as she returns to New York, Kellogg informs her that he is quitting his job. Owen Kellogg eventually reaches, and settles in, Galt's Gulch.
Fred Kinnan is a labor leader and member of the looter cabal. Unlike the others, however, Kinnan is straightforward and honest about his purpose. Kinnan is the only one to openly state the true motivations of himself and his fellow conspirators. At the end of Galt's three-hour speech, he expresses admiration for the man, as he says what he means. Despite this, Kinnan admits that he is one of the people Galt is out to destroy.
Paul Larkin is an unsuccessful, middle-aged businessman, a friend of the Rearden family. He meets with the other Looters to work out a plan to bring Rearden down. James Taggart knows he is friends with Hank Rearden and challenges his loyalty, and Larkin assures Taggart that he will go along with them.
Eugene Lawson heads the Community Bank of Madison, then gets a job with the government when his bank goes bankrupt due to new government policies. One of the looter's cabal, he is a collectivist who abhors production and money-making.
Mort Liddy is a hack composer who writes trite scores for movies and modern symphonies to which no one listens. He believes melody is a primitive vulgarity. He is one of Lillian Rearden's friends and a member of the cultural elite.
Clifton Locey is a friend of Jim Taggart who takes the position of vice-president of operation when Dagny Taggart quits.
Pat Logan is the engineer on the first run of the John Galt Line. He later strikes.
Kay Ludlow is a beautiful actress who quit Holywood because of the roles she was given and married secretly the pirate Ragnar Danneskjöld.
Roger Marsh is a producer of electrical equipment who joins the strike. Dagny finds him growing cabbage in Galt's Gulch.
Dick McNamara is a contractor who finished the San Sebastian Line. Dagny Taggart plans to hire him to lay the new Rearden Metal track for the Rio Norte Line, but before she does so, he mysteriously disappears. She later discovers that he has joined the strike and settled in Galt's Gulch.
Cuffy Meigs is the Director of Unification for the railroad business. He carries a pistol and a lucky rabbit's foot, dresses in a military uniform, and is described as "impervious to thought". Meigs seizes control of Project X and accidentally destroys it, demolishing the country's last railroad bridge across the Mississippi River and killing himself, his men, and Dr. Stadler.
Dave Mitchum is a state-hired superintendent of the Colorado Division of Taggart Transcontinental. He is partially responsible for the Taggart Tunnel disaster.
Chick Morrison holds the position of "Morale Conditioner" in the government. He quits when society begins to collapse and flees to a stronghold in Tennessee. His fellow looters consider it unlikely that he will survive.
Horace Bussby Mowen is the president of the Amalgamated Switch and Signal Company, Inc. of Connecticut. He is a businessman who sees nothing wrong with the moral code that is destroying society and would never dream of saying he is in business for any reason other than the good of society. Dagny Taggart hires Mowen to produce switches made of Rearden Metal. He is reluctant to build anything with this unproven technology, and has to be cajoled into accepting the contract. When pressured by public opinion, he discontinues production of the switches, forcing Dagny to find an alternative source.
Midas Mulligan is a wealthy banker who mysteriously disappeared in protest after he was given a court order to lend money to an incompetent applicant. When the order came down, he liquidated his entire business, paid off his depositors, and joined Galt's strike. He is the legal owner of the land where Galt's Gulch is located. Mulligan's birth name was Michael, but he had it legally changed after a news article called him "Midas" in a derogatory fashion, which Mulligan took as a compliment.
Judge Narragansett is an American jurist who ruled in favor of Midas Mulligan during the case brought against him by the incompetent loan applicant. When Narragansett's ruling was reversed on appeal, he retired and joined the strike. At the end of the novel, he is seen editing the United States Constitution, crossing out portions that contradict each other and adding an amendment to prohibit Congress from passing laws that restrain freedom of trade.
Ben Nealy is a railroad contractor whom Dagny Taggart hires to replace the track on the Rio Norte Line with Rearden Metal. Nealy is incompetent, but Dagny can find no one better in all the country. Nealy believes that anything can get done with enough muscle power. He sees no role for intelligence in human achievement. He relies on Dagny and Ellis Wyatt to run things, and resents them for doing it, because it appears to him like they are just bossing people around.
Ted Nielsen is the head of Nielsen Motors. He eventually goes on strike, along with most of the other industrialist "producer" types, by closing his motor factory. Dagny later finds him when she visits Galt's Gulch for the first time.
Betty Pope is a wealthy socialite who is having a meaningless sexual affair with James Taggart. She is deliberately crude in a way that casts ridicule on her high social position.
Dr. Potter holds some undefined position with the State Science Institute. He is sent to try to obtain the rights to Rearden Metal.
Dr. Simon Pritchett is the prestigious head of the Department of Philosophy at Patrick Henry University and is considered the leading philosopher of the age. He believes that man is nothing but a collection of chemicals, reason is a superstition, it is futile to seek meaning in life, and the duty of a philosopher is to show that nothing can be understood.
Rearden's mother, whose name is not mentioned, lives with Rearden at his home in Philadelphia. She is involved in charity work, and berates Rearden whenever she can. She dotes on her weak son Philip Rearden.
Philip Rearden is the younger brother of Hank Rearden. He lives in his brother's home in Philadelphia and is completely dependent on him. He is resentful of his brother's charity.
Dwight Sanders owns Sanders Aircraft, a producer of high-quality airplanes, and joins the strike.
Bertram Scudder is an editorial writer for the magazine The Future. He typically bashes business and businessmen, but he never says anything specific in his articles, relying on innuendo, sneers, and denunciation. He wrote a hatchet job on Hank Rearden called The Octopus. He is also vocal in support of the Equalization of Opportunity Bill. Scudder claims that the most important thing in life is "brother love" but seems to have nothing but hatred for those around him. He loses his job after Dagny Taggart reveals her affair with Hank Rearden over air on his radio show.
Claude Slagenhop is president of political organization Friends of Global Progress and one of Lillian Rearden's friends. He believes that ideas are just air, that this is no time for talk, but for action. Global Progress is a sponsor of the Equalization of Opportunity Bill.
Gerald and Ivy Starnes are the two surviving children of Jed Starnes, the founder of the Twentieth Century Motor Company. Together with their since-deceased brother Eric, they instituted a communistic payment-and-benefits program that drove the company into bankruptcy. Gerald, a dying alcoholic, and Ivy, a pseudo-Buddhist ascetic, continue to insist that the plan was perfect and that the failure of their father's company was entirely due to the workers. Eric was a weak, attention-seeking man with a pathological desire to be loved. He committed suicide after the woman he loved married another man. Gerald claims that he always acted for the good of the employees, but he was vain and incompetent and often threw lavish parties using company funds. Ivy, on the other hand, is described as a sadist who relishes seeing others in poverty, but who has no desire for wealth of her own.
Andrew Stockton runs the Stockton Foundry in Stockton, Colorado. When he joins the strike, he opens a foundry in Galt's Gulch.
Mr. Thompson is the "Head of the State" for the United States. He is not particularly intelligent and has a very undistinguished look. He knows politics, however, and is a master of public relations and back-room deals. Rand's notes indicate that she modeled him on President Harry S. Truman, and that she deliberately decided not to call him "President of the United States" as this title has "honorable connotations" which the character does not deserve.
Lester Tuck is the campaign manager for Kip Chalmers and one of his guests on the train trip to California. He dies in the Taggart Tunnel disaster.
Clem Weatherby is a government representative on the board of directors of Taggart Transcontinental. Dagny considers him the least bad of the government representatives, since he does have some real knowledge on the running of trains. She notices, however, that he is the least appreciated by his own bosses.
The Wet Nurse (Tony) is a young bureaucrat sent by the government to watch over Rearden's mills. Though he starts out as a cynical follower of the looters' code, his experience at the mills transforms him, and he comes to respect and admire the producers. He is shot attempting to inform Hank Rearden about a government plot, but does succeed in warning Rearden just before he dies.
Ellis Wyatt is the head of Wyatt Oil. He has almost single-handedly revived the economy of Colorado by discovering a new process for extracting more oil from what were thought to be exhausted oil wells. When first introduced, he is aggressive towards Dagny, whom he does not yet know and whom he blames for what are, in fact, her brother's policies which directly threaten his business. When the government passes laws and decrees which make it impossible for him to continue, he sets all his oil wells on fire, leaving a single note: "I am leaving it as I found it. Take over. It's yours." One particular burning well that resists all efforts to extinguish it becomes known as "Wyatt's Torch". Later Dagny meets him in Galt's Gulch.
Notes
References
Works cited
External links
Website with comprehensive list of individuals mentioned in Atlas Shrugged
Fictional socialites
Lists of literary characters
Literary characters introduced in 1957 |
580 | https://en.wikipedia.org/wiki/Astronomer | Astronomer | An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole.
Types
Astronomers usually fall under either of two main types: observational and theoretical. Observational astronomers make direct observations of celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate models of things that cannot be observed. Because it takes millions to billions of years for a system of stars or a galaxy to complete a life cycle, astronomers must observe snapshots of different systems at unique points in their evolution to determine how they form, evolve, and die. They use this data to create models or simulations to theorize how different celestial objects work.
Further subcategories under these two main branches of astronomy include planetary astronomy, galactic astronomy, or physical cosmology.
Academic
Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using physical laws. Today, that distinction has mostly disappeared and the terms "astronomer" and "astrophysicist" are interchangeable. Professional astronomers are highly educated individuals who typically have a PhD in physics or astronomy and are employed by research institutions or universities. They spend the majority of their time working on research, although they quite often have other duties such as teaching, building instruments, or aiding in the operation of an observatory.
The American Astronomical Society, which is the major organization of professional astronomers in North America, has approximately 7,000 members. This number includes scientists from other fields such as physics, geology, and engineering, whose research interests are closely related to astronomy. The International Astronomical Union comprises almost 10,145 members from 70 countries who are involved in astronomical research at the PhD level and beyond.
Contrary to the classical image of an old astronomer peering through a telescope through the dark hours of the night, it is far more common to use a charge-coupled device (CCD) camera to record a long, deep exposure, allowing a more sensitive image to be created because the light is added over time. Before CCDs, photographic plates were a common method of observation. Modern astronomers spend relatively little time at telescopes usually just a few weeks per year. Analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers' time.
Astronomers who serve as faculty spend much of their time teaching undergraduate and graduate classes. Most universities also have outreach programs including public telescope time and sometimes planetariums as a public service to encourage interest in the field.
Those who become astronomers usually have a broad background in maths, sciences and computing in high school. Taking courses that teach how to research, write, and present papers are also invaluable. In college/university most astronomers get a PhD in astronomy or physics.
Amateur astronomers
While there is a relatively low number of professional astronomers, the field is popular among amateurs. Most cities have amateur astronomy clubs that meet on a regular basis and often host star parties. The Astronomical Society of the Pacific is the largest general astronomical society in the world, comprising both professional and amateur astronomers as well as educators from 70 different nations. Like any hobby, most people who think of themselves as amateur astronomers may devote a few hours a month to stargazing and reading the latest developments in research. However, amateurs span the range from so-called "armchair astronomers" to the very ambitious, who own science-grade telescopes and instruments with which they are able to make their own discoveries and assist professional astronomers in research.
See also
List of astronomers
List of women astronomers
List of Muslim astronomers
List of French astronomers
List of Hungarian astronomers
List of Russian astronomers and astrophysicists
List of Slovenian astronomers
References
Sources
External links
American Astronomical Society
European Astronomical Society
International Astronomical Union
Astronomical Society of the Pacific
Space's astronomy news
Astronomy
Science occupations |
590 | https://en.wikipedia.org/wiki/Austin | Austin | Austin refers to:
Common meanings
Austin, Texas, United States, a city
Austin (given name), a list of people and fictional characters
Austin (surname), a list of people and fictional characters
Austin Motor Company, a British car manufacturer
Places
Canada
Austin, Manitoba, an unincorporated community
Austin, Ontario, a neighbourhood
Austin, Quebec, a municipality
Austin Island, Nunavut
United States
Austin, Arkansas, a city
Austin, Colorado, an unincorporated community
Austin, Chicago, Illinois, a community area
Austin, Indiana, a city
Austin, Kentucky
Austin, Minnesota, a city
Austin, Missouri, an unincorporated community
Austin, Nevada, an unincorporated town and census-designated place
Austin, Ohio, an unincorporated community
Austin, Oregon, an unincorporated community considered a ghost town
Austin, Pennsylvania, a borough
Austin, Texas, the capital city of Texas
Austin County, Texas
Austin Lake, Michigan
Lake Austin, a reservoir in Austin, Texas
Austin Airport (disambiguation)
Austin Township (disambiguation)
Elsewhere
Austin, Western Australia, Australia, a ghost town
Mount Austin (Antarctica), Palmer Land
Austin Peak, part of the Mirabito Range in Victoria Land, Antarctica
Mount Austin, Hong Kong, a hill also known as Victoria Peak
Schools
University of Texas at Austin, flagship institution of the University of Texas System
University of Austin, a private, nonsectarian liberal arts university in Austin, Texas
Austin College, Sherman, Texas, a private, liberal arts college affiliated with the Presbyterian Church
Austin High School (disambiguation)
Religion
Augustine of Hippo (354–430), also known as St. Austin, Christian theologian, philosopher, bishop and saint
An adjective for the Augustinians
Business
American Austin Car Company, short-lived American automobile maker
Austin Automobile Company, short-lived American automobile company
Austin Motor Company, British car manufacturer
Austin magazine, produced for the Austin Motor Company by in-house Nuffield Press
Austin Airways, a former Canadian passenger airline and freight carrier
Austin cookies and crackers, Keebler Company brand
Austin, a kangaroo Beanie Baby produced by Ty, Inc.
Military
USS Austin, three ships
Austin-class amphibious transport dock, a former US Navy ship class
Austin Armoured Car, a British First World War armoured car
Music
Austin (album), a 2023 studio album by Post Malone
"Austin" (Blake Shelton song), 2001
"Austin" (Dasha song), 2023
Sports
Austin FC, an American men's soccer club based in Austin, Texas
Austin FC II, reserve team for Austin FC
Austin Spurs, an NBA G League basketball team affiliated with the San Antonio Spurs
Austin Bruins, a junior ice hockey team based in Austin, Minnesota
Transportation
For companies in the transportation industry, see the Business section above.
Austin Road, Kowloon, Hong Kong
Austin station (disambiguation), three stations in the United States and one in Hong Kong
Other uses
Austin Hospital, Melbourne, Victoria, Australia
Austin (building), a building designed by artist Ellsworth Kelly in Austin, Texas
Stone Cold Steve Austin, ring name of American retired professional wrestler born Steven Anderson (born 1964)
Herbert Austin, 1st Baron Austin (1866–1941), English automobile designer and builder who founded the Austin Motor Company
See also
All pages beginning with Austin
Austin station (disambiguation)
Austins (disambiguation)
Austen (disambiguation) |
597 | https://en.wikipedia.org/wiki/Austroasiatic%20languages | Austroasiatic languages | The Austroasiatic languages ( ) are a large language family spoken throughout mainland Southeast Asia, South Asia and East Asia. These languages are natively spoken by the majority of the population in Vietnam and Cambodia, and by minority populations scattered throughout parts of Thailand, Laos, India, Myanmar, Malaysia, Bangladesh, Nepal, and southern China. Approximately 117 million people speak an Austroasiatic language, of which more than two-thirds are Vietnamese speakers. Of the Austroasiatic languages, only Vietnamese, Khmer, and Mon have lengthy, established presences in the historical record. Only two are presently considered to be the national languages of sovereign states: Vietnamese in Vietnam, and Khmer in Cambodia. The Mon language is a recognized indigenous language in Myanmar and Thailand, while the Wa language is a "recognized national language" in the de facto autonomous Wa State within Myanmar. Santali is one of the 22 scheduled languages of India. The remainder of the family's languages are spoken by minority groups and have no official status.
Ethnologue identifies 168 Austroasiatic languages. These form thirteen established families (plus perhaps Shompen, which is poorly attested, as a fourteenth), which have traditionally been grouped into two, as Mon–Khmer, and Munda. However, one recent classification posits three groups (Munda, Mon-Khmer, and Khasi–Khmuic), while another has abandoned Mon–Khmer as a taxon altogether, making it synonymous with the larger family.
Austroasiatic languages appear to be the extant autochthonous languages in mainland Southeast Asia, with the neighboring Kra–Dai, Hmong-Mien, Austronesian, and Sino-Tibetan languages having arrived via later migrations.
Etymology
The name Austroasiatic was coined by Wilhelm Schmidt () based on , the Latin word for "South" (but idiosyncratically used by Schmidt to refer to the southeast), and "Asia". Despite the literal meaning of its name, only three Austroasiatic branches are actually spoken in South Asia: Khasic, Munda, and Nicobarese.
Typology
Regarding word structure, Austroasiatic languages are well known for having an iambic "sesquisyllabic" pattern, with basic nouns and verbs consisting of an initial, unstressed, reduced minor syllable followed by a stressed, full syllable. This reduction of presyllables has led to a variety of phonological shapes of the same original Proto-Austroasiatic prefixes, such as the causative prefix, ranging from CVC syllables to consonant clusters to single consonants among the modern languages. As for word formation, most Austroasiatic languages have a variety of derivational prefixes, many have infixes, but suffixes are almost completely non-existent in most branches except Munda, and a few specialized exceptions in other Austroasiatic branches.
The Austroasiatic languages are further characterized as having unusually large vowel inventories and employing some sort of register contrast, either between modal (normal) voice and breathy (lax) voice or between modal voice and creaky voice. Languages in the Pearic branch and some in the Vietic branch can have a three- or even four-way voicing contrast.
However, some Austroasiatic languages have lost the register contrast by evolving more diphthongs or in a few cases, such as Vietnamese, tonogenesis. Vietnamese has been so heavily influenced by Chinese that its original Austroasiatic phonological quality is obscured and now resembles that of South Chinese languages, whereas Khmer, which had more influence from Sanskrit, has retained a more typically Austroasiatic structure.
Proto-language
Much work has been done on the reconstruction of Proto-Mon–Khmer in Harry L. Shorto's Mon–Khmer Comparative Dictionary. Little work has been done on the Munda languages, which are not well documented. With their demotion from a primary branch, Proto-Mon–Khmer becomes synonymous with Proto-Austroasiatic. Paul Sidwell (2005) reconstructs the consonant inventory of Proto-Mon–Khmer as follows:
This is identical to earlier reconstructions except for . is better preserved in the Katuic languages, which Sidwell has specialized in.
Internal classification
Linguists traditionally recognize two primary divisions of Austroasiatic: the Mon–Khmer languages of Southeast Asia, Northeast India and the Nicobar Islands, and the Munda languages of East and Central India and parts of Bangladesh and Nepal. However, no evidence for this classification has ever been published.
Each of the families that is written in boldface type below is accepted as a valid clade. By contrast, the relationships between these families within Austroasiatic are debated. In addition to the traditional classification, two recent proposals are given, neither of which accepts traditional "Mon–Khmer" as a valid unit. However, little of the data used for competing classifications has ever been published, and therefore cannot be evaluated by peer review.
In addition, there are suggestions that additional branches of Austroasiatic might be preserved in substrata of Acehnese in Sumatra (Diffloth), the Chamic languages of Vietnam, and the Land Dayak languages of Borneo (Adelaar 1995).
Diffloth (1974)
Diffloth's widely cited original classification, now abandoned by Diffloth himself, is used in Encyclopædia Britannica and—except for the breakup of Southern Mon–Khmer—in Ethnologue.
Austro‑Asiatic
Munda
North Munda
Korku
Kherwarian
South Munda
Kharia–Juang
Koraput Munda
Mon–Khmer
Eastern Mon–Khmer
Khmer (Cambodian)
Pearic
Bahnaric
Katuic
Vietic (Vietnamese, Muong)
Northern Mon–Khmer
Khasi (Meghalaya, India)
Palaungic
Khmuic
Southern Mon–Khmer
Mon
Aslian (Malaya)
Nicobarese (Nicobar Islands)
Peiros (2004)
Peiros is a lexicostatistic classification, based on percentages of shared vocabulary. This means that languages can appear to be more distantly related than they actually are due to language contact. Indeed, when Sidwell (2009) replicated Peiros's study with languages known well enough to account for loans, he did not find the internal (branching) structure below.
Austro‑Asiatic
Nicobarese
Munda–Khmer
Munda
Mon–Khmer
Khasi
Nuclear Mon–Khmer
Mangic (Mang + Palyu) (perhaps in Northern MK)
Vietic (perhaps in Northern MK)
Northern Mon–Khmer
Palaungic
Khmuic
Central Mon–Khmer
Khmer dialects
Pearic
Asli-Bahnaric
Aslian
Mon–Bahnaric
Monic
Katu–Bahnaric
Katuic
Bahnaric
Diffloth (2005)
Diffloth compares reconstructions of various clades, and attempts to classify them based on shared innovations, though like other classifications the evidence has not been published. As a schematic, we have:
Or in more detail,
Austro‑Asiatic
Munda languages (India)
Koraput: 7 languages
Core Munda languages
Kharian–Juang: 2 languages
North Munda languages
Korku
Kherwarian: 12 languages
Khasi–Khmuic languages (Northern Mon–Khmer)
Khasian: 3 languages of north eastern India and adjacent region of Bangladesh
Palaungo-Khmuic languages
Khmuic: 13 languages of Laos and Thailand
Palaungo-Pakanic languages
Pakanic or Palyu: 4 or 5 languages of southern China and Vietnam
Palaungic: 21 languages of Burma, southern China, and Thailand
Nuclear Mon–Khmer languages
Khmero-Vietic languages (Eastern Mon–Khmer)
Vieto-Katuic languages ?
Vietic: 10 languages of Vietnam and Laos, including Muong and Vietnamese, which has the most speakers of any Austroasiatic language.
Katuic: 19 languages of Laos, Vietnam, and Thailand.
Khmero-Bahnaric languages
Bahnaric: 40 languages of Vietnam, Laos, and Cambodia.
Khmeric languages
The Khmer dialects of Cambodia, Thailand, and Vietnam.
Pearic: 6 languages of Cambodia.
Nico-Monic languages (Southern Mon–Khmer)
Nicobarese: 6 languages of the Nicobar Islands, a territory of India.
Asli-Monic languages
Aslian: 19 languages of peninsular Malaysia and Thailand.
Monic: 2 languages, the Mon language of Burma and the Nyahkur language of Thailand.
Sidwell (2009–2015)
Paul Sidwell (2009), in a lexicostatistical comparison of 36 languages which are well known enough to exclude loanwords, finds little evidence for internal branching, though he did find an area of increased contact between the Bahnaric and Katuic languages, such that languages of all branches apart from the geographically distant Munda and Nicobarese show greater similarity to Bahnaric and Katuic the closer they are to those branches, without any noticeable innovations common to Bahnaric and Katuic.
He therefore takes the conservative view that the thirteen branches of Austroasiatic should be treated as equidistant on current evidence. Sidwell & Blench (2011) discuss this proposal in more detail, and note that there is good evidence for a Khasi–Palaungic node, which could also possibly be closely related to Khmuic.
If this would the case, Sidwell & Blench suggest that Khasic may have been an early offshoot of Palaungic that had spread westward. Sidwell & Blench (2011) suggest Shompen as an additional branch, and believe that a Vieto-Katuic connection is worth investigating. In general, however, the family is thought to have diversified too quickly for a deeply nested structure to have developed, since Proto-Austroasiatic speakers are believed by Sidwell to have radiated out from the central Mekong river valley relatively quickly.
Subsequently, Sidwell (2015a: 179) proposed that Nicobarese subgroups with Aslian, just as how Khasian and Palaungic subgroup with each other.
A subsequent computational phylogenetic analysis (Sidwell 2015b) suggests that Austroasiatic branches may have a loosely nested structure rather than a completely rake-like structure, with an east–west division (consisting of Munda, Khasic, Palaungic, and Khmuic forming a western group as opposed to all of the other branches) occurring possibly as early as 7,000 years before present. However, he still considers the subbranching dubious.
Integrating computational phylogenetic linguistics with recent archaeological findings, Paul Sidwell (2015c) further expanded his Mekong riverine hypothesis by proposing that Austroasiatic had ultimately expanded into Indochina from the Lingnan area of southern China, with the subsequent Mekong riverine dispersal taking place after the initial arrival of Neolithic farmers from southern China.
Sidwell (2015c) tentatively suggests that Austroasiatic may have begun to split up 5,000 years B.P. during the Neolithic transition era of mainland Southeast Asia, with all the major branches of Austroasiatic formed by 4,000 B.P. Austroasiatic would have had two possible dispersal routes from the western periphery of the Pearl River watershed of Lingnan, which would have been either a coastal route down the coast of Vietnam, or downstream through the Mekong River via Yunnan. Both the reconstructed lexicon of Proto-Austroasiatic and the archaeological record clearly show that early Austroasiatic speakers around 4,000 B.P. cultivated rice and millet, kept livestock such as dogs, pigs, and chickens, and thrived mostly in estuarine rather than coastal environments.
At 4,500 B.P., this "Neolithic package" suddenly arrived in Indochina from the Lingnan area without cereal grains and displaced the earlier pre-Neolithic hunter-gatherer cultures, with grain husks found in northern Indochina by 4,100 B.P. and in southern Indochina by 3,800 B.P. However, Sidwell (2015c) found that iron is not reconstructable in Proto-Austroasiatic, since each Austroasiatic branch has different terms for iron that had been borrowed relatively lately from Tai, Chinese, Tibetan, Malay, and other languages.
During the Iron Age about 2,500 B.P., relatively young Austroasiatic branches in Indochina such as Vietic, Katuic, Pearic, and Khmer were formed, while the more internally diverse Bahnaric branch (dating to about 3,000 B.P.) underwent more extensive internal diversification. By the Iron Age, all of the Austroasiatic branches were more or less in their present-day locations, with most of the diversification within Austroasiatic taking place during the Iron Age.
Paul Sidwell (2018) considers the Austroasiatic language family to have rapidly diversified around 4,000 years B.P. during the arrival of rice agriculture in Indochina, but notes that the origin of Proto-Austroasiatic itself is older than that date. The lexicon of Proto-Austroasiatic can be divided into an early and late stratum. The early stratum consists of basic lexicon including body parts, animal names, natural features, and pronouns, while the names of cultural items (agriculture terms and words for cultural artifacts, which are reconstructible in Proto-Austroasiatic) form part of the later stratum.
Roger Blench (2017) suggests that vocabulary related to aquatic subsistence strategies (such as boats, waterways, river fauna, and fish capture techniques) can be reconstructed for Proto-Austroasiatic. Blench (2017) finds widespread Austroasiatic roots for 'river, valley', 'boat', 'fish', 'catfish sp.', 'eel', 'prawn', 'shrimp' (Central Austroasiatic), 'crab', 'tortoise', 'turtle', 'otter', 'crocodile', 'heron, fishing bird', and 'fish trap'. Archaeological evidence for the presence of agriculture in northern Indochina (northern Vietnam, Laos, and other nearby areas) dates back to only about 4,000 years ago (2,000 BC), with agriculture ultimately being introduced from further up to the north in the Yangtze valley where it has been dated to 6,000 B.P.
Sidwell (2022) proposes that the locus of Proto-Austroasiatic was in the Red River Delta area about 4,000-4,500 years before present, instead of the Middle Mekong as he had previously proposed. Austroasiatic dispersed coastal maritime routes and also upstream through river valleys. Khmuic, Palaungic, and Khasic resulted from a westward dispersal that ultimately came from the Red Valley valley. Based on their current distributions, about half of all Austroasiatic branches (including Nicobaric and Munda) can be traced to coastal maritime dispersals.
Hence, this points to a relatively late riverine dispersal of Austroasiatic as compared to Sino-Tibetan, whose speakers had a distinct non-riverine culture. In addition to living an aquatic-based lifestyle, early Austroasiatic speakers would have also had access to livestock, crops, and newer types of watercraft. As early Austroasiatic speakers dispersed rapidly via waterways, they would have encountered speakers of older language families who were already settled in the area, such as Sino-Tibetan.
Sidwell (2018)
Sidwell (2018) (quoted in Sidwell 2021) gives a more nested classification of Austroasiatic branches as suggested by his computational phylogenetic analysis of Austroasiatic languages using a 200-word list. Many of the tentative groupings are likely linkages. Pakanic and Shompen were not included.
Possible extinct branches
Roger Blench (2009) also proposes that there might have been other primary branches of Austroasiatic that are now extinct, based on substrate evidence in modern-day languages.
Pre-Chamic languages (the languages of coastal Vietnam before the Chamic migrations). Chamic has various Austroasiatic loanwords that cannot be clearly traced to existing Austroasiatic branches (Sidwell 2006, 2007). Larish (1999) also notes that Moklenic languages contain many Austroasiatic loanwords, some of which are similar to the ones found in Chamic.
Acehnese substratum (Sidwell 2006). Acehnese has many basic words that are of Austroasiatic origin, suggesting that either Austronesian speakers have absorbed earlier Austroasiatic residents in northern Sumatra, or that words might have been borrowed from Austroasiatic languages in southern Vietnam – or perhaps a combination of both. Sidwell (2006) argues that Acehnese and Chamic had often borrowed Austroasiatic words independently of each other, while some Austroasiatic words can be traced back to Proto-Aceh-Chamic. Sidwell (2006) accepts that Acehnese and Chamic are related, but that they had separated from each other before Chamic had borrowed most of its Austroasiatic lexicon.
Bornean substrate languages (Blench 2010). Blench cites Austroasiatic-origin words in modern-day Bornean branches such as Land Dayak (Bidayuh, Dayak Bakatiq, etc.), Dusunic (Central Dusun, Visayan, etc.), Kayan, and Kenyah, noting especially resemblances with Aslian. As further evidence for his proposal, Blench also cites ethnographic evidence such as musical instruments in Borneo shared in common with Austroasiatic-speaking groups in mainland Southeast Asia. Adelaar (1995) has also noticed phonological and lexical similarities between Land Dayak and Aslian. Kaufman (2018) presents dozens of lexical comparisons showing similarities between various Bornean and Austroasiatic languages.
Lepcha substratum ("Rongic"). Many words of Austroasiatic origin have been noticed in Lepcha, suggesting a Sino-Tibetan superstrate laid over an Austroasiatic substrate. Blench (2013) calls this branch "Rongic" based on the Lepcha autonym Róng.
Other languages with proposed Austroasiatic substrata are:
Jiamao, based on evidence from the register system of Jiamao, a Hlai language (Thurgood 1992). Jiamao is known for its highly aberrant vocabulary in relation to other Hlai languages.
Kerinci: van Reijn (1974) notes that Kerinci, a Malayic language of central Sumatra, shares many phonological similarities with Austroasiatic languages, such as sesquisyllabic word structure and vowel inventory.
John Peterson (2017) suggests that "pre-Munda" ("proto-" in regular terminology) languages may have once dominated the eastern Indo-Gangetic Plain, and were then absorbed by Indo-Aryan languages at an early date as Indo-Aryan spread east. Peterson notes that eastern Indo-Aryan languages display many morphosyntactic features similar to those of Munda languages, while western Indo-Aryan languages do not.
Writing systems
Other than Latin-based alphabets, many Austroasiatic languages are written with the Khmer, Thai, Lao, and Burmese alphabets. Vietnamese divergently had an indigenous script based on Chinese logographic writing. This has since been supplanted by the Latin alphabet in the 20th century. The following are examples of past-used alphabets or current alphabets of Austroasiatic languages.
Chữ Nôm
Khmer alphabet
Khom script (used for a short period in the early 20th century for indigenous languages in Laos)
Old Mon script
Mon script
Pahawh Hmong was once used to write Khmu, under the name "Pahawh Khmu"
Tai Le (Palaung, Blang)
Tai Tham (Blang)
Ol Chiki alphabet (Santali alphabet)
Mundari Bani (Mundari alphabet)
Warang Citi (Ho alphabet)
Ol Onal (Bhumij alphabet)
Sorang Sompeng alphabet (Sora alphabet)
External relations
Austric languages
Austroasiatic is an integral part of the controversial Austric hypothesis, which also includes the Austronesian languages, and in some proposals also the Kra–Dai languages and the Hmong–Mien languages.
Hmong-Mien
Several lexical resemblances are found between the Hmong-Mien and Austroasiatic language families (Ratliff 2010), some of which had earlier been proposed by Haudricourt (1951). This could imply a relation or early language contact along the Yangtze.
According to Cai (et al. 2011), Hmong–Mien people are genetically related to Austroasiatic speakers, and their languages were heavily influenced by Sino-Tibetan, especially Tibeto-Burman languages.
Indo-Aryan languages
It is suggested that the Austroasiatic languages have some influence on Indo-Aryan languages including Sanskrit and middle Indo-Aryan languages. Indian linguist Suniti Kumar Chatterji pointed that a specific number of substantives in languages such as Hindi, Punjabi and Bengali were borrowed from Munda languages. Additionally, French linguist Jean Przyluski suggested a similarity between the tales from the Austroasiatic realm and the Indian mythological stories of Matsyagandha (Satyavati from Mahabharata) and the Nāgas.
Austroasiatic migrations and archaeogenetics
Mitsuru Sakitani suggests that Haplogroup O1b1, which is common in Austroasiatic people and some other ethnic groups in southern China, and haplogroup O1b2, which is common in today's Japanese and Koreans, are the carriers of early rice agriculture from southern China. Another study suggests that the haplogroup O1b1 is the major Austroasiatic paternal lineage and O1b2 the "para-Austroasiatic" lineage of the Koreans and Yayoi people.
A full genomic study by Lipson et al. (2018) identified a characteristic lineage that can be associated with the spread of Austroasiatic languages in Southeast Asia and which can be traced back to remains of Neolithic farmers from Mán Bạc () in the Red River Delta in northern Vietnam, and to closely related Ban Chiang and Vat Komnou remains in Thailand and Cambodia respectively. This Austroasiatic lineage can be modeled as a sister group of the Austronesian peoples with significant admixture (ca. 30%) from a deeply diverging eastern Eurasian source (modeled by the authors as sharing some genetic drift with the Onge, a modern Andamanese hunter-gatherer group) and which is ancestral to modern Austroasiatic-speaking groups of Southeast Asia such as the Mlabri and the Nicobarese, and partially to the Austroasiatic Munda-speaking groups of South Asia (e.g. the Juang). Significant levels of Austroasiatic ancestry were also found in Austronesian-speaking groups of Sumatra and Borneo. Austroasiatic-speaking groups in southern China (such as the Wa and Blang in Yunnan) predominatly carry the same Mainland Southeast Asian Neolithic farmer ancestry, but with additional geneflow from northern and southern East Asian lineages that can be associated with the spread of Tibeto-Burman and Kra-Dai languages, respectively.
Migration into India
According to Chaubey et al., "Austro-Asiatic speakers in India today are derived from dispersal from Southeast Asia, followed by extensive sex-specific admixture with local Indian populations." According to Riccio et al., the Munda peoples are likely descended from Austroasiatic migrants from Southeast Asia.
According to Zhang et al., Austroasiatic migrations from Southeast Asia into India took place after the Last Glacial Maximum, circa 10,000 years ago. Arunkumar et al., suggest Austroasiatic migrations from Southeast Asia occurred into Northeast India 5.2 ± 0.6 kya and into East India 4.3 ± 0.2 kya.
Notes
References
Sources
Adams, K. L. (1989). Systems of numeral classification in the Mon–Khmer, Nicobarese and Aslian subfamilies of Austroasiatic. Canberra, A.C.T., Australia: Dept. of Linguistics, Research School of Pacific Studies, Australian National University.
Alves, Mark J. (2015). Morphological functions among Mon-Khmer languages: beyond the basics. In N. J. Enfield & Bernard Comrie (eds.), Languages of Mainland Southeast Asia: the state of the art. Berlin: de Gruyter Mouton, 531–557.
Bradley, David (2012). "Languages and Language Families in China ", in Rint Sybesma (ed.), Encyclopedia of Chinese Language and Linguistics.
Chakrabarti, Byomkes. (1994). A Comparative Study of Santali and Bengali.
Diffloth, Gérard. (2005). "The contribution of linguistic palaeontology and Austro-Asiatic". in Laurent Sagart, Roger Blench and Alicia Sanchez-Mazas, eds. The Peopling of East Asia: Putting Together Archaeology, Linguistics and Genetics. 77–80. London: Routledge Curzon.
Filbeck, D. (1978). T'in: a historical study. Pacific linguistics, no. 49. Canberra: Dept. of Linguistics, Research School of Pacific Studies, Australian National University.
Hemeling, K. (1907). Die Nanking Kuanhua. (German language)
Jenny, Mathias and Paul Sidwell, eds (2015). The Handbook of Austroasiatic Languages . Leiden: Brill.
Peck, B. M., Comp. (1988). An Enumerative Bibliography of South Asian Language Dictionaries.
Peiros, Ilia. 1998. Comparative Linguistics in Southeast Asia. Pacific Linguistics Series C, No. 142. Canberra: Australian National University.
Shorto, Harry L. edited by Sidwell, Paul, Cooper, Doug and Bauer, Christian (2006). A Mon–Khmer comparative dictionary . Canberra: Australian National University. Pacific Linguistics.
Shorto, H. L. Bibliographies of Mon–Khmer and Tai Linguistics. London oriental bibliographies, v. 2. London: Oxford University Press, 1963.
van Driem, George. (2007). Austroasiatic phylogeny and the Austroasiatic homeland in light of recent population genetic studies. Mon-Khmer Studies, 37, 1–14.
Zide, Norman H., and Milton E. Barker. (1966) Studies in Comparative Austroasiatic Linguistics, The Hague: Mouton (Indo-Iranian monographs, v. 5.).
Further reading
Mann, Noel, Wendy Smith and Eva Ujlakyova. 2009. Linguistic clusters of Mainland Southeast Asia: an overview of the language families. Chiang Mai: Payap University.
Sidwell, Paul. 2016. Bibliography of Austroasiatic linguistics and related resources .
E. K. Brown (ed.) Encyclopedia of Languages and Linguistics. Oxford: Elsevier Press.
Gregory D. S. Anderson and Norman H. Zide. 2002. Issues in Proto-Munda and Proto-Austroasiatic Nominal Derivation: The Bimoraic Constraint. In Marlys A. Macken (ed.) Papers from the 10th Annual Meeting of the Southeast Asian Linguistics Society. Tempe, AZ: Arizona State University, South East Asian Studies Program, Monograph Series Press. pp. 55–74.
External links
Swadesh lists for Austro-Asiatic languages (from Wiktionary's Swadesh-list appendix)
Mon–Khmer.com Lectures by Paul Sidwell
Mon–Khmer Languages Project at SEAlang
Munda Languages Project at SEAlang
RWAAI (Repository and Workspace for Austroasiatic Intangible Heritage)
RWAAI Digital Archive
Michel Ferlus's recordings of Mon-Khmer (Austroasiatic) languages (CNRS)
Language families |
612 | https://en.wikipedia.org/wiki/Arithmetic%20mean | Arithmetic mean | In mathematics and statistics, the arithmetic mean ( ), arithmetic average, or just the mean or average (when the context is clear) is the sum of a collection of numbers divided by the count of numbers in the collection. The collection is often a set of results from an experiment, an observational study, or a survey. The term "arithmetic mean" is preferred in some mathematics and statistics contexts because it helps distinguish it from other types of means, such as geometric and harmonic.
In addition to mathematics and statistics, the arithmetic mean is frequently used in economics, anthropology, history, and almost every academic field to some extent. For example, per capita income is the arithmetic average income of a nation's population.
While the arithmetic mean is often used to report central tendencies, it is not a robust statistic: it is greatly influenced by outliers (values much larger or smaller than most others). For skewed distributions, such as the distribution of income for which a few people's incomes are substantially higher than most people's, the arithmetic mean may not coincide with one's notion of "middle". In that case, robust statistics, such as the median, may provide a better description of central tendency.
Definition
The arithmetic mean of a set of observed data is equal to the sum of the numerical values of each observation, divided by the total number of observations. Symbolically, for a data set consisting of the values , the arithmetic mean is defined by the formula:
(For an explanation of the summation operator, see summation.)
For example, if the monthly salaries of employees are , then the arithmetic mean is:
If the data set is a statistical population (i.e., consists of every possible observation and not just a subset of them), then the mean of that population is called the population mean and denoted by the Greek letter . If the data set is a statistical sample (a subset of the population), it is called the sample mean (which for a data set is denoted as ).
The arithmetic mean can be similarly defined for vectors in multiple dimensions, not only scalar values; this is often referred to as a centroid. More generally, because the arithmetic mean is a convex combination (meaning its coefficients sum to ), it can be defined on a convex space, not only a vector space.
Motivating properties
The arithmetic mean has several properties that make it interesting, especially as a measure of central tendency. These include:
If numbers have mean , then . Since is the distance from a given number to the mean, one way to interpret this property is by saying that the numbers to the left of the mean are balanced by the numbers to the right. The mean is the only number for which the residuals (deviations from the estimate) sum to zero. This can also be interpreted as saying that the mean is translationally invariant in the sense that for any real number , .
If it is required to use a single number as a "typical" value for a set of known numbers , then the arithmetic mean of the numbers does this best since it minimizes the sum of squared deviations from the typical value: the sum of . The sample mean is also the best single predictor because it has the lowest root mean squared error. If the arithmetic mean of a population of numbers is desired, then the estimate of it that is unbiased is the arithmetic mean of a sample drawn from the population.
The arithmetic mean is independent of scale of the units of measurement, in the sense that So, for example, calculating a mean of liters and then converting to gallons is the same as converting to gallons first and then calculating the mean. This is also called first order homogeneity.
Additional properties
The arithmetic mean of a sample is always between the largest and smallest values in that sample.
The arithmetic mean of any amount of equal-sized number groups together is the arithmetic mean of the arithmetic means of each group.
Contrast with median
The arithmetic mean may be contrasted with the median. The median is defined such that no more than half the values are larger, and no more than half are smaller than it. If elements in the data increase arithmetically when placed in some order, then the median and arithmetic average are equal. For example, consider the data sample . The mean is , as is the median. However, when we consider a sample that cannot be arranged to increase arithmetically, such as , the median and arithmetic average can differ significantly. In this case, the arithmetic average is , while the median is . The average value can vary considerably from most values in the sample and can be larger or smaller than most.
There are applications of this phenomenon in many fields. For example, since the 1980s, the median income in the United States has increased more slowly than the arithmetic average of income.
Generalizations
Weighted average
A weighted average, or weighted mean, is an average in which some data points count more heavily than others in that they are given more weight in the calculation. For example, the arithmetic mean of and is , or equivalently . In contrast, a weighted mean in which the first number receives, for example, twice as much weight as the second (perhaps because it is assumed to appear twice as often in the general population from which these numbers were sampled) would be calculated as . Here the weights, which necessarily sum to one, are and , the former being twice the latter. The arithmetic mean (sometimes called the "unweighted average" or "equally weighted average") can be interpreted as a special case of a weighted average in which all weights are equal to the same number ( in the above example and in a situation with numbers being averaged).
Continuous probability distributions
If a numerical property, and any sample of data from it, can take on any value from a continuous range instead of, for example, just integers, then the probability of a number falling into some range of possible values can be described by integrating a continuous probability distribution across this range, even when the naive probability for a sample number taking one certain value from infinitely many is zero. In this context, the analog of a weighted average, in which there are infinitely many possibilities for the precise value of the variable in each range, is called the mean of the probability distribution. The most widely encountered probability distribution is called the normal distribution; it has the property that all measures of its central tendency, including not just the mean but also the median mentioned above and the mode (the three Ms), are equal. This equality does not hold for other probability distributions, as illustrated for the log-normal distribution here.
Angles
Particular care is needed when using cyclic data, such as phases or angles. Taking the arithmetic mean of 1° and 359° yields a result of 180°.
This is incorrect for two reasons:
Firstly, angle measurements are only defined up to an additive constant of 360° ( or , if measuring in radians). Thus, these could easily be called 1° and -1°, or 361° and 719°, since each one of them produces a different average.
Secondly, in this situation, 0° (or 360°) is geometrically a better average value: there is lower dispersion about it (the points are both 1° from it and 179° from 180°, the putative average).
In general application, such an oversight will lead to the average value artificially moving towards the middle of the numerical range. A solution to this problem is to use the optimization formulation (that is, define the mean as the central point: the point about which one has the lowest dispersion) and redefine the difference as a modular distance (i.e., the distance on the circle: so the modular distance between 1° and 359° is 2°, not 358°).
Symbols and encoding
The arithmetic mean is often denoted by a bar (vinculum or macron), as in .
Some software (text processors, web browsers) may not display the "x̄" symbol correctly. For example, the HTML symbol "x̄" combines two codes — the base letter "x" plus a code for the line above ( ̄ or ¯).
In some document formats (such as PDF), the symbol may be replaced by a "¢" (cent) symbol when copied to a text processor such as Microsoft Word.
See also
Fréchet mean
Generalized mean
Inequality of arithmetic and geometric means
Sample mean and covariance
Standard deviation
Standard error of the mean
Summary statistics
Notes
References
Further reading
External links
Calculations and comparisons between arithmetic mean and geometric mean of two numbers
Calculate the arithmetic mean of a series of numbers on fxSolver
Means |
621 | https://en.wikipedia.org/wiki/Amphibian | Amphibian | Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods, excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds, and mammals). All extant (living) amphibians belong to the monophyletic subclass Lissamphibia, with three living orders: Anura (frogs), Urodela (salamanders), and Gymnophiona (caecilians). Evolved to be mostly semiaquatic, amphibians have adapted to inhabit a wide variety of habitats, with most species living in freshwater, wetland or terrestrial ecosystems (such as riparian woodland, fossorial and even arboreal habitats). Their life cycle typically starts out as aquatic larvae with gills known as tadpoles, but some species have developed behavioural adaptations to bypass this.
The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards, but unlike reptiles and other amniotes, require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; in recent decades there has been a dramatic decline in amphibian populations for many species around the globe.
The earliest amphibians evolved in the Devonian period from sarcopterygian fish with lungs and bony-limbed fins, features that were helpful in adapting to dry land. They diversified and became ecologically dominant during the Carboniferous and Permian periods, but were later displaced in terrestrial environments by early reptiles and basal synapsids (mammal predecessors). The origin of modern amphibians belonging to Lissamphibia, which first appeared during the Early Triassic, around 250 million years ago, has long been contentious. However the emerging consensus is that they likely originated from temnospondyls, the most diverse group of prehistoric amphibians, during the Permian period.
A fourth group of lissamphibians, the Albanerpetontidae, became extinct around 2 million years ago. The number of known amphibian species is approximately 8,000, of which nearly 90% are frogs. The smallest amphibian (and vertebrate) in the world is a frog from New Guinea (Paedophryne amauensis) with a length of just . The largest living amphibian is the South China giant salamander (Andrias sligoi), but this is dwarfed by prehistoric temnospondyls such as Mastodonsaurus which could reach up to in length. The study of amphibians is called batrachology, while the study of both reptiles and amphibians is called herpetology.
Classification
The word amphibian is derived from the Ancient Greek term (), which means 'both kinds of life', meaning 'of both kinds' and meaning 'life'. The term was initially used as a general adjective for animals that could live on land or in water, including seals and otters. Traditionally, the class Amphibia includes all tetrapod vertebrates that are not amniotes. Amphibia in its widest sense () was divided into three subclasses, two of which are extinct:
Subclass Lepospondyli† (A potentially polyphyletic Late Paleozoic group of small forms, likely more closely related to amniotes than Lissamphibia)
Subclass Temnospondyli† (diverse Late Paleozoic and early Mesozoic grade, some of which were large predators)
Subclass Lissamphibia (all modern amphibians, including frogs, toads, salamanders, newts and caecilians)
Salientia (frogs, toads and relatives): Early Triassic to present—7,360 current species in 53 families. Modern (crown group) salientians are described via the name Anura.
Caudata (salamanders, newts and relatives): Late Triassic to present—764 current species in 9 families. Modern (crown group) caudatans are described via the name Urodela.
Gymnophiona (caecilians and relatives): Late Triassic to present—215 current species in 10 families. The name Apoda is also sometimes used for caecilians.
Allocaudata† (Albanerpetontidae) Middle Jurassic – Early Pleistocene
These three subclasses do not include all extinct amphibians. Other extinct amphibian groups include Embolomeri (Late Paleozoic large aquatic predators), Seymouriamorpha (semiaquatic to terrestrial Permian forms related to amniotes), among others. Names such as Tetrapoda and Stegocephalia encompass the entirety of amphibian-grade tetrapods, while Reptiliomorpha or Anthracosauria are variably used to describe extinct amphibians more closely related to amniotes than to lissamphibians.
The actual number of species in each group depends on the taxonomic classification followed. The two most common systems are the classification adopted by the website AmphibiaWeb, University of California, Berkeley, and the classification by herpetologist Darrel Frost and the American Museum of Natural History, available as the online reference database "Amphibian Species of the World". The numbers of species cited above follows Frost and the total number of known (living) amphibian species as of March 31, 2019, is exactly 8,000, of which nearly 90% are frogs.
With the phylogenetic classification, the taxon Labyrinthodontia has been discarded as it is a polyparaphyletic group without unique defining features apart from shared primitive characteristics. Classification varies according to the preferred phylogeny of the author and whether they use a stem-based or a node-based classification. Traditionally, amphibians as a class are defined as all tetrapods with a larval stage, while the group that includes the common ancestors of all living amphibians (frogs, salamanders and caecilians) and all their descendants is called Lissamphibia. The phylogeny of Paleozoic amphibians is uncertain, and Lissamphibia may possibly fall within extinct groups, like the Temnospondyli (traditionally placed in the subclass Labyrinthodontia) or the Lepospondyli, and in some analyses even in the amniotes. This means that advocates of phylogenetic nomenclature have removed a large number of basal Devonian and Carboniferous amphibian-type tetrapod groups that were formerly placed in Amphibia in Linnaean taxonomy, and included them elsewhere under cladistic taxonomy. If the common ancestor of amphibians and amniotes is included in Amphibia, it becomes a paraphyletic group.
All modern amphibians are included in the subclass Lissamphibia, which is usually considered a clade, a group of species that have evolved from a common ancestor. The three modern orders are Anura (the frogs), Caudata (or Urodela, the salamanders), and Gymnophiona (or Apoda, the caecilians). It has been suggested that salamanders arose separately from a temnospondyl-like ancestor, and even that caecilians are the sister group of the advanced reptiliomorph amphibians, and thus of amniotes. Although the fossils of several older proto-frogs with primitive characteristics are known, the oldest "true frog", with hopping adaptations is Prosalirus bitis, from the Early Jurassic Kayenta Formation of Arizona. It is anatomically very similar to modern frogs. The oldest known caecilians are Funcusvermis gilmorei (from the Late Triassic) and Eocaecilia micropodia (from the Early Jurassic), both from Arizona. The earliest salamander is Beiyanerpeton jianpingensis from the Late Jurassic of northeastern China.
Authorities disagree as to whether Salientia is a superorder that includes the order Anura, or whether Anura is a sub-order of the order Salientia. The Lissamphibia are traditionally divided into three orders, but an extinct salamander-like family, the Albanerpetontidae, is now considered part of Lissamphibia alongside the superorder Salientia. Furthermore, Salientia includes all three recent orders plus the Triassic proto-frog, Triadobatrachus.
Evolutionary history
The first major groups of amphibians developed in the Devonian period, around 370 million years ago, from lobe-finned fish which were similar to the modern coelacanth and lungfish. These ancient lobe-finned fish had evolved multi-jointed leg-like fins with digits that enabled them to crawl along the sea bottom. Some fish had developed primitive lungs that help them breathe air when the stagnant pools of the Devonian swamps were low in oxygen. They could also use their strong fins to hoist themselves out of the water and onto dry land if circumstances so required. Eventually, their bony fins would evolve into limbs and they would become the ancestors to all tetrapods, including modern amphibians, reptiles, birds, and mammals. Despite being able to crawl on land, many of these prehistoric tetrapodomorph fish still spent most of their time in the water. They had started to develop lungs, but still breathed predominantly with gills.
Many examples of species showing transitional features have been discovered. Ichthyostega was one of the first primitive amphibians, with nostrils and more efficient lungs. It had four sturdy limbs, a neck, a tail with fins and a skull very similar to that of the lobe-finned fish, Eusthenopteron. Amphibians evolved adaptations that allowed them to stay out of the water for longer periods. Their lungs improved and their skeletons became heavier and stronger, better able to support the weight of their bodies on land. They developed "hands" and "feet" with five or more digits; the skin became more capable of retaining body fluids and resisting desiccation. The fish's hyomandibula bone in the hyoid region behind the gills diminished in size and became the stapes of the amphibian ear, an adaptation necessary for hearing on dry land. An affinity between the amphibians and the teleost fish is the multi-folded structure of the teeth and the paired supra-occipital bones at the back of the head, neither of these features being found elsewhere in the animal kingdom.
At the end of the Devonian period (360 million years ago), the seas, rivers and lakes were teeming with life while the land was the realm of early plants and devoid of vertebrates, though some, such as Ichthyostega, may have sometimes hauled themselves out of the water. It is thought they may have propelled themselves with their forelimbs, dragging their hindquarters in a similar manner to that used by the elephant seal. In the early Carboniferous (360 to 323 million years ago), the climate was relatively wet and warm. Extensive swamps developed with mosses, ferns, horsetails and calamites. Air-breathing arthropods evolved and invaded the land where they provided food for the carnivorous amphibians that began to adapt to the terrestrial environment. There were no other tetrapods on the land and the amphibians were at the top of the food chain, with some occupying ecological positions currently held by crocodiles. Though equipped with limbs and the ability to breathe air, most still had a long tapering body and strong tail. Others were the top land predators, sometimes reaching several metres in length, preying on the large insects of the period and the many types of fish in the water. They still needed to return to water to lay their shell-less eggs, and even most modern amphibians have a fully aquatic larval stage with gills like their fish ancestors. It was the development of the amniotic egg, which prevents the developing embryo from drying out, that enabled the reptiles to reproduce on land and which led to their dominance in the period that followed.
After the Carboniferous rainforest collapse amphibian dominance gave way to reptiles, and amphibians were further devastated by the Permian–Triassic extinction event. During the Triassic Period (252 to 201 million years ago), the reptiles continued to out-compete the amphibians, leading to a reduction in both the amphibians' size and their importance in the biosphere. According to the fossil record, Lissamphibia, which includes all modern amphibians and is the only surviving lineage, may have branched off from the extinct groups Temnospondyli and Lepospondyli at some period between the Late Carboniferous and the Early Triassic. The relative scarcity of fossil evidence precludes precise dating, but the most recent molecular study, based on multilocus sequence typing, suggests a Late Carboniferous/Early Permian origin for extant amphibians.
The origins and evolutionary relationships between the three main groups of amphibians is a matter of debate. A 2005 molecular phylogeny, based on rDNA analysis, suggests that salamanders and caecilians are more closely related to each other than they are to frogs. It also appears that the divergence of the three groups took place in the Paleozoic or early Mesozoic (around 250 million years ago), before the breakup of the supercontinent Pangaea and soon after their divergence from the lobe-finned fish. The briefness of this period, and the swiftness with which radiation took place, would help account for the relative scarcity of primitive amphibian fossils. There are large gaps in the fossil record, the discovery of the dissorophoid temnospondyl Gerobatrachus from the Early Permian in Texas in 2008 provided a missing link with many of the characteristics of modern frogs. Molecular analysis suggests that the frog–salamander divergence took place considerably earlier than the palaeontological evidence indicates. One study suggested suggested that the last common ancestor of all modern amphibians lived about 315 million years ago, and that stereospondyl temnospondyls are the closest relatives to the caecilians. However, most studies support a single monophyletic origin of all modern amphibians within the dissorophoid temnospondyls.
As they evolved from lunged fish, amphibians had to make certain adaptations for living on land, including the need to develop new means of locomotion. In the water, the sideways thrusts of their tails had propelled them forward, but on land, quite different mechanisms were required. Their vertebral columns, limbs, limb girdles and musculature needed to be strong enough to raise them off the ground for locomotion and feeding. Terrestrial adults discarded their lateral line systems and adapted their sensory systems to receive stimuli via the medium of the air. They needed to develop new methods to regulate their body heat to cope with fluctuations in ambient temperature. They developed behaviours suitable for reproduction in a terrestrial environment. Their skins were exposed to harmful ultraviolet rays that had previously been absorbed by the water. The skin changed to become more protective and prevent excessive water loss.
Characteristics
The superclass Tetrapoda is divided into four classes of vertebrate animals with four limbs. Reptiles, birds and mammals are amniotes, the eggs of which are either laid or carried by the female and are surrounded by several membranes, some of which are impervious. Lacking these membranes, amphibians require water bodies for reproduction, although some species have developed various strategies for protecting or bypassing the vulnerable aquatic larval stage. They are not found in the sea with the exception of one or two frogs that live in brackish water in mangrove swamps; the Anderson's salamander meanwhile occurs in brackish or salt water lakes. On land, amphibians are restricted to moist habitats because of the need to keep their skin damp.
Modern amphibians have a simplified anatomy compared to their ancestors due to paedomorphosis, caused by two evolutionary trends: miniaturization and an unusually large genome, which result in a slower growth and development rate compared to other vertebrates. Another reason for their size is associated with their rapid metamorphosis, which seems to have evolved only in the ancestors of lissamphibia; in all other known lines the development was much more gradual. Because a remodeling of the feeding apparatus means they do not eat during the metamorphosis, the metamorphosis has to go faster the smaller the individual is, so it happens at an early stage when the larvae are still small. (The largest species of salamanders do not go through a metamorphosis.) Amphibians that lay eggs on land often go through the whole metamorphosis inside the egg. An anamniotic terrestrial egg is less than 1 cm in diameter due to diffusion problems, a size which puts a limit on the amount of posthatching growth.
The smallest amphibian (and vertebrate) in the world is a microhylid frog from New Guinea (Paedophryne amauensis) first discovered in 2012. It has an average length of and is part of a genus that contains four of the world's ten smallest frog species. The largest living amphibian is the Chinese giant salamander (Andrias davidianus) but this is a great deal smaller than the largest amphibian that ever existed—the extinct Prionosuchus, a crocodile-like temnospondyl dating to 270 million years ago from the middle Permian of Brazil. The largest frog is the African Goliath frog (Conraua goliath), which can reach and weigh .
Amphibians are ectothermic (cold-blooded) vertebrates that do not maintain their body temperature through internal physiological processes. Their metabolic rate is low and as a result, their food and energy requirements are limited. In the adult state, they have tear ducts and movable eyelids, and most species have ears that can detect airborne or ground vibrations. They have muscular tongues, which in many species can be protruded. Modern amphibians have fully ossified vertebrae with articular processes. Their ribs are usually short and may be fused to the vertebrae. Their skulls are mostly broad and short, and are often incompletely ossified. Their skin contains little keratin and lacks scales, apart from a few fish-like scales in certain caecilians. The skin contains many mucous glands and in some species, poison glands (a type of granular gland). The hearts of amphibians have three chambers, two atria and one ventricle. They have a urinary bladder and nitrogenous waste products are excreted primarily as urea. Most amphibians lay their eggs in water and have aquatic larvae that undergo metamorphosis to become terrestrial adults. Amphibians breathe by means of a pump action in which air is first drawn into the buccopharyngeal region through the nostrils. These are then closed and the air is forced into the lungs by contraction of the throat. They supplement this with gas exchange through the skin.
Anura
The order Anura (from the Ancient Greek a(n)- meaning "without" and oura meaning "tail") comprises the frogs and toads. They usually have long hind limbs that fold underneath them, shorter forelimbs, webbed toes with no claws, no tails, large eyes and glandular moist skin. Members of this order with smooth skins are commonly referred to as frogs, while those with warty skins are known as toads. The difference is not a formal one taxonomically and there are numerous exceptions to this rule. Members of the family Bufonidae are known as the "true toads". Frogs range in size from the Goliath frog (Conraua goliath) of West Africa to the Paedophryne amauensis, first described in Papua New Guinea in 2012, which is also the smallest known vertebrate. Although most species are associated with water and damp habitats, some are specialised to live in trees or in deserts. They are found worldwide except for polar areas.
Anura is divided into three suborders that are broadly accepted by the scientific community, but the relationships between some families remain unclear. Future molecular studies should provide further insights into their evolutionary relationships. The suborder Archaeobatrachia contains four families of primitive frogs. These are Ascaphidae, Bombinatoridae, Discoglossidae and Leiopelmatidae which have few derived features and are probably paraphyletic with regard to other frog lineages. The six families in the more evolutionarily advanced suborder Mesobatrachia are the fossorial Megophryidae, Pelobatidae, Pelodytidae, Scaphiopodidae and Rhinophrynidae and the obligatorily aquatic Pipidae. These have certain characteristics that are intermediate between the two other suborders. Neobatrachia is by far the largest suborder and includes the remaining families of modern frogs, including most common species. Ninety-six percent of the over 5,000 extant species of frog are neobatrachians.
Caudata
The order Caudata (from the Latin cauda meaning "tail") consists of the salamanders—elongated, low-slung animals that mostly resemble lizards in form. This is a symplesiomorphic trait and they are no more closely related to lizards than they are to mammals. Salamanders lack claws, have scale-free skins, either smooth or covered with tubercles, and tails that are usually flattened from side to side and often finned. They range in size from the Chinese giant salamander (Andrias davidianus), which has been reported to grow to a length of , to the diminutive Thorius pennatulus from Mexico which seldom exceeds in length. Salamanders have a mostly Laurasian distribution, being present in much of the Holarctic region of the northern hemisphere. The family Plethodontidae is also found in Central America and South America north of the Amazon basin; South America was apparently invaded from Central America by about the start of the Miocene, 23 million years ago. Urodela is a name sometimes used for all the extant species of salamanders. Members of several salamander families have become paedomorphic and either fail to complete their metamorphosis or retain some larval characteristics as adults. Most salamanders are under long. They may be terrestrial or aquatic and many spend part of the year in each habitat. When on land, they mostly spend the day hidden under stones or logs or in dense vegetation, emerging in the evening and night to forage for worms, insects and other invertebrates.
The suborder Cryptobranchoidea contains the primitive salamanders. A number of fossil cryptobranchids have been found, but there are only three living species, the Chinese giant salamander (Andrias davidianus), the Japanese giant salamander (Andrias japonicus) and the hellbender (Cryptobranchus alleganiensis) from North America. These large amphibians retain several larval characteristics in their adult state; gills slits are present and the eyes are unlidded. A unique feature is their ability to feed by suction, depressing either the left side of their lower jaw or the right. The males excavate nests, persuade females to lay their egg strings inside them, and guard them. As well as breathing with lungs, they respire through the many folds in their thin skin, which has capillaries close to the surface.
The suborder Salamandroidea contains the advanced salamanders. They differ from the cryptobranchids by having fused prearticular bones in the lower jaw, and by using internal fertilisation. In salamandrids, the male deposits a bundle of sperm, the spermatophore, and the female picks it up and inserts it into her cloaca where the sperm is stored until the eggs are laid. The largest family in this group is Plethodontidae, the lungless salamanders, which includes 60% of all salamander species. The family Salamandridae includes the true salamanders and the name "newt" is given to members of its subfamily Pleurodelinae.
The third suborder, Sirenoidea, contains the four species of sirens, which are in a single family, Sirenidae. Members of this order are eel-like aquatic salamanders with much reduced forelimbs and no hind limbs. Some of their features are primitive while others are derived. Fertilisation is likely to be external as sirenids lack the cloacal glands used by male salamandrids to produce spermatophores and the females lack spermathecae for sperm storage. Despite this, the eggs are laid singly, a behaviour not conducive for external fertilisation.
Gymnophiona
The order Gymnophiona (from the Greek gymnos meaning "naked" and ophis meaning "serpent") or Apoda comprises the caecilians. These are long, cylindrical, limbless animals with a snake- or worm-like form. The adults vary in length from 8 to 75 centimetres (3 to 30 inches) with the exception of Thomson's caecilian (Caecilia thompsoni), which can reach . A caecilian's skin has a large number of transverse folds and in some species contains tiny embedded dermal scales. It has rudimentary eyes covered in skin, which are probably limited to discerning differences in light intensity. It also has a pair of short tentacles near the eye that can be extended and which have tactile and olfactory functions. Most caecilians live underground in burrows in damp soil, in rotten wood and under plant debris, but some are aquatic. Most species lay their eggs underground and when the larvae hatch, they make their way to adjacent bodies of water. Others brood their eggs and the larvae undergo metamorphosis before the eggs hatch. A few species give birth to live young, nourishing them with glandular secretions while they are in the oviduct. Caecilians have a mostly Gondwanan distribution, being found in tropical regions of Africa, Asia and Central and South America.
Anatomy and physiology
Skin
The integumentary structure contains some typical characteristics common to terrestrial vertebrates, such as the presence of highly cornified outer layers, renewed periodically through a moulting process controlled by the pituitary and thyroid glands. Local thickenings (often called warts) are common, such as those found on toads. The outside of the skin is shed periodically mostly in one piece, in contrast to mammals and birds where it is shed in flakes. Amphibians often eat the sloughed skin. Caecilians are unique among amphibians in having mineralized dermal scales embedded in the dermis between the furrows in the skin. The similarity of these to the scales of bony fish is largely superficial. Lizards and some frogs have somewhat similar osteoderms forming bony deposits in the dermis, but this is an example of convergent evolution with similar structures having arisen independently in diverse vertebrate lineages.
Amphibian skin is permeable to water. Gas exchange can take place through the skin (cutaneous respiration) and this allows adult amphibians to respire without rising to the surface of water and to hibernate at the bottom of ponds. To compensate for their thin and delicate skin, amphibians have evolved mucous glands, principally on their heads, backs and tails. The secretions produced by these help keep the skin moist. In addition, most species of amphibian have granular glands that secrete distasteful or poisonous substances. Some amphibian toxins can be lethal to humans while others have little effect. The main poison-producing glands, the parotoids, produce the neurotoxin bufotoxin and are located behind the ears of toads, along the backs of frogs, behind the eyes of salamanders and on the upper surface of caecilians.
The skin colour of amphibians is produced by three layers of pigment cells called chromatophores. These three cell layers consist of the melanophores (occupying the deepest layer), the guanophores (forming an intermediate layer and containing many granules, producing a blue-green colour) and the lipophores (yellow, the most superficial layer). The colour change displayed by many species is initiated by hormones secreted by the pituitary gland. Unlike bony fish, there is no direct control of the pigment cells by the nervous system, and this results in the colour change taking place more slowly than happens in fish. A vividly coloured skin usually indicates that the species is toxic and is a warning sign to predators.
Skeletal system and locomotion
Amphibians have a skeletal system that is structurally homologous to other tetrapods, though with a number of variations. They all have four limbs except for the legless caecilians and a few species of salamander with reduced or no limbs. The bones are hollow and lightweight. The musculoskeletal system is strong to enable it to support the head and body. The bones are fully ossified and the vertebrae interlock with each other by means of overlapping processes. The pectoral girdle is supported by muscle, and the well-developed pelvic girdle is attached to the backbone by a pair of sacral ribs. The ilium slopes forward and the body is held closer to the ground than is the case in mammals.
In most amphibians, there are four digits on the fore foot and five on the hind foot, but no claws on either. Some salamanders have fewer digits and the amphiumas are eel-like in appearance with tiny, stubby legs. The sirens are aquatic salamanders with stumpy forelimbs and no hind limbs. The caecilians are limbless. They burrow in the manner of earthworms with zones of muscle contractions moving along the body. On the surface of the ground or in water they move by undulating their body from side to side.
In frogs, the hind legs are larger than the fore legs, especially so in those species that principally move by jumping or swimming. In the walkers and runners the hind limbs are not so large, and the burrowers mostly have short limbs and broad bodies. The feet have adaptations for the way of life, with webbing between the toes for swimming, broad adhesive toe pads for climbing, and keratinised tubercles on the hind feet for digging (frogs usually dig backwards into the soil). In most salamanders, the limbs are short and more or less the same length and project at right angles from the body. Locomotion on land is by walking and the tail often swings from side to side or is used as a prop, particularly when climbing. In their normal gait, only one leg is advanced at a time in the manner adopted by their ancestors, the lobe-finned fish. Some salamanders in the genus Aneides and certain plethodontids climb trees and have long limbs, large toepads and prehensile tails. In aquatic salamanders and in frog tadpoles, the tail has dorsal and ventral fins and is moved from side to side as a means of propulsion. Adult frogs do not have tails and caecilians have only very short ones.
Salamanders use their tails in defence and some are prepared to jettison them to save their lives in a process known as autotomy. Certain species in the Plethodontidae have a weak zone at the base of the tail and use this strategy readily. The tail often continues to twitch after separation which may distract the attacker and allow the salamander to escape. Both tails and limbs can be regenerated. Adult frogs are unable to regrow limbs but tadpoles can do so.
Circulatory system
Amphibians have a juvenile stage and an adult stage, and the circulatory systems of the two are distinct. In the juvenile (or tadpole) stage, the circulation is similar to that of a fish; the two-chambered heart pumps the blood through the gills where it is oxygenated, and is spread around the body and back to the heart in a single loop. In the adult stage, amphibians (especially frogs) lose their gills and develop lungs. They have a heart that consists of a single ventricle and two atria. When the ventricle starts contracting, deoxygenated blood is pumped through the pulmonary artery to the lungs. Continued contraction then pumps oxygenated blood around the rest of the body. Mixing of the two bloodstreams is minimized by the anatomy of the chambers.
Nervous and sensory systems
The nervous system is basically the same as in other vertebrates, with a central brain, a spinal cord, and nerves throughout the body. The amphibian brain is relatively simple but broadly the same structurally as in reptiles, birds and mammals. Their brains are elongated, except in caecilians, and contain the usual motor and sensory areas of tetrapods. The pineal body, known to regulate sleep patterns in humans, is thought to produce the hormones involved in hibernation and aestivation in amphibians.
Tadpoles retain the lateral line system of their ancestral fishes, but this is lost in terrestrial adult amphibians. Many aquatic salamanders and some caecilians possess electroreceptors called ampullary organs (completely absent in anurans), that allow them to locate objects around them when submerged in water. The ears are well developed in frogs. There is no external ear, but the large circular eardrum lies on the surface of the head just behind the eye. This vibrates and sound is transmitted through a single bone, the stapes, to the inner ear. Only high-frequency sounds like mating calls are heard in this way, but low-frequency noises can be detected through another mechanism. There is a patch of specialized haircells, called papilla amphibiorum, in the inner ear capable of detecting deeper sounds. Another feature, unique to frogs and salamanders, is the columella-operculum complex adjoining the auditory capsule which is involved in the transmission of both airborne and seismic signals. The ears of salamanders and caecilians are less highly developed than those of frogs as they do not normally communicate with each other through the medium of sound.
The eyes of tadpoles lack lids, but at metamorphosis, the cornea becomes more dome-shaped, the lens becomes flatter, and eyelids and associated glands and ducts develop. The adult eyes are an improvement on invertebrate eyes and were a first step in the development of more advanced vertebrate eyes. They allow colour vision and depth of focus. In the retinas are green rods, which are receptive to a wide range of wavelengths.
Digestive and excretory systems
Many amphibians catch their prey by flicking out an elongated tongue with a sticky tip and drawing it back into the mouth before seizing the item with their jaws. Some use inertial feeding to help them swallow the prey, repeatedly thrusting their head forward sharply causing the food to move backwards in their mouth by inertia. Most amphibians swallow their prey whole without much chewing so they possess voluminous stomachs. The short oesophagus is lined with cilia that help to move the food to the stomach and mucus produced by glands in the mouth and pharynx eases its passage. The enzyme chitinase produced in the stomach helps digest the chitinous cuticle of arthropod prey.
Amphibians possess a pancreas, liver and gall bladder. The liver is usually large with two lobes. Its size is determined by its function as a glycogen and fat storage unit, and may change with the seasons as these reserves are built or used up. Adipose tissue is another important means of storing energy and this occurs in the abdomen (in internal structures called fat bodies), under the skin and, in some salamanders, in the tail.
There are two kidneys located dorsally, near the roof of the body cavity. Their job is to filter the blood of metabolic waste and transport the urine via ureters to the urinary bladder where it is stored before being passed out periodically through the cloacal vent. Larvae and most aquatic adult amphibians excrete the nitrogen as ammonia in large quantities of dilute urine, while terrestrial species, with a greater need to conserve water, excrete the less toxic product urea. Some tree frogs with limited access to water excrete most of their metabolic waste as uric acid.
Urinary bladder
Most aquatic and semi-aquatic amphibians have a membranous skin which allows them to absorb water directly through it. Some semi-aquatic animals also have similarly permeable bladder membrane. As a result, they tend to have high rates of urine production to offset this high water intake, and have urine which is low in dissolved salts. The urinary bladder assists such animals to retain salts. Some aquatic amphibian such as Xenopus do not reabsorb water, to prevent excessive water influx. For land-dwelling amphibians, dehydration results in reduced urine output.
The amphibian bladder is usually highly distensible and among some land-dwelling species of frogs and salamanders may account for between 20% and 50% of their total body weight. Urine flows from the kidneys through the ureters into the bladder and is periodically released from the bladder to the cloaca.
Respiratory system
The lungs in amphibians are primitive compared to those of amniotes, possessing few internal septa and large alveoli, and consequently having a comparatively slow diffusion rate for oxygen entering the blood. Ventilation is accomplished by buccal pumping. Most amphibians, however, are able to exchange gases with the water or air via their skin. To enable sufficient cutaneous respiration, the surface of their highly vascularised skin must remain moist to allow the oxygen to diffuse at a sufficiently high rate. Because oxygen concentration in the water increases at both low temperatures and high flow rates, aquatic amphibians in these situations can rely primarily on cutaneous respiration, as in the Titicaca water frog and the hellbender salamander. In air, where oxygen is more concentrated, some small species can rely solely on cutaneous gas exchange, most famously the plethodontid salamanders, which have neither lungs nor gills. Many aquatic salamanders and all tadpoles have gills in their larval stage, with some (such as the axolotl) retaining gills as aquatic adults.
Reproduction
For the purpose of reproduction most amphibians require fresh water although some lay their eggs on land and have developed various means of keeping them moist. A few (e.g. Fejervarya raja) can inhabit brackish water, but there are no true marine amphibians. There are reports, however, of particular amphibian populations unexpectedly invading marine waters. Such was the case with the Black Sea invasion of the natural hybrid Pelophylax esculentus reported in 2010.
Several hundred frog species in adaptive radiations (e.g., Eleutherodactylus, the Pacific Platymantis, the Australo-Papuan microhylids, and many other tropical frogs), however, do not need any water for breeding in the wild. They reproduce via direct development, an ecological and evolutionary adaptation that has allowed them to be completely independent from free-standing water. Almost all of these frogs live in wet tropical rainforests and their eggs hatch directly into miniature versions of the adult, passing through the tadpole stage within the egg. Reproductive success of many amphibians is dependent not only on the quantity of rainfall, but the seasonal timing.
In the tropics, many amphibians breed continuously or at any time of year. In temperate regions, breeding is mostly seasonal, usually in the spring, and is triggered by increasing day length, rising temperatures or rainfall. Experiments have shown the importance of temperature, but the trigger event, especially in arid regions, is often a storm. In anurans, males usually arrive at the breeding sites before females and the vocal chorus they produce may stimulate ovulation in females and the endocrine activity of males that are not yet reproductively active.
In caecilians, fertilisation is internal, the male extruding an intromittent organ, the , and inserting it into the female cloaca. The paired Müllerian glands inside the male cloaca secrete a fluid which resembles that produced by mammalian prostate glands and which may transport and nourish the sperm. Fertilisation probably takes place in the oviduct.
The majority of salamanders also engage in internal fertilisation. In most of these, the male deposits a spermatophore, a small packet of sperm on top of a gelatinous cone, on the substrate either on land or in the water. The female takes up the sperm packet by grasping it with the lips of the cloaca and pushing it into the vent. The spermatozoa move to the spermatheca in the roof of the cloaca where they remain until ovulation which may be many months later. Courtship rituals and methods of transfer of the spermatophore vary between species. In some, the spermatophore may be placed directly into the female cloaca while in others, the female may be guided to the spermatophore or restrained with an embrace called amplexus. Certain primitive salamanders in the families Sirenidae, Hynobiidae and Cryptobranchidae practice external fertilisation in a similar manner to frogs, with the female laying the eggs in water and the male releasing sperm onto the egg mass.
With a few exceptions, frogs use external fertilisation. The male grasps the female tightly with his forelimbs either behind the arms or in front of the back legs, or in the case of Epipedobates tricolor, around the neck. They remain in amplexus with their cloacae positioned close together while the female lays the eggs and the male covers them with sperm. Roughened nuptial pads on the male's hands aid in retaining grip. Often the male collects and retains the egg mass, forming a sort of basket with the hind feet. An exception is the granular poison frog (Oophaga granulifera) where the male and female place their cloacae in close proximity while facing in opposite directions and then release eggs and sperm simultaneously. The tailed frog (Ascaphus truei) exhibits internal fertilisation. The "tail" is only possessed by the male and is an extension of the cloaca and used to inseminate the female. This frog lives in fast-flowing streams and internal fertilisation prevents the sperm from being washed away before fertilisation occurs. The sperm may be retained in storage tubes attached to the oviduct until the following spring.
Most frogs can be classified as either prolonged or explosive breeders. Typically, prolonged breeders congregate at a breeding site, the males usually arriving first, calling and setting up territories. Other satellite males remain quietly nearby, waiting for their opportunity to take over a territory. The females arrive sporadically, mate selection takes place and eggs are laid. The females depart and territories may change hands. More females appear and in due course, the breeding season comes to an end. Explosive breeders on the other hand are found where temporary pools appear in dry regions after rainfall. These frogs are typically fossorial species that emerge after heavy rains and congregate at a breeding site. They are attracted there by the calling of the first male to find a suitable place, perhaps a pool that forms in the same place each rainy season. The assembled frogs may call in unison and frenzied activity ensues, the males scrambling to mate with the usually smaller number of females.
There is a direct competition between males to win the attention of the females in salamanders and newts, with elaborate courtship displays to keep the female's attention long enough to get her interested in choosing him to mate with. Some species store sperm through long breeding seasons, as the extra time may allow for interactions with rival sperm.
Life cycle
Most amphibians go through metamorphosis, a process of significant morphological change after birth. In typical amphibian development, eggs are laid in water and larvae are adapted to an aquatic lifestyle. Frogs, toads and salamanders all hatch from the egg as larvae with external gills. Metamorphosis in amphibians is regulated by thyroxine concentration in the blood, which stimulates metamorphosis, and prolactin, which counteracts thyroxine's effect. Specific events are dependent on threshold values for different tissues. Because most embryonic development is outside the parental body, it is subject to many adaptations due to specific environmental circumstances. For this reason tadpoles can have horny ridges instead of teeth, whisker-like skin extensions or fins. They also make use of a sensory lateral line organ similar to that of fish. After metamorphosis, these organs become redundant and will be reabsorbed by controlled cell death, called apoptosis. The variety of adaptations to specific environmental circumstances among amphibians is wide, with many discoveries still being made.
Eggs
In the egg, the embryo is suspended in perivitelline fluid and surrounded by semi-permeable gelatinous capsules, with the yolk mass providing nutrients. As the larvae hatch, the capsules are dissolved by enzymes secreted from gland at the tip of the snout. The eggs of some salamanders and frogs contain unicellular green algae. These penetrate the jelly envelope after the eggs are laid and may increase the supply of oxygen to the embryo through photosynthesis. They seem to both speed up the development of the larvae and reduce mortality. In the wood frog (Rana sylvatica), the interior of the globular egg cluster has been found to be up to warmer than its surroundings, which is an advantage in its cool northern habitat.
The eggs may be deposited singly, in cluster or in long strands. Sites for laying eggs include water, mud, burrows, debris and on plants or under logs or stones. The greenhouse frog (Eleutherodactylus planirostris) lays eggs in small groups in the soil where they develop in about two weeks directly into juvenile frogs without an intervening larval stage. The tungara frog (Physalaemus pustulosus) builds a floating nest from foam to protect its eggs. First a raft is built, then eggs are laid in the centre, and finally a foam cap is overlaid. The foam has anti-microbial properties. It contains no detergents but is created by whipping up proteins and lectins secreted by the female.
Larvae
The eggs of amphibians are typically laid in water and hatch into free-living larvae that complete their development in water and later transform into either aquatic or terrestrial adults. In many species of frog and in most lungless salamanders (Plethodontidae), direct development takes place, the larvae growing within the eggs and emerging as miniature adults. Many caecilians and some other amphibians lay their eggs on land, and the newly hatched larvae wriggle or are transported to water bodies. Some caecilians, the alpine salamander (Salamandra atra) and some of the African live-bearing toads (Nectophrynoides spp.) are viviparous. Their larvae feed on glandular secretions and develop within the female's oviduct, often for long periods. Other amphibians, but not caecilians, are ovoviviparous. The eggs are retained in or on the parent's body, but the larvae subsist on the yolks of their eggs and receive no nourishment from the adult. The larvae emerge at varying stages of their growth, either before or after metamorphosis, according to their species. The toad genus Nectophrynoides exhibits all of these developmental patterns among its dozen or so members. Amphibian larvae are known as tadpoles. They have thick, rounded bodies with powerful muscular tails.
Frogs
Unlike in other amphibians, frog tadpoles do not resemble adults. The free-living larvae are normally fully aquatic, but the tadpoles of some species (such as Nannophrys ceylonensis) are semi-terrestrial and live among wet rocks. Tadpoles have cartilaginous skeletons, gills for respiration (external gills at first, internal gills later), lateral line systems and large tails that they use for swimming. Newly hatched tadpoles soon develop gill pouches that cover the gills. These internal gills and operculum are not homologous with those of fish, and are only found in tadpoles as both salamanders and caecilians have external gills only. Combined with buccal pumping the internal gills has allowed tadpoles to adopt a filter feeding lifestyle, even if several species have since evolved other types of feeding strategies. The lungs develop early and are used as accessory breathing organs, the tadpoles rising to the water surface to gulp air. Some species complete their development inside the egg and hatch directly into small frogs. These larvae do not have gills but instead have specialised areas of skin through which respiration takes place. While tadpoles do not have true teeth, in most species, the jaws have long, parallel rows of small keratinized structures called keradonts surrounded by a horny beak. Front legs are formed under the gill sac and hind legs become visible a few days later.
Iodine and T4 (over stimulate the spectacular apoptosis [programmed cell death] of the cells of the larval gills, tail and fins) also stimulate the evolution of nervous systems transforming the aquatic, vegetarian tadpole into the terrestrial, carnivorous frog with better neurological, visuospatial, olfactory and cognitive abilities for hunting.
In fact, tadpoles developing in ponds and streams are typically herbivorous. Pond tadpoles tend to have deep bodies, large caudal fins and small mouths; they swim in the quiet waters feeding on growing or loose fragments of vegetation. Stream dwellers mostly have larger mouths, shallow bodies and caudal fins; they attach themselves to plants and stones and feed on the surface films of algae and bacteria. They also feed on diatoms, filtered from the water through the gills, and stir up the sediment at bottom of the pond, ingesting edible fragments. They have a relatively long, spiral-shaped gut to enable them to digest this diet. Some species are carnivorous at the tadpole stage, eating insects, smaller tadpoles and fish. Young of the Cuban tree frog (Osteopilus septentrionalis) can occasionally be cannibalistic, the younger tadpoles attacking a larger, more developed tadpole when it is undergoing metamorphosis.
At metamorphosis, rapid changes in the body take place as the lifestyle of the frog changes completely. The spiral‐shaped mouth with horny tooth ridges is reabsorbed together with the spiral gut. The animal develops a large jaw, and its gills disappear along with its gill sac. Eyes and legs grow quickly, and a tongue is formed. There are associated changes in the neural networks such as development of stereoscopic vision and loss of the lateral line system. All this can happen in about a day. A few days later, the tail is reabsorbed, due to the higher thyroxine concentration required for this to take place.
Salamanders
At hatching, a typical salamander larva has eyes without lids, teeth in both upper and lower jaws, three pairs of feathery external gills, and a long tail with dorsal and ventral fins. The forelimbs may be partially developed and the hind limbs are rudimentary in pond-living species but may be rather more developed in species that reproduce in moving water. Pond-type larvae often have a pair of balancers, rod-like structures on either side of the head that may prevent the gills from becoming clogged up with sediment. Both of these are able to breed. Some have larvae that never fully develop into the adult form, a condition known as neoteny. Neoteny occurs when the animal's growth rate is very low and is usually linked to adverse conditions such as low water temperatures that may change the response of the tissues to the hormone thyroxine. as well as lack of food. There are fifteen species of obligate neotenic salamanders, including species of Necturus, Proteus and Amphiuma, and many examples of facultative ones, such as the northwestern salamander (Ambystoma gracile) and the tiger salamander (A. tigrinum) that adopt this strategy under appropriate environmental circumstances.
Lungless salamanders in the family Plethodontidae are terrestrial and lay a small number of unpigmented eggs in a cluster among damp leaf litter. Each egg has a large yolk sac and the larva feeds on this while it develops inside the egg, emerging fully formed as a juvenile salamander. The female salamander often broods the eggs. In the genus Ensatinas, the female has been observed to coil around them and press her throat area against them, effectively massaging them with a mucous secretion.
In newts and salamanders, metamorphosis is less dramatic than in frogs. This is because the larvae are already carnivorous and continue to feed as predators when they are adults so few changes are needed to their digestive systems. Their lungs are functional early, but the larvae do not make as much use of them as do tadpoles. Their gills are never covered by gill sacs and are reabsorbed just before the animals leave the water. Other changes include the reduction in size or loss of tail fins, the closure of gill slits, thickening of the skin, the development of eyelids, and certain changes in dentition and tongue structure. Salamanders are at their most vulnerable at metamorphosis as swimming speeds are reduced and transforming tails are encumbrances on land. Adult salamanders often have an aquatic phase in spring and summer, and a land phase in winter. For adaptation to a water phase, prolactin is the required hormone, and for adaptation to the land phase, thyroxine. External gills do not return in subsequent aquatic phases because these are completely absorbed upon leaving the water for the first time.
Caecilians
Most terrestrial caecilians that lay eggs do so in burrows or moist places on land near bodies of water. The development of the young of Ichthyophis glutinosus, a species from Sri Lanka, has been much studied. The eel-like larvae hatch out of the eggs and make their way to water. They have three pairs of external red feathery gills, a blunt head with two rudimentary eyes, a lateral line system and a short tail with fins. They swim by undulating their body from side to side. They are mostly active at night, soon lose their gills and make sorties onto land. Metamorphosis is gradual. By the age of about ten months they have developed a pointed head with sensory tentacles near the mouth and lost their eyes, lateral line systems and tails. The skin thickens, embedded scales develop and the body divides into segments. By this time, the caecilian has constructed a burrow and is living on land.
In the majority of species of caecilians, the young are produced by viviparity. Typhlonectes compressicauda, a species from South America, is typical of these. Up to nine larvae can develop in the oviduct at any one time. They are elongated and have paired sac-like gills, small eyes and specialised scraping teeth. At first, they feed on the yolks of the eggs, but as this source of nourishment declines they begin to rasp at the ciliated epithelial cells that line the oviduct. This stimulates the secretion of fluids rich in lipids and mucoproteins on which they feed along with scrapings from the oviduct wall. They may increase their length sixfold and be two-fifths as long as their mother before being born. By this time they have undergone metamorphosis, lost their eyes and gills, developed a thicker skin and mouth tentacles, and reabsorbed their teeth. A permanent set of teeth grow through soon after birth.
Gills are only necessarily during embryonic development, and in species that give birth the offspring is born after gill degeneration. In egg laying caecilians the gills are either reabsorbed before hatching, or, in species that hatch with gill remnants still present, short lived and only leaves behind a gill slit. For species with scales under their skin, the scales does not form before during metamorphosis.
The ringed caecilian (Siphonops annulatus) has developed a unique adaptation for the purposes of reproduction. The progeny feed on a skin layer that is specially developed by the adult in a phenomenon known as maternal dermatophagy. The brood feed as a batch for about seven minutes at intervals of approximately three days which gives the skin an opportunity to regenerate. Meanwhile, they have been observed to ingest fluid exuded from the maternal cloaca.
Parental care
The care of offspring among amphibians has been little studied but, in general, the larger the number of eggs in a batch, the less likely it is that any degree of parental care takes place. Nevertheless, it is estimated that in up to 20% of amphibian species, one or both adults play some role in the care of the young. Those species that breed in smaller water bodies or other specialised habitats tend to have complex patterns of behaviour in the care of their young.
Many woodland salamanders lay clutches of eggs under dead logs or stones on land. The black mountain salamander (Desmognathus welteri) does this, the mother brooding the eggs and guarding them from predation as the embryos feed on the yolks of their eggs. When fully developed, they break their way out of the egg capsules and disperse as juvenile salamanders. The male hellbender, a primitive salamander, excavates an underwater nest and encourages females to lay there. The male then guards the site for the two or three months before the eggs hatch, using body undulations to fan the eggs and increase their supply of oxygen.
The male Colostethus subpunctatus, a tiny frog, protects the egg cluster which is hidden under a stone or log. When the eggs hatch, the male transports the tadpoles on his back, stuck there by a mucous secretion, to a temporary pool where he dips himself into the water and the tadpoles drop off. The male midwife toad (Alytes obstetricans) winds egg strings round his thighs and carries the eggs around for up to eight weeks. He keeps them moist and when they are ready to hatch, he visits a pond or ditch and releases the tadpoles. The female gastric-brooding frog (Rheobatrachus spp.) reared larvae in her stomach after swallowing either the eggs or hatchlings; however, this stage was never observed before the species became extinct. The tadpoles secrete a hormone that inhibits digestion in the mother whilst they develop by consuming their very large yolk supply. The pouched frog (Assa darlingtoni) lays eggs on the ground. When they hatch, the male carries the tadpoles around in brood pouches on his hind legs. The aquatic Surinam toad (Pipa pipa) raises its young in pores on its back where they remain until metamorphosis. The granular poison frog (Oophaga granulifera) is typical of a number of tree frogs in the poison dart frog family Dendrobatidae. Its eggs are laid on the forest floor and when they hatch, the tadpoles are carried one by one on the back of an adult to a suitable water-filled crevice such as the axil of a leaf or the rosette of a bromeliad. The female visits the nursery sites regularly and deposits unfertilised eggs in the water and these are consumed by the tadpoles.
Genetics and genomics
Amphibians are notable among vertebrates for their diversity of chromosomes and genomes. The karyotypes (chromosomes) have been determined for at least 1,193 (14.5%) of the ≈8,200 known (diploid) species, including 963 anurans, 209 salamanders, and 21 caecilians. Generally, the karyotypes of diploid amphibians are characterized by 20–26 bi-armed chromosomes. Amphibians have also very large genomes compared to other taxa of vertebrates and corresponding variation in genome size (C-value: picograms of DNA in haploid nuclei). The genome sizes range from 0.95 to 11.5 pg in frogs, from 13.89 to 120.56 pg in salamanders, and from 2.94 to 11.78 pg in caecilians.
The large genome sizes have prevented whole-genome sequencing of amphibians although a number of genomes have been published recently. The 1.7GB draft genome of Xenopus tropicalis was the first to be reported for amphibians in 2010. Compared to some salamanders this frog genome is tiny. For instance, the genome of the Mexican axolotl turned out to be 32 Gb, which is more than 10 times larger than the human genome (3GB).
Feeding and diet
With a few exceptions, adult amphibians are predators, feeding on virtually anything that moves that they can swallow. The diet mostly consists of small prey that do not move too fast such as beetles, caterpillars, earthworms and spiders. The sirens (Siren spp.) often ingest aquatic plant material with the invertebrates on which they feed and a Brazilian tree frog (Xenohyla truncata) includes a large quantity of fruit in its diet. The Mexican burrowing toad (Rhinophrynus dorsalis) has a specially adapted tongue for picking up ants and termites. It projects it with the tip foremost whereas other frogs flick out the rear part first, their tongues being hinged at the front.
Food is mostly selected by sight, even in conditions of dim light. Movement of the prey triggers a feeding response. Frogs have been caught on fish hooks baited with red flannel and green frogs (Rana clamitans) have been found with stomachs full of elm seeds that they had seen floating past. Toads, salamanders and caecilians also use smell to detect prey. This response is mostly secondary because salamanders have been observed to remain stationary near odoriferous prey but only feed if it moves. Cave-dwelling amphibians normally hunt by smell. Some salamanders seem to have learned to recognize immobile prey when it has no smell, even in complete darkness.
Amphibians usually swallow food whole but may chew it lightly first to subdue it. They typically have small hinged pedicellate teeth, a feature unique to amphibians. The base and crown of these are composed of dentine separated by an uncalcified layer and they are replaced at intervals. Salamanders, caecilians and some frogs have one or two rows of teeth in both jaws, but some frogs (Rana spp.) lack teeth in the lower jaw, and toads (Bufo spp.) have no teeth. In many amphibians there are also vomerine teeth attached to a facial bone in the roof of the mouth.
The tiger salamander (Ambystoma tigrinum) is typical of the frogs and salamanders that hide under cover ready to ambush unwary invertebrates. Others amphibians, such as the Bufo spp. toads, actively search for prey, while the Argentine horned frog (Ceratophrys ornata) lures inquisitive prey closer by raising its hind feet over its back and vibrating its yellow toes. Among leaf litter frogs in Panama, frogs that actively hunt prey have narrow mouths and are slim, often brightly coloured and toxic, while ambushers have wide mouths and are broad and well-camouflaged. Caecilians do not flick their tongues, but catch their prey by grabbing it with their slightly backward-pointing teeth. The struggles of the prey and further jaw movements work it inwards and the caecilian usually retreats into its burrow. The subdued prey is gulped down whole.
When they are newly hatched, frog larvae feed on the yolk of the egg. When this is exhausted some move on to feed on bacteria, algal crusts, detritus and raspings from submerged plants. Water is drawn in through their mouths, which are usually at the bottom of their heads, and passes through branchial food traps between their mouths and their gills where fine particles are trapped in mucus and filtered out. Others have specialised mouthparts consisting of a horny beak edged by several rows of labial teeth. They scrape and bite food of many kinds as well as stirring up the bottom sediment, filtering out larger particles with the papillae around their mouths. Some, such as the spadefoot toads, have strong biting jaws and are carnivorous or even cannibalistic.
Vocalization
The calls made by caecilians and salamanders are limited to occasional soft squeaks, grunts or hisses and have not been much studied. A clicking sound sometimes produced by caecilians may be a means of orientation, as in bats, or a form of communication. Most salamanders are considered voiceless, but the California giant salamander (Dicamptodon ensatus) has vocal cords and can produce a rattling or barking sound. Some species of salamander emit a quiet squeak or yelp if attacked.
Frogs are much more vocal, especially during the breeding season when they use their voices to attract mates. The presence of a particular species in an area may be more easily discerned by its characteristic call than by a fleeting glimpse of the animal itself. In most species, the sound is produced by expelling air from the lungs over the vocal cords into an air sac or sacs in the throat or at the corner of the mouth. This may distend like a balloon and acts as a resonator, helping to transfer the sound to the atmosphere, or the water at times when the animal is submerged. The main vocalisation is the male's loud advertisement call which seeks to both encourage a female to approach and discourage other males from intruding on its territory. This call is modified to a quieter courtship call on the approach of a female or to a more aggressive version if a male intruder draws near. Calling carries the risk of attracting predators and involves the expenditure of much energy. Other calls include those given by a female in response to the advertisement call and a release call given by a male or female during unwanted attempts at amplexus. When a frog is attacked, a distress or fright call is emitted, often resembling a scream. The usually nocturnal Cuban tree frog (Osteopilus septentrionalis) produces a rain call when there is rainfall during daylight hours.
Territorial behaviour
Little is known of the territorial behaviour of caecilians, but some frogs and salamanders defend home ranges. These are usually feeding, breeding or sheltering sites. Males normally exhibit such behaviour though in some species, females and even juveniles are also involved. Although in many frog species, females are larger than males, this is not the case in most species where males are actively involved in territorial defence. Some of these have specific adaptations such as enlarged teeth for biting or spines on the chest, arms or thumbs.
In salamanders, defence of a territory involves adopting an aggressive posture and if necessary attacking the intruder. This may involve snapping, chasing and sometimes biting, occasionally causing the loss of a tail. The behaviour of red back salamanders (Plethodon cinereus) has been much studied. 91% of marked individuals that were later recaptured were within a metre (yard) of their original daytime retreat under a log or rock. A similar proportion, when moved experimentally a distance of , found their way back to their home base. The salamanders left odour marks around their territories which averaged in size and were sometimes inhabited by a male and female pair. These deterred the intrusion of others and delineated the boundaries between neighbouring areas. Much of their behaviour seemed stereotyped and did not involve any actual contact between individuals. An aggressive posture involved raising the body off the ground and glaring at the opponent who often turned away submissively. If the intruder persisted, a biting lunge was usually launched at either the tail region or the naso-labial grooves. Damage to either of these areas can reduce the fitness of the rival, either because of the need to regenerate tissue or because it impairs its ability to detect food.
In frogs, male territorial behaviour is often observed at breeding locations; calling is both an announcement of ownership of part of this resource and an advertisement call to potential mates. In general, a deeper voice represents a heavier and more powerful individual, and this may be sufficient to prevent intrusion by smaller males. Much energy is used in the vocalization and it takes a toll on the territory holder who may be displaced by a fitter rival if he tires. There is a tendency for males to tolerate the holders of neighbouring territories while vigorously attacking unknown intruders. Holders of territories have a "home advantage" and usually come off better in an encounter between two similar-sized frogs. If threats are insufficient, chest to chest tussles may take place. Fighting methods include pushing and shoving, deflating the opponent's vocal sac, seizing him by the head, jumping on his back, biting, chasing, splashing, and ducking him under the water.
Defence mechanisms
Amphibians have soft bodies with thin skins, and lack claws, defensive armour, or spines. Nevertheless, they have evolved various defence mechanisms to keep themselves alive. The first line of defence in salamanders and frogs is the mucous secretion that they produce. This keeps their skin moist and makes them slippery and difficult to grip. The secretion is often sticky and distasteful or toxic. Snakes have been observed yawning and gaping when trying to swallow African clawed frogs (Xenopus laevis), which gives the frogs an opportunity to escape. Caecilians have been little studied in this respect, but the Cayenne caecilian (Typhlonectes compressicauda) produces toxic mucus that has killed predatory fish in a feeding experiment in Brazil. In some salamanders, the skin is poisonous. The rough-skinned newt (Taricha granulosa) from North America and other members of its genus contain the neurotoxin tetrodotoxin (TTX), the most toxic non-protein substance known and almost identical to that produced by pufferfish. Handling the newts does not cause harm, but ingestion of even the most minute amounts of the skin is deadly. In feeding trials, fish, frogs, reptiles, birds and mammals were all found to be susceptible. The only predators with some tolerance to the poison are certain populations of common garter snake (Thamnophis sirtalis).
In locations where both snake and salamander co-exist, the snakes have developed immunity through genetic changes and they feed on the amphibians with impunity. Coevolution occurs with the newt increasing its toxic capabilities at the same rate as the snake further develops its immunity. Some frogs and toads are toxic, the main poison glands being at the side of the neck and under the warts on the back. These regions are presented to the attacking animal and their secretions may be foul-tasting or cause various physical or neurological symptoms. Altogether, over 200 toxins have been isolated from the limited number of amphibian species that have been investigated.
Poisonous species often use bright colouring to warn potential predators of their toxicity. These warning colours tend to be red or yellow combined with black, with the fire salamander (Salamandra salamandra) being an example. Once a predator has sampled one of these, it is likely to remember the colouration next time it encounters a similar animal. In some species, such as the fire-bellied toad (Bombina spp.), the warning colouration is on the belly and these animals adopt a defensive pose when attacked, exhibiting their bright colours to the predator. The frog Allobates zaparo is not poisonous, but mimics the appearance of other toxic species in its locality, a strategy that may deceive predators.
Many amphibians are nocturnal and hide during the day, thereby avoiding diurnal predators that hunt by sight. Other amphibians use camouflage to avoid being detected. They have various colourings such as mottled browns, greys and olives to blend into the background. Some salamanders adopt defensive poses when faced by a potential predator such as the North American northern short-tailed shrew (Blarina brevicauda). Their bodies writhe and they raise and lash their tails which makes it difficult for the predator to avoid contact with their poison-producing granular glands. A few salamanders will autotomise their tails when attacked, sacrificing this part of their anatomy to enable them to escape. The tail may have a constriction at its base to allow it to be easily detached. The tail is regenerated later, but the energy cost to the animal of replacing it is significant.
Some frogs and toads inflate themselves to make themselves look large and fierce, and some spadefoot toads (Pelobates spp) scream and leap towards the attacker. Giant salamanders of the genus Andrias, as well as Ceratophrine and Pyxicephalus frogs possess sharp teeth and are capable of drawing blood with a defensive bite. The blackbelly salamander (Desmognathus quadramaculatus) can bite an attacking common garter snake (Thamnophis sirtalis) two or three times its size on the head and often manages to escape.
Cognition
In amphibians, there is evidence of habituation, associative learning through both classical and instrumental learning, and discrimination abilities. Amphibians are widely considered to be sentient, able to feel emotions such as anxiety and fear.
In one experiment, when offered live fruit flies (Drosophila virilis), salamanders chose the larger of 1 vs 2 and 2 vs 3. Frogs can distinguish between low numbers (1 vs 2, 2 vs 3, but not 3 vs 4) and large numbers (3 vs 6, 4 vs 8, but not 4 vs 6) of prey. This is irrespective of other characteristics, i.e. surface area, volume, weight and movement, although discrimination among large numbers may be based on surface area.
Conservation
Dramatic declines in amphibian populations, including population crashes and mass localized extinction, have been noted since the late 1980s from locations all over the world, and amphibian declines are thus perceived to be one of the most critical threats to global biodiversity. In 2004, the International Union for Conservation of Nature (IUCN) reported stating that currently birds, mammals, and amphibians extinction rates were at minimum 48 times greater than natural extinction rates—possibly 1,024 times higher. In 2006, there were believed to be 4,035 species of amphibians that depended on water at some stage during their life cycle. Of these, 1,356 (33.6%) were considered to be threatened and this figure is likely to be an underestimate because it excludes 1,427 species for which there was insufficient data to assess their status. A number of causes are believed to be involved, including habitat destruction and modification, over-exploitation, pollution, introduced species, global warming, endocrine-disrupting pollutants, destruction of the ozone layer (ultraviolet radiation has shown to be especially damaging to the skin, eyes, and eggs of amphibians), and diseases like chytridiomycosis. However, many of the causes of amphibian declines are still poorly understood, and are a topic of ongoing discussion.
Food webs and predation
Any decline in amphibian numbers will affect the patterns of predation. The loss of carnivorous species near the top of the food chain will upset the delicate ecosystem balance and may cause dramatic increases in opportunistic species.
Predators that feed on amphibians are affected by their decline. The western terrestrial garter snake (Thamnophis elegans) in California is largely aquatic and depends heavily on two species of frog that are decreasing in numbers, the Yosemite toad (Bufo canorus) and the mountain yellow-legged frog (Rana muscosa), putting the snake's future at risk. If the snake were to become scarce, this would affect birds of prey and other predators that feed on it. Meanwhile, in the ponds and lakes, fewer frogs means fewer tadpoles. These normally play an important role in controlling the growth of algae and also forage on detritus that accumulates as sediment on the bottom. A reduction in the number of tadpoles may lead to an overgrowth of algae, resulting in depletion of oxygen in the water when the algae later die and decompose. Aquatic invertebrates and fish might then die and there would be unpredictable ecological consequences.
Pollution and pesticides
The decline in amphibian and reptile populations has led to an awareness of the effects of pesticides on reptiles and amphibians. In the past, the argument that amphibians or reptiles were more susceptible to any chemical contamination than any land aquatic vertebrate was not supported by research until recently. Amphibians and reptiles have complex life cycles, live in different climate and ecological zones, and are more vulnerable to chemical exposure. Certain pesticides, such as organophosphates, neonicotinoids, and carbamates, react via cholinesterase inhibition. Cholinesterase is an enzyme that causes the hydrolysis of acetylcholine, an excitatory neurotransmitter that is abundant in the nervous system. AChE inhibitors are either reversible or irreversible, and carbamates are safer than organophosphorus insecticides, which are more likely to cause cholinergic poisoning. Reptile exposure to an AChE inhibitory pesticide may result in disruption of neural function in reptiles. The buildup of these inhibitory effects on motor performance, such as food consumption and other activities.
Conservation and protection strategies
The Amphibian Specialist Group of the IUCN is spearheading efforts to implement a comprehensive global strategy for amphibian conservation. Amphibian Ark is an organization that was formed to implement the ex-situ conservation recommendations of this plan, and they have been working with zoos and aquaria around the world, encouraging them to create assurance colonies of threatened amphibians. One such project is the Panama Amphibian Rescue and Conservation Project that built on existing conservation efforts in Panama to create a country-wide response to the threat of chytridiomycosis.
Another measure would be to stop exploitation of frogs for human consumption. In the Middle East, a growing appetite for eating frog legs and the consequent gathering of them for food was already linked to an increase in mosquitoes and thus has direct consequences for human health.
See also
Cultural depictions of amphibians
List of amphibians
List of amphibian genera
List of threatened reptiles and amphibians of the United States
References
Cited texts
Further reading
External links
Amphibians – AnimalSpot.net
ArchéoZooThèque : Amphibians skeletons drawings : available in vector, image and PDF formats
Amphibian Specialist Group
Amphibian Ark
AmphibiaWeb
Global Amphibian Assessment
Amphibian vocalisations on Archival Sound Recordings
Amphibious organisms
Extant Late Devonian first appearances
Taxa named by John Edward Gray |
628 | https://en.wikipedia.org/wiki/Aldous%20Huxley | Aldous Huxley | Aldous Leonard Huxley ( ; 26 July 1894 – 22 November 1963) was an English writer and philosopher. His bibliography spans nearly 50 books, including novels and non-fiction works, as well as essays, narratives, and poems.
Born into the prominent Huxley family, he graduated from Balliol College, Oxford, with an undergraduate degree in English literature. Early in his career, he published short stories and poetry and edited the literary magazine Oxford Poetry, before going on to publish travel writing, satire, and screenplays. He spent the latter part of his life in the United States, living in Los Angeles from 1937 until his death. By the end of his life, Huxley was widely acknowledged as one of the foremost intellectuals of his time. He was nominated for the Nobel Prize in Literature nine times, and was elected Companion of Literature by the Royal Society of Literature in 1962.
Huxley was a pacifist. He grew interested in philosophical mysticism, as well as universalism, addressing these subjects in his works such as The Perennial Philosophy (1945), which illustrates commonalities between Western and Eastern mysticism, and The Doors of Perception (1954), which interprets his own psychedelic experience with mescaline. In his most famous novel Brave New World (1932) and his final novel Island (1962), he presented his visions of dystopia and utopia, respectively.
Early life
Huxley was born in Godalming, Surrey, England, in 1894. He was the third son of the writer and schoolmaster Leonard Huxley, who edited The Cornhill Magazine, and his first wife, Julia Arnold, who founded Prior's Field School. Julia was the niece of poet and critic Matthew Arnold and the sister of Mrs. Humphry Ward. Julia named him Aldous after a character in one of her sister's novels. Aldous was the grandson of Thomas Henry Huxley, the zoologist, agnostic, and controversialist who had often been called "Darwin's Bulldog". His brother Julian Huxley and half-brother Andrew Huxley also became outstanding biologists. Aldous had another brother, Noel Trevenen Huxley (1889–1914), who took his own life after a period of clinical depression.
As a child, Huxley's nickname was "Ogie", short for "Ogre". He was described by his brother, Julian, as someone who frequently contemplated "the strangeness of things". According to his cousin and contemporary Gervas Huxley, he had an early interest in drawing.
Huxley's education began in his father's well-equipped botanical laboratory, after which he enrolled at Hillside School near Godalming. He was taught there by his own mother for several years until she became terminally ill. After Hillside he went on to Eton College. His mother died in 1908, when he was 14 (his father later remarried). He contracted the eye disease keratitis punctata in 1911; this "left [him] practically blind for two to three years" and "ended his early dreams of becoming a doctor". In October 1913, Huxley entered Balliol College, Oxford, where he studied English literature. He volunteered for the British Army in January 1916, for the Great War; however, he was rejected on health grounds, being half-blind in one eye. His eyesight later partly recovered. He edited Oxford Poetry in 1916, and in June of that year graduated BA with first class honours. His brother Julian wrote:
Following his years at Balliol, Huxley, being financially indebted to his father, decided to find employment. He taught French for a year at Eton College, where Eric Blair (who was to take the pen name George Orwell) and Steven Runciman were among his pupils. He was mainly remembered as being an incompetent schoolmaster unable to keep order in class. Nevertheless, Blair and others spoke highly of his excellent command of language.
Huxley also worked for a time during the 1920s at Brunner and Mond, an advanced chemical plant in Billingham in County Durham, northeast England. According to an introduction to his science fiction novel Brave New World (1932), the experience he had there of "an ordered universe in a world of planless incoherence" was an important source for the novel.
Career
Huxley completed his first (unpublished) novel at the age of 17 and began writing seriously in his early twenties, establishing himself as a successful writer and social satirist. His first published novels were social satires, Crome Yellow (1921), Antic Hay (1923), Those Barren Leaves (1925), and Point Counter Point (1928). Brave New World (1932) was his fifth novel and first dystopian work. In the 1920s, he was also a contributor to Vanity Fair and British Vogue magazines.
Contact with the Bloomsbury Set
During the First World War, Huxley spent much of his time at Garsington Manor near Oxford, home of Lady Ottoline Morrell, working as a farm labourer. While at the Manor, he met several Bloomsbury Group figures, including Bertrand Russell, Alfred North Whitehead, and Clive Bell. Later, in Crome Yellow (1921), he caricatured the Garsington lifestyle. Jobs were very scarce, but in 1919, John Middleton Murry was reorganising the Athenaeum and invited Huxley to join the staff. He accepted immediately, and quickly married the Belgian refugee Maria Nys (1899–1955), also at Garsington. They lived with their young son in Italy part of the time during the 1920s, where Huxley would visit his friend D. H. Lawrence. Following Lawrence's death in 1930 (he and Maria were present at his death in Provence), Huxley edited Lawrence's letters (1932). Very early in 1929, in London, Huxley met Gerald Heard, a writer and broadcaster, philosopher and interpreter of contemporary science.
Works of this period included novels about the dehumanising aspects of scientific progress, (his magnum opus Brave New World), and on pacifist themes (Eyeless in Gaza). In Brave New World, set in a dystopian London, Huxley portrays a society operating on the principles of mass production and Pavlovian conditioning. Huxley was strongly influenced by F. Matthias Alexander, on whom he based a character in Eyeless in Gaza.
During this period, Huxley began to write and edit non-fiction works on pacifist issues, including Ends and Means (1937), An Encyclopedia of Pacifism, and Pacifism and Philosophy, and was an active member of the Peace Pledge Union.
Life in the United States
In 1937, Huxley moved to Hollywood with his wife Maria, son Matthew Huxley, and friend Gerald Heard. Cyril Connolly wrote, of the two intellectuals (Huxley and Heard) in the late 1930s, "all European avenues had been exhausted in the search for a way forward – politics, art, science – pitching them both toward the US in 1937." Huxley lived in the U.S., mainly southern California, until his death, and for a time in Taos, New Mexico, where he wrote Ends and Means (1937). The book contains tracts on war, inequality, religion and ethics.
Heard introduced Huxley to Vedanta (Upanishad-centered philosophy), meditation, and vegetarianism through the principle of ahimsa. In 1938, Huxley befriended Jiddu Krishnamurti, whose teachings he greatly admired. Huxley and Krishnamurti entered into an enduring exchange (sometimes edging on debate) over many years, with Krishnamurti representing the more rarefied, detached, ivory-tower perspective and Huxley, with his pragmatic concerns, the more socially and historically informed position. Huxley wrote a foreword to Krishnamurti's quintessential statement, The First and Last Freedom (1954).
Huxley became a Vedantist in the group formed around Hindu Swami Prabhavananda, and subsequently introduced Christopher Isherwood to the circle. Not long afterwards, Huxley wrote his book on widely held spiritual values and ideas, The Perennial Philosophy, which discussed the teachings of renowned mystics of the world.
Huxley became a close friend of Remsen Bird, president of Occidental College. He spent much time at the college in the Eagle Rock neighbourhood of Los Angeles. The college appears as "Tarzana College" in his satirical novel After Many a Summer (1939). The novel won Huxley a British literary award, the 1939 James Tait Black Memorial Prize for fiction. Huxley also incorporated Bird into the novel.
During this period, Huxley earned a substantial income as a Hollywood screenwriter; Christopher Isherwood, in his autobiography My Guru and His Disciple, states that Huxley earned more than $3,000 per week (approximately $50,000 in 2020 dollars) as a screenwriter, and that he used much of it to transport Jewish and left-wing writer and artist refugees from Hitler's Germany to the US. In March 1938, Huxley's friend Anita Loos, a novelist and screenwriter, put him in touch with Metro-Goldwyn-Mayer (MGM), which hired him for Madame Curie which was originally to star Greta Garbo and be directed by George Cukor. (Eventually, the film was completed by MGM in 1943 with a different director and cast.) Huxley received screen credit for Pride and Prejudice (1940) and was paid for his work on a number of other films, including Jane Eyre (1944). He was commissioned by Walt Disney in 1945 to write a script based on Alice's Adventures in Wonderland and the biography of the story's author, Lewis Carroll. The script was not used, however.
Huxley wrote an introduction to the posthumous publication of J. D. Unwin's 1940 book Hopousia or The Sexual and Economic Foundations of a New Society.
On 21 October 1949, Huxley wrote to George Orwell, author of Nineteen Eighty-Four, congratulating him on "how fine and how profoundly important the book is". In his letter, he predicted:
In 1953, Huxley and Maria applied for United States citizenship and presented themselves for examination. When Huxley refused to bear arms for the U.S. and would not state that his objections were based on religious ideals, the only excuse allowed under the McCarran Act, the judge had to adjourn the proceedings. He withdrew his application. Nevertheless, he remained in the U.S. In 1959, Huxley turned down an offer to be made a Knight Bachelor by the Macmillan government without giving a reason; his brother Julian had been knighted in 1958, while his brother Andrew would be knighted in 1974.
In the fall semester of 1960 Huxley was invited by Professor Huston Smith to be the Carnegie Visiting professor of humanities at the Massachusetts Institute of Technology (MIT). As part of the MIT centennial program of events organised by the Department of Humanities, Huxley presented a series of lectures titled, "What a Piece of Work is a Man" which concerned history, language, and art.
Robert S. de Ropp (scientist, humanitarian, and author), who had spent time with Huxley in England in the 1930s, connected with him again in the U.S. in the early 1960s and wrote that "the enormous intellect, the beautifully modulated voice, the gentle objectivity, all were unchanged. He was one of the most highly civilized human beings I had ever met."
Late-in-life perspectives
Biographer Harold H. Watts wrote that Huxley's writings in the "final and extended period of his life" are "the work of a man who is meditating on the central problems of many modern men". Huxley had deeply felt apprehensions about the future the developed world might make for itself. From these, he made some warnings in his writings and talks. In a 1958 televised interview conducted by journalist Mike Wallace, Huxley outlined several major concerns: the difficulties and dangers of world overpopulation; the tendency towards distinctly hierarchical social organisation; the crucial importance of evaluating the use of technology in mass societies susceptible to persuasion; the tendency to promote modern politicians to a naive public as well-marketed commodities. In a December 1962 letter to brother Julian, summarizing a paper he had presented in Santa Barbara, he wrote, "What I said was that if we didn't pretty quickly start thinking of human problems in ecological terms rather than in terms of power politics we should very soon be in a bad way."
Huxley's engagement with Eastern wisdom traditions was entirely compatible with a strong appreciation of modern science. Biographer Milton Birnbaum wrote that Huxley "ended by embracing both science and Eastern religion". In his last book, Literature and Science, Huxley wrote that "The ethical and philosophical implications of modern science are more Buddhist than Christian...." In "A Philosopher's Visionary Prediction", published one month before he died, Huxley endorsed training in general semantics and "the nonverbal world of culturally uncontaminated consciousness", writing that "We must learn how to be mentally silent, we must cultivate the art of pure receptivity.... [T]he individual must learn to decondition himself, must be able to cut holes in the fence of verbalized symbols that hems him in."
Association with Vedanta
Beginning in 1939 and continuing until his death in 1963, Huxley had an extensive association with the Vedanta Society of Southern California, founded and headed by Swami Prabhavananda. Together with Gerald Heard, Christopher Isherwood and other followers, he was initiated by the Swami and was taught meditation and spiritual practices.
In 1944, Huxley wrote the introduction to the Bhagavad Gita – The Song of God, translated by Swami Prabhavananda and Christopher Isherwood, which was published by the Vedanta Society of Southern California.
From 1941 until 1960, Huxley contributed 48 articles to Vedanta and the West, published by the society. He also served on the editorial board with Isherwood, Heard, and playwright John Van Druten from 1951 through 1962.
Huxley also occasionally lectured at the Hollywood and Santa Barbara Vedanta temples. Two of those lectures have been released on CD: Knowledge and Understanding and Who Are We? from 1955. Nonetheless, Huxley's agnosticism, together with his speculative propensity, made it difficult for him to fully embrace any form of institutionalised religion.
Psychedelic drug use and mystical experiences
In early 1953, Huxley had his first experience with the psychedelic drug mescaline. Huxley had initiated a correspondence with Doctor Humphry Osmond, a British psychiatrist then employed in a Canadian institution, and eventually asked him to supply a dose of mescaline; Osmond obliged and supervised Huxley's session in southern California. After the publication of The Doors of Perception, in which he recounted this experience, Huxley and Swami Prabhavananda disagreed about the meaning and importance of the psychedelic drug experience, which may have caused the relationship to cool, but Huxley continued to write articles for the society's journal, lecture at the temple, and attend social functions. Huxley later had an experience on mescaline that he considered more profound than those detailed in The Doors of Perception.
Huxley wrote that "The mystical experience is doubly valuable; it is valuable because it gives the experiencer a better understanding of himself and the world and because it may help him to lead a less self-centered and more creative life."
Having tried LSD in the 1950s, he became an advisor to Timothy Leary and Richard Alpert in their early-1960s research work with psychedelic drugs at Harvard. Personality differences led Huxley to distance himself from Leary, when Huxley grew concerned that Leary had become too keen on promoting the drugs rather indiscriminately, even playing the rebel with a fondness for publicity.
Eyesight
Differing accounts exist about the details of the quality of Huxley's eyesight at specific points in his life. Circa 1939, Huxley encountered the Bates method, in which he was instructed by Margaret Darst Corbett. In 1940, Huxley relocated from Hollywood to a ranchito in the high desert hamlet of Llano, California, in northern Los Angeles County. Huxley then said that his sight improved dramatically with the Bates method and the extreme and pure natural lighting of the southwestern American desert. He reported that, for the first time in more than 25 years, he was able to read without glasses and without strain. He even tried driving a car along the dirt road beside the ranch. He wrote a book about his experiences with the Bates method, The Art of Seeing, which was published in 1942 (U.S.), 1943 (UK). The book contained some generally disputed theories, and its publication created a growing degree of popular controversy about Huxley's eyesight.
It was, and is, widely believed that Huxley was nearly blind since the illness in his teens, despite the partial recovery that had enabled him to study at Oxford. For example, some ten years after publication of The Art of Seeing, in 1952, Bennett Cerf was present when Huxley spoke at a Hollywood banquet, wearing no glasses and apparently reading his paper from the lectern without difficulty:
Brazilian author João Ubaldo Ribeiro, who as a young journalist spent several evenings in the Huxleys' company in the late 1950s, wrote that Huxley had said to him, with a wry smile: "I can hardly see at all. And I don't give a damn, really."
On the other hand, Huxley's second wife Laura later emphasised in her biographical account, This Timeless Moment: "One of the great achievements of his life: that of having regained his sight." After revealing a letter she wrote to the Los Angeles Times disclaiming the label of Huxley as a "poor fellow who can hardly see" by Walter C. Alvarez, she tempered her statement: Laura Huxley proceeded to elaborate a few nuances of inconsistency peculiar to Huxley's vision. Her account, in this respect, agrees with the following sample of Huxley's own words from The Art of Seeing: Nevertheless, the topic of Huxley's eyesight has continued to endure similar, significant controversy.
American popular science author Steven Johnson, in his book Mind Wide Open, quotes Huxley about his difficulties with visual encoding:
Personal life
Huxley married on 10 July 1919 Maria Nys (10 September 1899 – 12 February 1955), a Belgian epidemiologist from Bellem, a village near Aalter, he met at Garsington, Oxfordshire, in 1919. They had one child, Matthew Huxley (19 April 1920 – 10 February 2005), who had a career as an author, anthropologist, and prominent epidemiologist. In 1955, Maria Huxley died of cancer.
In 1956, Huxley married Laura Archera (1911–2007), also an author, as well as a violinist and psychotherapist. She wrote This Timeless Moment, a biography of Huxley. She told the story of their marriage through Mary Ann Braubach's 2010 documentary, Huxley on Huxley.
Huxley was diagnosed with laryngeal cancer in 1960; in the years that followed, with his health deteriorating, he wrote the utopian novel Island, and gave lectures on "Human Potentialities" both at the UCSF Medical Center and at the Esalen Institute. These lectures were fundamental to the beginning of the Human Potential Movement.
Huxley was a close friend of Jiddu Krishnamurti and Rosalind Rajagopal, and was involved in the creation of the Happy Valley School, now Besant Hill School, of Happy Valley, in Ojai, California.
The most substantial collection of Huxley's few remaining papers, following the destruction of most in the 1961 Bel Air Fire, is at the Library of the University of California, Los Angeles. Some are also at the Stanford University Libraries.
On 9 April 1962 Huxley was informed he was elected Companion of Literature by the Royal Society of Literature, the senior literary organisation in Britain, and he accepted the title via letter on 28 April 1962. The correspondence between Huxley and the society is kept at the Cambridge University Library. The society invited Huxley to appear at a banquet and give a lecture at Somerset House, London, in June 1963. Huxley wrote a draft of the speech he intended to give at the society; however, his deteriorating health meant he was not able to attend.
Death
On his deathbed, unable to speak owing to advanced laryngeal cancer, Huxley made a written request to his wife Laura for "LSD, 100 μg, intramuscular." According to her account of his death in This Timeless Moment, she obliged with an injection at 11:20 a.m. and a second dose an hour later; Huxley died aged 69, at 5:20 p.m. PST on 22 November 1963.
Media coverage of Huxley's death, along with that of fellow British author C. S. Lewis, was overshadowed by the assassination of John F. Kennedy on the same day, less than seven hours before Huxley's death. In a 2009 article for New York magazine titled "The Eclipsed Celebrity Death Club", Christopher Bonanos wrote:
This coincidence served as the basis for Peter Kreeft's book Between Heaven and Hell: A Dialog Somewhere Beyond Death with John F. Kennedy, C. S. Lewis, & Aldous Huxley, which imagines a conversation among the three men taking place in Purgatory following their deaths.
Huxley's memorial service took place in London in December 1963; it was led by his elder brother Julian. On 27 October 1971, his ashes were interred in the family grave at the Watts Cemetery, home of the Watts Mortuary Chapel in Compton, Guildford, Surrey, England.
Huxley had been a long-time friend of Russian composer Igor Stravinsky, who dedicated his last orchestral composition to Huxley. What became Variations: Aldous Huxley in memoriam was begun in July 1963, completed in October 1964, and premiered by the Chicago Symphony Orchestra on 17 April 1965.
Awards
1939: James Tait Black Memorial Prize
1959: American Academy of Arts and Letters Award of Merit .
1962: Companion of Literature
Commemoration
In 2021, Huxley was one of six British writers commemorated on a series of UK postage stamps issued by Royal Mail to celebrate British science fiction. One classic science fiction novel from each author was depicted, with Brave New World chosen to represent Huxley.
Publications and adaptations
See also
List of peace activists
References
Sources
. Reprinted in Perspectives on Schoenberg and Stravinsky, revised edition, edited by Benjamin Boretz and Edward T. Cone. New York: W. W. Norton, 1972.
Further reading
External links
Aldous Huxley full interview 1958: The Problems of Survival and Freedom in America
Portraits at the National Portrait Gallery
"Aldous Huxley: The Gravity of Light", a film essay by Oliver Hockenhull
BBC discussion programme In our time: "Brave New World". Huxley and the novel. 9 April 2009. (Audio, 45 minutes)
BBC In their own words series. 12 October 1958 (video, 12 mins)
"The Ultimate Revolution" (talk at UC Berkeley, 20 March 1962)
Huxley interviewed on The Mike Wallace Interview 18 May 1958 (video)
Centre for Huxley Research at the University of Münster
Aldous Huxley Papers at University of California, Los Angeles Library Special Collections
Aldous Huxley Collection at the Harry Ransom Center, University of Texas at Austin
Aldous Huxley Centre Zurich - World's largest exhibition of Huxley's works.
Online editions
1894 births
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20th-century English novelists
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Alumni of Balliol College, Oxford
Anti-consumerists
Bates method
English emigrants to the United States
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Burials in Surrey
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20th-century English philosophers
Lost Generation writers |
630 | https://en.wikipedia.org/wiki/Ada | Ada | Ada may refer to:
Arts and entertainment
Ada or Ardor: A Family Chronicle, a novel by Vladimir Nabokov
Film and television
Ada TV, a television channel in Northern Cyprus
Ada (1961 film), a 1961 film by Daniel Mann
Ada (2019 film), a short biopic about Ada Lovelace
Ada... A Way of Life, a 2008 Bollywood musical by Tanvir Ahmed
Ada (dog actor), a dog that played Colin on the sitcom Spaced
Ada, a character in 1991 movie Armour of God II: Operation Condor
Places
Africa
Ada Foah, a town in Ghana
Ada (Ghana parliament constituency)
Ada, Osun, a town in Nigeria
Asia
Ada, Urmia, a village in West Azerbaijan Province, Iran
Ada, Karaman, a village in Karaman Province, Turkey
Europe
Ada, Bosnia and Herzegovina, a village
Ada, Croatia, a village
Ada, Serbia, a town and municipality
Ada Ciganlija or Ada, a river island artificially turned into a peninsula in Belgrade, Serbia
United States
Ada, Alabama, an unincorporated community
Ada County, Idaho
Ada, Kansas, an unincorporated community
Ada Township, Michigan
Ada, Minnesota, a city
Ada Township, Dickey County, North Dakota
Ada, Ohio, a village
Ada, Oklahoma, a city
Ada, Oregon, an unincorporated community
Ada Township, Perkins County, South Dakota
Ada, West Virginia, an unincorporated community
Ada, Wisconsin, an unincorporated community
Mount Ada, a mountain in Alaska
Elsewhere
Ada River (disambiguation), various rivers
523 Ada, an asteroid
Science and technology
List of storms named Ada
Ada, the cryptocurrency of the Cardano blockchain platform
Biology
Ada (plant), a genus of orchids
Adenosine deaminase, an enzyme involved in purine metabolism
Ada (protein), an enzyme induced by treatment of bacterial cells
Computing
Ada (programming language), programming language based on Pascal
Ada (computer virus)
Schools
Ada, the National College for Digital Skills, a further education college in Tottenham Hale, London
Ada High School (Ohio), US
Ada Independent School District, Oklahoma, US
Transportation
Ada Air, a regional airline based in Tirana, Albania
Francisco C. Ada Airport, Saipan Island, Northern Mariana Islands
, a cargo vessel built for the London and South Western Railway
Ada (ship), a wooden ketch, wrecked near Newcastle, New South Wales, Australia
Ada-class corvette, a class of anti-submarine corvettes developed by Turkey
People
Ada (name), a feminine given name and a surname, including a list of people and fictional characters
Ada Lovelace (1815–1852), computer scientist sometimes regarded as the first computer programmer
Ada of Caria (fl. 377 – 326 BCE), satrap of ancient Caria and adoptive mother of Alexander the Great
Other uses
Ada (food), a traditional Kerala delicacy
Ada Bridge, Belgrade, Serbia
Dangme language (ISO 639-2 and 639-3 code: ada), spoken in Ghana
Ada Health, a German medical technology company
See also
ADA (disambiguation)
Ada regulon, an Escherichia coli adaptive response protein
Adah (disambiguation)
Adha (disambiguation)
Ada'a, a woreda in the Oromia Region of Ethiopia
Ade (disambiguation)
USS Little Ada, a steamer captured by the Union Navy during the American Civil War |
632 | https://en.wikipedia.org/wiki/Aberdeen%20%28disambiguation%29 | Aberdeen (disambiguation) | Aberdeen is a city in Scotland.
Aberdeen may also refer to:
Places
Africa
Aberdeen, Sierra Leone
Aberdeen, Eastern Cape, South Africa
Asia
Hong Kong
Aberdeen, Hong Kong, an area and town on southwest Hong Kong Island
Aberdeen Channel, a channel between Ap Lei Chau (Aberdeen Island) and Nam Long Shan on the Hong Kong Island in Hong Kong
Aberdeen Country Park, a country park in Hong Kong Island
Aberdeen floating village, at Aberdeen Harbour, containing approximately 600 junks, which house an estimated 6,000 people
Aberdeen Harbour, a harbour between Aberdeen, Hong Kong and Ap Lei Chau (Aberdeen Island)
Aberdeen Tunnel, a tunnel in Hong Kong Island
Aberdeen Tunnel Underground Laboratory, an underground particle physics laboratory in Hong Kong Island
Ap Lei Chau or Aberdeen Island, an island of Hong Kong
Aberdeen (Hong Kong constituency), a constituency of Southern District Council
India
Aberdeen Bazaar, a shopping centre in Port Blair, South Andaman Island
Sri Lanka
Aberdeen Falls, a waterfall in Sri Lanka
Australia
Aberdeen, New South Wales
Aberdeen, South Australia, one of the early townships that merged in 1940 to create the town of Burra
Aberdeen, Tasmania, a suburb of the City of Devonport
Caribbean
Aberdeen, Jamaica, a town in Saint Elizabeth, Jamaica
Europe
Aberdeen (Parliament of Scotland constituency)
Aberdeen (UK Parliament constituency) 1832-1885
Aberdeen Burghs (UK Parliament constituency) 1801-1832
Aberdeen Central (Scottish Parliament constituency)
Aberdeen Central (UK Parliament constituency)
Aberdeen Donside (Scottish Parliament constituency)
County of Aberdeen, a historic county of Scotland whose county town was Aberdeen
Old Aberdeen, a part of the city of Aberdeen in Scotland
North America
Canada
Aberdeen, community in the township of Champlain, Prescott and Russell County, Ontario
Aberdeen, Abbotsford, a neighbourhood in the City of Abbotsford, British Columbia
Aberdeen Centre, a shopping mall in Richmond, British Columbia
Aberdeen, Grey County, Ontario
Aberdeen, Kamloops, an area in the City of Kamloops, British Columbia
Aberdeen Lake (Nunavut), a lake in Kivalliq Region, Nunavut, Canada
Aberdeen, Nova Scotia, part of the Municipality of Inverness County, Nova Scotia
Aberdeen Parish, New Brunswick
Rural Municipality of Aberdeen No. 373, Saskatchewan
Aberdeen, Saskatchewan
Aberdeen Bay, a bay between southern Baffin Island and north-eastern Hector Island in the Nunavut territory
Aberdeen Township, Quebec, until 1960 part of Sheen-Esher-Aberdeen-et-Malakoff, now part of Rapides-des-Joachims, Quebec
Aberdeen River, a tributary of rivière aux Castors Noirs in Mauricie, Québec
New Aberdeen, Nova Scotia
United States
Aberdeen, Arkansas
Aberdeen, Colorado
Aberdeen, Florida
Aberdeen, Georgia
Aberdeen, Idaho
Aberdeen, Ohio County, Indiana
Aberdeen, Porter County, Indiana
Aberdeen, Kentucky
Aberdeen, Maryland
Aberdeen Proving Ground, a United States Army facility located near Aberdeen, Maryland
Aberdeen, Massachusetts, a neighborhood of Brighton, Boston
Aberdeen, Mississippi
Aberdeen Lake (Mississippi), a lake in northeast Mississippi on the Tennessee-Tombigbee Waterway, close to Aberdeen, Mississippi
Aberdeen Township, New Jersey
Aberdeen, North Carolina
Aberdeen Historic District (Aberdeen, North Carolina)
Aberdeen, Ohio
Aberdeen, South Dakota
Aberdeen Historic District (Aberdeen, South Dakota)
Aberdeen, Texas
Aberdeen (Disputanta, Virginia)
Aberdeen Gardens (Hampton, Virginia)
Aberdeen, Washington
Aberdeen Gardens, Washington
Aberdeen, West Virginia
See also
New Aberdeen (disambiguation)
Aberdeen City Council, the local authority body in the city
Arts and entertainment
Aberdeen (2000 film), a 2000 Norwegian-British film
Aberdeen (2014 film), a 2014 Hong Kong film
Aberdeen (band), an American rock band
Aberdeen (song), by Cage The Elephant
Businesses and organisations
Companies
Abrdn, formerly Standard Life Aberdeen
Aberdeen Asset Management
Education
Aberdeen Business School, Robert Gordon University, Aberdeen, Scotland
Aberdeen College, Aberdeen, Scotland
Aberdeen Grammar School, Aberdeen, Scotland
Aberdeen Hall, a university-preparatory school in Kelowna, British Columbia, Canada
Aberdeen High School (disambiguation)
University of Aberdeen, Aberdeen, Scotland
Sports
Aberdeen F.C., a Scottish professional football team
Aberdeen F.C. Women
Aberdeen GSFP RFC, an amateur rugby union club in Aberdeen, Scotland
Aberdeen IronBirds, a Minor League Baseball team in Aberdeen, Maryland, U.S.
Aberdeen L.F.C., a women's football team affiliated with Aberdeen F.C.
Transportation
Aberdeen Airport (disambiguation)
Aberdeen station (disambiguation)
Aberdeen Line, a British shipping company founded in 1825
Aberdeen (ship), the name of several ships
See also
Aberdeen Act
Aberdeen Angus, a Scottish breed of small beef cattle
Aberdeen Central (disambiguation)
Aberdeen Gardens (disambiguation)
Aberdeen Historic District (disambiguation)
Aberdeen Hospital (disambiguation)
Aberdeen Quarry, a granite quarry in Colorado
Battle of Aberdeen (disambiguation)
Diocese of Aberdeen and Orkney, one of the seven dioceses of the Scottish Episcopal Church
Etymology of Aberdeen
Marquess of Aberdeen and Temair, a title in the Peerage of the United Kingdom |
634 | https://en.wikipedia.org/wiki/Analysis%20of%20variance | Analysis of variance | Analysis of variance (ANOVA) is a collection of statistical models and their associated estimation procedures (such as the "variation" among and between groups) used to analyze the differences among means. ANOVA was developed by the statistician Ronald Fisher. ANOVA is based on the law of total variance, where the observed variance in a particular variable is partitioned into components attributable to different sources of variation. In its simplest form, ANOVA provides a statistical test of whether two or more population means are equal, and therefore generalizes the t-test beyond two means. In other words, the ANOVA is used to test the difference between two or more means.
History
While the analysis of variance reached fruition in the 20th century, antecedents extend centuries into the past according to Stigler. These include hypothesis testing, the partitioning of sums of squares, experimental techniques and the additive model. Laplace was performing hypothesis testing in the 1770s. Around 1800, Laplace and Gauss developed the least-squares method for combining observations, which improved upon methods then used in astronomy and geodesy. It also initiated much study of the contributions to sums of squares. Laplace knew how to estimate a variance from a residual (rather than a total) sum of squares. By 1827, Laplace was using least squares methods to address ANOVA problems regarding measurements of atmospheric tides. Before 1800, astronomers had isolated observational errors resulting
from reaction times (the "personal equation") and had developed methods of reducing the errors. The experimental methods used in the study of the personal equation were later accepted by the emerging field of psychology which developed strong (full factorial) experimental methods to which randomization and blinding were soon added. An eloquent non-mathematical explanation of the additive effects model was available in 1885.
Ronald Fisher introduced the term variance and proposed its formal analysis in a 1918 article on theoretical population genetics,The Correlation Between Relatives on the Supposition of Mendelian Inheritance. His first application of the analysis of variance to data analysis was published in 1921, Studies in Crop Variation I, This divided the variation of a time series into components representing annual causes and slow deterioration. Fisher's next piece, Studies in Crop Variation II, written with Winifred Mackenzie and published in 1923, studied the variation in yield across plots sown with different varieties and subjected to different fertiliser treatments. Analysis of variance became widely known after being included in Fisher's 1925 book Statistical Methods for Research Workers.
Randomization models were developed by several researchers. The first was published in Polish by Jerzy Neyman in 1923.
Example
The analysis of variance can be used to describe otherwise complex relations among variables. A dog show provides an example. A dog show is not a random sampling of the breed: it is typically limited to dogs that are adult, pure-bred, and exemplary. A histogram of dog weights from a show might plausibly be rather complex, like the yellow-orange distribution shown in the illustrations. Suppose we wanted to predict the weight of a dog based on a certain set of characteristics of each dog. One way to do that is to explain the distribution of weights by dividing the dog population into groups based on those characteristics. A successful grouping will split dogs such that (a) each group has a low variance of dog weights (meaning the group is relatively homogeneous) and (b) the mean of each group is distinct (if two groups have the same mean, then it isn't reasonable to conclude that the groups are, in fact, separate in any meaningful way).
In the illustrations to the right, groups are identified as X1, X2, etc. In the first illustration, the dogs are divided according to the product (interaction) of two binary groupings: young vs old, and short-haired vs long-haired (e.g., group 1 is young, short-haired dogs, group 2 is young, long-haired dogs, etc.). Since the distributions of dog weight within each of the groups (shown in blue) has a relatively large variance, and since the means are very similar across groups, grouping dogs by these characteristics does not produce an effective way to explain the variation in dog weights: knowing which group a dog is in doesn't allow us to predict its weight much better than simply knowing the dog is in a dog show. Thus, this grouping fails to explain the variation in the overall distribution (yellow-orange).
An attempt to explain the weight distribution by grouping dogs as pet vs working breed and less athletic vs more athletic would probably be somewhat more successful (fair fit). The heaviest show dogs are likely to be big, strong, working breeds, while breeds kept as pets tend to be smaller and thus lighter. As shown by the second illustration, the distributions have variances that are considerably smaller than in the first case, and the means are more distinguishable. However, the significant overlap of distributions, for example, means that we cannot distinguish X1 and X2 reliably. Grouping dogs according to a coin flip might produce distributions that look similar.
An attempt to explain weight by breed is likely to produce a very good fit. All Chihuahuas are light and all St Bernards are heavy. The difference in weights between Setters and Pointers does not justify separate breeds. The analysis of variance provides the formal tools to justify these intuitive judgments. A common use of the method is the analysis of experimental data or the development of models. The method has some advantages over correlation: not all of the data must be numeric and one result of the method is a judgment in the confidence in an explanatory relationship.
Classes of models
There are three classes of models used in the analysis of variance, and these are outlined here.
Fixed-effects models
The fixed-effects model (class I) of analysis of variance applies to situations in which the experimenter applies one or more treatments to the subjects of the experiment to see whether the response variable values change. This allows the experimenter to estimate the ranges of response variable values that the treatment would generate in the population as a whole.
Random-effects models
Random-effects model (class II) is used when the treatments are not fixed. This occurs when the various factor levels are sampled from a larger population. Because the levels themselves are random variables, some assumptions and the method of contrasting the treatments (a multi-variable generalization of simple differences) differ from the fixed-effects model.
Mixed-effects models
A mixed-effects model (class III) contains experimental factors of both fixed and random-effects types, with appropriately different interpretations and analysis for the two types.
Example
Teaching experiments could be performed by a college or university department to find a good introductory textbook, with each text considered a treatment. The fixed-effects model would compare a list of candidate texts. The random-effects model would determine whether important differences exist among a list of randomly selected texts. The mixed-effects model would compare the (fixed) incumbent texts to randomly selected alternatives.
Defining fixed and random effects has proven elusive, with multiple competing definitions.
Assumptions
The analysis of variance has been studied from several approaches, the most common of which uses a linear model that relates the response to the treatments and blocks. Note that the model is linear in parameters but may be nonlinear across factor levels. Interpretation is easy when data is balanced across factors but much deeper understanding is needed for unbalanced data.
Textbook analysis using a normal distribution
The analysis of variance can be presented in terms of a linear model, which makes the following assumptions about the probability distribution of the responses:
Independence of observations – this is an assumption of the model that simplifies the statistical analysis.
Normality – the distributions of the residuals are normal.
Equality (or "homogeneity") of variances, called homoscedasticity—the variance of data in groups should be the same.
The separate assumptions of the textbook model imply that the errors are independently, identically, and normally distributed for fixed effects models, that is, that the errors () are independent and
Randomization-based analysis
In a randomized controlled experiment, the treatments are randomly assigned to experimental units, following the experimental protocol. This randomization is objective and declared before the experiment is carried out. The objective random-assignment is used to test the significance of the null hypothesis, following the ideas of C. S. Peirce and Ronald Fisher. This design-based analysis was discussed and developed by Francis J. Anscombe at Rothamsted Experimental Station and by Oscar Kempthorne at Iowa State University. Kempthorne and his students make an assumption of unit treatment additivity, which is discussed in the books of Kempthorne and David R. Cox.
Unit-treatment additivity
In its simplest form, the assumption of unit-treatment additivity states that the observed response from experimental unit when receiving treatment can be written as the sum of the unit's response and the treatment-effect , that is
The assumption of unit-treatment additivity implies that, for every treatment , the th treatment has exactly the same effect on every experiment unit.
The assumption of unit treatment additivity usually cannot be directly falsified, according to Cox and Kempthorne. However, many consequences of treatment-unit additivity can be falsified. For a randomized experiment, the assumption of unit-treatment additivity implies that the variance is constant for all treatments. Therefore, by contraposition, a necessary condition for unit-treatment additivity is that the variance is constant.
The use of unit treatment additivity and randomization is similar to the design-based inference that is standard in finite-population survey sampling.
Derived linear model
Kempthorne uses the randomization-distribution and the assumption of unit treatment additivity to produce a derived linear model, very similar to the textbook model discussed previously. The test statistics of this derived linear model are closely approximated by the test statistics of an appropriate normal linear model, according to approximation theorems and simulation studies. However, there are differences. For example, the randomization-based analysis results in a small but (strictly) negative correlation between the observations. In the randomization-based analysis, there is no assumption of a normal distribution and certainly no assumption of independence. On the contrary, the observations are dependent!
The randomization-based analysis has the disadvantage that its exposition involves tedious algebra and extensive time. Since the randomization-based analysis is complicated and is closely approximated by the approach using a normal linear model, most teachers emphasize the normal linear model approach. Few statisticians object to model-based analysis of balanced randomized experiments.
Statistical models for observational data
However, when applied to data from non-randomized experiments or observational studies, model-based analysis lacks the warrant of randomization. For observational data, the derivation of confidence intervals must use subjective models, as emphasized by Ronald Fisher and his followers. In practice, the estimates of treatment-effects from observational studies generally are often inconsistent. In practice, "statistical models" and observational data are useful for suggesting hypotheses that should be treated very cautiously by the public.
Summary of assumptions
The normal-model based ANOVA analysis assumes the independence, normality, and homogeneity of variances of the residuals. The randomization-based analysis assumes only the homogeneity of the variances of the residuals (as a consequence of unit-treatment additivity) and uses the randomization procedure of the experiment. Both these analyses require homoscedasticity, as an assumption for the normal-model analysis and as a consequence of randomization and additivity for the randomization-based analysis.
However, studies of processes that change variances rather than means (called dispersion effects) have been successfully conducted using ANOVA. There are no necessary assumptions for ANOVA in its full generality, but the F-test used for ANOVA hypothesis testing has assumptions and practical
limitations which are of continuing interest.
Problems which do not satisfy the assumptions of ANOVA can often be transformed to satisfy the assumptions.
The property of unit-treatment additivity is not invariant under a "change of scale", so statisticians often use transformations to achieve unit-treatment additivity. If the response variable is expected to follow a parametric family of probability distributions, then the statistician may specify (in the protocol for the experiment or observational study) that the responses be transformed to stabilize the variance. Also, a statistician may specify that logarithmic transforms be applied to the responses which are believed to follow a multiplicative model.
According to Cauchy's functional equation theorem, the logarithm is the only continuous transformation that transforms real multiplication to addition.
Characteristics
ANOVA is used in the analysis of comparative experiments, those in which only the difference in outcomes is of interest. The statistical significance of the experiment is determined by a ratio of two variances. This ratio is independent of several possible alterations to the experimental observations: Adding a constant to all observations does not alter significance. Multiplying all observations by a constant does not alter significance. So ANOVA statistical significance result is independent of constant bias and scaling errors as well as the units used in expressing observations. In the era of mechanical calculation it was common to subtract a constant from all observations (when equivalent to dropping leading digits) to simplify data entry. This is an example of data coding.
Algorithm
The calculations of ANOVA can be characterized as computing a number of means and variances, dividing two variances and comparing the ratio to a handbook value to determine statistical significance. Calculating a treatment effect is then trivial: "the effect of any treatment is estimated by taking the difference between the mean of the observations which receive the treatment and the general mean".
Partitioning of the sum of squares
ANOVA uses traditional standardized terminology. The definitional equation of sample variance is , where the divisor is called the degrees of freedom (DF), the summation is called
the sum of squares (SS), the result is called the mean square (MS) and the squared terms are deviations from the sample mean. ANOVA estimates 3 sample variances: a total variance based on all the observation deviations from the grand mean, an error variance based on all the observation deviations from their appropriate treatment means, and a treatment variance. The treatment variance is based on the deviations of treatment means from the grand mean, the result being multiplied by the number of observations in each treatment to account for the difference between the variance of observations and the variance of means.
The fundamental technique is a partitioning of the total sum of squares SS into components related to the effects used in the model. For example, the model for a simplified ANOVA with one type of treatment at different levels.
The number of degrees of freedom DF can be partitioned in a similar way: one of these components (that for error) specifies a chi-squared distribution which describes the associated sum of squares, while the same is true for "treatments" if there is no treatment effect.
The F-test
The F-test is used for comparing the factors of the total deviation. For example, in one-way, or single-factor ANOVA, statistical significance is tested for by comparing the F test statistic
where MS is mean square, is the number of treatments and is the total number of cases
to the F-distribution with being the numerator degrees of freedom and the denominator degrees of freedom. Using the F-distribution is a natural candidate because the test statistic is the ratio of two scaled sums of squares each of which follows a scaled chi-squared distribution.
The expected value of F is (where is the treatment sample size) which is 1 for no treatment effect. As values of F increase above 1, the evidence is increasingly inconsistent with the null hypothesis. Two apparent experimental methods of increasing F are increasing the sample size and reducing the error variance by tight experimental controls.
There are two methods of concluding the ANOVA hypothesis test, both of which produce the same result:
The textbook method is to compare the observed value of F with the critical value of F determined from tables. The critical value of F is a function of the degrees of freedom of the numerator and the denominator and the significance level (α). If F ≥ FCritical, the null hypothesis is rejected.
The computer method calculates the probability (p-value) of a value of F greater than or equal to the observed value. The null hypothesis is rejected if this probability is less than or equal to the significance level (α).
The ANOVA F-test is known to be nearly optimal in the sense of minimizing false negative errors for a fixed rate of false positive errors (i.e. maximizing power for a fixed significance level). For example, to test the hypothesis that various medical treatments have exactly the same effect, the F-test's p-values closely approximate the permutation test's p-values: The approximation is particularly close when the design is balanced. Such permutation tests characterize tests with maximum power against all alternative hypotheses, as observed by Rosenbaum. The ANOVA F-test (of the null-hypothesis that all treatments have exactly the same effect) is recommended as a practical test, because of its robustness against many alternative distributions.
Extended algorithm
ANOVA consists of separable parts; partitioning sources of variance and hypothesis testing can be used individually. ANOVA is used to support other statistical tools. Regression is first used to fit more complex models to data, then ANOVA is used to compare models with the objective of selecting simple(r) models that adequately describe the data. "Such models could be fit without any reference to ANOVA, but ANOVA tools could then be used to make some sense of the fitted models, and to test hypotheses about batches of coefficients." "[W]e think of the analysis of variance as a way of understanding and structuring multilevel models—not as an alternative to regression but as a tool for summarizing complex high-dimensional inferences ..."
For a single factor
The simplest experiment suitable for ANOVA analysis is the completely randomized experiment with a single factor. More complex experiments with a single factor involve constraints on randomization and include completely randomized blocks and Latin squares (and variants: Graeco-Latin squares, etc.). The more complex experiments share many of the complexities of multiple factors. A relatively complete discussion of the analysis (models, data summaries, ANOVA table) of the completely randomized experiment is available.
There are some alternatives to conventional one-way analysis of variance, e.g.: Welch's heteroscedastic F test, Welch's heteroscedastic F test with trimmed means and Winsorized variances, Brown-Forsythe test, Alexander-Govern test, James second order test and Kruskal-Wallis test, available in onewaytests R
It is useful to represent each data point in the following form, called a statistical model:
where
i = 1, 2, 3, ..., R
j = 1, 2, 3, ..., C
μ = overall average (mean)
τj = differential effect (response) associated with the j level of X; this assumes that overall the values of τj add to zero (that is, )
εij = noise or error associated with the particular ij data value
That is, we envision an additive model that says every data point can be represented by summing three quantities: the true mean, averaged over all factor levels being investigated, plus an incremental component associated with the particular column (factor level), plus a final component associated with everything else affecting that specific data value.
For multiple factors
ANOVA generalizes to the study of the effects of multiple factors. When the experiment includes observations at all combinations of levels of each factor, it is termed factorial. Factorial experiments are more efficient than a series of single factor experiments and the efficiency grows as the number of factors increases. Consequently, factorial designs are heavily used.
The use of ANOVA to study the effects of multiple factors has a complication. In a 3-way ANOVA with factors x, y and z, the ANOVA model includes terms for the main effects (x, y, z) and terms for interactions (xy, xz, yz, xyz).
All terms require hypothesis tests. The proliferation of interaction terms increases the risk that some hypothesis test will produce a false positive by chance. Fortunately, experience says that high order interactions are rare.
The ability to detect interactions is a major advantage of multiple factor ANOVA. Testing one factor at a time hides interactions, but produces apparently inconsistent experimental results.
Caution is advised when encountering interactions; Test interaction terms first and expand the analysis beyond ANOVA if interactions are found. Texts vary in their recommendations regarding the continuation of the ANOVA procedure after encountering an interaction. Interactions complicate the interpretation of experimental data. Neither the calculations of significance nor the estimated treatment effects can be taken at face value. "A significant interaction will often mask the significance of main effects." Graphical methods are recommended to enhance understanding. Regression is often useful. A lengthy discussion of interactions is available in Cox (1958). Some interactions can be removed (by transformations) while others cannot.
A variety of techniques are used with multiple factor ANOVA to reduce expense. One technique used in factorial designs is to minimize replication (possibly no replication with support of analytical trickery) and to combine groups when effects are found to be statistically (or practically) insignificant. An experiment with many insignificant factors may collapse into one with a few factors supported by many replications.
Associated analysis
Some analysis is required in support of the design of the experiment while other analysis is performed after changes in the factors are formally found to produce statistically significant changes in the responses. Because experimentation is iterative, the results of one experiment alter plans for following experiments.
Preparatory analysis
The number of experimental units
In the design of an experiment, the number of experimental units is planned to satisfy the goals of the experiment. Experimentation is often sequential.
Early experiments are often designed to provide mean-unbiased estimates of treatment effects and of experimental error. Later experiments are often designed to test a hypothesis that a treatment effect has an important magnitude; in this case, the number of experimental units is chosen so that the experiment is within budget and has adequate power, among other goals.
Reporting sample size analysis is generally required in psychology. "Provide information on sample size and the process that led to sample size decisions." The analysis, which is written in the experimental protocol before the experiment is conducted, is examined in grant applications and administrative review boards.
Besides the power analysis, there are less formal methods for selecting the number of experimental units. These include graphical methods based on limiting the probability of false negative errors, graphical methods based on an expected variation increase (above the residuals) and methods based on achieving a desired confidence interval.
Power analysis
Power analysis is often applied in the context of ANOVA in order to assess the probability of successfully rejecting the null hypothesis if we assume a certain ANOVA design, effect size in the population, sample size and significance level. Power analysis can assist in study design by determining what sample size would be required in order to have a reasonable chance of rejecting the null hypothesis when the alternative hypothesis is true.
Effect size
Several standardized measures of effect have been proposed for ANOVA to summarize the strength of the association between a predictor(s) and the dependent variable or the overall standardized difference of the complete model. Standardized effect-size estimates facilitate comparison of findings across studies and disciplines. However, while standardized effect sizes are commonly used in much of the professional literature, a non-standardized measure of effect size that has immediately "meaningful" units may be preferable for reporting purposes.
Model confirmation
Sometimes tests are conducted to determine whether the assumptions of ANOVA appear to be violated. Residuals are examined or analyzed to confirm homoscedasticity and gross normality. Residuals should have the appearance of (zero mean normal distribution) noise when plotted as a function of anything including time and
modeled data values. Trends hint at interactions among factors or among observations.
Follow-up tests
A statistically significant effect in ANOVA is often followed by additional tests. This can be done in order to assess which groups are different from which other groups or to test various other focused hypotheses. Follow-up tests are often distinguished in terms of whether they are "planned" (a priori) or "post hoc." Planned tests are determined before looking at the data, and post hoc tests are conceived only after looking at the data (though the term "post hoc" is inconsistently used).
The follow-up tests may be "simple" pairwise comparisons of individual group means or may be "compound" comparisons (e.g., comparing the mean pooling across groups A, B and C to the mean of group D). Comparisons can also look at tests of trend, such as linear and quadratic relationships, when the independent variable involves ordered levels. Often the follow-up tests incorporate a method of adjusting for the multiple comparisons problem.
Follow-up tests to identify which specific groups, variables, or factors have statistically different means include the Tukey's range test, and Duncan's new multiple range test. In turn, these tests are often followed with a Compact Letter Display (CLD) methodology in order to render the output of the mentioned tests more transparent to a non-statistician audience.
Study designs
There are several types of ANOVA. Many statisticians base ANOVA on the design of the experiment, especially on the protocol that specifies the random assignment of treatments to subjects; the protocol's description of the assignment mechanism should include a specification of the structure of the treatments and of any blocking. It is also common to apply ANOVA to observational data using an appropriate statistical model.
Some popular designs use the following types of ANOVA:
One-way ANOVA is used to test for differences among two or more independent groups (means), e.g. different levels of urea application in a crop, or different levels of antibiotic action on several different bacterial species, or different levels of effect of some medicine on groups of patients. However, should these groups not be independent, and there is an order in the groups (such as mild, moderate and severe disease), or in the dose of a drug (such as 5 mg/mL, 10 mg/mL, 20 mg/mL) given to the same group of patients, then a linear trend estimation should be used. Typically, however, the one-way ANOVA is used to test for differences among at least three groups, since the two-group case can be covered by a t-test. When there are only two means to compare, the t-test and the ANOVA F-test are equivalent; the relation between ANOVA and t is given by .
Factorial ANOVA is used when there is more than one factor.
Repeated measures ANOVA is used when the same subjects are used for each factor (e.g., in a longitudinal study).
Multivariate analysis of variance (MANOVA) is used when there is more than one response variable.
Cautions
Balanced experiments (those with an equal sample size for each treatment) are relatively easy to interpret; unbalanced experiments offer more complexity. For single-factor (one-way) ANOVA, the adjustment for unbalanced data is easy, but the unbalanced analysis lacks both robustness and power. For more complex designs the lack of balance leads to further complications. "The orthogonality property of main effects and interactions present in balanced data does not carry over to the unbalanced case. This means that the usual analysis of variance techniques do not apply. Consequently, the analysis of unbalanced factorials is much more difficult than that for balanced designs." In the general case, "The analysis of variance can also be applied to unbalanced data, but then the sums of squares, mean squares, and F-ratios will depend on the order in which the sources of variation are considered."
ANOVA is (in part) a test of statistical significance. The American Psychological Association (and many other organisations) holds the view that simply reporting statistical significance is insufficient and that reporting confidence bounds is preferred.
Generalizations
ANOVA is considered to be a special case of linear regression which in turn is a special case of the general linear model. All consider the observations to be the sum of a model (fit) and a residual (error) to be minimized.
The Kruskal-Wallis test and the Friedman test are nonparametric tests which do not rely on an assumption of normality.
Connection to linear regression
Below we make clear the connection between multi-way ANOVA and linear regression.
Linearly re-order the data so that -th observation is associated with a response and factors where denotes the different factors and is the total number of factors. In one-way ANOVA and in two-way ANOVA . Furthermore, we assume the -th factor has levels, namely . Now, we can one-hot encode the factors into the dimensional vector .
The one-hot encoding function is defined such that the -th entry of is
The vector is the concatenation of all of the above vectors for all . Thus, . In order to obtain a fully general -way interaction ANOVA we must also concatenate every additional interaction term in the vector and then add an intercept term. Let that vector be .
With this notation in place, we now have the exact connection with linear regression. We simply regress response against the vector . However, there is a concern about identifiability. In order to overcome such issues we assume that the sum of the parameters within each set of interactions is equal to zero. From here, one can use F-statistics or other methods to determine the relevance of the individual factors.
Example
We can consider the 2-way interaction example where we assume that the first factor has 2 levels and the second factor has 3 levels.
Define if and if , i.e. is the one-hot encoding of the first factor and is the one-hot encoding of the second factor.
With that,
where the last term is an intercept term. For a more concrete example suppose that
Then,
See also
ANOVA on ranks
ANOVA-simultaneous component analysis
Analysis of covariance (ANCOVA)
Analysis of molecular variance (AMOVA)
Analysis of rhythmic variance (ANORVA)
Expected mean squares
Explained variation
Linear trend estimation
Mixed-design analysis of variance
Multivariate analysis of covariance (MANCOVA)
Permutational analysis of variance
Variance decomposition
Footnotes
Notes
References
Pre-publication chapters are available on-line.
Cohen, Jacob (1988). Statistical power analysis for the behavior sciences (2nd ed.). Routledge
Cox, David R. (1958). Planning of experiments. Reprinted as
Freedman, David A.(2005). Statistical Models: Theory and Practice, Cambridge University Press.
Lehmann, E.L. (1959) Testing Statistical Hypotheses. John Wiley & Sons.
Moore, David S. & McCabe, George P. (2003). Introduction to the Practice of Statistics (4e). W H Freeman & Co.
Rosenbaum, Paul R. (2002). Observational Studies (2nd ed.). New York: Springer-Verlag.
Further reading
External links
SOCR: ANOVA Activity
Examples of all ANOVA and ANCOVA models with up to three treatment factors, including randomized block, split plot, repeated measures, and Latin squares, and their analysis in R (University of Southampton)
NIST/SEMATECH e-Handbook of Statistical Methods, section 7.4.3: "Are the means equal?"
Analysis of variance: Introduction
Design of experiments
Statistical tests
Parametric statistics |
639 | https://en.wikipedia.org/wiki/Alkane | Alkane | In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula . The alkanes range in complexity from the simplest case of methane (), where n = 1 (sometimes called the parent molecule), to arbitrarily large and complex molecules, like pentacontane () or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane ().
The International Union of Pure and Applied Chemistry (IUPAC) defines alkanes as "acyclic branched or unbranched hydrocarbons having the general formula , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms". However, some sources use the term to denote any saturated hydrocarbon, including those that are either monocyclic (i.e. the cycloalkanes) or polycyclic, despite their having a distinct general formula (i.e. cycloalkanes are ).
In an alkane, each carbon atom is sp3-hybridized with 4 sigma bonds (either C–C or C–H), and each hydrogen atom is joined to one of the carbon atoms (in a C–H bond). The longest series of linked carbon atoms in a molecule is known as its carbon skeleton or carbon backbone. The number of carbon atoms may be considered as the size of the alkane.
One group of the higher alkanes are waxes, solids at standard ambient temperature and pressure (SATP), for which the number of carbon atoms in the carbon backbone is greater than about 17.
With their repeated – units, the alkanes constitute a homologous series of organic compounds in which the members differ in molecular mass by multiples of 14.03 u (the total mass of each such methylene-bridge unit, which comprises a single carbon atom of mass 12.01 u and two hydrogen atoms of mass ~1.01 u each).
Methane is produced by methanogenic bacteria and some long-chain alkanes function as pheromones in certain animal species or as protective waxes in plants and fungi. Nevertheless, most alkanes do not have much biological activity. They can be viewed as molecular trees upon which can be hung the more active/reactive functional groups of biological molecules.
The alkanes have two main commercial sources: petroleum (crude oil) and natural gas.
An alkyl group is an alkane-based molecular fragment that bears one open valence for bonding. They are generally abbreviated with the symbol for any organyl group, R, although Alk is sometimes used to specifically symbolize an alkyl group (as opposed to an alkenyl group or aryl group).
Structure and classification
Ordinarily the C-C single bond distance is .
Saturated hydrocarbons can be linear, branched, or cyclic. The third group is sometimes called cycloalkanes. Very complicated structures are possible by combining linear, branch, cyclic alkanes.
Isomerism
Alkanes with more than three carbon atoms can be arranged in various ways, forming structural isomers. The simplest isomer of an alkane is the one in which the carbon atoms are arranged in a single chain with no branches. This isomer is sometimes called the n-isomer (n for "normal", although it is not necessarily the most common). However, the chain of carbon atoms may also be branched at one or more points. The number of possible isomers increases rapidly with the number of carbon atoms. For example, for acyclic alkanes:
C1: methane only
C2: ethane only
C3: propane only
C4: 2 isomers: butane and isobutane
C5: 3 isomers: pentane, isopentane, and neopentane
C6: 5 isomers: hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, and 2,3-dimethylbutane
C7: 9 isomers: heptane, 2-methylhexane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane, 2,2,3-trimethylbutane
C8: 18 isomers: octane, 2-methylheptane, 3-methylheptane, 4-methylheptane, 2,2-dimethylhexane, 2,3-dimethylhexane, 2,4-dimethylhexane, 2,5-dimethylhexane, 3,3-dimethylhexane, 3,4-dimethylhexane, 3-ethylhexane, 2,2,3-trimethylpentane, 2,2,4-trimethylpentane, 2,3,3-trimethylpentane, 2,3,4-trimethylpentane, 3-ethyl-2-methylpentane, 3-ethyl-3-methylpentane, 2,2,3,3-tetramethylbutane
C9: 35 isomers
C10: 75 isomers
C12: 355 isomers
C32: 27,711,253,769 isomers
C60: 22,158,734,535,770,411,074,184 isomers, many of which are not stable
Branched alkanes can be chiral. For example, 3-methylhexane and its higher homologues are chiral due to their stereogenic center at carbon atom number 3. The above list only includes differences of connectivity, not stereochemistry. In addition to the alkane isomers, the chain of carbon atoms may form one or more rings. Such compounds are called cycloalkanes, and are also excluded from the above list because changing the number of rings changes the molecular formula. For example, cyclobutane and methylcyclopropane are isomers of each other (C4H8), but are not isomers of butane (C4H10).
Branched alkanes are more thermodynamically stable than their linear (or less branched) isomers. For example, the highly branched 2,2,3,3-tetramethylbutane is about 1.9 kcal/mol more stable than its linear isomer, n-octane.
Nomenclature
The IUPAC nomenclature (systematic way of naming compounds) for alkanes is based on identifying hydrocarbon chains. Unbranched, saturated hydrocarbon chains are named systematically with a Greek numerical prefix denoting the number of carbons and the suffix "-ane".
In 1866, August Wilhelm von Hofmann suggested systematizing nomenclature by using the whole sequence of vowels a, e, i, o and u to create suffixes -ane, -ene, -ine (or -yne), -one, -une, for the hydrocarbons CnH2n+2, CnH2n, CnH2n−2, CnH2n−4, CnH2n−6. In modern nomenclature, the first three specifically name hydrocarbons with single, double and triple bonds; while "-one" now represents a ketone.
Linear alkanes
Straight-chain alkanes are sometimes indicated by the prefix "n-" or "n-"(for "normal") where a non-linear isomer exists. Although this is not strictly necessary and is not part of the IUPAC naming system, the usage is still common in cases where one wishes to emphasize or distinguish between the straight-chain and branched-chain isomers, e.g., "n-butane" rather than simply "butane" to differentiate it from isobutane. Alternative names for this group used in the petroleum industry are linear paraffins or n-paraffins.
The first eight members of the series (in terms of number of carbon atoms) are named as follows:
methane CH4 – one carbon and 4 hydrogen
ethane C2H6 – two carbon and 6 hydrogen
propane C3H8 – three carbon and 8 hydrogen
butane C4H10 – four carbon and 10 hydrogen
pentane C5H12 – five carbon and 12 hydrogen
hexane C6H14 – six carbon and 14 hydrogen
heptane C7H16 – seven carbons and 16 hydrogen
octane C8H18 – eight carbons and 18 hydrogen
The first four names were derived from methanol, ether, propionic acid and butyric acid. Alkanes with five or more carbon atoms are named by adding the suffix -ane to the appropriate numerical multiplier prefix with elision of any terminal vowel (-a or -o) from the basic numerical term. Hence, pentane, C5H12; hexane, C6H14; heptane, C7H16; octane, C8H18; etc. The numeral prefix is generally Greek; however, alkanes with a carbon atom count ending in nine, for example nonane, use the Latin prefix non-.
Branched alkanes
Simple branched alkanes often have a common name using a prefix to distinguish them from linear alkanes, for example n-pentane, isopentane, and neopentane.
IUPAC naming conventions can be used to produce a systematic name.
The key steps in the naming of more complicated branched alkanes are as follows:
Identify the longest continuous chain of carbon atoms
Name this longest root chain using standard naming rules
Name each side chain by changing the suffix of the name of the alkane from "-ane" to "-yl"
Number the longest continuous chain in order to give the lowest possible numbers for the side-chains
Number and name the side chains before the name of the root chain
If there are multiple side chains of the same type, use prefixes such as "di-" and "tri-" to indicate it as such, and number each one.
Add side chain names in alphabetical (disregarding "di-" etc. prefixes) order in front of the name of the root chain
Saturated cyclic hydrocarbons
Though technically distinct from the alkanes, this class of hydrocarbons is referred to by some as the "cyclic alkanes." As their description implies, they contain one or more rings.
Simple cycloalkanes have a prefix "cyclo-" to distinguish them from alkanes. Cycloalkanes are named as per their acyclic counterparts with respect to the number of carbon atoms in their backbones, e.g., cyclopentane (C5H10) is a cycloalkane with 5 carbon atoms just like pentane (C5H12), but they are joined up in a five-membered ring. In a similar manner, propane and cyclopropane, butane and cyclobutane, etc.
Substituted cycloalkanes are named similarly to substituted alkanes – the cycloalkane ring is stated, and the substituents are according to their position on the ring, with the numbering decided by the Cahn–Ingold–Prelog priority rules.
Trivial/common names
The trivial (non-systematic) name for alkanes is 'paraffins'. Together, alkanes are known as the 'paraffin series'. Trivial names for compounds are usually historical artifacts. They were coined before the development of systematic names, and have been retained due to familiar usage in industry. Cycloalkanes are also called naphthenes.
Branched-chain alkanes are called isoparaffins. "Paraffin" is a general term and often does not distinguish between pure compounds and mixtures of isomers, i.e., compounds of the same chemical formula, e.g., pentane and isopentane.
In IUPAC
The following trivial names are retained in the IUPAC system:
isobutane for 2-methylpropane
isopentane for 2-methylbutane
neopentane for 2,2-dimethylpropane.
Non-IUPAC
Some non-IUPAC trivial names are occasionally used:
cetane, for hexadecane
cerane, for hexacosane
Physical properties
All alkanes are colorless. Alkanes with the lowest molecular weights are gases, those of intermediate molecular weight are liquids, and the heaviest are waxy solids.
Table of alkanes
Boiling point
Alkanes experience intermolecular van der Waals forces. The cumulative effects of these intermolecular forces give rise to greater boiling points of alkanes.
Two factors influence the strength of the van der Waals forces:
the number of electrons surrounding the molecule, which increases with the alkane's molecular weight
the surface area of the molecule
Under standard conditions, from CH4 to C4H10 alkanes are gaseous; from C5H12 to C17H36 they are liquids; and after C18H38 they are solids. As the boiling point of alkanes is primarily determined by weight, it should not be a surprise that the boiling point has an almost linear relationship with the size (molecular weight) of the molecule. As a rule of thumb, the boiling point rises 20–30 °C for each carbon added to the chain; this rule applies to other homologous series.
A straight-chain alkane will have a boiling point higher than a branched-chain alkane due to the greater surface area in contact, and thus greater van der Waals forces, between adjacent molecules. For example, compare isobutane (2-methylpropane) and n-butane (butane), which boil at −12 and 0 °C, and 2,2-dimethylbutane and 2,3-dimethylbutane which boil at 50 and 58 °C, respectively.
On the other hand, cycloalkanes tend to have higher boiling points than their linear counterparts due to the locked conformations of the molecules, which give a plane of intermolecular contact.
Melting points
The melting points of the alkanes follow a similar trend to boiling points for the same reason as outlined above. That is, (all other things being equal) the larger the molecule the higher the melting point. There is one significant difference between boiling points and melting points. Solids have a more rigid and fixed structure than liquids. This rigid structure requires energy to break down. Thus the better put together solid structures will require more energy to break apart. For alkanes, this can be seen from the graph above (i.e., the blue line). The odd-numbered alkanes have a lower trend in melting points than even-numbered alkanes. This is because even-numbered alkanes pack well in the solid phase, forming a well-organized structure which requires more energy to break apart. The odd-numbered alkanes pack less well and so the "looser"-organized solid packing structure requires less energy to break apart. For a visualization of the crystal structures see.
The melting points of branched-chain alkanes can be either higher or lower than those of the corresponding straight-chain alkanes, again depending on the ability of the alkane in question to pack well in the solid phase.
Conductivity and solubility
Alkanes do not conduct electricity in any way, nor are they substantially polarized by an electric field. For this reason, they do not form hydrogen bonds and are insoluble in polar solvents such as water. Since the hydrogen bonds between individual water molecules are aligned away from an alkane molecule, the coexistence of an alkane and water leads to an increase in molecular order (a reduction in entropy). As there is no significant bonding between water molecules and alkane molecules, the second law of thermodynamics suggests that this reduction in entropy should be minimized by minimizing the contact between alkane and water: Alkanes are said to be hydrophobic as they are insoluble in water.
Their solubility in nonpolar solvents is relatively high, a property that is called lipophilicity. Alkanes are, for example, miscible in all proportions among themselves.
The density of the alkanes usually increases with the number of carbon atoms but remains less than that of water. Hence, alkanes form the upper layer in an alkane–water mixture.
Molecular geometry
The molecular structure of the alkanes directly affects their physical and chemical characteristics. It is derived from the electron configuration of carbon, which has four valence electrons. The carbon atoms in alkanes are described as sp3 hybrids; that is to say that, to a good approximation, the valence electrons are in orbitals directed towards the corners of a tetrahedron which are derived from the combination of the 2s orbital and the three 2p orbitals. Geometrically, the angle between the bonds are cos−1(−) ≈ 109.47°. This is exact for the case of methane, while larger alkanes containing a combination of C–H and C–C bonds generally have bonds that are within several degrees of this idealized value.
Bond lengths and bond angles
An alkane has only C–H and C–C single bonds. The former result from the overlap of an sp3 orbital of carbon with the 1s orbital of a hydrogen; the latter by the overlap of two sp3 orbitals on adjacent carbon atoms. The bond lengths amount to 1.09 × 10−10 m for a C–H bond and 1.54 × 10−10 m for a C–C bond.
The spatial arrangement of the bonds is similar to that of the four sp3 orbitals—they are tetrahedrally arranged, with an angle of 109.47° between them. Structural formulae that represent the bonds as being at right angles to one another, while both common and useful, do not accurately depict the geometry.
Conformation
The spatial arrangement of the C-C and C-H bonds are described by the torsion angles of the molecule is known as its conformation. In ethane, the simplest case for studying the conformation of alkanes, there is nearly free rotation about a carbon–carbon single bond. Two limiting conformations are important: eclipsed conformation and staggered conformation. The staggered conformation is 12.6 kJ/mol (3.0 kcal/mol) lower in energy (more stable) than the eclipsed conformation (the least stable). In highly branched alkanes, the bond angle may differ from the optimal value (109.5°) to accommodate bulky groups. Such distortions introduce a tension in the molecule, known as steric hindrance or strain. Strain substantially increases reactivity.
Spectroscopic properties
Spectroscopic signatures for alkanes are obtainable by the major characterization techniques.
Infrared spectroscopy
The C-H stretching mode gives a strong absorptions between 2850 and 2960 cm−1 and weaker bands for the C-C stretching mode absorbs between 800 and 1300 cm−1. The carbon–hydrogen bending modes depend on the nature of the group: methyl groups show bands at 1450 cm−1 and 1375 cm−1, while methylene groups show bands at 1465 cm−1 and 1450 cm−1. Carbon chains with more than four carbon atoms show a weak absorption at around 725 cm−1.
NMR spectroscopy
The proton resonances of alkanes are usually found at δH = 0.5–1.5. The carbon-13 resonances depend on the number of hydrogen atoms attached to the carbon: δC = 8–30 (primary, methyl, –CH3), 15–55 (secondary, methylene, –CH2–), 20–60 (tertiary, methyne, C–H) and quaternary. The carbon-13 resonance of quaternary carbon atoms is characteristically weak, due to the lack of nuclear Overhauser effect and the long relaxation time, and can be missed in weak samples, or samples that have not been run for a sufficiently long time.
Mass spectrometry
Since alkanes have high ionization energies, their electron impact mass spectra show weak currents for their molecular ions. The fragmentation pattern can be difficult to interpret, but in the case of branched chain alkanes, the carbon chain is preferentially cleaved at tertiary or quaternary carbons due to the relative stability of the resulting free radicals. The mass spectra for straight-chain alkanes is illustrated by that for dodecane: the fragment resulting from the loss of a single methyl group (M − 15) is absent, fragments are more intense than the molecular ion and are spaced by intervals of 14 mass units, corresponding to loss of CH2 groups.
Chemical properties
Alkanes are only weakly reactive with most chemical compounds. They only reacts with the strongest of electrophilic reagents by virtue of their strong C–H bonds (~100 kcal/mol) and C–C bonds (~90 kcal/mol). They are also relatively unreactive toward free radicals. This inertness is the source of the term paraffins (with the meaning here of "lacking affinity"). In crude oil the alkane molecules have remained chemically unchanged for millions of years.
Acid-base behavior
The acid dissociation constant (pKa) values of all alkanes are estimated to range from 50 to 70, depending on the extrapolation method, hence they are extremely weak acids that are practically inert to bases (see: carbon acids). They are also extremely weak bases, undergoing no observable protonation in pure sulfuric acid (H0 ~ −12), although superacids that are at least millions of times stronger have been known to protonate them to give hypercoordinate alkanium ions (see: methanium ion). Thus, a mixture of antimony pentafluoride (SbF5) and fluorosulfonic acid (HSO3F), called magic acid, can protonate alkanes.
Reactions with oxygen (combustion reaction)
All alkanes react with oxygen in a combustion reaction, although they become increasingly difficult to ignite as the number of carbon atoms increases. The general equation for complete combustion is:
CnH2n+2 + (n + ) O2 → (n + 1) H2O + n CO2
or CnH2n+2 + () O2 → (n + 1) H2O + n CO2
In the absence of sufficient oxygen, carbon monoxide or even soot can be formed, as shown below:
CnH2n+2 + (n + ) O2 → (n + 1) H2O + n CO
CnH2n+2 + (n + ) O2 → (n + 1) H2O + n C
For example, methane:
2 CH4 + 3 O2 → 4 H2O + 2 CO
CH4 + O2 → 2 H2O + C
See the alkane heat of formation table for detailed data.
The standard enthalpy change of combustion, ΔcH⊖, for alkanes increases by about 650 kJ/mol per CH2 group. Branched-chain alkanes have lower values of ΔcH⊖ than straight-chain alkanes of the same number of carbon atoms, and so can be seen to be somewhat more stable.
Biodegradation
Some organisms are capable of metalbolizing alkanes. The methane monooxygenases convert methane to methanol. For higher alkanes, cytochrome P450 convert alkanes to alcohols, which are then susceptible to degradation.
Free radical reactions
Free radicals, molecules with unpaired electrons, play a large role in most reactions of alkanes. Free radical halogenation reactions occur with halogens, leading to the production of haloalkanes. The hydrogen atoms of the alkane are progressively replaced by halogen atoms. The reaction of alkanes and fluorine is highly exothermic and can lead to an explosion. These reactions are an important industrial route to halogenated hydrocarbons. There are three steps:
Initiation the halogen radicals form by homolysis. Usually, energy in the form of heat or light is required.
Chain reaction or Propagation then takes place—the halogen radical abstracts a hydrogen from the alkane to give an alkyl radical. This reacts further.
Chain termination where the radicals recombine.
Experiments have shown that all halogenation produces a mixture of all possible isomers, indicating that all hydrogen atoms are susceptible to reaction. The mixture produced, however, is not statistical: Secondary and tertiary hydrogen atoms are preferentially replaced due to the greater stability of secondary and tertiary free-radicals. An example can be seen in the monobromination of propane:
In the Reed reaction, sulfur dioxide and chlorineconvert hydrocarbons to sulfonyl chlorides under the influence of light.
Under some conditions, alkanes will undergo Nitration.
C-H activation
Certain transition metal complexes promote non-radical reactions with alkanes, resulting in so C–H bond activation reactions.
Cracking
Cracking breaks larger molecules into smaller ones. This reaction requires heat and catalysts. The thermal cracking process follows a homolytic mechanism with formation of free radicals. The catalytic cracking process involves the presence of acid catalysts (usually solid acids such as silica-alumina and zeolites), which promote a heterolytic (asymmetric) breakage of bonds yielding pairs of ions of opposite charges, usually a carbocation. Carbon-localized free radicals and cations are both highly unstable and undergo processes of chain rearrangement, C–C scission in position beta (i.e., cracking) and intra- and intermolecular hydrogen transfer or hydride transfer. In both types of processes, the corresponding reactive intermediates (radicals, ions) are permanently regenerated, and thus they proceed by a self-propagating chain mechanism. The chain of reactions is eventually terminated by radical or ion recombination.
Isomerization and reformation
Dragan and his colleague were the first to report about isomerization in alkanes. Isomerization and reformation are processes in which straight-chain alkanes are heated in the presence of a platinum catalyst. In isomerization, the alkanes become branched-chain isomers. In other words, it does not lose any carbons or hydrogens, keeping the same molecular weight. In reformation, the alkanes become cycloalkanes or aromatic hydrocarbons, giving off hydrogen as a by-product. Both of these processes raise the octane number of the substance. Butane is the most common alkane that is put under the process of isomerization, as it makes many branched alkanes with high octane numbers.
Other reactions
In steam reforming, alkanes react with steam in the presence of a nickel catalyst to give hydrogen and carbon monoxide.
Occurrence
Occurrence of alkanes in the Universe
Alkanes form a small portion of the atmospheres of the outer gas planets such as Jupiter (0.1% methane, 2 ppm ethane), Saturn (0.2% methane, 5 ppm ethane), Uranus (1.99% methane, 2.5 ppm ethane) and Neptune (1.5% methane, 1.5 ppm ethane). Titan (1.6% methane), a satellite of Saturn, was examined by the Huygens probe, which indicated that Titan's atmosphere periodically rains liquid methane onto the moon's surface. Also on Titan, the Cassini mission has imaged seasonal methane/ethane lakes near the polar regions of Titan. Methane and ethane have also been detected in the tail of the comet Hyakutake. Chemical analysis showed that the abundances of ethane and methane were roughly equal, which is thought to imply that its ices formed in interstellar space, away from the Sun, which would have evaporated these volatile molecules. Alkanes have also been detected in meteorites such as carbonaceous chondrites.
Occurrence of alkanes on Earth
Traces of methane gas (about 0.0002% or 1745 ppb) occur in the Earth's atmosphere, produced primarily by methanogenic microorganisms, such as Archaea in the gut of ruminants.
The most important commercial sources for alkanes are natural gas and oil. Natural gas contains primarily methane and ethane, with some propane and butane: oil is a mixture of liquid alkanes and other hydrocarbons. These hydrocarbons were formed when marine animals and plants (zooplankton and phytoplankton) died and sank to the bottom of ancient seas and were covered with sediments in an anoxic environment and converted over many millions of years at high temperatures and high pressure to their current form. Natural gas resulted thereby for example from the following reaction:
C6H12O6 → 3 CH4 + 3 CO2
These hydrocarbon deposits, collected in porous rocks trapped beneath impermeable cap rocks, comprise commercial oil fields. They have formed over millions of years and once exhausted cannot be readily replaced. The depletion of these hydrocarbons reserves is the basis for what is known as the energy crisis.
Alkanes have a low solubility in water, so the content in the oceans is negligible; however, at high pressures and low temperatures (such as at the bottom of the oceans), methane can co-crystallize with water to form a solid methane clathrate (methane hydrate). Although this cannot be commercially exploited at the present time, the amount of combustible energy of the known methane clathrate fields exceeds the energy content of all the natural gas and oil deposits put together. Methane extracted from methane clathrate is, therefore, a candidate for future fuels.
Biological occurrence
Aside from petroleum and natural gas, alkanes occur significantly in nature only as methane, which is produced by some archaea by the process of methanogenesis. These organisms are found in the gut of termites and cows. The methane is produced from carbon dioxide or other organic compounds. Energy is released by the oxidation of hydrogen:
CO2 + 4 H2 → CH4 + 2 H2O
It is probable that our current deposits of natural gas were formed in a similar way.
RCH2\sCH3}} (R = alkyl)
Another route to alkanes is hydrogenolysis, which entails cleavage of C-heteroatom bonds using hydrogen. In industry, the main substrates are organonitrogen and organosulfur impurities, i.e. the heteroatoms are N and S. The specific processes are called hydrodenitrification and hydrodesulfurization:
Hydrogenolysis can be applied to the conversion of virtually any functional group into hydrocarbons. Substrates include haloalkanes, alcohols, aldehydes, ketones, carboxylic acids, etc. Both hydrogenolysis and hydrogenation are practiced in refineries. The can be effected by using lithium aluminium hydride, Clemmenson reduction and other specialized routes.
Coal
Coal is a more traditional precursor to alkanes. A wide range of technologies have been intensively practiced for centuries. Simply heating coal gives alkanes, leaving behind coke. Relevant technologies include the Bergius process and coal liquifaction. Partial combustion of coal and related solid organic compounds generates carbon monoxide, which can be hydrogenated using the Fischer–Tropsch process. This technology allows the synthesize liquid hydrocarbons, including alkanes. This method is used to produce substitutes for petroleum distillates.
Laboratory preparation
Rarely is there any interest in the synthesis of alkanes, since they are usually commercially available and less valued than virtually any precursor. The best-known method is hydrogenation of alkenes. Many C-X bonds can be converted to C-H bonds using lithium aluminium hydride, Clemmenson reduction, and other specialized routes. Hydrolysis of Alkyl Grignard reagents and alkyl lithium compounds gives alkanes.
Applications
Fuels
The dominant use of alkanes is as fuels. Propane and butane, easily liquified gases, are commonly known as liquified petroleum gas (LPG). From pentane to octane the alkanes are highly volatile liquids. They are used as fuels in internal combustion engines, as they vaporize easily on entry into the combustion chamber without forming droplets, which would impair the uniformity of the combustion. Branched-chain alkanes are preferred as they are much less prone to premature ignition, which causes knocking, than their straight-chain homologues. This propensity to premature ignition is measured by the octane rating of the fuel, where 2,2,4-trimethylpentane (isooctane) has an arbitrary value of 100, and heptane has a value of zero. Apart from their use as fuels, the middle alkanes are also good solvents for nonpolar substances. Alkanes from nonane to, for instance, hexadecane (an alkane with sixteen carbon atoms) are liquids of higher viscosity, less and less suitable for use in gasoline. They form instead the major part of diesel and aviation fuel. Diesel fuels are characterized by their cetane number, cetane being an old name for hexadecane. However, the higher melting points of these alkanes can cause problems at low temperatures and in polar regions, where the fuel becomes too thick to flow correctly.
Precursors to chemicals
By the process of cracking, alkanes can be converted to alkenes. Simple alkenes are precursors to polymers, such as polyethylene and polypropylene. When the cracking is taken to extremes, alkanes can be converted to carbon black, which is a significant tire component.
Chlorination of methane gives chloromethanes, which are used as solvents and building blocks for complex compounds. Similarly treatment of methane with sulfur gives carbon disulfide. Still other chemicals are prepared by reaction with sulfur trioxide and nitric oxide
Other
Some light hydrocarbons are used as aerosol sprays.
Alkanes from hexadecane upwards form the most important components of fuel oil and lubricating oil. In the latter function, they work at the same time as anti-corrosive agents, as their hydrophobic nature means that water cannot reach the metal surface. Many solid alkanes find use as paraffin wax, for example, in candles. This should not be confused however with true wax, which consists primarily of esters.
Alkanes with a chain length of approximately 35 or more carbon atoms are found in bitumen, used, for example, in road surfacing. However, the higher alkanes have little value and are usually split into lower alkanes by cracking.
Hazards
Alkanes are highly flammable, but they have low toxicities. Methane "is toxicologically virtually inert." Alkanes can be asphyxiants and narcotic.
See also
Alkene
Alkyne
Cycloalkane
Higher alkanes
Aliphatic compound
References
Further reading
Virtual Textbook of Organic Chemistry
A visualization of the crystal structures of alkanes up to nonan
Hydrocarbons |
642 | https://en.wikipedia.org/wiki/Answer%20%28law%29 | Answer (law) | In law, an answer was originally a solemn assertion in opposition to someone or something, and thus generally any counter-statement or defense, a reply to a question or response, or objection, or a correct solution of a problem.
In the common law, an answer is the first pleading by a defendant, usually filed and served upon the plaintiff within a certain strict time limit after a civil complaint or criminal information or indictment has been served upon the defendant. It may have been preceded by an optional "pre-answer" motion to dismiss or demurrer; if such a motion is unsuccessful, the defendant must file an answer to the complaint or risk an adverse default judgment.
In a criminal case, there is usually an arraignment or some other kind of appearance before the defendant comes to court. The pleading in the criminal case, which is entered on the record in open court, is usually either guilty or not guilty. Generally, speaking in private, civil cases there is no plea entered of guilt or innocence. There is only a judgment that grants money damages or some other kind of equitable remedy such as restitution or a permanent injunction. Criminal cases may lead to fines or other punishment, such as imprisonment.
The famous Latin Responsa Prudentium ("answers of the learned ones") were the accumulated views of many successive generations of Roman lawyers, a body of legal opinion which gradually became authoritative.
During debates of a contentious nature, deflection, colloquially known as 'changing the topic', has been widely observed, and is often seen as a failure to answer a question.
Notes
Common law
Legal documents |
643 | https://en.wikipedia.org/wiki/Appellate%20court | Appellate court | An appellate court, commonly called a court of appeal(s), appeal court, court of second instance or second instance court, is any court of law that is empowered to hear an appeal of a trial court or other lower tribunal. In much of the world, court systems are divided into at least three levels: the trial court, which initially hears cases and reviews evidence and testimony to determine the facts of the case; at least one intermediate appellate court; and a supreme court (or court of last resort) which primarily reviews the decisions of the intermediate courts, often on a discretionary basis. A particular court system's supreme court is its highest appellate court. Appellate courts nationwide can operate under varying rules.
Under its standard of review, an appellate court decides the extent of the deference it would give to the lower court's decision, based on whether the appeal were one of fact or of law. In reviewing an issue of fact, an appellate court ordinarily gives deference to the trial court's findings. It is the duty of trial judges or juries to find facts, view the evidence firsthand, and observe witness testimony. When reviewing lower decisions on an issue of fact, courts of appeal generally look for clear error. The appellate court reviews issues of law (anew, no deference) and may reverse or modify the lower court's decision if the appellate court believes the lower court misapplied the facts or the law. An appellate court may also review the lower judge's discretionary decisions, such as whether the judge properly granted a new trial or disallowed evidence. The lower court's decision is only changed in cases of an "abuse of discretion". This standard tends to be even more deferential than the "clear error" standard.
Before hearing any case, the court must have jurisdiction to consider the appeal. The authority of appellate courts to review the decisions of lower courts varies widely from one jurisdiction to another. In some areas, the appellate court has limited powers of review. Generally, an appellate court's judgment provides the final directive of the appeals courts as to the matter appealed, setting out with specificity the court's determination that the action appealed from should be affirmed, reversed, remanded or modified. Depending on the type of case and the decision below, appellate review primarily consists of: an entirely new hearing (a non trial de novo); a hearing where the appellate court gives deference to factual findings of the lower court; or review of particular legal rulings made by the lower court (an appeal on the record).
Bifurcation of civil and criminal appeals
While many appellate courts have jurisdiction over all cases decided by lower courts, some systems have appellate courts divided by the type of jurisdiction they exercise. Some jurisdictions have specialized appellate courts, such as the Texas Court of Criminal Appeals, which only hears appeals raised in criminal cases, and the U.S. Court of Appeals for the Federal Circuit, which has general jurisdiction but derives most of its caseload from patent cases, on one hand, and appeals from the Court of Federal Claims on the other. In the United States, Alabama, Tennessee, and Oklahoma also have separate courts of criminal appeals. Texas and Oklahoma have the final determination of criminal cases vested in their respective courts of criminal appeals, while Alabama and Tennessee allow decisions of its court of criminal appeals to be finally appealed to the state supreme court.
Courts of criminal appeals
Civilian
Court of Criminal Appeal (England and Wales), abolished 1966
Court of Criminal Appeal (Ireland), abolished 2014
U.S. States:
Alabama Court of Criminal Appeals
Oklahoma Court of Criminal Appeals
Tennessee Court of Criminal Appeals
Texas Court of Criminal Appeals
Military
United States Army Court of Criminal Appeals
Navy-Marine Corps Court of Criminal Appeals (United States)
Coast Guard Court of Criminal Appeals (United States)
Air Force Court of Criminal Appeals (United States)
Courts of civil appeals
Alabama Court of Civil Appeals
Oklahoma Court of Civil Appeals
Appellate courts by country
Australia
The High Court has appellate jurisdiction over all other courts. Leave must be granted by the court, before the appeal matter is heard. The High Court is paramount to all federal courts. Further, it has an constitutionally entrenched general power of appeal from the Supreme Courts of the States and Territories. Appeals to the High Court are by special leave only, which is generally only granted in cases of public importance, matters involving the interpretation of the Commonwealth Constitution, or where the law has been inconsistently applied across the States and Territories.[19] Therefore, in the vast majority of cases, the appellate divisions of the Supreme Courts of each State and Territory and the Federal Court are the final courts of appeal.
New Zealand
The Court of Appeal of New Zealand, located in Wellington, is New Zealand's principal intermediate appellate court. In practice, most appeals are resolved at this intermediate appellate level, rather than in the Supreme Court.
Philippines
The Court of Appeals of the Philippines is the principal intermediate appellate court of that country. The Court of Appeals is primarily found in Manila, with three divisions each in Cebu City and Cagayan de Oro. Other appellate courts include the Sandiganbayan for cases involving graft and corruption, and the Court of Tax Appeals for cases involving tax. Appeals from all three appellate courts are to the Supreme Court.
Sri Lanka
The Court of Appeal of Sri Lanka, located in Colombo, is the second senior court in the Sri Lankan legal system.
United Kingdom
United States
In the United States, both state and federal appellate courts are usually restricted to examining whether the lower court made the correct legal determinations, rather than hearing direct evidence and determining what the facts of the case were. Furthermore, U.S. appellate courts are usually restricted to hearing appeals based on matters that were originally brought up before the trial court. Hence, such an appellate court will not consider an appellant's argument if it is based on a theory that is raised for the first time in the appeal.
In most U.S. states, and in U.S. federal courts, parties before the court are allowed one appeal as of right. This means that a party who is unsatisfied with the outcome of a trial may bring an appeal to contest that outcome. However, appeals may be costly, and the appellate court must find an error on the part of the court below that justifies upsetting the verdict. Therefore, only a small proportion of trial court decisions result in appeals. Some courts, particularly supreme courts, have the power of discretionary review, meaning that they can decide whether they will hear an appeal brought in a particular case.
Nomenclature
Many U.S. jurisdictions title their appellate court a court of appeal or court of appeals. Both terms are used in the United States, but the plural form is more common in American English, while in contrast, British English uses only the singular form. The correct form is whichever is the statutorily prescribed or customary form for a particular court and particular jurisdiction; in other words, one should never write "court of appeal" when the court at issue clearly prefers to be called a "court of appeals", and vice versa.
Historically, certain jurisdictions have titled their appellate court a court of errors (or court of errors and appeals), on the premise that it was intended to correct errors made by lower courts. Examples of such courts include the New Jersey Court of Errors and Appeals (which existed from 1844 to 1947), the Connecticut Supreme Court of Errors (which has been renamed the Connecticut Supreme Court), the Kentucky Court of Errors (renamed the Kentucky Supreme Court), and the Mississippi High Court of Errors and Appeals (since renamed the Supreme Court of Mississippi). In some jurisdictions, a court able to hear appeals is known as an appellate division.
The phrase "court of appeals" most often refers to intermediate appellate courts. However, the New York Court of Appeals is the highest appellate court in New York. The New York Supreme Court is a trial court of general jurisdiction. The Supreme Court of Maryland was known as the Court of Appeals, and the Appellate Court of Maryland was known as the Court of Special Appeals, until a 2022 constitutional amendment changed their names. Depending on the system, certain courts may serve as both trial courts and appellate courts, hearing appeals of decisions made by courts with more limited jurisdiction.
See also
Court of Criminal Appeal (disambiguation)
Court of Appeal (Hong Kong)
High Court (Hong Kong)
Court of Appeal (England and Wales)
Court of cassation
References
Citations
Sources
Lax, Jeffrey R. "Constructing Legal Rules on Appellate Courts." American Political Science Review 101.3 (2007): 591–604. Sociological Abstracts; Worldwide Political Science Abstracts. Web. 29 May 2012.
Courts by type
Appellate courts
Jurisdiction |
651 | https://en.wikipedia.org/wiki/America%20the%20Beautiful | America the Beautiful | "America the Beautiful" is a patriotic American song. Its lyrics were written by Katharine Lee Bates and its music was composed by church organist and choirmaster Samuel A. Ward at Grace Episcopal Church in Newark, New Jersey. The two never met.
Bates wrote the words as a poem, originally entitled "Pikes Peak". It was first published in the Fourth of July 1895 edition of the church periodical, The Congregationalist. At that time, the poem was entitled "America".
Ward had initially composed the song's melody in 1882 to accompany lyrics to "Materna", basis of the hymn, "O Mother dear, Jerusalem", though the hymn was not first published until 1892. The combination of Ward's melody and Bates's poem was first entitled "America the Beautiful" in 1910. The song is one of the most popular of the many American patriotic songs.
History
In 1893, at the age of 33, Bates, an English professor at Wellesley College, had taken a train trip to Colorado Springs, Colorado, to teach at Colorado College. Several of the sights on her trip inspired her, and they found their way into her poem, including the World's Columbian Exposition in Chicago, the "White City" with its promise of the future contained within its gleaming white buildings; the wheat fields of North America's heartland Kansas, through which her train was riding on July 16; and the majestic view of the Great Plains from high atop Pikes Peak.
On the pinnacle of that mountain, the words of the poem started to come to her, and she wrote them down upon returning to her hotel room at the original Antlers Hotel. The poem was initially published two years later in The Congregationalist to commemorate the Fourth of July. It quickly caught the public's fancy. An amended version was published in 1904.
The first known melody written for the song was sent in by Silas Pratt when the poem was published in The Congregationalist. By 1900, at least 75 different melodies had been written. A hymn tune composed in 1882 by Samuel A. Ward, the organist and choir director at Grace Church, Newark, was generally considered the best music as early as 1910 and is still the popular tune today. Just as Bates had been inspired to write her poem, Ward, too, was inspired. The tune came to him while he was on a ferryboat trip from Coney Island back to his home in New York City after a leisurely summer day and he immediately wrote it down. He composed the tune for the old hymn "O Mother Dear, Jerusalem", retitling the work "Materna". Ward's music combined with Bates's poem were first published together in 1910 and titled "America the Beautiful".
Ward died in 1903, not knowing the national stature his music would attain. Bates was more fortunate, since the song's popularity was well established by the time of her death in 1929. It is included in songbooks in many religious congregations in the United States.
At various times in the more than one hundred years that have elapsed since the song was written, particularly during the John F. Kennedy administration, there have been efforts to give "America the Beautiful" legal status either as a national hymn or as a national anthem equal to, or in place of, "The Star-Spangled Banner", but so far this has not succeeded. Proponents prefer "America the Beautiful" for various reasons, saying it is easier to sing, more melodic, and more adaptable to new orchestrations while still remaining as easily recognizable as "The Star-Spangled Banner". Some prefer "America the Beautiful" over "The Star-Spangled Banner" due to the latter's war-oriented imagery, while others object to the implicit support of slavery and racism in its third verse; others prefer "The Star-Spangled Banner" because of its war themes. While that national dichotomy has stymied any effort at changing the tradition of the national anthem, "America the Beautiful" continues to be held in high esteem by a large number of Americans, and was even being considered before 1931 as a candidate to become the national anthem of the United States.
Lyrics
Notable performances
Elvis Presley performed it many times in concerts starting in 1976.
Bing Crosby included the song in a medley on his album 101 Gang Songs (1961).
Frank Sinatra recorded the song with Nelson Riddle during the sessions for The Concert Sinatra in February 1963, for a projected 45 single release. The 45 was not commercially issued however, but the song was later added as a bonus track to the enhanced 2012 CD release of The Concert Sinatra.
In 1976, while the United States celebrated its bicentennial, a soulful version popularized by Ray Charles peaked at number 98 on the US R&B chart. His version was traditionally played on New Year's Eve in Times Square following the ball drop.
Three different renditions of the song have entered the Hot Country Songs charts. The first was by Charlie Rich, which went to number 22 in 1976. A second, by Mickey Newbury, peaked at number 82 in 1980. Aretha Franklin performed a rendition before an undisputed audience of 93,173 to open WrestleMania III, a performance meta-critic RJ City called "a lovely version". An all-star version of "America the Beautiful" performed by country singers Trace Adkins, Sherrié Austin, Billy Dean, Vince Gill, Carolyn Dawn Johnson, Toby Keith, Brenda Lee, Lonestar, Lyle Lovett, Lila McCann, Lorrie Morgan, Jamie O'Neal, The Oak Ridge Boys, Collin Raye, Kenny Rogers, Keith Urban and Phil Vassar reached number 58 in July 2001. The song re-entered the chart following the September 11 attacks.
Barbra Streisand released an official music video footage during Norman Lear's Special in 1982.
During her rise to stardom, R&B singer Mariah Carey sang the song at the 1990 NBA Finals.
Whitney Houston also recorded the song, covering Ray Charles' soulful rearranged version as the b-side to her 1991 rendition of "The Star Spangled Banner."
The song has been performed as part of the Indianapolis 500 pre-race ceremonies since 1991.
The US singer/songwriter Martin Sexton recorded a gospel-tinged version on his LP "Black Sheep," released in 1996.
Popularity of the song increased greatly in the decades following 9/11; at some sporting events it was sung in addition to the traditional singing of the national anthem. During the first taping of the Late Show with David Letterman following the attacks, CBS newsman Dan Rather cried briefly as he quoted the fourth verse.
The hymn has been featured in the pregame for a number of Super Bowls, the championship game for each NFL season. It is sung along with the "Star-Spangled Banner" and, more recently, the hymn "Lift Every Voice and Sing," commonly referred to as the "Black national anthem". For Super Bowl XLVIII, The Coca-Cola Company aired a multilingual version of the song, sung in several different languages. The commercial received some criticism on social media sites, such as Twitter and Facebook, and from some conservatives, such as Glenn Beck. Despite the controversies, Coca-Cola later reused the Super Bowl ad during Super Bowl LI, the opening ceremonies of the 2014 Winter Olympics and 2016 Summer Olympics and for patriotic holidays. Notable performers at the Super Bowl include Ray Charles, Alicia Keys, John Legend, Faith Hill, Mary J. Blige with Marc Anthony, Blake Shelton with Miranda Lambert, Queen Latifah, Leslie Odom Jr., and Babyface. Post Malone performed the song for the most recent game, Super Bowl LVIII, in 2024.
In 2016, American five-piece girl group Fifth Harmony performed a rendition to honor the United States women's national soccer team on defeating Japan 5–2 in the Final to win the 2015 FIFA Women's World Cup last July at BC Place in Vancouver, British Columbia, Canada before an undisputed AT&T Stadium audience of 101,763 to open WrestleMania 32 in Dallas, Texas.
In 2017, Jackie Evancho released Together We Stand, a disc containing three patriotic songs including "America the Beautiful." The song charted at No. 4 on Billboard's Classical Digital Song sales chart.
An abbreviated cover with the 1911 lyrics was performed by Greg Jong for the soundtrack of the 2020 video game Wasteland 3 and is played during the final hostile encounters in the Denver section.
In 2021, Jennifer Lopez performed the song at the inauguration of Joe Biden, as the second half of a medley with "This Land Is Your Land" by Woody Guthrie.
In 2023, Cécile McLorin Salvant performed the song at the US Open woman's final. In her rendition, Salvant notably skipped ahead to the lyrics of the second half of the second verse while singing the first verse (replacing "God shed His grace on thee..." with "God mend thine every flaw...", etc.). Jazz Critic Nate Chinen wrote the following day of the performance, "What does it mean for a singer such as Salvant to inhabit a platform like the US Open, and implore God to mend America’s every flaw? What does it mean, in the Year of Our Lord 2023, for a singer like Salvant to urge the nation to confirm thy soul in self-control, and find liberty in law? I’m not going to spell it out, but it means a lot."
Idioms
"From sea to shining sea", originally used in the charters of some of the English colonies in North America, is an American idiom meaning "from the Atlantic Ocean to the Pacific Ocean" (or vice versa). Other songs that have used this phrase include the American patriotic song "God Bless the U.S.A." and Schoolhouse Rock's "Elbow Room". The phrase and the song are also the namesake of the Shining Sea Bikeway, a bike path in Bates's hometown of Falmouth, Massachusetts. The phrase is similar to the Latin phrase "" ("From sea to sea"), which is the official motto of Canada.
"Purple mountain majesties" refers to the shade of Pikes Peak in Colorado Springs, Colorado, which inspired Bates to write the poem. The idiom inspired the Colorado Rockies to have purple as one of its team colors.
In 2003, Tori Amos appropriated the phrase "for amber waves of grain" to create a personification for her song "Amber Waves". Amos imagines Amber Waves as an exotic dancer, like the character of the same name portrayed by Julianne Moore in Boogie Nights.
Books
Lynn Sherr's 2001 book America the Beautiful: The Stirring True Story Behind Our Nation's Favorite Song discusses the origins of the song and the backgrounds of its authors in depth. The book points out that the poem has the same meter as that of "Auld Lang Syne"; the songs can be sung interchangeably. Additionally, Sherr discusses the evolution of the lyrics, for instance, changes to the original third verse written by Bates.
Melinda M. Ponder, in her 2017 biography Katharine Lee Bates: From Sea to Shining Sea, draws heavily on Bates's diaries and letters to trace the history of the poem and its place in American culture.
See also
"God Bless America"
Explanatory notes
References
External links
MP3 and RealAudio recordings available at the United States Library of Congress
America the Beautiful Park in Colorado Springs named for Katharine Lee Bates' words.
Archival collection of America the Beautiful lantern slides from the 1930s.
Another free sheet music
1895 songs
American Christian hymns
American patriotic songs
Pikes Peak
History of Colorado Springs, Colorado
Songs based on poems
Grammy Hall of Fame Award recipients
Concert band pieces
Ray Charles songs
Whitney Houston songs |
655 | https://en.wikipedia.org/wiki/Abacus | Abacus | An abacus (: abaci or abacuses), also called a counting frame, is a hand-operated calculating tool which was used from ancient times in the ancient Near East, Europe, China, and Russia, until the adoption of the Arabic numeral system. An abacus consists of a two-dimensional array of slidable beads (or similar objects). In their earliest designs, the beads could be loose on a flat surface or sliding in grooves. Later the beads were made to slide on rods and built into a frame, allowing faster manipulation.
Each rod typically represents one digit of a multi-digit number laid out using a positional numeral system such as base ten (though some cultures used different numerical bases). Roman and East Asian abacuses use a system resembling bi-quinary coded decimal, with a top deck (containing one or two beads) representing fives and a bottom deck (containing four or five beads) representing ones. Natural numbers are normally used, but some allow simple fractional components (e.g. , , and in Roman abacus), and a decimal point can be imagined for fixed-point arithmetic.
Any particular abacus design supports multiple methods to perform calculations, including addition, subtraction, multiplication, division, and square and cube roots. The beads are first arranged to represent a number, then are manipulated to perform a mathematical operation with another number, and their final position can be read as the result (or can be used as the starting number for subsequent operations).
In the ancient world, abacuses were a practical calculating tool. Although calculators and computers are commonly used today instead of abacuses, abacuses remain in everyday use in some countries. The abacus has an advantage of not requiring a writing implement and paper (needed for algorism) or an electric power source. Merchants, traders, and clerks in some parts of Eastern Europe, Russia, China, and Africa use abacuses. The abacus remains in common use as a scoring system in non-electronic table games. Others may use an abacus due to visual impairment that prevents the use of a calculator. The abacus is still used to teach the fundamentals of mathematics to children in most countries.
Etymology
The word abacus dates to at least AD 1387 when a Middle English work borrowed the word from Latin that described a sandboard abacus. The Latin word is derived from ancient Greek (abax) which means something without a base, and colloquially, any piece of rectangular material. Alternatively, without reference to ancient texts on etymology, it has been suggested that it means "a square tablet strewn with dust", or "drawing-board covered with dust (for the use of mathematics)" (the exact shape of the Latin perhaps reflects the genitive form of the Greek word, (abakos)). While the table strewn with dust definition is popular, some argue evidence is insufficient for that conclusion. Greek probably borrowed from a Northwest Semitic language like Phoenician, evidenced by a cognate with the Hebrew word ʾābāq (), or "dust" (in the post-Biblical sense "sand used as a writing surface").
Both abacuses and abaci are used as plurals. The user of an abacus is called an abacist.
History
Mesopotamia
The Sumerian abacus appeared between 2700 and 2300 BC. It held a table of successive columns which delimited the successive orders of magnitude of their sexagesimal (base 60) number system.
Some scholars point to a character in Babylonian cuneiform that may have been derived from a representation of the abacus. It is the belief of Old Babylonian scholars, such as Ettore Carruccio, that Old Babylonians "seem to have used the abacus for the operations of addition and subtraction; however, this primitive device proved difficult to use for more complex calculations".
Egypt
Greek historian Herodotus mentioned the abacus in Ancient Egypt. He wrote that the Egyptians manipulated the pebbles from right to left, opposite in direction to the Greek left-to-right method. Archaeologists have found ancient disks of various sizes that are thought to have been used as counters. However, wall depictions of this instrument are yet to be discovered.
Persia
At around 600 BC, Persians first began to use the abacus, during the Achaemenid Empire. Under the Parthian, Sassanian, and Iranian empires, scholars concentrated on exchanging knowledge and inventions with the countries around them – India, China, and the Roman Empire- which is how the abacus may have been exported to other countries.
Greece
The earliest archaeological evidence for the use of the Greek abacus dates to the 5th century BC. Demosthenes (384 BC–322 BC) complained that the need to use pebbles for calculations was too difficult. A play by Alexis from the 4th century BC mentions an abacus and pebbles for accounting, and both Diogenes and Polybius use the abacus as a metaphor for human behavior, stating "that men that sometimes stood for more and sometimes for less" like the pebbles on an abacus. The Greek abacus was a table of wood or marble, pre-set with small counters in wood or metal for mathematical calculations. This Greek abacus was used in Achaemenid Persia, the Etruscan civilization, Ancient Rome, and the Western Christian world until the French Revolution.
A tablet found on the Greek island Salamis in 1846 AD (the Salamis Tablet) dates to 300 BC, making it the oldest counting board discovered so far. It is a slab of white marble in length, wide, and thick, on which are 5 groups of markings. In the tablet's center is a set of 5 parallel lines equally divided by a vertical line, capped with a semicircle at the intersection of the bottom-most horizontal line and the single vertical line. Below these lines is a wide space with a horizontal crack dividing it. Below this crack is another group of eleven parallel lines, again divided into two sections by a line perpendicular to them, but with the semicircle at the top of the intersection; the third, sixth and ninth of these lines are marked with a cross where they intersect with the vertical line. Also from this time frame, the Darius Vase was unearthed in 1851. It was covered with pictures, including a "treasurer" holding a wax tablet in one hand while manipulating counters on a table with the other.
Rome
The normal method of calculation in ancient Rome, as in Greece, was by moving counters on a smooth table. Originally pebbles (Latin: calculi) were used. Marked lines indicated units, fives, tens, etc. as in the Roman numeral system.
Writing in the 1st century BC, Horace refers to the wax abacus, a board covered with a thin layer of black wax on which columns and figures were inscribed using a stylus.
One example of archaeological evidence of the Roman abacus, shown nearby in reconstruction, dates to the 1st century AD. It has eight long grooves containing up to five beads in each and eight shorter grooves having either one or no beads in each. The groove marked I indicates units, X tens, and so on up to millions. The beads in the shorter grooves denote fives (five units, five tens, etc.) resembling a bi-quinary coded decimal system related to the Roman numerals. The short grooves on the right may have been used for marking Roman "ounces" (i.e. fractions).
Medieval Europe
The Roman system of 'counter casting' was used widely in medieval Europe, and persisted in limited use into the nineteenth century. Wealthy abacists used decorative minted counters, called jetons.
Due to Pope Sylvester II's reintroduction of the abacus with modifications, it became widely used in Europe again during the 11th century It used beads on wires, unlike the traditional Roman counting boards, which meant the abacus could be used much faster and was more easily moved.
China
The earliest known written documentation of the Chinese abacus dates to the 2nd century BC.
The Chinese abacus, also known as the suanpan (算盤/算盘, lit. "calculating tray"), comes in various lengths and widths, depending on the operator. It usually has more than seven rods. There are two beads on each rod in the upper deck and five beads each in the bottom one, to represent numbers in a bi-quinary coded decimal-like system. The beads are usually rounded and made of hardwood. The beads are counted by moving them up or down towards the beam; beads moved toward the beam are counted, while those moved away from it are not. One of the top beads is 5, while one of the bottom beads is 1. Each rod has a number under it, showing the place value. The suanpan can be reset to the starting position instantly by a quick movement along the horizontal axis to spin all the beads away from the horizontal beam at the center.
The prototype of the Chinese abacus appeared during the Han dynasty, and the beads are oval. The Song dynasty and earlier used the 1:4 type or four-beads abacus similar to the modern abacus including the shape of the beads commonly known as Japanese-style abacus.
In the early Ming dynasty, the abacus began to appear in a 1:5 ratio. The upper deck had one bead and the bottom had five beads. In the late Ming dynasty, the abacus styles appeared in a 2:5 ratio. The upper deck had two beads, and the bottom had five.
Various calculation techniques were devised for Suanpan enabling efficient calculations. Some schools teach students how to use it.
In the long scroll Along the River During the Qingming Festival painted by Zhang Zeduan during the Song dynasty (960–1297), a suanpan is clearly visible beside an account book and doctor's prescriptions on the counter of an apothecary's (Feibao).
The similarity of the Roman abacus to the Chinese one suggests that one could have inspired the other, given evidence of a trade relationship between the Roman Empire and China. However, no direct connection has been demonstrated, and the similarity of the abacuses may be coincidental, both ultimately arising from counting with five fingers per hand. Where the Roman model (like most modern Korean and Japanese) has 4 plus 1 bead per decimal place, the standard suanpan has 5 plus 2. Incidentally, this allows use with a hexadecimal numeral system (or any base up to 18) which may have been used for traditional Chinese measures of weight. (Instead of running on wires as in the Chinese, Korean, and Japanese models, the Roman model used grooves, presumably making arithmetic calculations much slower.)
Another possible source of the suanpan is Chinese counting rods, which operated with a decimal system but lacked the concept of zero as a placeholder. The zero was probably introduced to the Chinese in the Tang dynasty (618–907) when travel in the Indian Ocean and the Middle East would have provided direct contact with India, allowing them to acquire the concept of zero and the decimal point from Indian merchants and mathematicians.
India
The Abhidharmakośabhāṣya of Vasubandhu (316-396), a Sanskrit work on Buddhist philosophy, says that the second-century CE philosopher Vasumitra said that "placing a wick (Sanskrit vartikā) on the number one (ekāṅka) means it is a one while placing the wick on the number hundred means it is called a hundred, and on the number one thousand means it is a thousand". It is unclear exactly what this arrangement may have been. Around the 5th century, Indian clerks were already finding new ways of recording the contents of the abacus. Hindu texts used the term śūnya (zero) to indicate the empty column on the abacus.
Japan
In Japan, the abacus is called soroban (, lit. "counting tray"). It was imported from China in the 14th century. It was probably in use by the working class a century or more before the ruling class adopted it, as the class structure obstructed such changes. The 1:4 abacus, which removes the seldom-used second and fifth bead, became popular in the 1940s.
Today's Japanese abacus is a 1:4 type, four-bead abacus, introduced from China in the Muromachi era. It adopts the form of the upper deck one bead and the bottom four beads. The top bead on the upper deck was equal to five and the bottom one is similar to the Chinese or Korean abacus, and the decimal number can be expressed, so the abacus is designed as a one:four device. The beads are always in the shape of a diamond. The quotient division is generally used instead of the division method; at the same time, in order to make the multiplication and division digits consistently use the division multiplication. Later, Japan had a 3:5 abacus called 天三算盤, which is now in the Ize Rongji collection of Shansi Village in Yamagata City. Japan also used a 2:5 type abacus.
The four-bead abacus spread, and became common around the world. Improvements to the Japanese abacus arose in various places. In China an aluminium frame plastic bead abacus was used. The file is next to the four beads, and pressing the "clearing" button put the upper bead in the upper position, and the lower bead in the lower position.
The abacus is still manufactured in Japan even with the proliferation, practicality, and affordability of pocket electronic calculators. The use of the soroban is still taught in Japanese primary schools as part of mathematics, primarily as an aid to faster mental calculation. Using visual imagery can complete a calculation as quickly as a physical instrument.
Korea
The Chinese abacus migrated from China to Korea around 1400 AD. Koreans call it jupan (주판), supan (수판) or jusan (주산). The four-beads abacus (1:4) was introduced during the Goryeo Dynasty. The 5:1 abacus was introduced to Korea from China during the Ming Dynasty.
Native America
Some sources mention the use of an abacus called a nepohualtzintzin in ancient Aztec culture. This Mesoamerican abacus used a 5-digit base-20 system. The word Nepōhualtzintzin comes from Nahuatl, formed by the roots; Ne – personal -; pōhual or pōhualli – the account -; and tzintzin – small similar elements. Its complete meaning was taken as: counting with small similar elements. Its use was taught in the Calmecac to the temalpouhqueh , who were students dedicated to taking the accounts of skies, from childhood.
The Nepōhualtzintzin was divided into two main parts separated by a bar or intermediate cord. In the left part were four beads. Beads in the first row have unitary values (1, 2, 3, and 4), and on the right side, three beads had values of 5, 10, and 15, respectively. In order to know the value of the respective beads of the upper rows, it is enough to multiply by 20 (by each row), the value of the corresponding count in the first row.
The device featured 13 rows with 7 beads, 91 in total. This was a basic number for this culture. It had a close relation to natural phenomena, the underworld, and the cycles of the heavens. One Nepōhualtzintzin (91) represented the number of days that a season of the year lasts, two Nepōhualtzitzin (182) is the number of days of the corn's cycle, from its sowing to its harvest, three Nepōhualtzintzin (273) is the number of days of a baby's gestation, and four Nepōhualtzintzin (364) completed a cycle and approximated one year. When translated into modern computer arithmetic, the Nepōhualtzintzin amounted to the rank from 10 to 18 in floating point, which precisely calculated large and small amounts, although round off was not allowed.
The rediscovery of the Nepōhualtzintzin was due to the Mexican engineer David Esparza Hidalgo, who in his travels throughout Mexico found diverse engravings and paintings of this instrument and reconstructed several of them in gold, jade, encrustations of shell, etc. Very old Nepōhualtzintzin are attributed to the Olmec culture, and some bracelets of Mayan origin, as well as a diversity of forms and materials in other cultures.
Sanchez wrote in Arithmetic in Maya that another base 5, base 4 abacus had been found in the Yucatán Peninsula that also computed calendar data. This was a finger abacus, on one hand, 0, 1, 2, 3, and 4 were used; and on the other hand 0, 1, 2, and 3 were used. Note the use of zero at the beginning and end of the two cycles.
The quipu of the Incas was a system of colored knotted cords used to record numerical data, like advanced tally sticks – but not used to perform calculations. Calculations were carried out using a yupana (Quechua for "counting tool"; see figure) which was still in use after the conquest of Peru. The working principle of a yupana is unknown, but in 2001 Italian mathematician De Pasquale proposed an explanation. By comparing the form of several yupanas, researchers found that calculations were based using the Fibonacci sequence 1, 1, 2, 3, 5 and powers of 10, 20, and 40 as place values for the different fields in the instrument. Using the Fibonacci sequence would keep the number of grains within any one field at a minimum.
Russia
The Russian abacus, the schoty (, plural from , counting), usually has a single slanted deck, with ten beads on each wire (except one wire with four beads for quarter-ruble fractions). 4-bead wire was introduced for quarter-kopeks, which were minted until 1916. The Russian abacus is used vertically, with each wire running horizontally. The wires are usually bowed upward in the center, to keep the beads pinned to either side. It is cleared when all the beads are moved to the right. During manipulation, beads are moved to the left. For easy viewing, the middle 2 beads on each wire (the 5th and 6th bead) usually are of a different color from the other eight. Likewise, the left bead of the thousands wire (and the million wire, if present) may have a different color.
The Russian abacus was in use in shops and markets throughout the former Soviet Union, and its usage was taught in most schools until the 1990s. Even the 1874 invention of mechanical calculator, Odhner arithmometer, had not replaced them in Russia. According to Yakov Perelman, some businessmen attempting to import calculators into the Russian Empire were known to leave in despair after watching a skilled abacus operator. Likewise, the mass production of Felix arithmometers since 1924 did not significantly reduce abacus use in the Soviet Union. The Russian abacus began to lose popularity only after the mass production of domestic microcalculators in 1974.
The Russian abacus was brought to France around 1820 by mathematician Jean-Victor Poncelet, who had served in Napoleon's army and had been a prisoner of war in Russia. The abacus had fallen out of use in western Europe in the 16th century with the rise of decimal notation and algorismic methods. To Poncelet's French contemporaries, it was something new. Poncelet used it, not for any applied purpose, but as a teaching and demonstration aid. The Turks and the Armenian people used abacuses similar to the Russian schoty. It was named a coulba by the Turks and a choreb by the Armenians.
School abacus
Around the world, abacuses have been used in pre-schools and elementary schools as an aid in teaching the numeral system and arithmetic.
In Western countries, a bead frame similar to the Russian abacus but with straight wires and a vertical frame is common (see image).
The wireframe may be used either with positional notation like other abacuses (thus the 10-wire version may represent numbers up to 9,999,999,999), or each bead may represent one unit (e.g. 74 can be represented by shifting all beads on 7 wires and 4 beads on the 8th wire, so numbers up to 100 may be represented). In the bead frame shown, the gap between the 5th and 6th wire, corresponding to the color change between the 5th and the 6th bead on each wire, suggests the latter use. Teaching multiplication, e.g. 6 times 7, may be represented by shifting 7 beads on 6 wires.
The red-and-white abacus is used in contemporary primary schools for a wide range of number-related lessons. The twenty bead version, referred to by its Dutch name rekenrek ("calculating frame"), is often used, either on a string of beads or on a rigid framework.
Feynman vs the abacus
Physicist Richard Feynman was noted for facility in mathematical calculations. He wrote about an encounter in Brazil with a Japanese abacus expert, who challenged him to speed contests between Feynman's pen and paper, and the abacus. The abacus was much faster for addition, somewhat faster for multiplication, but Feynman was faster at division. When the abacus was used for a really difficult challenge, i.e. cube roots, Feynman won easily. However, the number chosen at random was close to a number Feynman happened to know was an exact cube, allowing him to use approximate methods.
Neurological analysis
Learning how to calculate with the abacus may improve capacity for mental calculation. Abacus-based mental calculation (AMC), which was derived from the abacus, is the act of performing calculations, including addition, subtraction, multiplication, and division, in the mind by manipulating an imagined abacus. It is a high-level cognitive skill that runs calculations with an effective algorithm. People doing long-term AMC training show higher numerical memory capacity and experience more effectively connected neural pathways. They are able to retrieve memory to deal with complex processes. AMC involves both visuospatial and visuomotor processing that generate the visual abacus and move the imaginary beads. Since it only requires that the final position of beads be remembered, it takes less memory and less computation time.
Renaissance abacuses
Binary abacus
The binary abacus is used to explain how computers manipulate numbers. The abacus shows how numbers, letters, and signs can be stored in a binary system on a computer, or via ASCII. The device consists of a series of beads on parallel wires arranged in three separate rows. The beads represent a switch on the computer in either an "on" or "off" position.
Visually impaired users
An adapted abacus, invented by Tim Cranmer, and called a Cranmer abacus is commonly used by visually impaired users. A piece of soft fabric or rubber is placed behind the beads, keeping them in place while the users manipulate them. The device is then used to perform the mathematical functions of multiplication, division, addition, subtraction, square root, and cube root.
Although blind students have benefited from talking calculators, the abacus is often taught to these students in early grades. Blind students can also complete mathematical assignments using a braille-writer and Nemeth code (a type of braille code for mathematics) but large multiplication and long division problems are tedious. The abacus gives these students a tool to compute mathematical problems that equals the speed and mathematical knowledge required by their sighted peers using pencil and paper. Many blind people find this number machine a useful tool throughout life.
See also
Chinese Zhusuan
Chisanbop
Logical abacus
Mental abacus
Napier's bones
Sand table
Slide rule
Soroban
Suanpan
Notes
Footnotes
References
Reading
External links
Tutorials
Min Multimedia
History
Curiosities
Abacus in Various Number Systems at cut-the-knot
Java applet of Chinese, Japanese and Russian abaci
An atomic-scale abacus
Examples of Abaci
Aztex Abacus
Indian Abacus
Mathematical tools
Chinese mathematics
Egyptian mathematics
Greek mathematics
Indian mathematics
Japanese mathematics
Korean mathematics
Roman mathematics |
656 | https://en.wikipedia.org/wiki/Acid | Acid | An acid is a molecule or ion capable of either donating a proton (i.e. hydrogen ion, H+), known as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid.
The first category of acids are the proton donors, or Brønsted–Lowry acids. In the special case of aqueous solutions, proton donors form the hydronium ion H3O+ and are known as Arrhenius acids. Brønsted and Lowry generalized the Arrhenius theory to include non-aqueous solvents. A Brønsted or Arrhenius acid usually contains a hydrogen atom bonded to a chemical structure that is still energetically favorable after loss of H+.
Aqueous Arrhenius acids have characteristic properties that provide a practical description of an acid. Acids form aqueous solutions with a sour taste, can turn blue litmus red, and react with bases and certain metals (like calcium) to form salts. The word acid is derived from the Latin , meaning 'sour'. An aqueous solution of an acid has a pH less than 7 and is colloquially also referred to as "acid" (as in "dissolved in acid"), while the strict definition refers only to the solute. A lower pH means a higher acidity, and thus a higher concentration of positive hydrogen ions in the solution. Chemicals or substances having the property of an acid are said to be acidic.
Common aqueous acids include hydrochloric acid (a solution of hydrogen chloride that is found in gastric acid in the stomach and activates digestive enzymes), acetic acid (vinegar is a dilute aqueous solution of this liquid), sulfuric acid (used in car batteries), and citric acid (found in citrus fruits). As these examples show, acids (in the colloquial sense) can be solutions or pure substances, and can be derived from acids (in the strict sense) that are solids, liquids, or gases. Strong acids and some concentrated weak acids are corrosive, but there are exceptions such as carboranes and boric acid.
The second category of acids are Lewis acids, which form a covalent bond with an electron pair. An example is boron trifluoride (BF3), whose boron atom has a vacant orbital that can form a covalent bond by sharing a lone pair of electrons on an atom in a base, for example the nitrogen atom in ammonia (NH3). Lewis considered this as a generalization of the Brønsted definition, so that an acid is a chemical species that accepts electron pairs either directly or by releasing protons (H+) into the solution, which then accept electron pairs. Hydrogen chloride, acetic acid, and most other Brønsted–Lowry acids cannot form a covalent bond with an electron pair, however, and are therefore not Lewis acids. Conversely, many Lewis acids are not Arrhenius or Brønsted–Lowry acids. In modern terminology, an acid is implicitly a Brønsted acid and not a Lewis acid, since chemists almost always refer to a Lewis acid explicitly as such.
Definitions and concepts
Modern definitions are concerned with the fundamental chemical reactions common to all acids.
Most acids encountered in everyday life are aqueous solutions, or can be dissolved in water, so the Arrhenius and Brønsted–Lowry definitions are the most relevant.
The Brønsted–Lowry definition is the most widely used definition; unless otherwise specified, acid–base reactions are assumed to involve the transfer of a proton (H+) from an acid to a base.
Hydronium ions are acids according to all three definitions. Although alcohols and amines can be Brønsted–Lowry acids, they can also function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms.
Arrhenius acids
In 1884, Svante Arrhenius attributed the properties of acidity to hydrogen ions (H+), later described as protons or hydrons. An Arrhenius acid is a substance that, when added to water, increases the concentration of H+ ions in the water. Chemists often write H+(aq) and refer to the hydrogen ion when describing acid–base reactions but the free hydrogen nucleus, a proton, does not exist alone in water, it exists as the hydronium ion (H3O+) or other forms (H5O2+, H9O4+). Thus, an Arrhenius acid can also be described as a substance that increases the concentration of hydronium ions when added to water. Examples include molecular substances such as hydrogen chloride and acetic acid.
An Arrhenius base, on the other hand, is a substance that increases the concentration of hydroxide (OH−) ions when dissolved in water. This decreases the concentration of hydronium because the ions react to form H2O molecules:
H3O + OH ⇌ H2O(liq) + H2O(liq)
Due to this equilibrium, any increase in the concentration of hydronium is accompanied by a decrease in the concentration of hydroxide. Thus, an Arrhenius acid could also be said to be one that decreases hydroxide concentration, while an Arrhenius base increases it.
In an acidic solution, the concentration of hydronium ions is greater than 10−7 moles per liter. Since pH is defined as the negative logarithm of the concentration of hydronium ions, acidic solutions thus have a pH of less than 7.
Brønsted–Lowry acids
While the Arrhenius concept is useful for describing many reactions, it is also quite limited in its scope. In 1923, chemists Johannes Nicolaus Brønsted and Thomas Martin Lowry independently recognized that acid–base reactions involve the transfer of a proton. A Brønsted–Lowry acid (or simply Brønsted acid) is a species that donates a proton to a Brønsted–Lowry base. Brønsted–Lowry acid–base theory has several advantages over Arrhenius theory. Consider the following reactions of acetic acid (CH3COOH), the organic acid that gives vinegar its characteristic taste:
Both theories easily describe the first reaction: CH3COOH acts as an Arrhenius acid because it acts as a source of H3O+ when dissolved in water, and it acts as a Brønsted acid by donating a proton to water. In the second example CH3COOH undergoes the same transformation, in this case donating a proton to ammonia (NH3), but does not relate to the Arrhenius definition of an acid because the reaction does not produce hydronium. Nevertheless, CH3COOH is both an Arrhenius and a Brønsted–Lowry acid.
Brønsted–Lowry theory can be used to describe reactions of molecular compounds in nonaqueous solution or the gas phase. Hydrogen chloride (HCl) and ammonia combine under several different conditions to form ammonium chloride, NH4Cl. In aqueous solution HCl behaves as hydrochloric acid and exists as hydronium and chloride ions. The following reactions illustrate the limitations of Arrhenius's definition:
H3O + Cl + NH3 → Cl + NH(aq) + H2O
HCl(benzene) + NH3(benzene) → NH4Cl(s)
HCl(g) + NH3(g) → NH4Cl(s)
As with the acetic acid reactions, both definitions work for the first example, where water is the solvent and hydronium ion is formed by the HCl solute. The next two reactions do not involve the formation of ions but are still proton-transfer reactions. In the second reaction hydrogen chloride and ammonia (dissolved in benzene) react to form solid ammonium chloride in a benzene solvent and in the third gaseous HCl and NH3 combine to form the solid.
Lewis acids
A third, only marginally related concept was proposed in 1923 by Gilbert N. Lewis, which includes reactions with acid–base characteristics that do not involve a proton transfer. A Lewis acid is a species that accepts a pair of electrons from another species; in other words, it is an electron pair acceptor. Brønsted acid–base reactions are proton transfer reactions while Lewis acid–base reactions are electron pair transfers. Many Lewis acids are not Brønsted–Lowry acids. Contrast how the following reactions are described in terms of acid–base chemistry:
In the first reaction a fluoride ion, F−, gives up an electron pair to boron trifluoride to form the product tetrafluoroborate. Fluoride "loses" a pair of valence electrons because the electrons shared in the B—F bond are located in the region of space between the two atomic nuclei and are therefore more distant from the fluoride nucleus than they are in the lone fluoride ion. BF3 is a Lewis acid because it accepts the electron pair from fluoride. This reaction cannot be described in terms of Brønsted theory because there is no proton transfer. The second reaction can be described using either theory. A proton is transferred from an unspecified Brønsted acid to ammonia, a Brønsted base; alternatively, ammonia acts as a Lewis base and transfers a lone pair of electrons to form a bond with a hydrogen ion. The species that gains the electron pair is the Lewis acid; for example, the oxygen atom in H3O+ gains a pair of electrons when one of the H—O bonds is broken and the electrons shared in the bond become localized on oxygen. Depending on the context, a Lewis acid may also be described as an oxidizer or an electrophile. Organic Brønsted acids, such as acetic, citric, or oxalic acid, are not Lewis acids. They dissociate in water to produce a Lewis acid, H+, but at the same time also yield an equal amount of a Lewis base (acetate, citrate, or oxalate, respectively, for the acids mentioned). This article deals mostly with Brønsted acids rather than Lewis acids.
Dissociation and equilibrium
Reactions of acids are often generalized in the form , where HA represents the acid and A− is the conjugate base. This reaction is referred to as protolysis. The protonated form (HA) of an acid is also sometimes referred to as the free acid.
Acid–base conjugate pairs differ by one proton, and can be interconverted by the addition or removal of a proton (protonation and deprotonation, respectively). The acid can be the charged species and the conjugate base can be neutral in which case the generalized reaction scheme could be written as . In solution there exists an equilibrium between the acid and its conjugate base. The equilibrium constant K is an expression of the equilibrium concentrations of the molecules or the ions in solution. Brackets indicate concentration, such that [H2O] means the concentration of H2O. The acid dissociation constant Ka is generally used in the context of acid–base reactions. The numerical value of Ka is equal to the product (multiplication) of the concentrations of the products divided by the concentration of the reactants, where the reactant is the acid (HA) and the products are the conjugate base and H+.
The stronger of two acids will have a higher Ka than the weaker acid; the ratio of hydrogen ions to acid will be higher for the stronger acid as the stronger acid has a greater tendency to lose its proton. Because the range of possible values for Ka spans many orders of magnitude, a more manageable constant, pKa is more frequently used, where pKa = −log10 Ka. Stronger acids have a smaller pKa than weaker acids. Experimentally determined pKa at 25 °C in aqueous solution are often quoted in textbooks and reference material.
Nomenclature
Arrhenius acids are named according to their anions. In the classical naming system, the ionic suffix is dropped and replaced with a new suffix, according to the table following. The prefix "hydro-" is used when the acid is made up of just hydrogen and one other element. For example, HCl has chloride as its anion, so the hydro- prefix is used, and the -ide suffix makes the name take the form hydrochloric acid.
Classical naming system:
In the IUPAC naming system, "aqueous" is simply added to the name of the ionic compound. Thus, for hydrogen chloride, as an acid solution, the IUPAC name is aqueous hydrogen chloride.
Acid strength
The strength of an acid refers to its ability or tendency to lose a proton. A strong acid is one that completely dissociates in water; in other words, one mole of a strong acid HA dissolves in water yielding one mole of H+ and one mole of the conjugate base, A−, and none of the protonated acid HA. In contrast, a weak acid only partially dissociates and at equilibrium both the acid and the conjugate base are in solution. Examples of strong acids are hydrochloric acid (HCl), hydroiodic acid (HI), hydrobromic acid (HBr), perchloric acid (HClO4), nitric acid (HNO3) and sulfuric acid (H2SO4). In water each of these essentially ionizes 100%. The stronger an acid is, the more easily it loses a proton, H+. Two key factors that contribute to the ease of deprotonation are the polarity of the H—A bond and the size of atom A, which determines the strength of the H—A bond. Acid strengths are also often discussed in terms of the stability of the conjugate base.
Stronger acids have a larger acid dissociation constant, Ka and a lower pKa than weaker acids.
Sulfonic acids, which are organic oxyacids, are a class of strong acids. A common example is toluenesulfonic acid (tosylic acid). Unlike sulfuric acid itself, sulfonic acids can be solids. In fact, polystyrene functionalized into polystyrene sulfonate is a solid strongly acidic plastic that is filterable.
Superacids are acids stronger than 100% sulfuric acid. Examples of superacids are fluoroantimonic acid, magic acid and perchloric acid. The strongest known acid is helium hydride ion, with a proton affinity of 177.8kJ/mol. Superacids can permanently protonate water to give ionic, crystalline hydronium "salts". They can also quantitatively stabilize carbocations.
While Ka measures the strength of an acid compound, the strength of an aqueous acid solution is measured by pH, which is an indication of the concentration of hydronium in the solution. The pH of a simple solution of an acid compound in water is determined by the dilution of the compound and the compound's Ka.
Lewis acid strength in non-aqueous solutions
Lewis acids have been classified in the ECW model and it has been shown that there is no one order of acid strengths. The relative acceptor strength of Lewis acids toward a series of bases, versus other Lewis acids, can be illustrated by C-B plots. It has been shown that to define the order of Lewis acid strength at least two properties must be considered. For Pearson's qualitative HSAB theory the two properties are hardness and strength while for Drago's quantitative ECW model the two properties are electrostatic and covalent.
Chemical characteristics
Monoprotic acids
Monoprotic acids, also known as monobasic acids, are those acids that are able to donate one proton per molecule during the process of dissociation (sometimes called ionization) as shown below (symbolized by HA):
Ka
Common examples of monoprotic acids in mineral acids include hydrochloric acid (HCl) and nitric acid (HNO3). On the other hand, for organic acids the term mainly indicates the presence of one carboxylic acid group and sometimes these acids are known as monocarboxylic acid. Examples in organic acids include formic acid (HCOOH), acetic acid (CH3COOH) and benzoic acid (C6H5COOH).
Polyprotic acids
Polyprotic acids, also known as polybasic acids, are able to donate more than one proton per acid molecule, in contrast to monoprotic acids that only donate one proton per molecule. Specific types of polyprotic acids have more specific names, such as diprotic (or dibasic) acid (two potential protons to donate), and triprotic (or tribasic) acid (three potential protons to donate). Some macromolecules such as proteins and nucleic acids can have a very large number of acidic protons.
A diprotic acid (here symbolized by H2A) can undergo one or two dissociations depending on the pH. Each dissociation has its own dissociation constant, Ka1 and Ka2.
Ka1
Ka2
The first dissociation constant is typically greater than the second (i.e., Ka1 > Ka2). For example, sulfuric acid (H2SO4) can donate one proton to form the bisulfate anion (HSO), for which Ka1 is very large; then it can donate a second proton to form the sulfate anion (SO), wherein the Ka2 is intermediate strength. The large Ka1 for the first dissociation makes sulfuric a strong acid. In a similar manner, the weak unstable carbonic acid can lose one proton to form bicarbonate anion and lose a second to form carbonate anion (CO). Both Ka values are small, but Ka1 > Ka2 .
A triprotic acid (H3A) can undergo one, two, or three dissociations and has three dissociation constants, where Ka1 > Ka2 > Ka3.
Ka1
Ka2
Ka3
An inorganic example of a triprotic acid is orthophosphoric acid (H3PO4), usually just called phosphoric acid. All three protons can be successively lost to yield H2PO, then HPO, and finally PO, the orthophosphate ion, usually just called phosphate. Even though the positions of the three protons on the original phosphoric acid molecule are equivalent, the successive Ka values differ since it is energetically less favorable to lose a proton if the conjugate base is more negatively charged. An organic example of a triprotic acid is citric acid, which can successively lose three protons to finally form the citrate ion.
Although the subsequent loss of each hydrogen ion is less favorable, all of the conjugate bases are present in solution. The fractional concentration, α (alpha), for each species can be calculated. For example, a generic diprotic acid will generate 3 species in solution: H2A, HA−, and A2−. The fractional concentrations can be calculated as below when given either the pH (which can be converted to the [H+]) or the concentrations of the acid with all its conjugate bases:
A plot of these fractional concentrations against pH, for given K1 and K2, is known as a Bjerrum plot. A pattern is observed in the above equations and can be expanded to the general n -protic acid that has been deprotonated i -times:
where K0 = 1 and the other K-terms are the dissociation constants for the acid.
Neutralization
Neutralization is the reaction between an acid and a base, producing a salt and neutralized base; for example, hydrochloric acid and sodium hydroxide form sodium chloride and water:
HCl(aq) + NaOH(aq) → H2O(l) + NaCl(aq)
Neutralization is the basis of titration, where a pH indicator shows equivalence point when the equivalent number of moles of a base have been added to an acid. It is often wrongly assumed that neutralization should result in a solution with pH 7.0, which is only the case with similar acid and base strengths during a reaction.
Neutralization with a base weaker than the acid results in a weakly acidic salt. An example is the weakly acidic ammonium chloride, which is produced from the strong acid hydrogen chloride and the weak base ammonia. Conversely, neutralizing a weak acid with a strong base gives a weakly basic salt (e.g., sodium fluoride from hydrogen fluoride and sodium hydroxide).
Weak acid–weak base equilibrium
In order for a protonated acid to lose a proton, the pH of the system must rise above the pKa of the acid. The decreased concentration of H+ in that basic solution shifts the equilibrium towards the conjugate base form (the deprotonated form of the acid). In lower-pH (more acidic) solutions, there is a high enough H+ concentration in the solution to cause the acid to remain in its protonated form.
Solutions of weak acids and salts of their conjugate bases form buffer solutions.
Titration
To determine the concentration of an acid in an aqueous solution, an acid–base titration is commonly performed. A strong base solution with a known concentration, usually NaOH or KOH, is added to neutralize the acid solution according to the color change of the indicator with the amount of base added. The titration curve of an acid titrated by a base has two axes, with the base volume on the x-axis and the solution's pH value on the y-axis. The pH of the solution always goes up as the base is added to the solution.
Example: Diprotic acid
For each diprotic acid titration curve, from left to right, there are two midpoints, two equivalence points, and two buffer regions.
Equivalence points
Due to the successive dissociation processes, there are two equivalence points in the titration curve of a diprotic acid. The first equivalence point occurs when all first hydrogen ions from the first ionization are titrated. In other words, the amount of OH− added equals the original amount of H2A at the first equivalence point. The second equivalence point occurs when all hydrogen ions are titrated. Therefore, the amount of OH− added equals twice the amount of H2A at this time. For a weak diprotic acid titrated by a strong base, the second equivalence point must occur at pH above 7 due to the hydrolysis of the resulted salts in the solution. At either equivalence point, adding a drop of base will cause the steepest rise of the pH value in the system.
Buffer regions and midpoints
A titration curve for a diprotic acid contains two midpoints where pH=pKa. Since there are two different Ka values, the first midpoint occurs at pH=pKa1 and the second one occurs at pH=pKa2. Each segment of the curve that contains a midpoint at its center is called the buffer region. Because the buffer regions consist of the acid and its conjugate base, it can resist pH changes when base is added until the next equivalent points.
Applications of acids
In industry
Acids are fundamental reagents in treating almost all processes in modern industry. Sulfuric acid, a diprotic acid, is the most widely used acid in industry, and is also the most-produced industrial chemical in the world. It is mainly used in producing fertilizer, detergent, batteries and dyes, as well as used in processing many products such like removing impurities. According to the statistics data in 2011, the annual production of sulfuric acid was around 200 million tonnes in the world. For example, phosphate minerals react with sulfuric acid to produce phosphoric acid for the production of phosphate fertilizers, and zinc is produced by dissolving zinc oxide into sulfuric acid, purifying the solution and electrowinning.
In the chemical industry, acids react in neutralization reactions to produce salts. For example, nitric acid reacts with ammonia to produce ammonium nitrate, a fertilizer. Additionally, carboxylic acids can be esterified with alcohols, to produce esters.
Acids are often used to remove rust and other corrosion from metals in a process known as pickling. They may be used as an electrolyte in a wet cell battery, such as sulfuric acid in a car battery.
In food
Tartaric acid is an important component of some commonly used foods like unripened mangoes and tamarind. Natural fruits and vegetables also contain acids. Citric acid is present in oranges, lemon and other citrus fruits. Oxalic acid is present in tomatoes, spinach, and especially in carambola and rhubarb; rhubarb leaves and unripe carambolas are toxic because of high concentrations of oxalic acid. Ascorbic acid (Vitamin C) is an essential vitamin for the human body and is present in such foods as amla (Indian gooseberry), lemon, citrus fruits, and guava.
Many acids can be found in various kinds of food as additives, as they alter their taste and serve as preservatives. Phosphoric acid, for example, is a component of cola drinks. Acetic acid is used in day-to-day life as vinegar. Citric acid is used as a preservative in sauces and pickles.
Carbonic acid is one of the most common acid additives that are widely added in soft drinks. During the manufacturing process, CO2 is usually pressurized to dissolve in these drinks to generate carbonic acid. Carbonic acid is very unstable and tends to decompose into water and CO2 at room temperature and pressure. Therefore, when bottles or cans of these kinds of soft drinks are opened, the soft drinks fizz and effervesce as CO2 bubbles come out.
Certain acids are used as drugs. Acetylsalicylic acid (Aspirin) is used as a pain killer and for bringing down fevers.
In human bodies
Acids play important roles in the human body. The hydrochloric acid present in the stomach aids digestion by breaking down large and complex food molecules. Amino acids are required for synthesis of proteins required for growth and repair of body tissues. Fatty acids are also required for growth and repair of body tissues. Nucleic acids are important for the manufacturing of DNA and RNA and transmitting of traits to offspring through genes. Carbonic acid is important for maintenance of pH equilibrium in the body.
Human bodies contain a variety of organic and inorganic compounds, among those dicarboxylic acids play an essential role in many biological behaviors. Many of those acids are amino acids, which mainly serve as materials for the synthesis of proteins. Other weak acids serve as buffers with their conjugate bases to keep the body's pH from undergoing large scale changes that would be harmful to cells. The rest of the dicarboxylic acids also participate in the synthesis of various biologically important compounds in human bodies.
Acid catalysis
Acids are used as catalysts in industrial and organic chemistry; for example, sulfuric acid is used in very large quantities in the alkylation process to produce gasoline. Some acids, such as sulfuric, phosphoric, and hydrochloric acids, also effect dehydration and condensation reactions. In biochemistry, many enzymes employ acid catalysis.
Biological occurrence
Many biologically important molecules are acids. Nucleic acids, which contain acidic phosphate groups, include DNA and RNA. Nucleic acids contain the genetic code that determines many of an organism's characteristics, and is passed from parents to offspring. DNA contains the chemical blueprint for the synthesis of proteins, which are made up of amino acid subunits. Cell membranes contain fatty acid esters such as phospholipids.
An α-amino acid has a central carbon (the α or alpha carbon) that is covalently bonded to a carboxyl group (thus they are carboxylic acids), an amino group, a hydrogen atom and a variable group. The variable group, also called the R group or side chain, determines the identity and many of the properties of a specific amino acid. In glycine, the simplest amino acid, the R group is a hydrogen atom, but in all other amino acids it is contains one or more carbon atoms bonded to hydrogens, and may contain other elements such as sulfur, oxygen or nitrogen. With the exception of glycine, naturally occurring amino acids are chiral and almost invariably occur in the L-configuration. Peptidoglycan, found in some bacterial cell walls contains some D-amino acids. At physiological pH, typically around 7, free amino acids exist in a charged form, where the acidic carboxyl group (-COOH) loses a proton (-COO−) and the basic amine group (-NH2) gains a proton (-NH). The entire molecule has a net neutral charge and is a zwitterion, with the exception of amino acids with basic or acidic side chains. Aspartic acid, for example, possesses one protonated amine and two deprotonated carboxyl groups, for a net charge of −1 at physiological pH.
Fatty acids and fatty acid derivatives are another group of carboxylic acids that play a significant role in biology. These contain long hydrocarbon chains and a carboxylic acid group on one end. The cell membrane of nearly all organisms is primarily made up of a phospholipid bilayer, a micelle of hydrophobic fatty acid esters with polar, hydrophilic phosphate "head" groups. Membranes contain additional components, some of which can participate in acid–base reactions.
In humans and many other animals, hydrochloric acid is a part of the gastric acid secreted within the stomach to help hydrolyze proteins and polysaccharides, as well as converting the inactive pro-enzyme, pepsinogen into the enzyme, pepsin. Some organisms produce acids for defense; for example, ants produce formic acid.
Acid–base equilibrium plays a critical role in regulating mammalian breathing. Oxygen gas (O2) drives cellular respiration, the process by which animals release the chemical potential energy stored in food, producing carbon dioxide (CO2) as a byproduct. Oxygen and carbon dioxide are exchanged in the lungs, and the body responds to changing energy demands by adjusting the rate of ventilation. For example, during periods of exertion the body rapidly breaks down stored carbohydrates and fat, releasing CO2 into the blood stream. In aqueous solutions such as blood CO2 exists in equilibrium with carbonic acid and bicarbonate ion.
It is the decrease in pH that signals the brain to breathe faster and deeper, expelling the excess CO2 and resupplying the cells with O2.
Cell membranes are generally impermeable to charged or large, polar molecules because of the lipophilic fatty acyl chains comprising their interior. Many biologically important molecules, including a number of pharmaceutical agents, are organic weak acids that can cross the membrane in their protonated, uncharged form but not in their charged form (i.e., as the conjugate base). For this reason the activity of many drugs can be enhanced or inhibited by the use of antacids or acidic foods. The charged form, however, is often more soluble in blood and cytosol, both aqueous environments. When the extracellular environment is more acidic than the neutral pH within the cell, certain acids will exist in their neutral form and will be membrane soluble, allowing them to cross the phospholipid bilayer. Acids that lose a proton at the intracellular pH will exist in their soluble, charged form and are thus able to diffuse through the cytosol to their target. Ibuprofen, aspirin and penicillin are examples of drugs that are weak acids.
Common acids
Mineral acids (inorganic acids)
Hydrogen halides and their solutions: hydrofluoric acid (HF), hydrochloric acid (HCl), hydrobromic acid (HBr), hydroiodic acid (HI)
Halogen oxoacids: hypochlorous acid (HClO), chlorous acid (HClO2), chloric acid (HClO3), perchloric acid (HClO4), and corresponding analogs for bromine and iodine
Hypofluorous acid (HFO), the only known oxoacid for fluorine.
Sulfuric acid (H2SO4)
Fluorosulfuric acid (HSO3F)
Nitric acid (HNO3)
Phosphoric acid (H3PO4)
Fluoroantimonic acid (HSbF6)
Fluoroboric acid (HBF4)
Hexafluorophosphoric acid (HPF6)
Chromic acid (H2CrO4)
Boric acid (H3BO3)
Sulfonic acids
A sulfonic acid has the general formula RS(=O)2–OH, where R is an organic radical.
Methanesulfonic acid (or mesylic acid, CH3SO3H)
Ethanesulfonic acid (or esylic acid, CH3CH2SO3H)
Benzenesulfonic acid (or besylic acid, C6H5SO3H)
p-Toluenesulfonic acid (or tosylic acid, CH3C6H4SO3H)
Trifluoromethanesulfonic acid (or triflic acid, CF3SO3H)
Polystyrene sulfonic acid (sulfonated polystyrene, [CH2CH(C6H4)SO3H]n)
Carboxylic acids
A carboxylic acid has the general formula R-C(O)OH, where R is an organic radical. The carboxyl group -C(O)OH contains a carbonyl group, C=O, and a hydroxyl group, O-H.
Acetic acid (CH3COOH)
Citric acid (C6H8O7)
Formic acid (HCOOH)
Gluconic acid HOCH2-(CHOH)4-COOH
Lactic acid (CH3-CHOH-COOH)
Oxalic acid (HOOC-COOH)
Tartaric acid (HOOC-CHOH-CHOH-COOH)
Halogenated carboxylic acids
Halogenation at alpha position increases acid strength, so that the following acids are all stronger than acetic acid.
Fluoroacetic acid
Trifluoroacetic acid
Chloroacetic acid
Dichloroacetic acid
Trichloroacetic acid
Vinylogous carboxylic acids
Normal carboxylic acids are the direct union of a carbonyl group and a hydroxyl group. In vinylogous carboxylic acids, a carbon-carbon double bond separates the carbonyl and hydroxyl groups.
Ascorbic acid
Nucleic acids
Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)
References
Listing of strengths of common acids and bases
External links
Curtipot: Acid–Base equilibria diagrams, pH calculation and titration curves simulation and analysis – freeware
Acid–base chemistry |
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Voluntary consensus standards quicken the market acceptance of products while making clear how to improve the safety of those products for the protection of consumers. There are approximately 9,500 American National Standards that carry the ANSI designation.
The American National Standards process involves:
consensus by a group that is open to representatives from all interested parties
broad-based public review and comment on draft standards
consideration of and response to comments
incorporation of submitted changes that meet the same consensus requirements into a draft standard
availability of an appeal by any participant alleging that these principles were not respected during the standards-development process.
International activities
In addition to facilitating the formation of standards in the United States, ANSI promotes the use of U.S. standards internationally, advocates U.S. policy and technical positions in international and regional standards organizations, and encourages the adoption of international standards as national standards where appropriate.
The institute is the official U.S. representative to the two major international standards organizations, the International Organization for Standardization (ISO), as a founding member, and the International Electrotechnical Commission (IEC), via the U.S. National Committee (USNC). ANSI participates in almost the entire technical program of both the ISO and the IEC, and administers many key committees and subgroups. In many instances, U.S. standards are taken forward to ISO and IEC, through ANSI or the USNC, where they are adopted in whole or in part as international standards.
Adoption of ISO and IEC standards as American standards increased from 0.2% in 1986 to 15.5% in May 2012.
Standards panels
The Institute administers nine standards panels:
ANSI Homeland Defense and Security Standardization Collaborative (HDSSC)
ANSI Nanotechnology Standards Panel (ANSI-NSP)
ID Theft Prevention and ID Management Standards Panel (IDSP)
ANSI Energy Efficiency Standardization Coordination Collaborative (EESCC)
Nuclear Energy Standards Coordination Collaborative (NESCC)
Electric Vehicles Standards Panel (EVSP)
ANSI-NAM Network on Chemical Regulation
ANSI Biofuels Standards Coordination Panel
Healthcare Information Technology Standards Panel (HITSP)
Each of the panels works to identify, coordinate, and harmonize voluntary standards relevant to these areas.
In 2009, ANSI and the National Institute of Standards and Technology (NIST) formed the Nuclear Energy Standards Coordination Collaborative (NESCC). NESCC is a joint initiative to identify and respond to the current need for standards in the nuclear industry.
American national standards
The ASA (as for American Standards Association) photographic exposure system, originally defined in ASA Z38.2.1 (since 1943) and ASA PH2.5 (since 1954), together with the DIN system (DIN 4512 since 1934), became the basis for the ISO system (since 1974), currently used worldwide (ISO 6, ISO 2240, ISO 5800, ISO 12232).
A standard for the set of values used to represent characters in digital computers. The ANSI code standard extended the previously created ASCII seven bit code standard (ASA X3.4-1963), with additional codes for European alphabets (see also Extended Binary Coded Decimal Interchange Code or EBCDIC). In Microsoft Windows, the phrase "ANSI" refers to the Windows ANSI code pages (even though they are not ANSI standards). Most of these are fixed width, though some characters for ideographic languages are variable width. Since these characters are based on a draft of the ISO-8859 series, some of Microsoft's symbols are visually very similar to the ISO symbols, leading many to falsely assume that they are identical.
The first computer programming language standard was "American Standard Fortran" (informally known as "FORTRAN 66"), approved in March 1966 and published as ASA X3.9-1966.
The programming language COBOL had ANSI standards in 1968, 1974, and 1985. The COBOL 2002 standard was issued by ISO.
The original standard implementation of the C programming language was standardized as ANSI X3.159-1989, becoming the well-known ANSI C.
The X3J13 committee was created in 1986 to formalize the ongoing consolidation of Common Lisp, culminating in 1994 with the publication of ANSI's first object-oriented programming standard.
A popular Unified Thread Standard for nuts and bolts is ANSI/ASME B1.1 which was defined in 1935, 1949, 1989, and 2003.
The ANSI-NSF International standards used for commercial kitchens, such as restaurants, cafeterias, delis, etc.
The ANSI/APSP (Association of Pool & Spa Professionals) standards used for pools, spas, hot tubs, barriers, and suction entrapment avoidance.
The ANSI/HI (Hydraulic Institute) standards used for pumps.
The ANSI for eye protection is Z87.1, which gives a specific impact resistance rating to the eyewear. This standard is commonly used for shop glasses, shooting glasses, and many other examples of protective eyewear. While compliance to this standard is required by United States federal law, it is not made freely available by ANSI, who charges $65 to read a PDF of it.
The ANSI paper sizes (ANSI/ASME Y14.1).
See also
Accredited Crane Operator Certification
ANSI ASC X9
ANSI ASC X12
ANSI C
Institute of Environmental Sciences and Technology (IEST)
Institute of Nuclear Materials Management (INMM)
ISO (to which ANSI is the official US representative)
National Information Standards Organization (NISO)
National Institute of Standards and Technology (NIST)
Open standards
References
External links
1918 establishments in the United States
501(c)(3) organizations
Charities based in Washington, D.C.
ISO member bodies
Organizations established in 1918
Technical specifications |
661 | https://en.wikipedia.org/wiki/Argument%20%28disambiguation%29 | Argument (disambiguation) | In logic and philosophy, an argument is an attempt to persuade someone of something, or give evidence or reasons for accepting a particular conclusion.
Argument may also refer to:
Mathematics and computer science
Argument (complex analysis), a function which returns the polar angle of a complex number
Command-line argument, an item of information provided to a program when it is started
Parameter (computer programming), a piece of data provided as input to a subroutine
Argument principle, a theorem in complex analysis
An argument of a function, also known as an independent variable
Language and rhetoric
Argument (literature), a brief summary, often in prose, of a poem or section of a poem or other work
Argument (linguistics), a phrase that appears in a syntactic relationship with the verb in a clause
Oral argument in the United States, a spoken presentation to a judge or appellate court by a lawyer (or parties when representing themselves) of the legal reasons why they should prevail
Closing argument, in law, the concluding statement of each party's counsel reiterating the important arguments in a court case
Other uses
Musical argument, a concept in the theory of musical form
Argument (ship), an Australian sloop wrecked in 1809
Das Argument, a German academic journal
Argument Clinic, a Monty Python sketch
A disagreement between two or more parties or the discussion of the disagreement
Argument (horse)
See also
The Argument (disambiguation)
argumentation |
662 | https://en.wikipedia.org/wiki/Apollo%2011 | Apollo 11 | Apollo 11 (July 16–24, 1969) was the American spaceflight that first landed humans on the Moon. Commander Neil Armstrong and Lunar Module Pilot Buzz Aldrin landed the Apollo Lunar Module Eagle on July 20, 1969, at 20:17 UTC, and Armstrong became the first person to step onto the Moon's surface six hours and 39 minutes later, on July 21 at 02:56 UTC. Aldrin joined him 19 minutes later, and they spent about two and a quarter hours together exploring the site they had named Tranquility Base upon landing. Armstrong and Aldrin collected of lunar material to bring back to Earth as pilot Michael Collins flew the Command Module Columbia in lunar orbit, and were on the Moon's surface for 21 hours, 36 minutes before lifting off to rejoin Columbia.
Apollo 11 was launched by a Saturn V rocket from Kennedy Space Center on Merritt Island, Florida, on July 16 at 13:32 UTC, and it was the fifth crewed mission of NASA's Apollo program. The Apollo spacecraft had three parts: a command module (CM) with a cabin for the three astronauts, the only part that returned to Earth; a service module (SM), which supported the command module with propulsion, electrical power, oxygen, and water; and a lunar module (LM) that had two stages—a descent stage for landing on the Moon and an ascent stage to place the astronauts back into lunar orbit.
After being sent to the Moon by the Saturn V's third stage, the astronauts separated the spacecraft from it and traveled for three days until they entered lunar orbit. Armstrong and Aldrin then moved into Eagle and landed in the Sea of Tranquility on July 20. The astronauts used Eagles ascent stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that propelled Columbia out of the last of its 30 lunar orbits onto a trajectory back to Earth. They returned to Earth and splashed down in the Pacific Ocean on July 24 after more than eight days in space.
Armstrong's first step onto the lunar surface was broadcast on live TV to a worldwide audience. He described the event as "one small step for [a] man, one giant leap for mankind." Apollo 11 effectively proved U.S. victory in the Space Race to demonstrate spaceflight superiority, by fulfilling a national goal proposed in 1961 by President John F. Kennedy, "before this decade is out, of landing a man on the Moon and returning him safely to the Earth."
Background
In the late 1950s and early 1960s, the United States was engaged in the Cold War, a geopolitical rivalry with the Soviet Union. On October 4, 1957, the Soviet Union launched Sputnik 1, the first artificial satellite. This surprise success fired fears and imaginations around the world. It demonstrated that the Soviet Union had the capability to deliver nuclear weapons over intercontinental distances, and challenged American claims of military, economic, and technological superiority. This precipitated the Sputnik crisis, and triggered the Space Race to prove which superpower would achieve superior spaceflight capability. President Dwight D. Eisenhower responded to the Sputnik challenge by creating the National Aeronautics and Space Administration (NASA), and initiating Project Mercury, which aimed to launch a man into Earth orbit. But on April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first person in space, and the first to orbit the Earth. Nearly a month later, on May 5, 1961, Alan Shepard became the first American in space, completing a 15-minute suborbital journey. After being recovered from the Atlantic Ocean, he received a congratulatory telephone call from Eisenhower's successor, John F. Kennedy.
Since the Soviet Union had higher lift capacity launch vehicles, Kennedy chose, from among options presented by NASA, a challenge beyond the capacity of the existing generation of rocketry, so that the US and Soviet Union would be starting from a position of equality. A crewed mission to the Moon would serve this purpose.
On May 25, 1961, Kennedy addressed the United States Congress on "Urgent National Needs" and declared:
On September 12, 1962, Kennedy delivered another speech before a crowd of about 40,000 people in the Rice University football stadium in Houston, Texas. A widely quoted refrain from the middle portion of the speech reads as follows:
In spite of that, the proposed program faced the opposition of many Americans and was dubbed a "moondoggle" by Norbert Wiener, a mathematician at the Massachusetts Institute of Technology. The effort to land a man on the Moon already had a name: Project Apollo. When Kennedy met with Nikita Khrushchev, the Premier of the Soviet Union in June 1961, he proposed making the Moon landing a joint project, but Khrushchev did not take up the offer. Kennedy again proposed a joint expedition to the Moon in a speech to the United Nations General Assembly on September 20, 1963. The idea of a joint Moon mission was abandoned after Kennedy's death.
An early and crucial decision was choosing lunar orbit rendezvous over both direct ascent and Earth orbit rendezvous. A space rendezvous is an orbital maneuver in which two spacecraft navigate through space and meet up. In July 1962 NASA head James Webb announced that lunar orbit rendezvous would be used and that the Apollo spacecraft would have three major parts: a command module (CM) with a cabin for the three astronauts, and the only part that returned to Earth; a service module (SM), which supported the command module with propulsion, electrical power, oxygen, and water; and a lunar module (LM) that had two stages—a descent stage for landing on the Moon, and an ascent stage to place the astronauts back into lunar orbit. This design meant the spacecraft could be launched by a single Saturn V rocket that was then under development.
Technologies and techniques required for Apollo were developed by Project Gemini. The Apollo project was enabled by NASA's adoption of new advances in semiconductor electronic technology, including metal–oxide–semiconductor field-effect transistors (MOSFETs) in the Interplanetary Monitoring Platform (IMP) and silicon integrated circuit (IC) chips in the Apollo Guidance Computer (AGC).
Project Apollo was abruptly halted by the Apollo 1 fire on January 27, 1967, in which astronauts Gus Grissom, Ed White, and Roger B. Chaffee died, and the subsequent investigation. In October 1968, Apollo 7 evaluated the command module in Earth orbit, and in December Apollo 8 tested it in lunar orbit. In March 1969, Apollo 9 put the lunar module through its paces in Earth orbit, and in May Apollo 10 conducted a "dress rehearsal" in lunar orbit. By July 1969, all was in readiness for Apollo 11 to take the final step onto the Moon.
The Soviet Union appeared to be winning the Space Race by beating the US to firsts, but its early lead was overtaken by the US Gemini program and Soviet failure to develop the N1 launcher, which would have been comparable to the Saturn V. The Soviets tried to beat the US to return lunar material to the Earth by means of uncrewed probes. On July 13, three days before Apollo 11's launch, the Soviet Union launched Luna 15, which reached lunar orbit before Apollo 11. During descent, a malfunction caused Luna 15 to crash in Mare Crisium about two hours before Armstrong and Aldrin took off from the Moon's surface to begin their voyage home. The Nuffield Radio Astronomy Laboratories radio telescope in England recorded transmissions from Luna 15 during its descent, and these were released in July 2009 for the 40th anniversary of Apollo 11.
Personnel
Prime crew
The initial crew assignment of Commander Neil Armstrong, Command Module Pilot (CMP) Jim Lovell, and Lunar Module Pilot (LMP) Buzz Aldrin on the backup crew for Apollo 9 was officially announced on November 20, 1967. Lovell and Aldrin had previously flown together as the crew of Gemini 12. Due to design and manufacturing delays in the LM, Apollo 8 and Apollo 9 swapped prime and backup crews, and Armstrong's crew became the backup for Apollo 8. Based on the normal crew rotation scheme, Armstrong was then expected to command Apollo 11.
There would be one change. Michael Collins, the CMP on the Apollo 8 crew, began experiencing trouble with his legs. Doctors diagnosed the problem as a bony growth between his fifth and sixth vertebrae, requiring surgery. Lovell took his place on the Apollo 8 crew, and when Collins recovered he joined Armstrong's crew as CMP. In the meantime, Fred Haise filled in as backup LMP, and Aldrin as backup CMP for Apollo 8. Apollo 11 was the second American mission where all the crew members had prior spaceflight experience, the first being Apollo 10. The next was STS-26 in 1988.
Deke Slayton gave Armstrong the option to replace Aldrin with Lovell, since some thought Aldrin was difficult to work with. Armstrong had no issues working with Aldrin but thought it over for a day before declining. He thought Lovell deserved to command his own mission (eventually Apollo 13).
The Apollo 11 prime crew had none of the close cheerful camaraderie characterized by that of Apollo 12. Instead, they forged an amiable working relationship. Armstrong in particular was notoriously aloof, but Collins, who considered himself a loner, confessed to rebuffing Aldrin's attempts to create a more personal relationship. Aldrin and Collins described the crew as "amiable strangers". Armstrong did not agree with the assessment, and said "... all the crews I was on worked very well together."
Backup crew
The backup crew consisted of Lovell as Commander, William Anders as CMP, and Haise as LMP. Anders had flown with Lovell on Apollo 8. In early 1969, Anders accepted a job with the National Aeronautics and Space Council effective August 1969, and announced he would retire as an astronaut at that time. Ken Mattingly was moved from the support crew into parallel training with Anders as backup CMP in case Apollo 11 was delayed past its intended July launch date, at which point Anders would be unavailable.
By the normal crew rotation in place during Apollo, Lovell, Mattingly, and Haise were scheduled to fly on Apollo 14, but the three of them were bumped to Apollo 13: there was a crew issue for Apollo 13 as none of them except Edgar Mitchell flew in space again. George Mueller rejected the crew and this was the first time an Apollo crew was rejected. To give Alan Shepard more training time, Lovell's crew were bumped to Apollo 13. Mattingly would later be replaced by Jack Swigert as CMP on Apollo 13.
Support crew
During Projects Mercury and Gemini, each mission had a prime and a backup crew. For Apollo, a third crew of astronauts was added, known as the support crew. The support crew maintained the flight plan, checklists and mission ground rules, and ensured the prime and backup crews were apprised of changes. They developed procedures, especially those for emergency situations, so these were ready for when the prime and backup crews came to train in the simulators, allowing them to concentrate on practicing and mastering them. For Apollo 11, the support crew consisted of Ken Mattingly, Ronald Evans and Bill Pogue.
Capsule communicators
The capsule communicator (CAPCOM) was an astronaut at the Mission Control Center in Houston, Texas, who was the only person who communicated directly with the flight crew. For Apollo 11, the CAPCOMs were: Charles Duke, Ronald Evans, Bruce McCandless II, James Lovell, William Anders, Ken Mattingly, Fred Haise, Don L. Lind, Owen K. Garriott and Harrison Schmitt.
Flight directors
The flight directors for this mission were:
Other key personnel
Other key personnel who played important roles in the Apollo 11 mission include the following.
Preparations
Insignia
The Apollo 11 mission emblem was designed by Collins, who wanted a symbol for "peaceful lunar landing by the United States". At Lovell's suggestion, he chose the bald eagle, the national bird of the United States, as the symbol. Tom Wilson, a simulator instructor, suggested an olive branch in its beak to represent their peaceful mission. Collins added a lunar background with the Earth in the distance. The sunlight in the image was coming from the wrong direction; the shadow should have been in the lower part of the Earth instead of the left. Aldrin, Armstrong and Collins decided the Eagle and the Moon would be in their natural colors, and decided on a blue and gold border. Armstrong was concerned that "eleven" would not be understood by non-English speakers, so they went with "Apollo 11", and they decided not to put their names on the patch, so it would "be representative of everyone who had worked toward a lunar landing".
An illustrator at the Manned Spacecraft Center (MSC) did the artwork, which was then sent off to NASA officials for approval. The design was rejected. Bob Gilruth, the director of the MSC felt the talons of the eagle looked "too warlike". After some discussion, the olive branch was moved to the talons. When the Eisenhower dollar coin was released in 1971, the patch design provided the eagle for its reverse side. The design was also used for the smaller Susan B. Anthony dollar unveiled in 1979.
Call signs
After the crew of Apollo 10 named their spacecraft Charlie Brown and Snoopy, assistant manager for public affairs Julian Scheer wrote to George Low, the Manager of the Apollo Spacecraft Program Office at the MSC, to suggest the Apollo 11 crew be less flippant in naming their craft. The name Snowcone was used for the CM and Haystack was used for the LM in both internal and external communications during early mission planning.
The LM was named Eagle after the motif which was featured prominently on the mission insignia. At Scheer's suggestion, the CM was named Columbia after Columbiad, the giant cannon that launched a spacecraft (also from Florida) in Jules Verne's 1865 novel From the Earth to the Moon. It also referred to Columbia, a historical name of the United States. In Collins' 1976 book, he said Columbia was in reference to Christopher Columbus.
Mementos
The astronauts had personal preference kits (PPKs), small bags containing personal items of significance they wanted to take with them on the mission. Five PPKs were carried on Apollo 11: three (one for each astronaut) were stowed on Columbia before launch, and two on Eagle.
Neil Armstrong's LM PPK contained a piece of wood from the Wright brothers' 1903 Wright Flyers left propeller and a piece of fabric from its wing, along with a diamond-studded astronaut pin originally given to Slayton by the widows of the Apollo 1 crew. This pin had been intended to be flown on that mission and given to Slayton afterwards, but following the disastrous launch pad fire and subsequent funerals, the widows gave the pin to Slayton. Armstrong took it with him on Apollo 11.
Site selection
NASA's Apollo Site Selection Board announced five potential landing sites on February 8, 1968. These were the result of two years' worth of studies based on high-resolution photography of the lunar surface by the five uncrewed probes of the Lunar Orbiter program and information about surface conditions provided by the Surveyor program. The best Earth-bound telescopes could not resolve features with the resolution Project Apollo required. The landing site had to be close to the lunar equator to minimize the amount of propellant required, clear of obstacles to minimize maneuvering, and flat to simplify the task of the landing radar. Scientific value was not a consideration.
Areas that appeared promising on photographs taken on Earth were often found to be totally unacceptable. The original requirement that the site be free of craters had to be relaxed, as no such site was found. Five sites were considered: Sites 1 and 2 were in the Sea of Tranquility (Mare Tranquillitatis); Site 3 was in the Central Bay (Sinus Medii); and Sites 4 and 5 were in the Ocean of Storms (Oceanus Procellarum).
The final site selection was based on seven criteria:
The site needed to be smooth, with relatively few craters;
with approach paths free of large hills, tall cliffs or deep craters that might confuse the landing radar and cause it to issue incorrect readings;
reachable with a minimum amount of propellant;
allowing for delays in the launch countdown;
providing the Apollo spacecraft with a free-return trajectory, one that would allow it to coast around the Moon and safely return to Earth without requiring any engine firings should a problem arise on the way to the Moon;
with good visibility during the landing approach, meaning the Sun would be between 7 and 20 degrees behind the LM; and
a general slope of less than two degrees in the landing area.
The requirement for the Sun angle was particularly restrictive, limiting the launch date to one day per month. A landing just after dawn was chosen to limit the temperature extremes the astronauts would experience. The Apollo Site Selection Board selected Site 2, with Sites 3 and 5 as backups in the event of the launch being delayed. In May 1969, Apollo 10's lunar module flew to within of Site 2, and reported it was acceptable.
First-step decision
During the first press conference after the Apollo 11 crew was announced, the first question was, "Which one of you gentlemen will be the first man to step onto the lunar surface?" Slayton told the reporter it had not been decided, and Armstrong added that it was "not based on individual desire".
One of the first versions of the egress checklist had the lunar module pilot exit the spacecraft before the commander, which matched what had been done on Gemini missions, where the commander had never performed the spacewalk. Reporters wrote in early 1969 that Aldrin would be the first man to walk on the Moon, and Associate Administrator George Mueller told reporters he would be first as well. Aldrin heard that Armstrong would be the first because Armstrong was a civilian, which made Aldrin livid. Aldrin attempted to persuade other lunar module pilots he should be first, but they responded cynically about what they perceived as a lobbying campaign. Attempting to stem interdepartmental conflict, Slayton told Aldrin that Armstrong would be first since he was the commander. The decision was announced in a press conference on April 14, 1969.
For decades, Aldrin believed the final decision was largely driven by the lunar module's hatch location. Because the astronauts had their spacesuits on and the spacecraft was so small, maneuvering to exit the spacecraft was difficult. The crew tried a simulation in which Aldrin left the spacecraft first, but he damaged the simulator while attempting to egress. While this was enough for mission planners to make their decision, Aldrin and Armstrong were left in the dark on the decision until late spring. Slayton told Armstrong the plan was to have him leave the spacecraft first, if he agreed. Armstrong said, "Yes, that's the way to do it."
The media accused Armstrong of exercising his commander's prerogative to exit the spacecraft first. Chris Kraft revealed in his 2001 autobiography that a meeting occurred between Gilruth, Slayton, Low, and himself to make sure Aldrin would not be the first to walk on the Moon. They argued that the first person to walk on the Moon should be like Charles Lindbergh, a calm and quiet person. They made the decision to change the flight plan so the commander was the first to egress from the spacecraft.
Pre-launch
The ascent stage of LM-5 Eagle arrived at the Kennedy Space Center on January 8, 1969, followed by the descent stage four days later, and CSM-107 Columbia on January 23. There were several differences between Eagle and Apollo 10's LM-4 Snoopy; Eagle had a VHF radio antenna to facilitate communication with the astronauts during their EVA on the lunar surface; a lighter ascent engine; more thermal protection on the landing gear; and a package of scientific experiments known as the Early Apollo Scientific Experiments Package (EASEP). The only change in the configuration of the command module was the removal of some insulation from the forward hatch. The CSM was mated on January 29, and moved from the Operations and Checkout Building to the Vehicle Assembly Building on April 14.
The S-IVB third stage of Saturn V AS-506 had arrived on January 18, followed by the S-II second stage on February 6, S-IC first stage on February 20, and the Saturn V Instrument Unit on February 27. At 12:30 on May 20, the assembly departed the Vehicle Assembly Building atop the crawler-transporter, bound for Launch Pad 39A, part of Launch Complex 39, while Apollo 10 was still on its way to the Moon. A countdown test commenced on June 26, and concluded on July 2. The launch complex was floodlit on the night of July 15, when the crawler-transporter carried the mobile service structure back to its parking area. In the early hours of the morning, the fuel tanks of the S-II and S-IVB stages were filled with liquid hydrogen. Fueling was completed by three hours before launch. Launch operations were partly automated, with 43 programs written in the ATOLL programming language.
Slayton roused the crew shortly after 04:00, and they showered, shaved, and had the traditional pre-flight breakfast of steak and eggs with Slayton and the backup crew. They then donned their space suits and began breathing pure oxygen. At 06:30, they headed out to Launch Complex 39. Haise entered Columbia about three hours and ten minutes before launch time. Along with a technician, he helped Armstrong into the left-hand couch at 06:54. Five minutes later, Collins joined him, taking up his position on the right-hand couch. Finally, Aldrin entered, taking the center couch. Haise left around two hours and ten minutes before launch. The closeout crew sealed the hatch, and the cabin was purged and pressurized. The closeout crew then left the launch complex about an hour before launch time. The countdown became automated at three minutes and twenty seconds before launch time. Over 450 personnel were at the consoles in the firing room.
Mission
Launch and flight to lunar orbit
An estimated one million spectators watched the launch of Apollo 11 from the highways and beaches in the vicinity of the launch site. Dignitaries included the Chief of Staff of the United States Army, General William Westmoreland, four cabinet members, 19 state governors, 40 mayors, 60 ambassadors and 200 congressmen. Vice President Spiro Agnew viewed the launch with former president Lyndon B. Johnson and his wife Lady Bird Johnson. Around 3,500 media representatives were present. About two-thirds were from the United States; the rest came from 55 other countries. The launch was televised live in 33 countries, with an estimated 25 million viewers in the United States alone. Millions more around the world listened to radio broadcasts. President Richard Nixon viewed the launch from his office in the White House with his NASA liaison officer, Apollo astronaut Frank Borman.
Saturn V AS-506 launched Apollo 11 on July 16, 1969, at 13:32:00 UTC (9:32:00 EDT). At 13.2 seconds into the flight, the launch vehicle began to roll into its flight azimuth of 72.058°. Full shutdown of the first-stage engines occurred about 2 minutes and 42 seconds into the mission, followed by separation of the S-IC and ignition of the S-II engines. The second stage engines then cut off and separated at about 9 minutes and 8 seconds, allowing the first ignition of the S-IVB engine a few seconds later.
Apollo 11 entered a near-circular Earth orbit at an altitude of by , twelve minutes into its flight. After one and a half orbits, a second ignition of the S-IVB engine pushed the spacecraft onto its trajectory toward the Moon with the trans-lunar injection (TLI) burn at 16:22:13 UTC. About 30 minutes later, with Collins in the left seat and at the controls, the transposition, docking, and extraction maneuver was performed. This involved separating Columbia from the spent S-IVB stage, turning around, and docking with Eagle still attached to the stage. After the LM was extracted, the combined spacecraft headed for the Moon, while the rocket stage flew on a trajectory past the Moon. This was done to avoid the third stage colliding with the spacecraft, the Earth, or the Moon. A slingshot effect from passing around the Moon threw it into an orbit around the Sun.
On July 19 at 17:21:50 UTC, Apollo 11 passed behind the Moon and fired its service propulsion engine to enter lunar orbit. In the thirty orbits that followed, the crew saw passing views of their landing site in the southern Sea of Tranquility about southwest of the crater Sabine D. The site was selected in part because it had been characterized as relatively flat and smooth by the automated Ranger 8 and Surveyor 5 landers and the Lunar Orbiter mapping spacecraft, and because it was unlikely to present major landing or EVA challenges. It lay about southeast of the Surveyor 5 landing site, and southwest of Ranger 8's crash site.
Lunar descent
At 12:52:00 UTC on July 20, Aldrin and Armstrong entered Eagle, and began the final preparations for lunar descent. At 17:44:00 Eagle separated from Columbia. Collins, alone aboard Columbia, inspected Eagle as it pirouetted before him to ensure the craft was not damaged, and that the landing gear was correctly deployed. Armstrong exclaimed: "The Eagle has wings!"
As the descent began, Armstrong and Aldrin found themselves passing landmarks on the surface two or three seconds early, and reported that they were "long"; they would land miles west of their target point. Eagle was traveling too fast. The problem could have been mascons—concentrations of high mass in a region or regions of the Moon's crust that contains a gravitational anomaly, potentially altering Eagle trajectory. Flight Director Gene Kranz speculated that it could have resulted from extra air pressure in the docking tunnel, or a result of Eagles pirouette maneuver.
Five minutes into the descent burn, and above the surface of the Moon, the LM guidance computer (LGC) distracted the crew with the first of several unexpected 1201 and 1202 program alarms. Inside Mission Control Center, computer engineer Jack Garman told Guidance Officer Steve Bales it was safe to continue the descent, and this was relayed to the crew. The program alarms indicated "executive overflows", meaning the guidance computer could not complete all its tasks in real-time and had to postpone some of them. Margaret Hamilton, the Director of Apollo Flight Computer Programming at the MIT Charles Stark Draper Laboratory later recalled:
During the mission, the cause was diagnosed as the rendezvous radar switch being in the wrong position, causing the computer to process data from both the rendezvous and landing radars at the same time. Software engineer Don Eyles concluded in a 2005 Guidance and Control Conference paper that the problem was due to a hardware design bug previously seen during testing of the first uncrewed LM in Apollo 5. Having the rendezvous radar on (so it was warmed up in case of an emergency landing abort) should have been irrelevant to the computer, but an electrical phasing mismatch between two parts of the rendezvous radar system could cause the stationary antenna to appear to the computer as dithering back and forth between two positions, depending upon how the hardware randomly powered up. The extra spurious cycle stealing, as the rendezvous radar updated an involuntary counter, caused the computer alarms.
Landing
When Armstrong again looked outside, he saw that the computer's landing target was in a boulder-strewn area just north and east of a crater (later determined to be West crater), so he took semi-automatic control. Armstrong considered landing short of the boulder field so they could collect geological samples from it, but could not since their horizontal velocity was too high. Throughout the descent, Aldrin called out navigation data to Armstrong, who was busy piloting Eagle. Now above the surface, Armstrong knew their propellant supply was dwindling and was determined to land at the first possible landing site.
Armstrong found a clear patch of ground and maneuvered the spacecraft towards it. As he got closer, now above the surface, he discovered his new landing site had a crater in it. He cleared the crater and found another patch of level ground. They were now from the surface, with only 90 seconds of propellant remaining. Lunar dust kicked up by the LM's engine began to impair his ability to determine the spacecraft's motion. Some large rocks jutted out of the dust cloud, and Armstrong focused on them during his descent so he could determine the spacecraft's speed.
A light informed Aldrin that at least one of the probes hanging from Eagle footpads had touched the surface a few moments before the landing and he said: "Contact light!" Armstrong was supposed to immediately shut the engine down, as the engineers suspected the pressure caused by the engine's own exhaust reflecting off the lunar surface could make it explode, but he forgot. Three seconds later, Eagle landed and Armstrong shut the engine down. Aldrin immediately said "Okay, engine stop. ACA—out of detent." Armstrong acknowledged: "Out of detent. Auto." Aldrin continued: "Mode control—both auto. Descent engine command override off. Engine arm—off. 413 is in."
ACA was the Attitude Control Assembly—the LM's control stick. Output went to the LGC to command the reaction control system (RCS) jets to fire. "Out of Detent" meant the stick had moved away from its centered position; it was spring-centered like the turn indicator in a car. Address 413 of the Abort Guidance System (AGS) contained the variable that indicated the LM had landed.
Eagle landed at 20:17:40 UTC on Sunday July 20 with of usable fuel remaining. Information available to the crew and mission controllers during the landing showed the LM had enough fuel for another 25 seconds of powered flight before an abort without touchdown would have become unsafe, but post-mission analysis showed that the real figure was probably closer to 50 seconds. Apollo 11 landed with less fuel than most subsequent missions, and the astronauts encountered a premature low fuel warning. This was later found to be the result of the propellant sloshing more than expected, uncovering a fuel sensor. On subsequent missions, extra anti-slosh baffles were added to the tanks to prevent this.
Armstrong acknowledged Aldrin's completion of the post-landing checklist with "Engine arm is off", before responding to the CAPCOM, Charles Duke, with the words, "Houston, Tranquility Base here. The Eagle has landed." Armstrong's unrehearsed change of call sign from "Eagle" to "Tranquility Base" emphasized to listeners that landing was complete and successful. Duke expressed the relief at Mission Control: "Roger, Twan—Tranquility, we copy you on the ground. You got a bunch of guys about to turn blue. We're breathing again. Thanks a lot."
Two and a half hours after landing, before preparations began for the EVA, Aldrin radioed to Earth:
He then took communion privately. At this time NASA was still fighting a lawsuit brought by atheist Madalyn Murray O'Hair (who had objected to the Apollo 8 crew reading from the Book of Genesis) demanding that their astronauts refrain from broadcasting religious activities while in space. For this reason, Aldrin chose to refrain from directly mentioning taking communion on the Moon. Aldrin was an elder at the Webster Presbyterian Church, and his communion kit was prepared by the pastor of the church, Dean Woodruff. Webster Presbyterian possesses the chalice used on the Moon and commemorates the event each year on the Sunday closest to July 20. The schedule for the mission called for the astronauts to follow the landing with a five-hour sleep period, but they chose to begin preparations for the EVA early, thinking they would be unable to sleep.
Lunar surface operations
Preparations for Neil Armstrong and Buzz Aldrin to walk on the Moon began at 23:43 UTC. These took longer than expected; three and a half hours instead of two. During training on Earth, everything required had been neatly laid out in advance, but on the Moon the cabin contained a large number of other items as well, such as checklists, food packets, and tools. Six hours and thirty-nine minutes after landing, Armstrong and Aldrin were ready to go outside, and Eagle was depressurized.
Eagles hatch was opened at 02:39:33. Armstrong initially had some difficulties squeezing through the hatch with his portable life support system (PLSS). Some of the highest heart rates recorded from Apollo astronauts occurred during LM egress and ingress. At 02:51 Armstrong began his descent to the lunar surface. The remote control unit on his chest kept him from seeing his feet. Climbing down the nine-rung ladder, Armstrong pulled a D-ring to deploy the modular equipment stowage assembly (MESA) folded against Eagle side and activate the TV camera.
Apollo 11 used slow-scan television (TV) incompatible with broadcast TV, so it was displayed on a special monitor and a conventional TV camera viewed this monitor (thus, a broadcast of a broadcast), significantly reducing the quality of the picture. The signal was received at Goldstone in the United States, but with better fidelity by Honeysuckle Creek Tracking Station near Canberra in Australia. Minutes later the feed was switched to the more sensitive Parkes radio telescope in Australia. Despite some technical and weather difficulties, black and white images of the first lunar EVA were received and broadcast to at least 600 million people on Earth. Copies of this video in broadcast format were saved and are widely available, but recordings of the original slow scan source transmission from the lunar surface were likely destroyed during routine magnetic tape re-use at NASA.
After describing the surface dust as "very fine-grained" and "almost like a powder", at 02:56:15, six and a half hours after landing, Armstrong stepped off Eagle landing pad and declared: "That's one small step for [a] man, one giant leap for mankind."
Armstrong intended to say "That's one small step for a man", but the word "a" is not audible in the transmission, and thus was not initially reported by most observers of the live broadcast. When later asked about his quote, Armstrong said he believed he said "for a man", and subsequent printed versions of the quote included the "a" in square brackets. One explanation for the absence may be that his accent caused him to slur the words "for a" together; another is the intermittent nature of the audio and video links to Earth, partly because of storms near Parkes Observatory. A more recent digital analysis of the tape claims to reveal the "a" may have been spoken but obscured by static. Other analysis points to the claims of static and slurring as "face-saving fabrication", and that Armstrong himself later admitted to misspeaking the line.
About seven minutes after stepping onto the Moon's surface, Armstrong collected a contingency soil sample using a sample bag on a stick. He then folded the bag and tucked it into a pocket on his right thigh. This was to guarantee there would be some lunar soil brought back in case an emergency required the astronauts to abandon the EVA and return to the LM. Twelve minutes after the sample was collected, he removed the TV camera from the MESA and made a panoramic sweep, then mounted it on a tripod. The TV camera cable remained partly coiled and presented a tripping hazard throughout the EVA. Still photography was accomplished with a Hasselblad camera that could be operated hand-held or mounted on Armstrong's Apollo space suit. Aldrin joined Armstrong on the surface. He described the view with the simple phrase: "Magnificent desolation."
Armstrong said moving in the lunar gravity, one-sixth of Earth's, was "even perhaps easier than the simulations ... It's absolutely no trouble to walk around." Aldrin joined him on the surface and tested methods for moving around, including two-footed kangaroo hops. The PLSS backpack created a tendency to tip backward, but neither astronaut had serious problems maintaining balance. Loping became the preferred method of movement. The astronauts reported that they needed to plan their movements six or seven steps ahead. The fine soil was quite slippery. Aldrin remarked that moving from sunlight into Eagle shadow produced no temperature change inside the suit, but the helmet was warmer in sunlight, so he felt cooler in shadow. The MESA failed to provide a stable work platform and was in shadow, slowing work somewhat. As they worked, the moonwalkers kicked up gray dust, which soiled the outer part of their suits.
The astronauts planted the Lunar Flag Assembly containing a flag of the United States on the lunar surface, in clear view of the TV camera. Aldrin remembered, "Of all the jobs I had to do on the Moon the one I wanted to go the smoothest was the flag raising." But the astronauts struggled with the telescoping rod and could only insert the pole about into the hard lunar surface. Aldrin was afraid it might topple in front of TV viewers, but gave "a crisp West Point salute". Before Aldrin could take a photo of Armstrong with the flag, President Richard Nixon spoke to them through a telephone-radio transmission, which Nixon called "the most historic phone call ever made from the White House." Nixon originally had a long speech prepared to read during the phone call, but Frank Borman, who was at the White House as a NASA liaison during Apollo 11, convinced Nixon to keep his words brief.
They deployed the EASEP, which included a Passive Seismic Experiment Package used to measure moonquakes and a retroreflector array used for the lunar laser ranging experiment. Then Armstrong walked from the LM to take photographs at the rim of Little West Crater while Aldrin collected two core samples. He used the geologist's hammer to pound in the tubes—the only time the hammer was used on Apollo 11—but was unable to penetrate more than deep. The astronauts then collected rock samples using scoops and tongs on extension handles. Many of the surface activities took longer than expected, so they had to stop documenting sample collection halfway through the allotted 34 minutes. Aldrin shoveled of soil into the box of rocks in order to pack them in tightly. Two types of rocks were found in the geological samples: basalt and breccia. Three new minerals were discovered in the rock samples collected by the astronauts: armalcolite, tranquillityite, and pyroxferroite. Armalcolite was named after Armstrong, Aldrin, and Collins. All have subsequently been found on Earth.
While on the surface, Armstrong uncovered a plaque mounted on the LM ladder, bearing two drawings of Earth (of the Western and Eastern Hemispheres), an inscription, and signatures of the astronauts and President Nixon. The inscription read:
At the behest of the Nixon administration to add a reference to God, NASA included the vague date as a reason to include A.D., which stands for Anno Domini ("in the year of our Lord").
Mission Control used a coded phrase to warn Armstrong his metabolic rates were high, and that he should slow down. He was moving rapidly from task to task as time ran out. As metabolic rates remained generally lower than expected for both astronauts throughout the walk, Mission Control granted the astronauts a 15-minute extension. In a 2010 interview, Armstrong explained that NASA limited the first moonwalk's time and distance because there was no empirical proof of how much cooling water the astronauts' PLSS backpacks would consume to handle their body heat generation while working on the Moon.
Lunar ascent
Aldrin entered Eagle first. With some difficulty the astronauts lifted film and two sample boxes containing of lunar surface material to the LM hatch using a flat cable pulley device called the Lunar Equipment Conveyor (LEC). This proved to be an inefficient tool, and later missions preferred to carry equipment and samples up to the LM by hand. Armstrong reminded Aldrin of a bag of memorial items in his sleeve pocket, and Aldrin tossed the bag down. Armstrong then jumped onto the ladder's third rung, and climbed into the LM. After transferring to LM life support, the explorers lightened the ascent stage for the return to lunar orbit by tossing out their PLSS backpacks, lunar overshoes, an empty Hasselblad camera, and other equipment. The hatch was closed again at 05:11:13. They then pressurized the LM and settled down to sleep.
Presidential speech writer William Safire had prepared an In Event of Moon Disaster announcement for Nixon to read in the event the Apollo 11 astronauts were stranded on the Moon. The remarks were in a memo from Safire to Nixon's White House Chief of Staff H. R. Haldeman, in which Safire suggested a protocol the administration might follow in reaction to such a disaster. According to the plan, Mission Control would "close down communications" with the LM, and a clergyman would "commend their souls to the deepest of the deep" in a public ritual likened to burial at sea. The last line of the prepared text contained an allusion to Rupert Brooke's World War I poem "The Soldier".
While moving inside the cabin, Aldrin accidentally damaged the circuit breaker that would arm the main engine for liftoff from the Moon. There was a concern this would prevent firing the engine, stranding them on the Moon. The nonconductive tip of a Duro felt-tip pen was sufficient to activate the switch.
After more than hours on the lunar surface, in addition to the scientific instruments, the astronauts left behind: an Apollo 1 mission patch in memory of astronauts Roger Chaffee, Gus Grissom, and Edward White, who died when their command module caught fire during a test in January 1967; two memorial medals of Soviet cosmonauts Vladimir Komarov and Yuri Gagarin, who died in 1967 and 1968 respectively; a memorial bag containing a gold replica of an olive branch as a traditional symbol of peace; and a silicon message disk carrying the goodwill statements by Presidents Eisenhower, Kennedy, Johnson, and Nixon along with messages from leaders of 73 countries around the world. The disk also carries a listing of the leadership of the US Congress, a listing of members of the four committees of the House and Senate responsible for the NASA legislation, and the names of NASA's past and then-current top management.
After about seven hours of rest, the crew was awakened by Houston to prepare for the return flight. Two and a half hours later, at 17:54:00 UTC, they lifted off in Eagle ascent stage to rejoin Collins aboard Columbia in lunar orbit. Film taken from the LM ascent stage upon liftoff from the Moon reveals the American flag, planted some from the descent stage, whipping violently in the exhaust of the ascent stage engine. Aldrin looked up in time to witness the flag topple: "The ascent stage of the LM separated ... I was concentrating on the computers, and Neil was studying the attitude indicator, but I looked up long enough to see the flag fall over." Subsequent Apollo missions planted their flags farther from the LM.
Columbia in lunar orbit
During his day flying solo around the Moon, Collins never felt lonely. Although it has been said "not since Adam has any human known such solitude", Collins felt very much a part of the mission. In his autobiography he wrote: "this venture has been structured for three men, and I consider my third to be as necessary as either of the other two". In the 48 minutes of each orbit when he was out of radio contact with the Earth while Columbia passed round the far side of the Moon, the feeling he reported was not fear or loneliness, but rather "awareness, anticipation, satisfaction, confidence, almost exultation".
One of Collins' first tasks was to identify the lunar module on the ground. To give Collins an idea where to look, Mission Control radioed that they believed the lunar module landed about off target. Each time he passed over the suspected lunar landing site, he tried in vain to find the module. On his first orbits on the back side of the Moon, Collins performed maintenance activities such as dumping excess water produced by the fuel cells and preparing the cabin for Armstrong and Aldrin to return.
Just before he reached the dark side on the third orbit, Mission Control informed Collins there was a problem with the temperature of the coolant. If it became too cold, parts of Columbia might freeze. Mission Control advised him to assume manual control and implement Environmental Control System Malfunction Procedure 17. Instead, Collins flicked the switch on the system from automatic to manual and back to automatic again, and carried on with normal housekeeping chores, while keeping an eye on the temperature. When Columbia came back around to the near side of the Moon again, he was able to report that the problem had been resolved. For the next couple of orbits, he described his time on the back side of the Moon as "relaxing". After Aldrin and Armstrong completed their EVA, Collins slept so he could be rested for the rendezvous. While the flight plan called for Eagle to meet up with Columbia, Collins was prepared for a contingency in which he would fly Columbia down to meet Eagle.
Return
Eagle rendezvoused with Columbia at 21:24 UTC on July 21, and the two docked at 21:35. Eagles ascent stage was jettisoned into lunar orbit at 23:41. Just before the Apollo 12 flight, it was noted that Eagle was still likely to be orbiting the Moon. Later NASA reports mentioned that Eagle orbit had decayed, resulting in it impacting in an "uncertain location" on the lunar surface. In 2021, however, some calculations show that the lander may still be in orbit.
On July 23, the last night before splashdown, the three astronauts made a television broadcast in which Collins commented:
Aldrin added:
Armstrong concluded:
On the return to Earth, a bearing at the Guam tracking station failed, potentially preventing communication on the last segment of the Earth return. A regular repair was not possible in the available time but the station director, Charles Force, had his ten-year-old son Greg use his small hands to reach into the housing and pack it with grease. Greg was later thanked by Armstrong.
Splashdown and quarantine
The aircraft carrier , under the command of Captain Carl J. Seiberlich, was selected as the primary recovery ship (PRS) for Apollo 11 on June 5, replacing its sister ship, the LPH , which had recovered Apollo 10 on May 26. Hornet was then at her home port of Long Beach, California. On reaching Pearl Harbor on July 5, Hornet embarked the Sikorsky SH-3 Sea King helicopters of HS-4, a unit which specialized in recovery of Apollo spacecraft, specialized divers of UDT Detachment Apollo, a 35-man NASA recovery team, and about 120 media representatives. To make room, most of Hornets air wing was left behind in Long Beach. Special recovery equipment was also loaded, including a boilerplate command module used for training.
On July 12, with Apollo 11 still on the launch pad, Hornet departed Pearl Harbor for the recovery area in the central Pacific, in the vicinity of . A presidential party consisting of Nixon, Borman, Secretary of State William P. Rogers and National Security Advisor Henry Kissinger flew to Johnston Atoll on Air Force One, then to the command ship USS Arlington in Marine One. After a night on board, they would fly to Hornet in Marine One for a few hours of ceremonies. On arrival aboard Hornet, the party was greeted by the Commander-in-Chief, Pacific Command (CINCPAC), Admiral John S. McCain Jr., and NASA Administrator Thomas O. Paine, who flew to Hornet from Pago Pago in one of Hornets carrier onboard delivery aircraft.
Weather satellites were not yet common, but US Air Force Captain Hank Brandli had access to top-secret spy satellite images. He realized that a storm front was headed for the Apollo recovery area. Poor visibility which could make locating the capsule difficult, and strong upper-level winds which "would have ripped their parachutes to shreds" according to Brandli, posed a serious threat to the safety of the mission. Brandli alerted Navy Captain Willard S. Houston Jr., the commander of the Fleet Weather Center at Pearl Harbor, who had the required security clearance. On their recommendation, Rear Admiral Donald C. Davis, commander of Manned Spaceflight Recovery Forces, Pacific, advised NASA to change the recovery area, each man risking his career. A new location was selected northeast.
This altered the flight plan. A different sequence of computer programs was used, one never before attempted. In a conventional entry, trajectory event P64 was followed by P67. For a skip-out re-entry, P65 and P66 were employed to handle the exit and entry parts of the skip. In this case, because they were extending the re-entry but not actually skipping out, P66 was not invoked and instead, P65 led directly to P67. The crew were also warned they would not be in a full-lift (heads-down) attitude when they entered P67. The first program's acceleration subjected the astronauts to ; the second, to .
Before dawn on July 24, Hornet launched four Sea King helicopters and three Grumman E-1 Tracers. Two of the E-1s were designated as "air boss" while the third acted as a communications relay aircraft. Two of the Sea Kings carried divers and recovery equipment. The third carried photographic equipment, and the fourth carried the decontamination swimmer and the flight surgeon. At 16:44 UTC (05:44 local time) Columbias drogue parachutes were deployed. This was observed by the helicopters. Seven minutes later Columbia struck the water forcefully east of Wake Island, south of Johnston Atoll, and from Hornet, at . with seas and winds at from the east were reported under broken clouds at with visibility of at the recovery site. Reconnaissance aircraft flying to the original splashdown location reported the conditions Brandli and Houston had predicted.
During splashdown, Columbia landed upside down but was righted within ten minutes by flotation bags activated by the astronauts. A diver from the Navy helicopter hovering above attached a sea anchor to prevent it from drifting. More divers attached flotation collars to stabilize the module and positioned rafts for astronaut extraction.
The divers then passed biological isolation garments (BIGs) to the astronauts, and assisted them into the life raft. The possibility of bringing back pathogens from the lunar surface was considered remote, but NASA took precautions at the recovery site. The astronauts were rubbed down with a sodium hypochlorite solution and Columbia wiped with Povidone-iodine to remove any lunar dust that might be present. The astronauts were winched on board the recovery helicopter. BIGs were worn until they reached isolation facilities on board Hornet. The raft containing decontamination materials was intentionally sunk.
After touchdown on Hornet at 17:53 UTC, the helicopter was lowered by the elevator into the hangar bay, where the astronauts walked the to the Mobile quarantine facility (MQF), where they would begin the Earth-based portion of their 21 days of quarantine. This practice would continue for two more Apollo missions, Apollo 12 and Apollo 14, before the Moon was proven to be barren of life, and the quarantine process dropped. Nixon welcomed the astronauts back to Earth. He told them: "[A]s a result of what you've done, the world has never been closer together before."
After Nixon departed, Hornet was brought alongside the Columbia, which was lifted aboard by the ship's crane, placed on a dolly and moved next to the MQF. It was then attached to the MQF with a flexible tunnel, allowing the lunar samples, film, data tapes and other items to be removed. Hornet returned to Pearl Harbor, where the MQF was loaded onto a Lockheed C-141 Starlifter and airlifted to the Manned Spacecraft Center. The astronauts arrived at the Lunar Receiving Laboratory at 10:00 UTC on July 28. Columbia was taken to Ford Island for deactivation, and its pyrotechnics made safe. It was then taken to Hickham Air Force Base, from whence it was flown to Houston in a Douglas C-133 Cargomaster, reaching the Lunar Receiving Laboratory on July 30.
In accordance with the Extra-Terrestrial Exposure Law, a set of regulations promulgated by NASA on July 16 to codify its quarantine protocol, the astronauts continued in quarantine. After three weeks in confinement (first in the Apollo spacecraft, then in their trailer on Hornet, and finally in the Lunar Receiving Laboratory), the astronauts were given a clean bill of health. On August 10, 1969, the Interagency Committee on Back Contamination met in Atlanta and lifted the quarantine on the astronauts, on those who had joined them in quarantine (NASA physician William Carpentier and MQF project engineer John Hirasaki), and on Columbia itself. Loose equipment from the spacecraft remained in isolation until the lunar samples were released for study.
Celebrations
On August 13, the three astronauts rode in ticker-tape parades in their honor in New York and Chicago, with an estimated six million attendees. On the same evening in Los Angeles there was an official state dinner to celebrate the flight, attended by members of Congress, 44 governors, Chief Justice of the United States Warren E. Burger and his predecessor, Earl Warren, and ambassadors from 83 nations at the Century Plaza Hotel. Nixon and Agnew honored each astronaut with a presentation of the Presidential Medal of Freedom.
The three astronauts spoke before a joint session of Congress on September 16, 1969. They presented two US flags, one to the House of Representatives and the other to the Senate, that they had carried with them to the surface of the Moon. The flag of American Samoa on Apollo 11 is on display at the Jean P. Haydon Museum in Pago Pago, the capital of American Samoa.
This celebration began a 38-day world tour that brought the astronauts to 22 countries and included visits with many world leaders. The crew toured from September 29 to November 5. The world tour started in Mexico City and ended in Tokyo. Stops on the tour in order were: Mexico City, Bogota, Buenos Aires, Rio de Janeiro, Las Palmas in the Canary Islands, Madrid, Paris, Amsterdam, Brussels, Oslo, Cologne, Berlin, London, Rome, Belgrade, Ankara, Kinshasa, Tehran, Mumbai, Dhaka, Bangkok, Darwin, Sydney, Guam, Seoul, Tokyo and Honolulu.
Many nations honored the first human Moon landing with special features in magazines or by issuing Apollo 11 commemorative postage stamps or coins.
Legacy
Cultural significance
Humans walking on the Moon and returning safely to Earth accomplished Kennedy's goal set eight years earlier. In Mission Control during the Apollo 11 landing, Kennedy's speech flashed on the screen, followed by the words "TASK ACCOMPLISHED, July 1969". The success of Apollo 11 demonstrated the United States' technological superiority; and with the success of Apollo 11, America had won the Space Race.
New phrases permeated into the English language. "If they can send a man to the Moon, why can't they ...?" became a common saying following Apollo 11. Armstrong's words on the lunar surface also spun off various parodies.
While most people celebrated the accomplishment, disenfranchised Americans saw it as a symbol of the divide in America, evidenced by protesters led by Ralph Abernathy outside of Kennedy Space Center the day before Apollo 11 launched. NASA Administrator Thomas Paine met with Abernathy at the occasion, both hoping that the space program can spur progress also in other regards, such as poverty in the US. Paine was then asked, and agreed, to host protesters as spectators at the launch, and Abernathy, awestruck by the spectacle, prayed for the astronauts. Racial and financial inequalities frustrated citizens who wondered why money spent on the Apollo program was not spent taking care of humans on Earth. A poem by Gil Scott-Heron called "Whitey on the Moon" (1970) illustrated the racial inequality in the United States that was highlighted by the Space Race. The poem starts with:
Twenty percent of the world's population watched humans walk on the Moon for the first time. While Apollo 11 sparked the interest of the world, the follow-on Apollo missions did not hold the interest of the nation. One possible explanation was the shift in complexity. Landing someone on the Moon was an easy goal to understand; lunar geology was too abstract for the average person. Another is that Kennedy's goal of landing humans on the Moon had already been accomplished. A well-defined objective helped Project Apollo accomplish its goal, but after it was completed it was hard to justify continuing the lunar missions.
While most Americans were proud of their nation's achievements in space exploration, only once during the late 1960s did the Gallup Poll indicate that a majority of Americans favored "doing more" in space as opposed to "doing less". By 1973, 59 percent of those polled favored cutting spending on space exploration. The Space Race had been won, and Cold War tensions were easing as the US and Soviet Union entered the era of détente. This was also a time when inflation was rising, which put pressure on the government to reduce spending. What saved the space program was that it was one of the few government programs that had achieved something great. Drastic cuts, warned Caspar Weinberger, the deputy director of the Office of Management and Budget, might send a signal that "our best years are behind us".
After the Apollo 11 mission, officials from the Soviet Union said landing humans on the Moon was dangerous and unnecessary. At the time the Soviet Union was attempting to retrieve lunar samples robotically. The Soviets publicly denied there was a race to the Moon, and indicated they were not making an attempt. Mstislav Keldysh said in July 1969, "We are concentrating wholly on the creation of large satellite systems." It was revealed in 1989 that the Soviets had tried to send people to the Moon, but were unable due to technological difficulties. The public's reaction in the Soviet Union was mixed. The Soviet government limited the release of information about the lunar landing, which affected the reaction. A portion of the populace did not give it any attention, and another portion was angered by it.
The Apollo 11 landing is referenced in the songs "Armstrong, Aldrin and Collins" by the Byrds on the 1969 album Ballad of Easy Rider and "Coon on the Moon" by Howlin' Wolf on the 1973 album The Back Door Wolf.
Spacecraft
The command module Columbia went on a tour of the United States, visiting 49 state capitals, the District of Columbia, and Anchorage, Alaska. In 1971, it was transferred to the Smithsonian Institution, and was displayed at the National Air and Space Museum (NASM) in Washington, DC. It was in the central Milestones of Flight exhibition hall in front of the Jefferson Drive entrance, sharing the main hall with other pioneering flight vehicles such as the Wright Flyer, Spirit of St. Louis, Bell X-1, North American X-15 and Friendship 7.
Columbia was moved in 2017 to the NASM Mary Baker Engen Restoration Hangar at the Steven F. Udvar-Hazy Center in Chantilly, Virginia, to be readied for a four-city tour titled Destination Moon: The Apollo 11 Mission. This included Space Center Houston from October 14, 2017, to March 18, 2018, the Saint Louis Science Center from April 14 to September 3, 2018, the Senator John Heinz History Center in Pittsburgh from September 29, 2018, to February 18, 2019, and its last location at Museum of Flight in Seattle from March 16 to September 2, 2019. Continued renovations at the Smithsonian allowed time for an additional stop for the capsule, and it was moved to the Cincinnati Museum Center. The ribbon cutting ceremony was on September 29, 2019.
For 40 years Armstrong's and Aldrin's space suits were displayed in the museum's Apollo to the Moon exhibit, until it permanently closed on December 3, 2018, to be replaced by a new gallery which was scheduled to open in 2022. A special display of Armstrong's suit was unveiled for the 50th anniversary of Apollo 11 in July 2019. The quarantine trailer, the flotation collar and the flotation bags are in the Smithsonian's Steven F. Udvar-Hazy Center annex near Washington Dulles International Airport in Chantilly, Virginia, where they are on display along with a test lunar module.
The descent stage of the LM Eagle remains on the Moon. In 2009, the Lunar Reconnaissance Orbiter (LRO) imaged the various Apollo landing sites on the surface of the Moon, for the first time with sufficient resolution to see the descent stages of the lunar modules, scientific instruments, and foot trails made by the astronauts.
The remains of the ascent stage are assumed to lie at an unknown location on the lunar surface. The ascent stage, Eagle, was not tracked after it was jettisoned. The lunar gravity field is sufficiently non-uniform to make low Moon orbits unstable after a short time, leading the orbiting object to impact the surface. However, using a program developed by NASA, and high-resolution lunar gravity data, a paper was published, in 2021, indicating that Eagle might still be in orbit as late as 2020. Using the orbital elements published by NASA, a Monte Carlo method was used to generate parameter sets that bracket the uncertainties in these elements. All simulations, of the orbit, predicted that Eagle would never impact the lunar surface.
In March 2012 a team of specialists financed by Amazon founder Jeff Bezos located the F-1 engines from the S-IC stage that launched Apollo 11 into space. They were found on the Atlantic seabed using advanced sonar scanning. His team brought parts of two of the five engines to the surface. In July 2013, a conservator discovered a serial number under the rust on one of the engines raised from the Atlantic, which NASA confirmed was from Apollo 11. The S-IVB third stage which performed Apollo 11's trans-lunar injection remains in a solar orbit near to that of Earth.
Moon rocks
The main repository for the Apollo Moon rocks is the Lunar Sample Laboratory Facility at the Lyndon B. Johnson Space Center in Houston, Texas. For safekeeping, there is also a smaller collection stored at White Sands Test Facility near Las Cruces, New Mexico. Most of the rocks are stored in nitrogen to keep them free of moisture. They are handled only indirectly, using special tools. Over 100 research laboratories worldwide conduct studies of the samples; approximately 500 samples are prepared and sent to investigators every year.
In November 1969, Nixon asked NASA to make up about 250 presentation Apollo 11 lunar sample displays for 135 nations, the fifty states of the United States and its possessions, and the United Nations. Each display included Moon dust from Apollo 11 and flags, including one of the Soviet Union, taken along by Apollo 11. The rice-sized particles were four small pieces of Moon soil weighing about 50 mg and were enveloped in a clear acrylic button about as big as a United States half dollar coin. This acrylic button magnified the grains of lunar dust. Nixon gave the Apollo 11 lunar sample displays as goodwill gifts in 1970.
Experiment results
The Passive Seismic Experiment ran until the command uplink failed on August 25, 1969. The downlink failed on December 14, 1969. , the Lunar Laser Ranging experiment remains operational.
Moonwalk camera
The Hasselblad camera used during the moonwalk was thought to be lost or left on the Moon surface.
LM memorabilia
In 2015, after Armstrong died in 2012, his widow contacted the National Air and Space Museum to inform them she had found a white cloth bag in one of Armstrong's closets. The bag contained various items, which should have been left behind in the lunar module, including the 16mm Data Acquisition Camera that had been used to capture images of the first Moon landing. The camera is currently on display at the National Air and Space Museum.
Anniversary events
40th anniversary
On July 15, 2009, Life.com released a photo gallery of previously unpublished photos of the astronauts taken by Life photographer Ralph Morse prior to the Apollo 11 launch. From July 16 to 24, 2009, NASA streamed the original mission audio on its website in real time 40 years to the minute after the events occurred. It is in the process of restoring the video footage and has released a preview of key moments. In July 2010, air-to-ground voice recordings and film footage shot in Mission Control during the Apollo 11 powered descent and landing was re-synchronized and released for the first time. The John F. Kennedy Presidential Library and Museum set up an Adobe Flash website that rebroadcasts the transmissions of Apollo 11 from launch to landing on the Moon.
On July 20, 2009, Armstrong, Aldrin, and Collins met with US President Barack Obama at the White House. "We expect that there is, as we speak, another generation of kids out there who are looking up at the sky and are going to be the next Armstrong, Collins, and Aldrin", Obama said. "We want to make sure that NASA is going to be there for them when they want to take their journey." On August 7, 2009, an act of Congress awarded the three astronauts a Congressional Gold Medal, the highest civilian award in the United States. The bill was sponsored by Florida Senator Bill Nelson and Florida Representative Alan Grayson.
A group of British scientists interviewed as part of the anniversary events reflected on the significance of the Moon landing:
50th anniversary
On June 10, 2015, Congressman Bill Posey introduced resolution H.R. 2726 to the 114th session of the United States House of Representatives directing the United States Mint to design and sell commemorative coins in gold, silver and clad for the 50th anniversary of the Apollo 11 mission. On January 24, 2019, the Mint released the Apollo 11 Fiftieth Anniversary commemorative coins to the public on its website.
A documentary film, Apollo 11, with restored footage of the 1969 event, premiered in IMAX on March 1, 2019, and broadly in theaters on March 8.
The Smithsonian Institute's National Air and Space Museum and NASA sponsored the "Apollo 50 Festival" on the National Mall in Washington DC. The three day (July 18 to 20, 2019) outdoor festival featured hands-on exhibits and activities, live performances, and speakers such as Adam Savage and NASA scientists.
As part of the festival, a projection of the tall Saturn V rocket was displayed on the east face of the tall Washington Monument from July 16 through the 20th from 9:30 pm until 11:30 pm (EDT). The program also included a 17-minute show that combined full-motion video projected on the Washington Monument to recreate the assembly and launch of the Saturn V rocket. The projection was joined by a wide recreation of the Kennedy Space Center countdown clock and two large video screens showing archival footage to recreate the time leading up to the moon landing. There were three shows per night on July 19–20, with the last show on Saturday, delayed slightly so the portion where Armstrong first set foot on the Moon would happen exactly 50 years to the second after the actual event.
On July 19, 2019, the Google Doodle paid tribute to the Apollo 11 Moon Landing, complete with a link to an animated YouTube video with voiceover by astronaut Michael Collins.
Aldrin, Collins, and Armstrong's sons were hosted by President Donald Trump in the Oval Office.
Films and documentaries
Footprints on the Moon, a 1969 documentary film by Bill Gibson and Barry Coe, about the Apollo 11 mission
Moonwalk One, a 1971 documentary film by Theo Kamecke
Apollo 11: As It Happened, a 1994 six-hour documentary on ABC News' coverage of the event
First Man, 2018 film by Damien Chazelle based on the 2005 James R. Hansen book First Man: The Life of Neil A. Armstrong.
Apollo 11, a 2019 documentary film by Todd Douglas Miller with restored footage of the 1969 event
Chasing the Moon, a July 2019 PBS three-night six-hour documentary, directed by Robert Stone, examined the events leading up to the Apollo 11 mission. An accompanying book of the same name was also released.
8 Days: To the Moon and Back, a PBS and BBC Studios 2019 documentary film by Anthony Philipson re-enacting major portions of the Apollo 11 mission using mission audio recordings, new studio footage, NASA and news archives, and computer-generated imagery.
See also
List of species that have landed on the Moon
References
Notes
Citations
In some of the following sources, times are shown in the format hours:minutes:seconds (e.g. 109:24:15), referring to the mission's Ground Elapsed Time (GET), based on the official launch time of July 16, 1969, 13:32:00 UTC (000:00:00 GET).
Sources
External links
"Apollo 11 transcripts" at Spacelog
Apollo 11 in real time
Apollo 11 Press Conference filmed by KPRC-TV at Texas Archive of the Moving Image
Apollo 11 and 13 Checklists at The Museum of Flight Digital Collections.
Apollo 11, 12, and 14 Traverses, at the Lunar and Planetary Institute
Multimedia
Remastered videos of the original landing.
Dynamic timeline of lunar excursion. Lunar Reconnaissance Orbiter Camera
Apollo 11 Restored EVA Part 1 (1hour of restored footage)
Apollo 11: As They Photographed It (Augmented Reality)—The New York Times, Interactive, July 18, 2019
"Coverage of the Flight of Apollo 11" provided by Todd Kosovich for RadioTapes.com. Radio station recordings (airchecks) covering the flight of Apollo 11.
1969 on the Moon
Buzz Aldrin
Apollo program missions
Neil Armstrong
Articles containing video clips
Michael Collins (astronaut)
Crewed missions to the Moon
Soft landings on the Moon
Spacecraft launched by Saturn rockets |
665 | https://en.wikipedia.org/wiki/A%20Modest%20Proposal | A Modest Proposal | A Modest Proposal for Preventing the Children of Poor People from Being a Burthen to Their Parents or Country, and for Making Them Beneficial to the Publick, commonly referred to as A Modest Proposal, is a Juvenalian satirical essay written and published anonymously by Anglo-Irish writer and clergyman Jonathan Swift in 1729. The essay suggests that poor people in Ireland could ease their economic troubles by selling their children as food to the elite. Swift's use of satirical hyperbole was intended to mock hostile attitudes towards the poor and anti-Catholicism among the Protestant Ascendancy as well as the Dublin Castle administration's policies in general. In English writing, the phrase "a modest proposal" is now conventionally an allusion to this style of straight-faced satire.
Synopsis
Swift's essay is widely held to be one of the greatest examples of sustained irony in the history of English literature. Much of its shock value derives from the fact that the first portion of the essay describes the plight of starving beggars in Ireland, so that the reader is unprepared for the surprise of Swift's solution when he states: "A young healthy child well nursed, is, at a year old, a most delicious nourishing and wholesome food, whether stewed, roasted, baked, or boiled; and I make no doubt that it will equally serve in a fricassee, or a ragout."
Swift goes to great lengths to support his argument, including a list of possible preparation styles for the children, and calculations showing the financial benefits of his suggestion. He uses methods of argument throughout his essay which lampoon the then-influential William Petty and the social engineering popular among followers of Francis Bacon. These lampoons include appealing to the authority of "a very knowing American of my acquaintance in London" and "the famous Psalmanazar, a native of the island Formosa" (who had already confessed to not being from Formosa in 1706).
In the tradition of Roman satire, Swift introduces the reforms he is actually suggesting by paralipsis:
Population solutions
George Wittkowsky argued that Swift's main target in A Modest Proposal was not the conditions in Ireland, but rather the can-do spirit of the times that led people to devise a number of illogical schemes that would purportedly solve social and economic ills. Swift was especially attacking projects that tried to fix population and labour issues with a simple cure-all solution. A memorable example of these sorts of schemes "involved the idea of running the poor through a joint-stock company". In response, Swift's Modest Proposal was "a burlesque of projects concerning the poor" that were in vogue during the early 18th century.
Ian McBride argues that the point of A Modest Proposal was to "find a suitably decisive means of dehumanizing the settlers who had failed so comprehensively to meet their social responsibilities."
A Modest Proposal also targets the calculating way people perceived the poor in designing their projects. The pamphlet targets reformers who "regard people as commodities". In the piece, Swift adopts the "technique of a political arithmetician" to show the utter ridiculousness of trying to prove any proposal with dispassionate statistics.
Critics differ about Swift's intentions in using this faux-mathematical philosophy. Edmund Wilson argues that statistically "the logic of the 'Modest proposal' can be compared with defence of crime (arrogated to Marx) in which he argues that crime takes care of the superfluous population". Wittkowsky counters that Swift's satiric use of statistical analysis is an effort to enhance his satire that "springs from a spirit of bitter mockery, not from the delight in calculations for their own sake".
Rhetoric
Author Charles K. Smith argues that Swift's rhetorical style persuades the reader to detest the speaker and pity the Irish. Swift's specific strategy is twofold, using a "trap" to create sympathy for the Irish and a dislike of the narrator who, in the span of one sentence, "details vividly and with rhetorical emphasis the grinding poverty" but feels emotion solely for members of his own class. Swift's use of gripping details of poverty and his narrator's cool approach towards them create "two opposing points of view" that "alienate the reader, perhaps unconsciously, from a narrator who can view with 'melancholy' detachment a subject that Swift has directed us, rhetorically, to see in a much less detached way."
Swift has his proposer further degrade the Irish by using language ordinarily reserved for animals. Lewis argues that the speaker uses "the vocabulary of animal husbandry" to describe the Irish. Once the children have been commodified, Swift's rhetoric can easily turn "people into animals, then meat, and from meat, logically, into tonnage worth a price per pound".
Swift uses the proposer's serious tone to highlight the absurdity of his proposal. In making his argument, the speaker uses the conventional, textbook-approved order of argument from Swift's time (which was derived from the Latin rhetorician Quintilian). The contrast between the "careful control against the almost inconceivable perversion of his scheme" and "the ridiculousness of the proposal" create a situation in which the reader has "to consider just what perverted values and assumptions would allow such a diligent, thoughtful, and conventional man to propose so perverse a plan".
Influences
Scholars have speculated about which earlier works Swift may have had in mind when he wrote A Modest Proposal.
Tertullian's Apology
James William Johnson argues that A Modest Proposal was largely influenced and inspired by Tertullian's Apology: a satirical attack against early Roman persecution of Christianity. Johnson believes that Swift saw major similarities between the two situations. Johnson notes Swift's obvious affinity for Tertullian and the bold stylistic and structural similarities between the works A Modest Proposal and Apology. In structure, Johnson points out the same central theme, that of cannibalism and the eating of babies as well as the same final argument, that "human depravity is such that men will attempt to justify their own cruelty by accusing their victims of being lower than human". Stylistically, Swift and Tertullian share the same command of sarcasm and language. In agreement with Johnson, Donald C. Baker points out the similarity between both authors' tones and use of irony. Baker notes the uncanny way that both authors imply an ironic "justification by ownership" over the subject of sacrificing children—Tertullian while attacking pagan parents, and Swift while attacking the mistreatment of the poor in Ireland.
Defoe's The Generous Projector
It has also been argued that A Modest Proposal was, at least in part, a response to the 1728 essay The Generous Projector or, A Friendly Proposal to Prevent Murder and Other Enormous Abuses, By Erecting an Hospital for Foundlings and Bastard Children by Swift's rival Daniel Defoe.
Mandeville's Modest Defence of Publick Stews
Bernard Mandeville's Modest Defence of Publick Stews asked to introduce public and state-controlled bordellos. The 1726 paper acknowledges women's interests and—while not being a completely satirical text—has also been discussed as an inspiration for Jonathan Swift's title. Mandeville had by 1705 already become famous for The Fable of the Bees and deliberations on private vices and public benefits.
John Locke's First Treatise of Government
John Locke commented: "Be it then as Sir Robert says, that Anciently, it was usual for Men to sell and Castrate their Children. Let it be, that they exposed them; Add to it, if you please, for this is still greater Power, that they begat them for their Tables to fat and eat them: If this proves a right to do so, we may, by the same Argument, justifie Adultery, Incest and Sodomy, for there are examples of these too, both Ancient and Modern; Sins, which I suppose, have the Principle Aggravation from this, that they cross the main intention of Nature, which willeth the increase of Mankind, and the continuation of the Species in the highest perfection, and the distinction of Families, with the Security of the Marriage Bed, as necessary thereunto". (First Treatise, sec. 59).
Economic themes
Robert Phiddian's article "Have you eaten yet? The Reader in A Modest Proposal" focuses on two aspects of A Modest Proposal: the voice of Swift and the voice of the Proposer. Phiddian stresses that a reader of the pamphlet must learn to distinguish between the satirical voice of Jonathan Swift and the apparent economic projections of the Proposer. He reminds readers that "there is a gap between the narrator's meaning and the text's, and that a moral-political argument is being carried out by means of parody".
While Swift's proposal is obviously not a serious economic proposal, George Wittkowsky, author of "Swift's Modest Proposal: The Biography of an Early Georgian Pamphlet", argues that to understand the piece fully it is important to understand the economics of Swift's time. Wittowsky argued that an insufficient number of critics have taken the time to focus directly on mercantilism and theories of labour in Georgian era Britain. "If one regards the Modest Proposal simply as a criticism of condition, about all one can say is that conditions were bad and that Swift's irony brilliantly underscored this fact".
"People are the riches of a nation"
At the start of a new industrial age in the 18th century, it was believed that "people are the riches of the nation", and there was a general faith in an economy that paid its workers low wages because high wages meant workers would work less. Furthermore, "in the mercantilist view no child was too young to go into industry". In those times, the "somewhat more humane attitudes of an earlier day had all but disappeared and the laborer had come to be regarded as a commodity".
Louis A. Landa composed a conducive analysis when he noted that it would have been healthier for the Irish economy to more appropriately utilize their human assets by giving the people an opportunity to "become a source of wealth to the nation" or else they "must turn to begging and thievery". This opportunity may have included giving the farmers more coin to work for, diversifying their professions, or even consider enslaving their people to lower coin usage and build up financial stock in Ireland. Landa wrote that, "Swift is maintaining that the maxim—people are the riches of a nation—applies to Ireland only if Ireland is permitted slavery or cannibalism"
Landa presents Swift's A Modest Proposal as a critique of the popular and unjustified maxim of mercantilism in the 18th century that "people are the riches of a nation". Swift presents the dire state of Ireland and shows that mere population itself, in Ireland's case, did not always mean greater wealth and economy. The uncontrolled maxim fails to take into account that a person who does not produce in an economic or political way makes a country poorer, not richer. Swift also recognises the implications of this fact in making mercantilist philosophy a paradox: the wealth of a country is based on the poverty of the majority of its citizens. Landa argued that Swift was putting the onus "on England of vitiating the working of natural economic law in Ireland" by denying Irishmen "the same natural rights common to the rest of mankind."
Public reaction
Swift's essay created a backlash within Georgian society after its publication. The work was aimed at the elite, and they responded in turn. Several prominent members of society wrote to Swift regarding the work. Lord Bathurst's letter (12 February 1729–30) intimated that he certainly understood the message, and interpreted it as a work of comedy:
Modern usage
A Modest Proposal is included in many literature courses as an example of early modern western satire. It also serves as an introduction to the concept and use of argumentative language, lending itself to secondary and post-secondary essay courses. Outside of the realm of English studies, A Modest Proposal is included in many comparative and global literature and history courses, as well as those of numerous other disciplines in the arts, humanities, and even the social sciences.
A Modest Video Game Proposal is the title of an open letter sent by activist/former attorney Jack Thompson on 10 October 2005.
The 2012 horror film Butcher Boys, written by the original The Texas Chain Saw Massacre scribe Kim Henkel, is said to be an updating of Jonathan Swift's A Modest Proposal. Henkel imagined the descendants of folks who actually took Swift up on his proposal. The film opens with a quote from J. Swift.
The 2023 song "Eat Your Young" written by Irish musician Hozier might be a reference to "A Modest Proposal". It combines themes regarding the anti-war and anti-income-inequality movement, and uses Swift's essay as a framework to compare those modern problems to those same problems during Swift's time.
The July 2023 Channel 4 mockumentary Gregg Wallace: The British Miracle Meat, written by British comedy writer Matt Edmonds, updates A Modest Proposal and presents it in a similar format to Wallace's Inside the Factory, with human meat given as a potential solution to the UK's cost of living crisis. The words "a modest proposal" are used in Wallace's summing up at the end of the programme, and Swift is credited.
See also
Child cannibalism
Notes
References
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External links
A Modest Proposal (CELT)
A Modest Proposal (Gutenberg)
A Modest Proposal – Annotated text aligned to Common Core Standards
A Modest Proposal BBC Radio 4 In Our Time with Melvyn Bragg
'A modest proposal For preventing the children of poor people From being a Burthen to their Parents or the Country, And for making them Beneficial to the publick. The Third Edition, Dublin, Printed: And Reprinted at London, for Weaver Bickerton, in Devereux-Court near the Middle-Temple, 1730.
1729 essays
1729 in Great Britain
1729 books
Essays by Jonathan Swift
Satirical essays
Pamphlets
Works published anonymously
British satire
Fiction about cannibalism
Works about Ireland |
674 | https://en.wikipedia.org/wiki/Anatomy | Anatomy | Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated, both over immediate and long-term timescales. Anatomy and physiology, which study the structure and function of organisms and their parts respectively, make a natural pair of related disciplines, and are often studied together. Human anatomy is one of the essential basic sciences that are applied in medicine, and is often studied alongside physiology.
Anatomy is a complex and dynamic field that is constantly evolving as new discoveries are made. In recent years, there has been a significant increase in the use of advanced imaging techniques, such as MRI and CT scans, which allow for more detailed and accurate visualizations of the body's structures.
The discipline of anatomy is divided into macroscopic and microscopic parts. Macroscopic anatomy, or gross anatomy, is the examination of an animal's body parts using unaided eyesight. Gross anatomy also includes the branch of superficial anatomy. Microscopic anatomy involves the use of optical instruments in the study of the tissues of various structures, known as histology, and also in the study of cells.
The history of anatomy is characterized by a progressive understanding of the functions of the organs and structures of the human body. Methods have also improved dramatically, advancing from the examination of animals by dissection of carcasses and cadavers (corpses) to 20th-century medical imaging techniques, including X-ray, ultrasound, and magnetic resonance imaging.
Etymology and definition
Derived from the Greek anatomē "dissection" (from anatémnō "I cut up, cut open" from ἀνά aná "up", and τέμνω témnō "I cut"), anatomy is the scientific study of the structure of organisms including their systems, organs and tissues. It includes the appearance and position of the various parts, the materials from which they are composed, and their relationships with other parts. Anatomy is quite distinct from physiology and biochemistry, which deal respectively with the functions of those parts and the chemical processes involved. For example, an anatomist is concerned with the shape, size, position, structure, blood supply and innervation of an organ such as the liver; while a physiologist is interested in the production of bile, the role of the liver in nutrition and the regulation of bodily functions.
The discipline of anatomy can be subdivided into a number of branches, including gross or macroscopic anatomy and microscopic anatomy. Gross anatomy is the study of structures large enough to be seen with the naked eye, and also includes superficial anatomy or surface anatomy, the study by sight of the external body features. Microscopic anatomy is the study of structures on a microscopic scale, along with histology (the study of tissues), and embryology (the study of an organism in its immature condition). Regional anatomy is the study of the interrelationships of all of the structures in a specific body region, such as the abdomen. In contrast, systemic anatomy is the study of the structures that make up a discrete body system—that is, a group of structures that work together to perform a unique body function, such as the digestive system.
Anatomy can be studied using both invasive and non-invasive methods with the goal of obtaining information about the structure and organization of organs and systems. Methods used include dissection, in which a body is opened and its organs studied, and endoscopy, in which a video camera-equipped instrument is inserted through a small incision in the body wall and used to explore the internal organs and other structures. Angiography using X-rays or magnetic resonance angiography are methods to visualize blood vessels.
The term "anatomy" is commonly taken to refer to human anatomy. However, substantially similar structures and tissues are found throughout the rest of the animal kingdom, and the term also includes the anatomy of other animals. The term zootomy is also sometimes used to specifically refer to non-human animals. The structure and tissues of plants are of a dissimilar nature and they are studied in plant anatomy.
Animal tissues
The kingdom Animalia contains multicellular organisms that are heterotrophic and motile (although some have secondarily adopted a sessile lifestyle). Most animals have bodies differentiated into separate tissues and these animals are also known as eumetazoans. They have an internal digestive chamber, with one or two openings; the gametes are produced in multicellular sex organs, and the zygotes include a blastula stage in their embryonic development. Metazoans do not include the sponges, which have undifferentiated cells.
Unlike plant cells, animal cells have neither a cell wall nor chloroplasts. Vacuoles, when present, are more in number and much smaller than those in the plant cell. The body tissues are composed of numerous types of cells, including those found in muscles, nerves and skin. Each typically has a cell membrane formed of phospholipids, cytoplasm and a nucleus. All of the different cells of an animal are derived from the embryonic germ layers. Those simpler invertebrates which are formed from two germ layers of ectoderm and endoderm are called diploblastic and the more developed animals whose structures and organs are formed from three germ layers are called triploblastic. All of a triploblastic animal's tissues and organs are derived from the three germ layers of the embryo, the ectoderm, mesoderm and endoderm.
Animal tissues can be grouped into four basic types: connective, epithelial, muscle and nervous tissue.
Connective tissue
Connective tissues are fibrous and made up of cells scattered among inorganic material called the extracellular matrix. Often called fascia (from the Latin "fascia," meaning "band" or "bandage"), connective tissues give shape to organs and holds them in place. The main types are loose connective tissue, adipose tissue, fibrous connective tissue, cartilage and bone. The extracellular matrix contains proteins, the chief and most abundant of which is collagen. Collagen plays a major part in organizing and maintaining tissues. The matrix can be modified to form a skeleton to support or protect the body. An exoskeleton is a thickened, rigid cuticle which is stiffened by mineralization, as in crustaceans or by the cross-linking of its proteins as in insects. An endoskeleton is internal and present in all developed animals, as well as in many of those less developed.
Epithelium
Epithelial tissue is composed of closely packed cells, bound to each other by cell adhesion molecules, with little intercellular space. Epithelial cells can be squamous (flat), cuboidal or columnar and rest on a basal lamina, the upper layer of the basement membrane, the lower layer is the reticular lamina lying next to the connective tissue in the extracellular matrix secreted by the epithelial cells. There are many different types of epithelium, modified to suit a particular function. In the respiratory tract there is a type of ciliated epithelial lining; in the small intestine there are microvilli on the epithelial lining and in the large intestine there are intestinal villi. Skin consists of an outer layer of keratinized stratified squamous epithelium that covers the exterior of the vertebrate body. Keratinocytes make up to 95% of the cells in the skin. The epithelial cells on the external surface of the body typically secrete an extracellular matrix in the form of a cuticle. In simple animals this may just be a coat of glycoproteins. In more advanced animals, many glands are formed of epithelial cells.
Muscle tissue
Muscle cells (myocytes) form the active contractile tissue of the body. Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs. Muscle is formed of contractile filaments and is separated into three main types; smooth muscle, skeletal muscle and cardiac muscle. Smooth muscle has no striations when examined microscopically. It contracts slowly but maintains contractibility over a wide range of stretch lengths. It is found in such organs as sea anemone tentacles and the body wall of sea cucumbers. Skeletal muscle contracts rapidly but has a limited range of extension. It is found in the movement of appendages and jaws. Obliquely striated muscle is intermediate between the other two. The filaments are staggered and this is the type of muscle found in earthworms that can extend slowly or make rapid contractions. In higher animals striated muscles occur in bundles attached to bone to provide movement and are often arranged in antagonistic sets. Smooth muscle is found in the walls of the uterus, bladder, intestines, stomach, oesophagus, respiratory airways, and blood vessels. Cardiac muscle is found only in the heart, allowing it to contract and pump blood round the body.
Nervous tissue
Nervous tissue is composed of many nerve cells known as neurons which transmit information. In some slow-moving radially symmetrical marine animals such as ctenophores and cnidarians (including sea anemones and jellyfish), the nerves form a nerve net, but in most animals they are organized longitudinally into bundles. In simple animals, receptor neurons in the body wall cause a local reaction to a stimulus. In more complex animals, specialized receptor cells such as chemoreceptors and photoreceptors are found in groups and send messages along neural networks to other parts of the organism. Neurons can be connected together in ganglia. In higher animals, specialized receptors are the basis of sense organs and there is a central nervous system (brain and spinal cord) and a peripheral nervous system. The latter consists of sensory nerves that transmit information from sense organs and motor nerves that influence target organs. The peripheral nervous system is divided into the somatic nervous system which conveys sensation and controls voluntary muscle, and the autonomic nervous system which involuntarily controls smooth muscle, certain glands and internal organs, including the stomach.
Vertebrate anatomy
All vertebrates have a similar basic body plan and at some point in their lives, mostly in the embryonic stage, share the major chordate characteristics: a stiffening rod, the notochord; a dorsal hollow tube of nervous material, the neural tube; pharyngeal arches; and a tail posterior to the anus. The spinal cord is protected by the vertebral column and is above the notochord, and the gastrointestinal tract is below it. Nervous tissue is derived from the ectoderm, connective tissues are derived from mesoderm, and gut is derived from the endoderm. At the posterior end is a tail which continues the spinal cord and vertebrae but not the gut. The mouth is found at the anterior end of the animal, and the anus at the base of the tail. The defining characteristic of a vertebrate is the vertebral column, formed in the development of the segmented series of vertebrae. In most vertebrates the notochord becomes the nucleus pulposus of the intervertebral discs. However, a few vertebrates, such as the sturgeon and the coelacanth, retain the notochord into adulthood. Jawed vertebrates are typified by paired appendages, fins or legs, which may be secondarily lost. The limbs of vertebrates are considered to be homologous because the same underlying skeletal structure was inherited from their last common ancestor. This is one of the arguments put forward by Charles Darwin to support his theory of evolution.
Fish anatomy
The body of a fish is divided into a head, trunk and tail, although the divisions between the three are not always externally visible. The skeleton, which forms the support structure inside the fish, is either made of cartilage, in cartilaginous fish, or bone in bony fish. The main skeletal element is the vertebral column, composed of articulating vertebrae which are lightweight yet strong. The ribs attach to the spine and there are no limbs or limb girdles. The main external features of the fish, the fins, are composed of either bony or soft spines called rays, which with the exception of the caudal fins, have no direct connection with the spine. They are supported by the muscles which compose the main part of the trunk. The heart has two chambers and pumps the blood through the respiratory surfaces of the gills and on round the body in a single circulatory loop. The eyes are adapted for seeing underwater and have only local vision. There is an inner ear but no external or middle ear. Low frequency vibrations are detected by the lateral line system of sense organs that run along the length of the sides of fish, and these respond to nearby movements and to changes in water pressure.
Sharks and rays are basal fish with numerous primitive anatomical features similar to those of ancient fish, including skeletons composed of cartilage. Their bodies tend to be dorso-ventrally flattened, they usually have five pairs of gill slits and a large mouth set on the underside of the head. The dermis is covered with separate dermal placoid scales. They have a cloaca into which the urinary and genital passages open, but not a swim bladder. Cartilaginous fish produce a small number of large, yolky eggs. Some species are ovoviviparous and the young develop internally but others are oviparous and the larvae develop externally in egg cases.
The bony fish lineage shows more derived anatomical traits, often with major evolutionary changes from the features of ancient fish. They have a bony skeleton, are generally laterally flattened, have five pairs of gills protected by an operculum, and a mouth at or near the tip of the snout. The dermis is covered with overlapping scales. Bony fish have a swim bladder which helps them maintain a constant depth in the water column, but not a cloaca. They mostly spawn a large number of small eggs with little yolk which they broadcast into the water column.
Amphibian anatomy
Amphibians are a class of animals comprising frogs, salamanders and caecilians. They are tetrapods, but the caecilians and a few species of salamander have either no limbs or their limbs are much reduced in size. Their main bones are hollow and lightweight and are fully ossified and the vertebrae interlock with each other and have articular processes. Their ribs are usually short and may be fused to the vertebrae. Their skulls are mostly broad and short, and are often incompletely ossified. Their skin contains little keratin and lacks scales, but contains many mucous glands and in some species, poison glands. The hearts of amphibians have three chambers, two atria and one ventricle. They have a urinary bladder and nitrogenous waste products are excreted primarily as urea. Amphibians breathe by means of buccal pumping, a pump action in which air is first drawn into the buccopharyngeal region through the nostrils. These are then closed and the air is forced into the lungs by contraction of the throat. They supplement this with gas exchange through the skin which needs to be kept moist.
In frogs the pelvic girdle is robust and the hind legs are much longer and stronger than the forelimbs. The feet have four or five digits and the toes are often webbed for swimming or have suction pads for climbing. Frogs have large eyes and no tail. Salamanders resemble lizards in appearance; their short legs project sideways, the belly is close to or in contact with the ground and they have a long tail. Caecilians superficially resemble earthworms and are limbless. They burrow by means of zones of muscle contractions which move along the body and they swim by undulating their body from side to side.
Reptile anatomy
Reptiles are a class of animals comprising turtles, tuataras, lizards, snakes and crocodiles. They are tetrapods, but the snakes and a few species of lizard either have no limbs or their limbs are much reduced in size. Their bones are better ossified and their skeletons stronger than those of amphibians. The teeth are conical and mostly uniform in size. The surface cells of the epidermis are modified into horny scales which create a waterproof layer. Reptiles are unable to use their skin for respiration as do amphibians and have a more efficient respiratory system drawing air into their lungs by expanding their chest walls. The heart resembles that of the amphibian but there is a septum which more completely separates the oxygenated and deoxygenated bloodstreams. The reproductive system has evolved for internal fertilization, with a copulatory organ present in most species. The eggs are surrounded by amniotic membranes which prevents them from drying out and are laid on land, or develop internally in some species. The bladder is small as nitrogenous waste is excreted as uric acid.
Turtles are notable for their protective shells. They have an inflexible trunk encased in a horny carapace above and a plastron below. These are formed from bony plates embedded in the dermis which are overlain by horny ones and are partially fused with the ribs and spine. The neck is long and flexible and the head and the legs can be drawn back inside the shell. Turtles are vegetarians and the typical reptile teeth have been replaced by sharp, horny plates. In aquatic species, the front legs are modified into flippers.
Tuataras superficially resemble lizards but the lineages diverged in the Triassic period. There is one living species, Sphenodon punctatus. The skull has two openings (fenestrae) on either side and the jaw is rigidly attached to the skull. There is one row of teeth in the lower jaw and this fits between the two rows in the upper jaw when the animal chews. The teeth are merely projections of bony material from the jaw and eventually wear down. The brain and heart are more primitive than those of other reptiles, and the lungs have a single chamber and lack bronchi. The tuatara has a well-developed parietal eye on its forehead.
Lizards have skulls with only one fenestra on each side, the lower bar of bone below the second fenestra having been lost. This results in the jaws being less rigidly attached which allows the mouth to open wider. Lizards are mostly quadrupeds, with the trunk held off the ground by short, sideways-facing legs, but a few species have no limbs and resemble snakes. Lizards have moveable eyelids, eardrums are present and some species have a central parietal eye.
Snakes are closely related to lizards, having branched off from a common ancestral lineage during the Cretaceous period, and they share many of the same features. The skeleton consists of a skull, a hyoid bone, spine and ribs though a few species retain a vestige of the pelvis and rear limbs in the form of pelvic spurs. The bar under the second fenestra has also been lost and the jaws have extreme flexibility allowing the snake to swallow its prey whole. Snakes lack moveable eyelids, the eyes being covered by transparent "spectacle" scales. They do not have eardrums but can detect ground vibrations through the bones of their skull. Their forked tongues are used as organs of taste and smell and some species have sensory pits on their heads enabling them to locate warm-blooded prey.
Crocodilians are large, low-slung aquatic reptiles with long snouts and large numbers of teeth. The head and trunk are dorso-ventrally flattened and the tail is laterally compressed. It undulates from side to side to force the animal through the water when swimming. The tough keratinized scales provide body armour and some are fused to the skull. The nostrils, eyes and ears are elevated above the top of the flat head enabling them to remain above the surface of the water when the animal is floating. Valves seal the nostrils and ears when it is submerged. Unlike other reptiles, crocodilians have hearts with four chambers allowing complete separation of oxygenated and deoxygenated blood.
Bird anatomy
Birds are tetrapods but though their hind limbs are used for walking or hopping, their front limbs are wings covered with feathers and adapted for flight. Birds are endothermic, have a high metabolic rate, a light skeletal system and powerful muscles. The long bones are thin, hollow and very light. Air sac extensions from the lungs occupy the centre of some bones. The sternum is wide and usually has a keel and the caudal vertebrae are fused. There are no teeth and the narrow jaws are adapted into a horn-covered beak. The eyes are relatively large, particularly in nocturnal species such as owls. They face forwards in predators and sideways in ducks.
The feathers are outgrowths of the epidermis and are found in localized bands from where they fan out over the skin. Large flight feathers are found on the wings and tail, contour feathers cover the bird's surface and fine down occurs on young birds and under the contour feathers of water birds. The only cutaneous gland is the single uropygial gland near the base of the tail. This produces an oily secretion that waterproofs the feathers when the bird preens. There are scales on the legs, feet and claws on the tips of the toes.
Mammal anatomy
Mammals are a diverse class of animals, mostly terrestrial but some are aquatic and others have evolved flapping or gliding flight. They mostly have four limbs, but some aquatic mammals have no limbs or limbs modified into fins, and the forelimbs of bats are modified into wings. The legs of most mammals are situated below the trunk, which is held well clear of the ground. The bones of mammals are well ossified and their teeth, which are usually differentiated, are coated in a layer of prismatic enamel. The teeth are shed once (milk teeth) during the animal's lifetime or not at all, as is the case in cetaceans. Mammals have three bones in the middle ear and a cochlea in the inner ear. They are clothed in hair and their skin contains glands which secrete sweat. Some of these glands are specialized as mammary glands, producing milk to feed the young. Mammals breathe with lungs and have a muscular diaphragm separating the thorax from the abdomen which helps them draw air into the lungs. The mammalian heart has four chambers, and oxygenated and deoxygenated blood are kept entirely separate. Nitrogenous waste is excreted primarily as urea.
Mammals are amniotes, and most are viviparous, giving birth to live young. Exceptions to this are the egg-laying monotremes, the platypus and the echidnas of Australia. Most other mammals have a placenta through which the developing foetus obtains nourishment, but in marsupials, the foetal stage is very short and the immature young is born and finds its way to its mother's pouch where it latches on to a nipple and completes its development.
Human anatomy
Humans have the overall body plan of a mammal. Humans have a head, neck, trunk (which includes the thorax and abdomen), two arms and hands, and two legs and feet.
Generally, students of certain biological sciences, paramedics, prosthetists and orthotists, physiotherapists, occupational therapists, nurses, podiatrists, and medical students learn gross anatomy and microscopic anatomy from anatomical models, skeletons, textbooks, diagrams, photographs, lectures and tutorials and in addition, medical students generally also learn gross anatomy through practical experience of dissection and inspection of cadavers. The study of microscopic anatomy (or histology) can be aided by practical experience examining histological preparations (or slides) under a microscope.
Human anatomy, physiology and biochemistry are complementary basic medical sciences, which are generally taught to medical students in their first year at medical school. Human anatomy can be taught regionally or systemically; that is, respectively, studying anatomy by bodily regions such as the head and chest, or studying by specific systems, such as the nervous or respiratory systems. The major anatomy textbook, Gray's Anatomy, has been reorganized from a systems format to a regional format, in line with modern teaching methods. A thorough working knowledge of anatomy is required by physicians, especially surgeons and doctors working in some diagnostic specialties, such as histopathology and radiology.
Academic anatomists are usually employed by universities, medical schools or teaching hospitals. They are often involved in teaching anatomy, and research into certain systems, organs, tissues or cells.
Invertebrate anatomy
Invertebrates constitute a vast array of living organisms ranging from the simplest unicellular eukaryotes such as Paramecium to such complex multicellular animals as the octopus, lobster and dragonfly. They constitute about 95% of the animal species. By definition, none of these creatures has a backbone. The cells of single-cell protozoans have the same basic structure as those of multicellular animals but some parts are specialized into the equivalent of tissues and organs. Locomotion is often provided by cilia or flagella or may proceed via the advance of pseudopodia, food may be gathered by phagocytosis, energy needs may be supplied by photosynthesis and the cell may be supported by an endoskeleton or an exoskeleton. Some protozoans can form multicellular colonies.
Metazoans are a multicellular organism, with different groups of cells serving different functions. The most basic types of metazoan tissues are epithelium and connective tissue, both of which are present in nearly all invertebrates. The outer surface of the epidermis is normally formed of epithelial cells and secretes an extracellular matrix which provides support to the organism. An endoskeleton derived from the mesoderm is present in echinoderms, sponges and some cephalopods. Exoskeletons are derived from the epidermis and is composed of chitin in arthropods (insects, spiders, ticks, shrimps, crabs, lobsters). Calcium carbonate constitutes the shells of molluscs, brachiopods and some tube-building polychaete worms and silica forms the exoskeleton of the microscopic diatoms and radiolaria. Other invertebrates may have no rigid structures but the epidermis may secrete a variety of surface coatings such as the pinacoderm of sponges, the gelatinous cuticle of cnidarians (polyps, sea anemones, jellyfish) and the collagenous cuticle of annelids. The outer epithelial layer may include cells of several types including sensory cells, gland cells and stinging cells. There may also be protrusions such as microvilli, cilia, bristles, spines and tubercles.
Marcello Malpighi, the father of microscopical anatomy, discovered that plants had tubules similar to those he saw in insects like the silk worm. He observed that when a ring-like portion of bark was removed on a trunk a swelling occurred in the tissues above the ring, and he unmistakably interpreted this as growth stimulated by food coming down from the leaves, and being captured above the ring.
Arthropod anatomy
Arthropods comprise the largest phylum of invertebrates in the animal kingdom with over a million known species.
Insects possess segmented bodies supported by a hard-jointed outer covering, the exoskeleton, made mostly of chitin. The segments of the body are organized into three distinct parts, a head, a thorax and an abdomen. The head typically bears a pair of sensory antennae, a pair of compound eyes, one to three simple eyes (ocelli) and three sets of modified appendages that form the mouthparts. The thorax has three pairs of segmented legs, one pair each for the three segments that compose the thorax and one or two pairs of wings. The abdomen is composed of eleven segments, some of which may be fused and houses the digestive, respiratory, excretory and reproductive systems. There is considerable variation between species and many adaptations to the body parts, especially wings, legs, antennae and mouthparts.
Spiders a class of arachnids have four pairs of legs; a body of two segments—a cephalothorax and an abdomen. Spiders have no wings and no antennae. They have mouthparts called chelicerae which are often connected to venom glands as most spiders are venomous. They have a second pair of appendages called pedipalps attached to the cephalothorax. These have similar segmentation to the legs and function as taste and smell organs. At the end of each male pedipalp is a spoon-shaped cymbium that acts to support the copulatory organ.
Other branches of anatomy
Surface anatomy is important as the study of anatomical landmarks that can be readily seen from the exterior contours of the body. It enables medics and veterinarians to gauge the position and anatomy of the associated deeper structures. Superficial is a directional term that indicates that structures are located relatively close to the surface of the body.
Comparative anatomy relates to the comparison of anatomical structures (both gross and microscopic) in different animals.
Artistic anatomy relates to anatomic studies of body proportions for artistic reasons.
History
Ancient
In 1600 BCE, the Edwin Smith Papyrus, an Ancient Egyptian medical text, described the heart and its vessels, as well as the brain and its meninges and cerebrospinal fluid, and the liver, spleen, kidneys, uterus and bladder, and it showed the blood vessels diverging from the heart. The Ebers Papyrus () features a "treatise on the heart", with vessels carrying all the body's fluids to or from every member of the body.
Ancient Greek anatomy and physiology underwent great changes and advances throughout the early medieval world. Over time, this medical practice expanded by a continually developing understanding of the functions of organs and structures in the body. Phenomenal anatomical observations of the human body were made, which have contributed towards the understanding of the brain, eye, liver, reproductive organs and the nervous system.
The Hellenistic Egyptian city of Alexandria was the stepping-stone for Greek anatomy and physiology. Alexandria not only housed the biggest library for medical records and books of the liberal arts in the world during the time of the Greeks, but was also home to many medical practitioners and philosophers. Great patronage of the arts and sciences from the Ptolemaic dynasty of Egypt helped raise Alexandria up, further rivalling the cultural and scientific achievements of other Greek states.
Some of the most striking advances in early anatomy and physiology took place in Hellenistic Alexandria. Two of the most famous anatomists and physiologists of the third century were Herophilus and Erasistratus. These two physicians helped pioneer human dissection for medical research, using the cadavers of condemned criminals, which was considered taboo until the Renaissance—Herophilus was recognized as the first person to perform systematic dissections. Herophilus became known for his anatomical works making impressing contributions to many branches of anatomy and many other aspects of medicine. Some of the works included classifying the system of the pulse, the discovery that human arteries had thicker walls than veins, and that the atria were parts of the heart. Herophilus's knowledge of the human body has provided vital input towards understanding the brain, eye, liver, reproductive organs and nervous system, and characterizing the course of disease. Erasistratus accurately described the structure of the brain, including the cavities and membranes, and made a distinction between its cerebrum and cerebellum During his study in Alexandria, Erasistratus was particularly concerned with studies of the circulatory and nervous systems. He was able to distinguish the sensory and the motor nerves in the human body and believed that air entered the lungs and heart, which was then carried throughout the body. His distinction between the arteries and veins—the arteries carrying the air through the body, while the veins carried the blood from the heart was a great anatomical discovery. Erasistratus was also responsible for naming and describing the function of the epiglottis and the valves of the heart, including the tricuspid. During the third century, Greek physicians were able to differentiate nerves from blood vessels and tendons and to realize that the nerves convey neural impulses. It was Herophilus who made the point that damage to motor nerves induced paralysis. Herophilus named the meninges and ventricles in the brain, appreciated the division between cerebellum and cerebrum and recognized that the brain was the "seat of intellect" and not a "cooling chamber" as propounded by Aristotle Herophilus is also credited with describing the optic, oculomotor, motor division of the trigeminal, facial, vestibulocochlear and hypoglossal nerves.
Great feats were made during the third century BCE in both the digestive and reproductive systems. Herophilus was able to discover and describe not only the salivary glands, but the small intestine and liver. He showed that the uterus is a hollow organ and described the ovaries and uterine tubes. He recognized that spermatozoa were produced by the testes and was the first to identify the prostate gland.
The anatomy of the muscles and skeleton is described in the Hippocratic Corpus, an Ancient Greek medical work written by unknown authors. Aristotle described vertebrate anatomy based on animal dissection. Praxagoras identified the difference between arteries and veins. Also in the 4th century BCE, Herophilos and Erasistratus produced more accurate anatomical descriptions based on vivisection of criminals in Alexandria during the Ptolemaic period.
In the 2nd century, Galen of Pergamum, an anatomist, clinician, writer and philosopher, wrote the final and highly influential anatomy treatise of ancient times. He compiled existing knowledge and studied anatomy through dissection of animals. He was one of the first experimental physiologists through his vivisection experiments on animals. Galen's drawings, based mostly on dog anatomy, became effectively the only anatomical textbook for the next thousand years. His work was known to Renaissance doctors only through Islamic Golden Age medicine until it was translated from the Greek some time in the 15th century.
Medieval to early modern
Anatomy developed little from classical times until the sixteenth century; as the historian Marie Boas writes, "Progress in anatomy before the sixteenth century is as mysteriously slow as its development after 1500 is startlingly rapid". Between 1275 and 1326, the anatomists Mondino de Luzzi, Alessandro Achillini and Antonio Benivieni at Bologna carried out the first systematic human dissections since ancient times. Mondino's Anatomy of 1316 was the first textbook in the medieval rediscovery of human anatomy. It describes the body in the order followed in Mondino's dissections, starting with the abdomen, then the thorax, then the head and limbs. It was the standard anatomy textbook for the next century.
Leonardo da Vinci (1452–1519) was trained in anatomy by Andrea del Verrocchio. He made use of his anatomical knowledge in his artwork, making many sketches of skeletal structures, muscles and organs of humans and other vertebrates that he dissected.
Andreas Vesalius (1514–1564), professor of anatomy at the University of Padua, is considered the founder of modern human anatomy. Originally from Brabant, Vesalius published the influential book De humani corporis fabrica ("the structure of the human body"), a large format book in seven volumes, in 1543. The accurate and intricately detailed illustrations, often in allegorical poses against Italianate landscapes, are thought to have been made by the artist Jan van Calcar, a pupil of Titian.
In England, anatomy was the subject of the first public lectures given in any science; these were given by the Company of Barbers and Surgeons in the 16th century, joined in 1583 by the Lumleian lectures in surgery at the Royal College of Physicians.
Late modern
In the United States, medical schools began to be set up towards the end of the 18th century. Classes in anatomy needed a continual stream of cadavers for dissection and these were difficult to obtain. Philadelphia, Baltimore and New York were all renowned for body snatching activity as criminals raided graveyards at night, removing newly buried corpses from their coffins. A similar problem existed in Britain where demand for bodies became so great that grave-raiding and even anatomy murder were practised to obtain cadavers. Some graveyards were in consequence protected with watchtowers. The practice was halted in Britain by the Anatomy Act of 1832, while in the United States, similar legislation was enacted after the physician William S. Forbes of Jefferson Medical College was found guilty in 1882 of "complicity with resurrectionists in the despoliation of graves in Lebanon Cemetery".
The teaching of anatomy in Britain was transformed by Sir John Struthers, Regius Professor of Anatomy at the University of Aberdeen from 1863 to 1889. He was responsible for setting up the system of three years of "pre-clinical" academic teaching in the sciences underlying medicine, including especially anatomy. This system lasted until the reform of medical training in 1993 and 2003. As well as teaching, he collected many vertebrate skeletons for his museum of comparative anatomy, published over 70 research papers, and became famous for his public dissection of the Tay Whale. From 1822 the Royal College of Surgeons regulated the teaching of anatomy in medical schools. Medical museums provided examples in comparative anatomy, and were often used in teaching. Ignaz Semmelweis investigated puerperal fever and he discovered how it was caused. He noticed that the frequently fatal fever occurred more often in mothers examined by medical students than by midwives. The students went from the dissecting room to the hospital ward and examined women in childbirth. Semmelweis showed that when the trainees washed their hands in chlorinated lime before each clinical examination, the incidence of puerperal fever among the mothers could be reduced dramatically.
Before the modern medical era, the main means for studying the internal structures of the body were dissection of the dead and inspection, palpation and auscultation of the living. It was the advent of microscopy that opened up an understanding of the building blocks that constituted living tissues. Technical advances in the development of achromatic lenses increased the resolving power of the microscope and around 1839, Matthias Jakob Schleiden and Theodor Schwann identified that cells were the fundamental unit of organization of all living things. Study of small structures involved passing light through them and the microtome was invented to provide sufficiently thin slices of tissue to examine. Staining techniques using artificial dyes were established to help distinguish between different types of tissue. Advances in the fields of histology and cytology began in the late 19th century along with advances in surgical techniques allowing for the painless and safe removal of biopsy specimens. The invention of the electron microscope brought a great advance in resolution power and allowed research into the ultrastructure of cells and the organelles and other structures within them. About the same time, in the 1950s, the use of X-ray diffraction for studying the crystal structures of proteins, nucleic acids and other biological molecules gave rise to a new field of molecular anatomy.
Equally important advances have occurred in non-invasive techniques for examining the interior structures of the body. X-rays can be passed through the body and used in medical radiography and fluoroscopy to differentiate interior structures that have varying degrees of opaqueness. Magnetic resonance imaging, computed tomography, and ultrasound imaging have all enabled examination of internal structures in unprecedented detail to a degree far beyond the imagination of earlier generations.
See also
Anatomical model
Outline of human anatomy
Plastination
References
External links
Anatomy, In Our Time. BBC Radio 4. Melvyn Bragg with guests Ruth Richardson, Andrew Cunningham and Harold Ellis.
"Anatomy of the Human Body". 20th edition. 1918. Henry Gray
Anatomia Collection: anatomical plates 1522 to 1867 (digitized books and images)
Lyman, Henry Munson. The Book of Health (1898). Science History Institute Digital Collections .
Gunther von Hagens True Anatomy for New Ways of Teaching.
Sources
Anatomical terminology
Branches of biology
Morphology (biology) |
675 | https://en.wikipedia.org/wiki/Affirming%20the%20consequent | Affirming the consequent | In propositional logic, affirming the consequent, sometimes called converse error, fallacy of the converse, or confusion of necessity and sufficiency, is a formal fallacy of taking a true conditional statement (e.g., "if the lamp were broken, then the room would be dark") under certain assumptions (there are no other lights in the room, it is nighttime and the windows are closed), and invalidly inferring its converse ("the room is dark, so the lamp must be broken"), even though that statement may not be true under the same assumptions. This arises when the consequent ("the room would be dark") has other possible antecedents (for example, "the lamp is in working order, but is switched off" or "there is no lamp in the room").
Converse errors are common in everyday thinking and communication and can result from, among other causes, communication issues, misconceptions about logic, and failure to consider other causes.
The opposite statement, denying the consequent, is called modus tollens and is a valid form of argument.
Formal description
Affirming the consequent is the action of taking a true statement and invalidly concluding its converse . The name affirming the consequent derives from using the consequent, Q, of , to conclude the antecedent P. This fallacy can be summarized formally as or, alternatively, .
The root cause of such a logical error is sometimes failure to realize that just because P is a possible condition for Q, P may not be the only condition for Q, i.e. Q may follow from another condition as well.
Affirming the consequent can also result from overgeneralizing the experience of many statements having true converses. If P and Q are "equivalent" statements, i.e. , it is possible to infer P under the condition Q. For example, the statements "It is August 13, so it is my birthday" and "It is my birthday, so it is August 13" are equivalent and both true consequences of the statement "August 13 is my birthday" (an abbreviated form of ).
Of the possible forms of "mixed hypothetical syllogisms," two are valid and two are invalid. Affirming the antecedent (modus ponens) and denying the consequent (modus tollens) are valid. Affirming the consequent and denying the antecedent are invalid.
Additional examples
Example 1
One way to demonstrate the invalidity of this argument form is with a counterexample with true premises but an obviously false conclusion. For example:
If someone lives in San Diego, then they live in California.
Joe lives in California.
Therefore, Joe lives in San Diego.
There are many places to live in California other than San Diego. On the other hand, one can affirm with certainty that "if someone does not live in California" (non-Q), then "this person does not live in San Diego" (non-P). This is the contrapositive of the first statement, and it must be true if and only if the original statement is true.
Example 2
If an animal is a dog, then it has four legs.
My cat has four legs.
Therefore, my cat is a dog.
Here, it is immediately intuitive that any number of other antecedents ("If an animal is a deer...", "If an animal is an elephant...", "If an animal is a moose...", etc.) can give rise to the consequent ("then it has four legs"), and that it is preposterous to suppose that having four legs must imply that the animal is a dog and nothing else. This is useful as a teaching example since most people can immediately recognize that the conclusion reached must be wrong (intuitively, a cat cannot be a dog), and that the method by which it was reached must therefore be fallacious.
Example 3
In Catch-22, the chaplain is interrogated for supposedly being "Washington Irving"/"Irving Washington", who has been blocking out large portions of soldiers' letters home. The colonel has found such a letter, but with the Chaplain's name signed.
"You can read, though, can't you?" the colonel persevered sarcastically. "The author signed his name."
"That's my name there."
"Then you wrote it. Q.E.D."
P in this case is 'The chaplain signs his own name', and Q 'The chaplain's name is written'. The chaplain's name may be written, but he did not necessarily write it, as the colonel falsely concludes.See also
Abductive reasoning
Appeal to consequences
Confusion of the inverse
Denying the antecedent
Fallacies of illicit transference
Fallacy of the single cause
Fallacy of the undistributed middle
Modus ponens Modus tollens Necessity and sufficiency
Post hoc ergo propter hoc''
References
Formal fallacies |
678 | https://en.wikipedia.org/wiki/Abel | Abel | Abel is a Biblical figure in the Book of Genesis within Abrahamic religions. He was a younger brother of Cain, and the second son of Adam and Eve, the first couple in Biblical history. He was a shepherd who offered his firstborn flock up to God as an offering. God accepted his offering but not his brother's. Cain then killed Abel out of jealousy.
According to Genesis, this was the first murder and Abel was the first dead person in the history of mankind.
Life and death
Interpretations
Jewish and Christian interpretations
According to the narrative in Genesis, Abel ( Hébel, in pausa Hā́ḇel; Hábel; , Hābēl) is Eve's second son. His name in Hebrew is composed of the same three consonants as a root meaning "the air that remains after you exhale" also synonymous in Hebrew to “nothing”, as stated in “ Ecclesiastes”. Julius Wellhausen has proposed that the name is independent of the root. Eberhard Schrader had previously put forward the Akkadian (Old Assyrian dialect) ablu ("son") as a more likely etymology.
In Christianity, comparisons are sometimes made between the death of Abel and that of Jesus, the former thus seen as being the first martyr. In Jesus speaks of Abel as "righteous", and the Epistle to the Hebrews states that "The blood of sprinkling ... [speaks] better things than that of Abel" (). The blood of Jesus is interpreted as bringing mercy; but that of Abel as demanding vengeance (hence the curse and mark).
Abel is invoked in the litany for the dying in the Roman Catholic Church, and his sacrifice is mentioned in the Canon of the Mass along with those of Abraham and Melchizedek. The Alexandrian Rite commemorates him with a feast day on December 28.
According to the Coptic Book of Adam and Eve (at 2:1–15), and the Syriac Cave of Treasures, Abel's body, after many days of mourning, was placed in the Cave of Treasures, before which Adam and Eve, and descendants, offered their prayers. In addition, the Sethite line of the Generations of Adam swear by Abel's blood to segregate themselves from the unrighteous.
In the Book of Enoch (22:7), regarded by most Christian and Jewish traditions as extra-biblical, the soul of Abel is described as having been appointed as the chief of martyrs, crying for vengeance, for the destruction of the seed of Cain. A similar view is later shown in the Testament of Abraham (A:13 / B:11), where Abel has been raised to the position as the judge of the souls.
In Bereshit Rabbah (22:2), a discussion of Gen. 4:1 ff. has Rabbi Yehoshua ben Korcha mentioning that Cain was born with a twin sister, and Abel with two twin sisters. This is based on the principle that the otherwise superfluous accusative article "et" always conveys some additional teaching (Pesachim 22b). The "et"'s are parsed slightly differently in Yebamot 62a where the two "et"'s in Gen. 4:2 indicate Cain and his sister, and Abel and his (one) sister.
Sethian Gnostic interpretation
In the Apocryphon of John, a work belonging to Sethian Gnosticism, Abel is the offspring of Yaldaboath and Eve, who is placed over the elements of water and earth as Elohim, but was only given his name as a form of deception.
Mandaean interpretation
According to Mandaean beliefs and scriptures including the Qolastā, the Book of John and Genzā Rabbā, Abel is cognate with the angelic soteriological figure Hibil Ziwa, (, sometimes translated "Splendid Hibel"), who is spoken of as a son of Hayyi or of Manda d-Hayyi, and as a brother to Anush (Enosh) and to Sheetil (Seth), who is the son of Adam. Elsewhere, Anush is spoken of as the son of Sheetil, and Sheetil as the son of Hibil, where Hibil came to Adam and Eve as a young boy when they were still virgins, but was called their son. Hibil is an important lightworld being (uthra) who conquered the World of Darkness. As Yawar Hibil, he is one of multiple figures known as Yawar (), being so named by and after his father.
Islamic interpretation
According to Shi'a Muslim belief, Abel ("Habeel") is buried in the Nabi Habeel Mosque, located on the west mountains of Damascus, near the Zabadani Valley, overlooking the villages of the Barada river (Wadi Barada), in Syria. Shi'a are frequent visitors of this mosque for ziyarat. The mosque was built by Ottoman Wali Ahmad Pasha in 1599.
In modern media
Abel is portrayed by Franco Nero in the film The Bible: In the Beginning... (1966).
Paul Rudd played the role of Abel in the 2009 film Year One.
In the SCP series, an anomaly named Able with the codename SCP-076 is based on Abel.
In Shin Megami Tensei: Devil Survivor, the main character Kazuya is the reincarnation of Abel
Notes
References
Bereshit (parashah)
Biblical murder victims
Book of Genesis people
Children of Adam and Eve
Shepherds
Uthras |
682 | https://en.wikipedia.org/wiki/Adobe | Adobe | Adobe ( ; ) is a building material made from earth and organic materials. is Spanish for mudbrick. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is used to refer to any kind of earthen construction, or various architectural styles like Pueblo Revival or Territorial Revival. Most adobe buildings are similar in appearance to cob and rammed earth buildings. Adobe is among the earliest building materials, and is used throughout the world.
Adobe architecture has been dated to before 5,100 BC.
Description
Adobe bricks are rectangular prisms small enough that they can quickly air dry individually without cracking. They can be subsequently assembled, with the application of adobe mud to bond the individual bricks into a structure. There is no standard size, with substantial variations over the years and in different regions. In some areas a popular size measured weighing about ; in other contexts the size is weighing about . The maximum sizes can reach up to ; above this weight it becomes difficult to move the pieces, and it is preferred to ram the mud in situ, resulting in a different typology known as rammed earth.
Strength
In dry climates, adobe structures are extremely durable, and account for some of the oldest existing buildings in the world. Adobe buildings offer significant advantages due to their greater thermal mass, but they are known to be particularly susceptible to earthquake damage if they are not reinforced. Cases where adobe structures were widely damaged during earthquakes include the 1976 Guatemala earthquake, the 2003 Bam earthquake, and the 2010 Chile earthquake.
Distribution
Buildings made of sun-dried earth are common throughout the world (Middle East, Western Asia, North Africa, West Africa, South America, Southwestern North America, Southwestern and Eastern Europe.). Adobe had been in use by indigenous peoples of the Americas in the Southwestern United States, Mesoamerica, and the Andes for several thousand years. Puebloan peoples built their adobe structures with handsful or basketsful of adobe, until the Spanish introduced them to making bricks. Adobe bricks were used in Spain from the Late Bronze and Iron Ages (eighth century BCE onwards). Its wide use can be attributed to its simplicity of design and manufacture, and economics.
Etymology
The word adobe has existed for around 4,000 years with relatively little change in either pronunciation or meaning. The word can be traced from the Middle Egyptian () word ḏbt "mud brick" (with vowels unwritten). Middle Egyptian evolved into Late Egyptian and finally to Coptic (), where it appeared as ⲧⲱⲃⲉ tōbə. This was adopted into Arabic as aṭ-ṭawbu or aṭ-ṭūbu, with the definite article al- attached to the root tuba. This was assimilated into the Old Spanish language as adobe , probably via Mozarabic. English borrowed the word from Spanish in the early 18th century, still referring to mudbrick construction.
In more modern English usage, the term adobe has come to include a style of architecture popular in the desert climates of North America, especially in New Mexico, regardless of the construction method.
Composition
An adobe brick is a composite material made of earth mixed with water and an organic material such as straw or dung. The soil composition typically contains sand, silt and clay. Straw is useful in binding the brick together and allowing the brick to dry evenly, thereby preventing cracking due to uneven shrinkage rates through the brick. Dung offers the same advantage. The most desirable soil texture for producing the mud of adobe is 15% clay, 10–30% silt, and 55–75% fine sand. Another source quotes 15–25% clay and the remainder sand and coarser particles up to cobbles , with no deleterious effect. Modern adobe is stabilized with either emulsified asphalt or Portland cement up to 10% by weight.
No more than half the clay content should be expansive clays, with the remainder non-expansive illite or kaolinite. Too much expansive clay results in uneven drying through the brick, resulting in cracking, while too much kaolinite will make a weak brick. Typically the soils of the Southwest United States, where such construction has been widely used, are an adequate composition.
Material properties
Adobe walls are load bearing, i.e. they carry their own weight into the foundation rather than by another structure, hence the adobe must have sufficient compressive strength. In the United States, most building codes call for a minimum compressive strength of 300 lbf/in2 (2.07 newton/mm2) for the adobe block. Adobe construction should be designed so as to avoid lateral structural loads that would cause bending loads. The building codes require the building sustain a 1 g lateral acceleration earthquake load. Such an acceleration will cause lateral loads on the walls, resulting in shear and bending and inducing tensile stresses. To withstand such loads, the codes typically call for a tensile modulus of rupture strength of at least 50 lbf/in2 (0.345 newton/mm2) for the finished block.
In addition to being an inexpensive material with a small resource cost, adobe can serve as a significant heat reservoir due to the thermal properties inherent in the massive walls typical in adobe construction. In climates typified by hot days and cool nights, the high thermal mass of adobe mediates the high and low temperatures of the day, moderating the temperature of the living space. The massive walls require a large and relatively long input of heat from the sun (radiation) and from the surrounding air (convection) before they warm through to the interior. After the sun sets and the temperature drops, the warm wall will continue to transfer heat to the interior for several hours due to the time-lag effect. Thus, a well-planned adobe wall of the appropriate thickness is very effective at controlling inside temperature through the wide daily fluctuations typical of desert climates, a factor which has contributed to its longevity as a building material.
Thermodynamic material properties have significant variation in the literature. Some experiments suggest that the standard consideration of conductivity is not adequate for this material, as its main thermodynamic property is inertia, and conclude that experimental tests should be performed over a longer period of time than usual - preferably with changing thermal jumps. There is an effective R-value for a north facing 10-in wall of R0=10 hr ft2 °F/Btu, which corresponds to thermal conductivity k=10 in x 1 ft/12 in /R0=0.33 Btu/(hr ft °F) or 0.57 W/(m K) in agreement with the thermal conductivity reported from another source. To determine the total R-value of a wall, scale R0 by the thickness of the wall in inches. The thermal resistance of adobe is also stated as an R-value for a 10-inch wall R0=4.1 hr ft2 °F/Btu. Another source provides the following properties: conductivity=0.30 Btu/(hr ft °F) or 0.52 W/(m K); specific heat capacity=0.24 Btu/(lb °F) or 1 kJ/(kg K) and density=106 lb/ft3 or 1700 kg/m3, giving heat capacity=25.4 Btu/(ft3 °F) or 1700 kJ/(m3 K). Using the average value of the thermal conductivity as k = 32 Btu/(hr ft °F) or 0.55 W/(m K), the thermal diffusivity is calculated to be 0.013 ft2/h or 3.3x10−7 m2/s.
Uses
Poured and puddled adobe walls
Poured and puddled adobe (puddled clay, piled earth), today called cob, is made by placing soft adobe in layers, rather than by making individual dried bricks or using a form. "Puddle" is a general term for a clay or clay and sand-based material worked into a dense, plastic state. These are the oldest methods of building with adobe in the Americas until holes in the ground were used as forms, and later wooden forms used to make individual bricks were introduced by the Spanish.
Adobe bricks
Bricks made from adobe are usually made by pressing the mud mixture into an open timber frame. In North America, the brick is typically about in size. The mixture is molded into the frame, which is removed after initial setting. After drying for a few hours, the bricks are turned on edge to finish drying. Slow drying in shade reduces cracking.
The same mixture, without straw, is used to make mortar and often plaster on interior and exterior walls. Some cultures used lime-based cement for the plaster to protect against rain damage.
Depending on the form into which the mixture is pressed, adobe can encompass nearly any shape or size, provided drying is even and the mixture includes reinforcement for larger bricks. Reinforcement can include manure, straw, cement, rebar, or wooden posts. Straw, cement, or manure added to a standard adobe mixture can produce a stronger, more crack-resistant brick. A test is done on the soil content first. To do so, a sample of the soil is mixed into a clear container with some water, creating an almost completely saturated liquid. The container is shaken vigorously for one minute. It is then allowed to settle for a day until the soil has settled into layers. Heavier particles settle out first, sand above, silt above that, and very fine clay and organic matter will stay in suspension for days. After the water has cleared, percentages of the various particles can be determined. Fifty to 60 percent sand and 35 to 40 percent clay will yield strong bricks. The Cooperative State Research, Education, and Extension Service at New Mexico State University recommends a mix of not more than clay, not less than sand, and never more than silt.
During the Great Depression, designer and builder Hugh W. Comstock used cheaper materials and made a specialized adobe brick called "Bitudobe." His first adobe house was built in 1936. In 1948, he published the book Post-Adobe; Simplified Adobe Construction Combining A Rugged Timber Frame And Modern Stabilized Adobe, which described his method of construction, including how to make "Bitudobe." In 1938, he served as an adviser to the architects Franklin & Kump Associates, who built the Carmel High School, which used his Post-adobe system.
Adobe wall construction
The ground supporting an adobe structure should be compressed, as the weight of adobe wall is significant and foundation settling may cause cracking of the wall. Footing depth is to be below the ground frost level. The footing and stem wall are commonly 24 and 14 inches thick, respectively. Modern construction codes call for the use of reinforcing steel in the footing and stem wall. Adobe bricks are laid by course. Adobe walls usually never rise above two stories as they are load bearing and adobe has low structural strength. When creating window and door openings, a lintel is placed on top of the opening to support the bricks above. Atop the last courses of brick, bond beams made of heavy wood beams or modern reinforced concrete are laid to provide a horizontal bearing plate for the roof beams and to redistribute lateral earthquake loads to shear walls more able to carry the forces. To protect the interior and exterior adobe walls, finishes such as mud plaster, whitewash or stucco can be applied. These protect the adobe wall from water damage, but need to be reapplied periodically. Alternatively, the walls can be finished with other nontraditional plasters that provide longer protection. Bricks made with stabilized adobe generally do not need protection of plasters.
Adobe roof
The traditional adobe roof has been constructed using a mixture of soil/clay, water, sand and organic materials. The mixture was then formed and pressed into wood forms, producing rows of dried earth bricks that would then be laid across a support structure of wood and plastered into place with more adobe.
Depending on the materials available, a roof may be assembled using wood or metal beams to create a framework to begin layering adobe bricks. Depending on the thickness of the adobe bricks, the framework has been preformed using a steel framing and a layering of a metal fencing or wiring over the framework to allow an even load as masses of adobe are spread across the metal fencing like cob and allowed to air dry accordingly. This method was demonstrated with an adobe blend heavily impregnated with cement to allow even drying and prevent cracking.
The more traditional flat adobe roofs are functional only in dry climates that are not exposed to snow loads. The heaviest wooden beams, called vigas, lie atop the wall. Across the vigas lie smaller members called latillas and upon those brush is then laid. Finally, the adobe layer is applied.
To construct a flat adobe roof, beams of wood were laid to span the building, the ends of which were attached to the tops of the walls. Once the vigas, latillas and brush are laid, adobe bricks are placed. An adobe roof is often laid with bricks slightly larger in width to ensure a greater expanse is covered when placing the bricks onto the roof. Following each individual brick should be a layer of adobe mortar, recommended to be at least thick to make certain there is ample strength between the brick's edges and also to provide a relative moisture barrier during rain.
Roof design evolved around 1850 in the American Southwest. Three inches of adobe mud was applied on top of the latillas, then 18 inches of dry adobe dirt applied to the roof. The dirt was contoured into a low slope to a downspout aka a 'canal'. When moisture was applied to the roof the clay particles expanded to create a waterproof membrane. Once a year it was necessary to pull the weeds from the roof and re-slope the dirt as needed.
Depending on the materials, adobe roofs can be inherently fire-proof. The construction of a chimney can greatly influence the construction of the roof supports, creating an extra need for care in choosing the materials. The builders can make an adobe chimney by stacking simple adobe bricks in a similar fashion as the surrounding walls.
In 1927, the Uniform Building Code (UBC) was adopted in the United States. Local ordinances, referencing the UBC added requirements to building with adobe. These included: restriction of building height of adobe structures to 1-story, requirements for adobe mix (compressive and shear strength) and new requirements which stated that every building shall be designed to withstand seismic activity, specifically lateral forces. By the 1980s however, seismic related changes in the California Building Code effectively ended solid wall adobe construction in California; however Post-and-Beam adobe and veneers are still being used.
Adobe around the world
The largest structure ever made from adobe is the Arg-é Bam built by the Achaemenid Empire. Other large adobe structures are the Huaca del Sol in Peru, with 100 million signed bricks and the ciudellas of Chan Chan and Tambo Colorado, both in Peru.
See also
used adobe walls
(waterproofing plaster)
(also known as Ctesiphon Arch) in Iraq is the largest mud brick arch in the world, built beginning in 540 AD
References
External links
Soil-based building materials
Masonry
Adobe buildings and structures
Appropriate technology
Vernacular architecture
Sustainable building
Western (genre) staples and terminology |
683 | https://en.wikipedia.org/wiki/Adventure | Adventure | An adventure is an exciting experience or undertaking that is typically bold, sometimes risky. Adventures may be activities with danger such as traveling, exploring, skydiving, mountain climbing, scuba diving, river rafting, or other extreme sports. Adventures are often undertaken to create psychological arousal or in order to achieve a greater goal, such as the pursuit of knowledge that can only be obtained by such activities.
Motivation
Adventurous experiences create psychological arousal, which can be interpreted as negative (e.g. fear) or positive (e.g. flow). For some people, adventure becomes a major pursuit in and of itself. According to adventurer André Malraux, in his Man's Fate (1933), "If a man is not ready to risk his life, where is his dignity?"
Similarly, Helen Keller stated that "Life is either a daring adventure or nothing."
Outdoor adventurous activities are typically undertaken for the purposes of recreation or excitement: examples are adventure racing and adventure tourism. Adventurous activities can also lead to gains in knowledge, such as those undertaken by explorers and pioneersthe British adventurer Jason Lewis, for example, uses adventures to draw global sustainability lessons from living within finite environmental constraints on expeditions to share with schoolchildren. Adventure education intentionally uses challenging experiences for learning.
Author Jon Levy suggests that an experience should meet several criteria to be considered an adventure:
Be remarkable—that is, worth talking about
Involve adversity or perceived risk
Bring about personal growth.
Mythology and fiction
Some of the oldest and most widespread stories in the world are stories of adventure, such as Homer's Odyssey.
The knight errant was the form the "adventure seeker" character took in the Late Middle Ages.
Adventure fiction exhibits these "protagonist on adventurous journey" characteristics, as do many popular feature films, such as Star Wars and Raiders of the Lost Ark.
Outdoors
Adventure books may have the theme of the hero or main character going to face the wilderness or Mother Nature. Examples include books such as Hatchet or My Side of the Mountain. These books are less about "questing", such as in mythology or other adventure novels, but more about surviving on their own, living off the land, gaining new experiences, and becoming closer to the natural world.
Questing
Many adventures are based on the idea of a quest: the hero goes off in pursuit of a reward, whether it be a skill, prize, treasure, or perhaps the safety of a person. On the way, the hero must overcome various obstacles to obtain their reward.
Video games
In video game culture, an adventure game is a video game in which the player assumes the role of a protagonist in an interactive story driven by exploration and puzzle solving. The genre's focus on story allows it to draw heavily from other narrative-based media, literature and film, encompassing a wide variety of literary genres. Many adventure games (text and graphic) are designed for a single player, since this emphasis on story and character makes multi-player design difficult.
Nonfiction works
From ancient times, travelers and explorers have written about their adventures. Journals which became best-sellers in their day were written, such as Marco Polo's journal The Travels of Marco Polo or Mark Twain's Roughing It. Others were personal journals, only later published, such as the journals of Meriwether Lewis and William Clark or Captain James Cook's journals. There are also books written by those not directly a part of the adventure in question, such as The Right Stuff by Tom Wolfe or books written by those participating in the adventure but in a format other than that of a journal, such as Conquistadors of the Useless by Lionel Terray. Documentaries often use the theme of adventure as well.
Adventure sports
There are many sports classified as adventure sports, due to their inherent danger and excitement. Some of these include mountain climbing, skydiving, or other extreme sports.
See also
Adventure film
Adventure playground
Adventure travel
Expedition
Exploration
Filibuster (military)
List of genres
Novelty seeking
Overlanding
Sports
Tourism
Travel
References
External links
Martin Feeney Going on a journey: Life in Year 10
Website of the Research Unit "Philology of Adventure": ongoing research project on the literary history of the adventure pattern
What is an adventure? A definition of "adventure", "hero" and "epic" with an illustration of the hero's journey.
Wikivoyage |
694 | https://en.wikipedia.org/wiki/Asia%20Minor%20%28disambiguation%29 | Asia Minor (disambiguation) | Asia Minor is an alternative name for Anatolia, the westernmost protrusion of Asia, comprising the majority of the Republic of Turkey.
Asia Minor may also refer to:
Asia Minor (album), an album by Jamaican-born jazz trumpeter Dizzy Reece
"Asia Minor" (instrumental), a 1961 instrumental recording by Jimmy Wisner (operating under the name Kokomo)
See also
Asia Major (disambiguation) |
705 | https://en.wikipedia.org/wiki/Politics%20of%20Angola | Politics of Angola | The current political regime in Angola is presidentialism, in which the President of the Republic is also head of state and government; it is advised by a Council of Ministers, which together with the President form the national executive power. Legislative power rests with the 220 parliamentarians elected to the National Assembly. The President of the Republic, together with the parliament, appoints the majority of the members of the two highest bodies of the judiciary, that is, the Constitutional Court and the Supreme Court. The judiciary is still made up of the Court of Auditors and the Supreme Military Court.
The Angolan government is composed of three branches of government: executive, legislative and judicial. For decades, political power has been concentrated in the presidency with the People's Movement for the Liberation of Angola.
History
Since the adoption of a new constitution in 2010, the politics of Angola takes place in a framework of a presidential republic, whereby the President of Angola is both head of state and head of government, and of a multi-party system. Executive power is exercised by the government. Legislative power is vested in the President, the government and parliament.
Angola changed from a one-party Marxist-Leninist system ruled by the Popular Movement for the Liberation of Angola (MPLA), in place since independence in 1975, to a multiparty democracy based on a new constitution adopted in 1992. That same year the first parliamentary and presidential elections were held. The MPLA won an absolute majority in the parliamentary elections. In the presidential elections, President José Eduardo dos Santos won the first round election with more than 49% of the vote to Jonas Savimbi's 40%. A runoff election would have been necessary, but never took place. The renewal of civil war immediately after the elections, which were considered as fraudulent by UNITA, and the collapse of the Lusaka Protocol, created a split situation. To a certain degree the new democratic institutions worked, notably the National Assembly, with the active participation of UNITA's and the FNLA's elected MPs - while José Eduardo dos Santos continued to exercise his functions without democratic legitimation. However the armed forces of the MPLA (now the official armed forces of the Angolan state) and of UNITA fought each other until the leader of UNITA, Jonas Savimbi, was killed in action in 2002.
From 2002 to 2010, the system as defined by the constitution of 1992 functioned in a relatively normal way. The executive branch of the government was composed of the President, the Prime Minister and Council of Ministers. The Council of Ministers, composed of all ministers and vice ministers, met regularly to discuss policy issues. Governors of the 18 provinces were appointed by and served at the pleasure of the president. The Constitutional Law of 1992 established the broad outlines of government structure and the rights and duties of citizens. The legal system was based on Portuguese and customary law but was weak and fragmented. Courts operated in only 12 of more than 140 municipalities. A Supreme Court served as the appellate tribunal; a Constitutional Court with powers of judicial review was never constituted despite statutory authorization. In practice, power was more and more concentrated in the hands of the President who, supported by an ever-increasing staff, largely controlled parliament, government, and the judiciary.
The 26-year-long civil war has ravaged the country's political and social institutions. The UN estimates of 1.8 million internally displaced persons (IDPs), while generally the accepted figure for war-affected people is 4 million. Daily conditions of life throughout the country and specifically Luanda (population approximately 6 million) mirror the collapse of administrative infrastructure as well as many social institutions. The ongoing grave economic situation largely prevents any government support for social institutions. Hospitals are without medicines or basic equipment, schools are without books, and public employees often lack the basic supplies for their day-to-day work.
José Eduardo dos Santos stepped down as President of Angola after 38 years in 2017, being peacefully succeeded by João Lourenço, Santos' chosen successor. However, President João Lourenço started a campaign against corruption of the dos Santos era. In November 2017, Isabel dos Santos, the billionaire daughter of former President José Eduardo dos Santos, was fired from her position as head of the country's state oil company Sonangol. In August 2020, José Filomeno dos Santos, son of Angola's former president, was sentenced for five years in jail for fraud and corruption.
In August 2022, the ruling party, MPLA, won another outright majority and President Joao Lourenco won a second five-year term in the election. However, the election was the tightest in Angola’s history.
Executive branch
The 2010 constitution grants the President almost absolute power. Elections for the National assembly are to take place every five years, and the President is automatically the leader of the winning party or coalition. It is for the President to appoint (and dismiss) all of the following:
The members of the government (state ministers, ministers, state secretaries and vice-ministers);
The members of the Constitutional Court;
The members of the Supreme Court;
The members of the Court of Auditors;
The members of the Military Supreme Court;
The Governor and Vice-Governors of the National Angolan Bank;
The General-Attorney, the Vice-General-Attorneys and their deputies (as well as the military homologous);
The Governors of the provinces;
The members of the Republic Council;
The members of the National Security Council;
The members of the Superior Magistrates Councils;
The General Chief of the Armed Forces and his deputy;
All other command posts in the military;
The Police General Commander, and the 2nd in command;
All other command posts in the police;
The chiefs and directors of the intelligence and security organs.
The President is also provided a variety of powers, like defining the policy of the country. Even though it's not up to him/her to make laws (only to promulgate them and make edicts), the President is the leader of the winning party.
The only "relevant" post that is not directly appointed by the President is the Vice-President, which is the second in the winning party.
José Eduardo dos Santos stepped down as President of Angola after 38 years in 2017, being peacefully succeeded by João Lourenço, Santos' chosen successor.
Legislative branch
The National Assembly (Assembleia Nacional) has 223 members, elected for a four-year term, 130 members by proportional representation, 90 members in provincial districts, and 3 members to represent Angolans abroad. The general elections in 1997 were rescheduled for 5 September 2008. The ruling party MPLA won 82% (191 seats in the National Assembly) and the main opposition party won only 10% (16 seats). The elections however have been described as only partly free but certainly not fair. A White Book on the elections in 2008 lists up all irregularities surrounding the Parliamentary elections of 2008.
Political parties and elections
Judicial branch
Supreme Court (or "Tribunal da Relacao") judges of the Supreme Court are appointed by the president. The Constitutional Court, with the power of judicial review, contains 11 justices. Four are appointed by the President, four by the National Assembly, two by the Superior Council of the Judiciary, and one elected by the public.
Administrative divisions
Angola has eighteen provinces: Bengo, Benguela, Bie, Cabinda, Cuando Cubango, Cuanza Norte, Cuanza Sul, Cunene, Huambo, Huila, Luanda, Lunda Norte, Lunda Sul, Malanje, Moxico, Namibe, Uige, Zaire
Political pressure groups and leaders
Front for the Liberation of the Enclave of Cabinda or FLEC (Henrique N'zita Tiago; António Bento Bembe)
note: FLEC is waging a small-scale, highly factionalized, armed struggle for the independence of Cabinda Province
International organization participation
African, Caribbean and Pacific Group of States, AfDB, CEEAC, United Nations Economic Commission for Africa, FAO, Group of 77, IAEA, IBRD, ICAO, International Criminal Court (signatory), ICFTU, International Red Cross and Red Crescent Movement, International Development Association, IFAD, IFC, IFRCS, International Labour Organization, International Monetary Fund, International Maritime Organization, Interpol, IOC, International Organization for Migration, ISO (correspondent), ITU, Non-Aligned Council (temporary), UNCTAD, UNESCO, UNIDO, UPU, World Customs Organization, World Federation of Trade Unions, WHO, WIPO, WMO, WToO, WTrO
See also
References
Further reading
ANGOLA LIVRO BRANCO SOBRE AS ELEIÇÕES DE 2008. http://www.kas.de/proj/home/pub/8/2/year-2009/dokument_id-17396/index.html
Bösl, Anton (2008). Angola's Parliamentary Elections in 2008. A Country on its Way to One-Party-Democracy, KAS Auslandsinformationen 10/2008. http://www.kas.de/wf/de/33.15186/
Amundsen, I. (2011) Angola Party Politics: Into the African Trend. Angola Brief vol. 1 no. 9
External links
The Chr. Michelsen Institute The largest centre for development research in Scandinavia. In particular, see their collaborative Angola Programme. |
708 | https://en.wikipedia.org/wiki/Transport%20in%20Angola | Transport in Angola | Transport in Angola comprises:
Roads
Two trans-African automobile routes pass through Angola:
the Tripoli-Cape Town Highway
the Beira-Lobito Highway
Railways
There are three separate railway lines in Angola:
Luanda Railway (CFL) (northern);
Benguela Railway (CFB) (central), operated by the Lobito Atlantic Railway joint venture;
Moçâmedes Railway (CFM) (southern);
Reconstruction of these three lines began in 2005 and they are now all operational. The Benguela Railway connects to the Democratic Republic of the Congo.
Waterways
1,300 km navigable (2008)
country comparison to the world: 36
Pipelines
gas 352 km; liquid petroleum gas 85 km; crude oil 1,065 km (2013)
In April 2012, the Zambian Development Agency (ZDA) and an Angolan company signed a memorandum of understanding (MoU) to build a multi-product pipeline from Lobito to Lusaka, Zambia, to deliver various refined products to Zambia.
Angola plans to build an oil refinery in Lobito in the coming years.
Ports and harbors
The government plans to build a deep-water port at Barra do Dande, north of Luanda, in Bengo province near Caxito.
Merchant marine
total: 58
country comparison to the world: 115
by type: cargo 13, oil tanker 8, other 37 (2008)
Airports
102 (2021)
Airports – with paved runways
total: 30
over 3,047 m: 5
2,438 to 3,047 m: 8
1,524 to 2,437 m: 12
914 to 1,523 m: 4
under 914 m: 1 (2008)
Airports – with unpaved runways
total: 181 (2008)
over 3,047 m: 2
2,438 to 3,047 m: 5
1,524 to 2,437 m: 32
914 to 1,523 m: 100
under 914 m: 42 (2008)
Angolan Airlines
TAAG Angola Airlines
Sonair
Fly Angola
Heliports
total: 1 (2021)
International and domestic services are maintained by TAAG Angola Airlines, Turkish Airlines, Aeroflot, British Airways, Brussels Airlines, Lufthansa, Air France, Cubana, Ethiopian Airlines, Emirates, Delta Air Lines, Royal Air Maroc, Iberia, Hainan Airlines, Kenya Airways, South African Airways, TAP Air Portugal and several regional carriers. There are airstrips at Benguela, Cabinda, Huambo, Moçâmedes, and Catumbela.
References |
709 | https://en.wikipedia.org/wiki/Angolan%20Armed%20Forces | Angolan Armed Forces | The Angolan Armed Forces () or FAA is the military of Angola. The FAA consist of the Angolan Army (), the Angolan Navy () and the National Air Force of Angola (). Reported total manpower in 2021 was about 107,000. The FAA is headed by the Chief of the General Staff António Egídio de Sousa Santos since 2018, who reports to the minister of National Defense, currently João Ernesto dos Santos.
History
Roots
The FAA succeeded to the previous People's Armed Forces for the Liberation of Angola (FAPLA) following the abortive Bicesse Accord with the Armed Forces of the Liberation of Angola (FALA), armed wing of the National Union for the Total Independence of Angola (UNITA). As part of the peace agreement, troops from both armies were to be demilitarized and then integrated. Integration was never completed as UNITA and FALA went back to war in 1992. Later, consequences for FALA personnel in Luanda were harsh with FAPLA veterans persecuting their erstwhile opponents in certain areas and reports of vigilantism.
Founding
The Angolan Armed Forces were created on 9 October 1991. The institutionalization of the FAA was made in the Bicesse Accords, signed in 1991, between the Angolan Government and UNITA. The principles that would govern the FAA were defined in a joint proposal presented on September 24, 1991 and approved on 9 October. On 14 November 1991, Generals João Baptista de Matos and Abílio Kamalata Numa were appointed to the Superior Command of the Armed Forces. The ceremony took place at the Hotel Presidente Luanda, and was presided over by the then-minister França Vandúnem.
Branches
Army
The Army (Exército) is the land component of the FAA. It is organized in six military regions (Cabinda, Luanda, North, Center, East and South), with an infantry division being based in each one. Distributed by the six military regions / infantry divisions, there are 25 motorized infantry brigades, one tank brigade and one engineering brigade. The Army also includes an artillery regiment, the Military Artillery School, the Army Military Academy, an anti-aircraft defense group, a composite land artillery group, a military police regiment, a logistical transportation regiment and a field artillery brigade. The Army further includes the Special Forces Brigade (including Commandos and Special Operations units), but this unit is under the direct command of the General Staff of the FAA.
Air Force
The National Air Force of Angola (FANA, Força Aérea Nacional de Angola) is the air component of the FAA. It is organized in six aviation regiments, each including several squadrons. To each of the regiments correspond an air base. Besides the aviation regiments, there is also a Pilot Training School.
The Air Force's personnel total about 8,000; its equipment includes transport aircraft and six Russian-manufactured Sukhoi Su-27 fighter aircraft. In 2002, one was lost during the civil war with UNITA forces.
In 1991, the Air Force/Air Defense Forces had 8,000 personnel and 90 combat-capable aircraft, including 22 fighters, 59 fighter ground attack aircraft and 16 attack helicopters.
Navy
The Angola Navy (MGA, Marinha de Guerra de Angola) is the naval component of the FAA. It is organized in two naval zones (North and South), with naval bases in Luanda, Lobito and Moçâmedes. It includes a Marines Brigade and a Marines School, based in Ambriz. The Navy numbers about 1,000 personnel and operates only a handful of small patrol craft and barges.
The Navy has been neglected and ignored as a military arm mainly due to the guerrilla struggle against the Portuguese and the nature of the civil war. From the early 1990s to the present the Angolan Navy has shrunk from around 4,200 personnel to around 1,000, resulting in the loss of skills and expertise needed to maintain equipment. Portugal has been providing training through its Technical Military Cooperation (CTM) programme. The Navy is requesting procurement of a frigate, three corvettes, three offshore patrol vessel and additional fast patrol boats.
Most of the vessels in the navy's inventory dates back from the 1980s or earlier, and many of its ships are inoperable due to age and lack of maintenance. However the navy acquired new boats from Spain and France in the 1990s. Germany has delivered several Fast Attack Craft for border protection in 2011.
In September 2014 it was reported that the Angolan Navy would acquire seven Macaé-class patrol vessels from Brazil as part of a Technical Memorandum of Understanding (MoU) covering the production of the vessels as part of Angola's Naval Power Development Programme (Pronaval). The military of Angola aims to modernize its naval capability, presumably due to a rise in maritime piracy within the Gulf of Guinea which may have an adverse effect on the country's economy.
The navy's current known inventory includes the following:
Fast attack craft
4 Mandume class craft (Bazan Cormoran type, refurbished in 2009)
Patrol boats
3 18.3m long Patrulheiro patrol boats (refurbished in 2002)
5 ARESA PVC-170
2 Namacurra-class harbour patrol boats
Fisheries Patrol Boats
Ngola Kiluange and Nzinga Mbandi (delivered in September and October 2012 from Damen Shipyards)(Operated by Navy personnel under the Ministry of Agriculture, Rural Development and Fisheries)
28-metre FRV 2810 (Pensador) (Operated by Navy personnel under the Ministry of Agriculture, Rural Development and Fisheries)
Landing craft
LDM-400 – 1 or 3 (reportedly has serviceability issues)
Coastal defense equipment (CRTOC)
SS-C1 Sepal radar system
The navy also has several aircraft for maritime patrol:
Specialized units
Special forces
The FAA include several types of special forces, namely the Commandos, the Special Operations and the Marines. The Angolan special forces follow the general model of the analogous Portuguese special forces, receiving a similar training.
The Commandos and the Special forces are part of the Special Forces Brigade (BRIFE, Brigada de Forças Especiais), based at Cabo Ledo, in the Bengo Province. The BRIFE includes two battalions of commandos, a battalion of special operations and sub-units of combat support and service support. The BRIFE also included the Special Actions Group (GAE, Grupo de Ações Especiais), which is presently inactive and that was dedicated to long range reconnaissance, covert and sabotage operations. In the Cabo Ledo base is also installed the Special Forces Training School (EFFE, Escola de Formação de Forças Especiais). Both the BRIFE and the EFFE are directly under the Directorate of Special Forces of the General Staff of the Armed Forces.
The marines (fuzileiros navais) constitute the Marines Brigade of the Angolan Navy. The Marines Brigade is not permanently dependent of the Directorate of Special Forces, but can detach their units and elements to be put under the command of that body for the conduction of exercises or real operations.
Since the disbandment of the Angolan Parachute Battalion in 2004, the FAA do not have a specialized paratrooper unit. However, elements of the commandos, special operations and marines are parachute qualified.
Territorial troops
The Directorate of People's Defense and Territorial Troops of the Defence Ministry or ODP was established in late 1975. It had 600,000 members, having personnel in virtually every village by 1979. It had both armed and unarmed units dispersed in villages throughout the country. The People's Vigilance Brigades () also serve a similar purpose.
Training establishments
Armed Forces Academy
The Military Academy () is a military university public higher education establishment whose mission is to train officers of the Permanent Staff of the Army. It has been in operation since 21 August 2009 by presidential decree. Its headquarters are in Lobito. It trains in the following specialties:
Infantry
Tanks
Land Artillery
Anti-Air Defense
Military Engineering
Logistics
Telecommunications
Hidden Direction of Troops
Military Administration
Armament and Technique
Chemical Defense
Operational Military Intelligence
Technical Repair and Maintenance Platoon of Auto and Armored Technique
Navy
Naval War Institute (INSG)
Naval Academy
Naval Specialist School
Air Force
Angolan Military Aviation School
Pilot Basic Training School (Lobito)
Institutions/other units
Museum of the Armed Forces
Military Hospitals
The Military hospital of the FAA is the Main Military Hospital. It has the following lineage:
1961 – Evacuation Infirmary
1962 – Military Hospital of Luanda
1975 – Military Hospital
1976 – Central Military Hospital
1989 – Main Military Hospital
It provides specialized medical assistance in accordance with the military health system; It also promotes post-graduate education and scientific research. Currently, the Main Military Hospital serves 39 special medical specialties. It is a headed by a Director General whose main supporting body is the Board of Directors.
Supreme Military Court
The Supreme Military Court is the highest organ of the hierarchy of military courts. The Presiding Judge, the Deputy Presiding Judge and the other Counselor Judges of the Supreme Military Court are appointed by the President of the Republic. The composition, organization, powers and functioning of the Supreme Military Court are established by law.
Military Bands
The FAA maintains Portuguese-style military bands in all three branches and in individual units. The primary band is the 100-member Music Band of the Presidential Security Household. The music band of the Army Command was created on 16 June 1994 and four years later, on 15 August 1998, the National Air Force created a music band within an artistic brigade. The navy has its own marching band, as well as a small musical group known as Banda 10 de Julho (10th July Band), based at the Luanda Naval Base.
Foreign deployments
The FAPLA's main counterinsurgency effort was directed against UNITA in the southeast, and its conventional capabilities were demonstrated principally in the undeclared South African Border War. The FAPLA first performed its external assistance mission with the dispatch of 1,000 to 1,500 troops to São Tomé and Príncipe in 1977 to bolster the socialist regime of President Manuel Pinto da Costa. During the next several years, Angolan forces conducted joint exercises with their counterparts and exchanged technical operational visits. The Angolan expeditionary force was reduced to about 500 in early 1985.
The Angolan Armed Forces were controversially involved in training the armed forces of fellow Lusophone states Cape Verde and Guinea-Bissau. In the case of the latter, the 2012 Guinea-Bissau coup d'état was cited by the coup leaders as due to Angola's involvement in trying to "reform" the military in connivance with the civilian leadership.
A small number of FAA personnel are stationed in the Democratic Republic of the Congo (Kinshasa). A presence during the unrest in Ivory Coast, 2010–2011, were not officially confirmed. However, the , citing Jeune Afrique, said that among President Gbagbo's guards were 92 personnel of President Dos Santos's Presidential Guard Unit. Angola is basically interested in the participation of the FAA operations of the African Union and has formed special units for this purpose.
In 2021, the Angolan Parliament approved integration of FAA into Southern African Development Community (SADC)'s mission for peace in Cabo Delgado, Mozambique. Angola sent a team of 20 officers to participate.
References
Further reading
Human Rights Watch, Angola Unravels: The Rise and Fall of the Lusaka Peace Process, October 1999
Utz Ebertz and Marie Müller, Legacy of a resource-fueled war: The role of generals in Angola's mining sector, BICC Focus, June 2013
Area Handbook for Angola, August 1967, Angola, A Country Study (1979 and 1991)
Rocky Williams, "National defence reform and the African Union." SIPRI Yearbook 2004: 231–249.
Weigert, Stephen L. Angola: a modern military history, 1961–2002. Palgrave Macmillan, 2011.
Martin Rupiya et al., 'Angola', in Evolutions and Revolutions
The Twenty-Seventh of May: An Historical Note on the Abortive 1977 "coup" in Angola
David Birmingham, African Affairs, Vol. 77, No. 309 (Oct. 1978), pp. 554–564
Published by: Oxford University Press on behalf of The Royal African Society
External links
Official site of the Angolan Ministry of National Defence
World Navies
Brinkman, Inge "Language, Names, and War: The Case of Angola", African Studies Review
Military of Angola
Military history of Angola
Angolan Civil War
1991 establishments in Angola
Military units and formations established in 1991 |
710 | https://en.wikipedia.org/wiki/Foreign%20relations%20of%20Angola | Foreign relations of Angola | The foreign relations of Angola are based on Angola's strong support of U.S. foreign policy as the Angolan economy is dependent on U.S. foreign aid.
From 1975 to 1989, Angola was aligned with the Eastern bloc, in particular the Soviet Union, Libya, and Cuba. Since then, it has focused on improving relationships with Western countries, cultivating links with other Portuguese-speaking countries, and asserting its own national interests in Central Africa through military and diplomatic intervention. In 1993, it established formal diplomatic relations with the United States. It has entered the Southern African Development Community as a vehicle for improving ties with its largely Anglophone neighbors to the south. Zimbabwe and Namibia joined Angola in its military intervention in the Democratic Republic of the Congo, where Angolan troops remain in support of the Joseph Kabila government. It also has intervened in the Republic of the Congo (Brazzaville) in support of Denis Sassou-Nguesso in the civil war.
Since 1998, Angola has successfully worked with the United Nations Security Council to impose and carry out sanctions on UNITA. More recently, it has extended those efforts to controls on conflict diamonds, the primary source of revenue for UNITA during the Civil War that ended in 2002. At the same time, Angola has promoted the revival of the Community of Portuguese-Speaking Countries (CPLP) as a forum for cultural exchange and expanding ties with Portugal (its former ruler) and Brazil (which shares many cultural affinities with Angola) in particular. Angola is a member of the Port Management Association of Eastern and Southern Africa (PMAESA).
Diplomatic relations
List of countries which Angola maintains diplomatic relations with:
Bilateral relations
Africa
Americas
Asia
Europe
See also
List of diplomatic missions in Angola
List of diplomatic missions of Angola
Visa requirements for Angolan citizens
References
External links |
713 | https://en.wikipedia.org/wiki/Android%20%28robot%29 | Android (robot) | An android is a humanoid robot or other artificial being often made from a flesh-like material. Historically, androids existed only in the domain of science fiction and were frequently seen in film and television, but advances in robot technology have allowed the design of functional and realistic humanoid robots.
Terminology
The Oxford English Dictionary traces the earliest use (as "Androides") to Ephraim Chambers' 1728 Cyclopaedia, in reference to an automaton that St. Albertus Magnus allegedly created. By the late 1700s, "androides", elaborate mechanical devices resembling humans performing human activities, were displayed in exhibit halls.
The term "android" appears in US patents as early as 1863 in reference to miniature human-like toy automatons. The term android was used in a more modern sense by the French author Auguste Villiers de l'Isle-Adam in his work Tomorrow's Eve (1886), featuring an artificial humanoid robot named Hadaly. The term made an impact into English pulp science fiction starting from Jack Williamson's The Cometeers (1936) and the distinction between mechanical robots and fleshy androids was popularized by Edmond Hamilton's Captain Future stories (1940–1944).
Although Karel Čapek's robots in R.U.R. (Rossum's Universal Robots) (1921)—the play that introduced the word robot to the world—were organic artificial humans, the word "robot" has come to primarily refer to mechanical humans, animals, and other beings. The term "android" can mean either one of these, while a cyborg ("cybernetic organism" or "bionic man") would be a creature that is a combination of organic and mechanical parts.
The term "droid", popularized by George Lucas in the original Star Wars film and now used widely within science fiction, originated as an abridgment of "android", but has been used by Lucas and others to mean any robot, including distinctly non-human form machines like R2-D2. The word "android" was used in Star Trek: The Original Series episode "What Are Little Girls Made Of?" The abbreviation "andy", coined as a pejorative by writer Philip K. Dick in his novel Do Androids Dream of Electric Sheep?, has seen some further usage, such as within the TV series Total Recall 2070.
While the term "android" is used in reference to human-looking robots in general (not necessarily male-looking humanoid robots), a robot with a female appearance can also be referred to as a gynoid. Besides one can refer to robots without alluding to their sexual appearance by calling them anthrobots (a portmanteau of anthrōpos and robot; see anthrobotics) or anthropoids (short for anthropoid robots; the term humanoids is not appropriate because it is already commonly used to refer to human-like organic species in the context of science fiction, futurism and speculative astrobiology).
Authors have used the term android in more diverse ways than robot or cyborg. In some fictional works, the difference between a robot and android is only superficial, with androids being made to look like humans on the outside but with robot-like internal mechanics. In other stories, authors have used the word "android" to mean a wholly organic, yet artificial, creation. Other fictional depictions of androids fall somewhere in between.
Eric G. Wilson, who defines an android as a "synthetic human being", distinguishes between three types of android, based on their body's composition:
the mummy type – made of "dead things" or "stiff, inanimate, natural material", such as mummies, puppets, dolls and statues
the golem type – made from flexible, possibly organic material, including golems and homunculi
the automaton type – made from a mix of dead and living parts, including automatons and robots
Although human morphology is not necessarily the ideal form for working robots, the fascination in developing robots that can mimic it can be found historically in the assimilation of two concepts: simulacra (devices that exhibit likeness) and automata (devices that have independence).
Projects
Several projects aiming to create androids that look, and, to a certain degree, speak or act like a human being have been launched or are underway.
Japan
Japanese robotics have been leading the field since the 1970s. Waseda University initiated the WABOT project in 1967, and in 1972 completed the WABOT-1, the first android, a full-scale humanoid intelligent robot. Its limb control system allowed it to walk with the lower limbs, and to grip and transport objects with hands, using tactile sensors. Its vision system allowed it to measure distances and directions to objects using external receptors, artificial eyes and ears. And its conversation system allowed it to communicate with a person in Japanese, with an artificial mouth.
In 1984, WABOT-2 was revealed, and made a number of improvements. It was capable of playing the organ. Wabot-2 had ten fingers and two feet, and was able to read a score of music. It was also able to accompany a person. In 1986, Honda began its humanoid research and development program, to create humanoid robots capable of interacting successfully with humans.
The Intelligent Robotics Lab, directed by Hiroshi Ishiguro at Osaka University, and the Kokoro company demonstrated the Actroid at Expo 2005 in Aichi Prefecture, Japan and released the Telenoid R1 in 2010. In 2006, Kokoro developed a new DER 2 android. The height of the human body part of DER2 is 165 cm. There are 47 mobile points. DER2 can not only change its expression but also move its hands and feet and twist its body. The "air servosystem" which Kokoro developed originally is used for the actuator. As a result of having an actuator controlled precisely with air pressure via a servosystem, the movement is very fluid and there is very little noise. DER2 realized a slimmer body than that of the former version by using a smaller cylinder. Outwardly DER2 has a more beautiful proportion. Compared to the previous model, DER2 has thinner arms and a wider repertoire of expressions. Once programmed, it is able to choreograph its motions and gestures with its voice.
The Intelligent Mechatronics Lab, directed by Hiroshi Kobayashi at the Tokyo University of Science, has developed an android head called Saya, which was exhibited at Robodex 2002 in Yokohama, Japan. There are several other initiatives around the world involving humanoid research and development at this time, which will hopefully introduce a broader spectrum of realized technology in the near future. Now Saya is working at the Science University of Tokyo as a guide.
The Waseda University (Japan) and NTT docomo's manufacturers have succeeded in creating a shape-shifting robot WD-2. It is capable of changing its face. At first, the creators decided the positions of the necessary points to express the outline, eyes, nose, and so on of a certain person. The robot expresses its face by moving all points to the decided positions, they say. The first version of the robot was first developed back in 2003. After that, a year later, they made a couple of major improvements to the design. The robot features an elastic mask made from the average head dummy. It uses a driving system with a 3DOF unit. The WD-2 robot can change its facial features by activating specific facial points on a mask, with each point possessing three degrees of freedom. This one has 17 facial points, for a total of 56 degrees of freedom. As for the materials they used, the WD-2's mask is fabricated with a highly elastic material called Septom, with bits of steel wool mixed in for added strength. Other technical features reveal a shaft driven behind the mask at the desired facial point, driven by a DC motor with a simple pulley and a slide screw. Apparently, the researchers can also modify the shape of the mask based on actual human faces. To "copy" a face, they need only a 3D scanner to determine the locations of an individual's 17 facial points. After that, they are then driven into position using a laptop and 56 motor control boards. In addition, the researchers also mention that the shifting robot can even display an individual's hair style and skin color if a photo of their face is projected onto the 3D Mask.
Singapore
Prof Nadia Thalmann, a Nanyang Technological University scientist, directed efforts of the Institute for Media Innovation along with the School of Computer Engineering in the development of a social robot, Nadine. Nadine is powered by software similar to Apple's Siri or Microsoft's Cortana. Nadine may become a personal assistant in offices and homes in future, or she may become a companion for the young and the elderly.
Assoc Prof Gerald Seet from the School of Mechanical & Aerospace Engineering and the BeingThere Centre led a three-year R&D development in tele-presence robotics, creating EDGAR. A remote user can control EDGAR with the user's face and expressions displayed on the robot's face in real time. The robot also mimics their upper body movements.
South Korea
KITECH researched and developed EveR-1, an android interpersonal communications model capable of emulating human emotional expression via facial "musculature" and capable of rudimentary conversation, having a vocabulary of around 400 words. She is tall and weighs , matching the average figure of a Korean woman in her twenties. EveR-1's name derives from the Biblical Eve, plus the letter r for robot. EveR-1's advanced computing processing power enables speech recognition and vocal synthesis, at the same time processing lip synchronization and visual recognition by 90-degree micro-CCD cameras with face recognition technology. An independent microchip inside her artificial brain handles gesture expression, body coordination, and emotion expression. Her whole body is made of highly advanced synthetic jelly silicon and with 60 artificial joints in her face, neck, and lower body; she is able to demonstrate realistic facial expressions and sing while simultaneously dancing. In South Korea, the Ministry of Information and Communication had an ambitious plan to put a robot in every household by 2020. Several robot cities have been planned for the country: the first will be built in 2016 at a cost of 500 billion won (US$440 million), of which 50 billion is direct government investment. The new robot city will feature research and development centers for manufacturers and part suppliers, as well as exhibition halls and a stadium for robot competitions. The country's new Robotics Ethics Charter will establish ground rules and laws for human interaction with robots in the future, setting standards for robotics users and manufacturers, as well as guidelines on ethical standards to be programmed into robots to prevent human abuse of robots and vice versa.
United States
Walt Disney and a staff of Imagineers created Great Moments with Mr. Lincoln that debuted at the 1964 New York World's Fair.
Dr. William Barry, an Education Futurist and former visiting West Point Professor of Philosophy and Ethical Reasoning at the United States Military Academy, created an AI android character named "Maria Bot". This Interface AI android was named after the infamous fictional robot Maria in the 1927 film Metropolis, as a well-behaved distant relative. Maria Bot is the first AI Android Teaching Assistant at the university level. Maria Bot has appeared as a keynote speaker as a duo with Barry for a TEDx talk in Everett, Washington in February 2020.
Resembling a human from the shoulders up, Maria Bot is a virtual being android that has complex facial expressions and head movement and engages in conversation about a variety of subjects. She uses AI to process and synthesize information to make her own decisions on how to talk and engage. She collects data through conversations, direct data inputs such as books or articles, and through internet sources.
Maria Bot was built by an international high-tech company for Barry to help improve education quality and eliminate education poverty. Maria Bot is designed to create new ways for students to engage and discuss ethical issues raised by the increasing presence of robots and artificial intelligence. Barry also uses Maria Bot to demonstrate that programming a robot with life-affirming, ethical framework makes them more likely to help humans to do the same.
Maria Bot is an ambassador robot for good and ethical AI technology.
Hanson Robotics, Inc., of Texas and KAIST produced an android portrait of Albert Einstein, using Hanson's facial android technology mounted on KAIST's life-size walking bipedal robot body. This Einstein android, also called "Albert Hubo", thus represents the first full-body walking android in history. Hanson Robotics, the FedEx Institute of Technology, and the University of Texas at Arlington also developed the android portrait of sci-fi author Philip K. Dick (creator of Do Androids Dream of Electric Sheep?, the basis for the film Blade Runner), with full conversational capabilities that incorporated thousands of pages of the author's works. In 2005, the PKD android won a first-place artificial intelligence award from AAAI.
Use in fiction
Androids are a staple of science fiction. Isaac Asimov pioneered the fictionalization of the science of robotics and artificial intelligence, notably in his 1950s series I, Robot. One thing common to most fictional androids is that the real-life technological challenges associated with creating thoroughly human-like robots—such as the creation of strong artificial intelligence—are assumed to have been solved. Fictional androids are often depicted as mentally and physically equal or superior to humans—moving, thinking and speaking as fluidly as them.
The tension between the nonhuman substance and the human appearance—or even human ambitions—of androids is the dramatic impetus behind most of their fictional depictions. Some android heroes seek, like Pinocchio, to become human, as in the film Bicentennial Man, or Data in Star Trek: The Next Generation. Others, as in the film Westworld, rebel against abuse by careless humans. Android hunter Deckard in Do Androids Dream of Electric Sheep? and its film adaptation Blade Runner discovers that his targets appear to be, in some ways, more "human" than he is. Android stories, therefore, are not essentially stories "about" androids; they are stories about the human condition and what it means to be human.
One aspect of writing about the meaning of humanity is to use discrimination against androids as a mechanism for exploring racism in society, as in Blade Runner. Perhaps the clearest example of this is John Brunner's 1968 novel Into the Slave Nebula, where the blue-skinned android slaves are explicitly shown to be fully human. More recently, the androids Bishop and Annalee Call in the films Aliens and Alien Resurrection are used as vehicles for exploring how humans deal with the presence of an "Other". The 2018 video game Detroit: Become Human also explores how androids are treated as second class citizens in a near future society.
Female androids, or "gynoids", are often seen in science fiction, and can be viewed as a continuation of the long tradition of men attempting to create the stereotypical "perfect woman". Examples include the Greek myth of Pygmalion and the female robot Maria in Fritz Lang's Metropolis. Some gynoids, like Pris in Blade Runner, are designed as sex-objects, with the intent of "pleasing men's violent sexual desires", or as submissive, servile companions, such as in The Stepford Wives. Fiction about gynoids has therefore been described as reinforcing "essentialist ideas of femininity", although others have suggested that the treatment of androids is a way of exploring racism and misogyny in society.
The 2015 Japanese film Sayonara, starring Geminoid F, was promoted as "the first movie to feature an android performing opposite a human actor".
See also
References
Further reading
Kerman, Judith B. (1991). Retrofitting Blade Runner: Issues in Ridley Scott's Blade Runner and Philip K. Dick's Do Androids Dream of Electric Sheep? Bowling Green, OH: Bowling Green State University Popular Press. .
Perkowitz, Sidney (2004). Digital People: From Bionic Humans to Androids. Joseph Henry Press. .
Shelde, Per (1993). Androids, Humanoids, and Other Science Fiction Monsters: Science and Soul in Science Fiction Films. New York: New York University Press. .
Ishiguro, Hiroshi. "Android science." Cognitive Science Society. 2005.
Glaser, Horst Albert and Rossbach, Sabine: The Artificial Human, Frankfurt/M., Bern, New York 2011 "The Artificial Human"
TechCast Article Series, Jason Rupinski and Richard Mix, "Public Attitudes to Androids: Robot Gender, Tasks, & Pricing"
An-droid, "Similar to the Android name"
Carpenter, J. (2009). Why send the Terminator to do R2D2s job?: Designing androids as rhetorical phenomena. Proceedings of HCI 2009: Beyond Gray Droids: Domestic Robot Design for the 21st Century. Cambridge, UK. 1 September.
Telotte, J.P. Replications: A Robotic History of the Science Fiction Film. University of Illinois Press, 1995.
External links
Japanese inventions
South Korean inventions
Osaka University research
Science fiction themes
Human–machine interaction
Robots |
728 | https://en.wikipedia.org/wiki/List%20of%20anthropologists | List of anthropologists | Anthropologist
A
John Adair
B. R. Ambedkar
Giulio Angioni
Jon Altman
Arjun Appadurai
Talal Asad
Timothy Asch
Scott Atran
Marc Augé
B
Nigel Barley
Fredrik Barth
Vasily Bartold
Keith H. Basso
Daisy Bates
Gregory Bateson
Mary Catherine Bateson
Richard Bauman
Ruth Behar
Ruth Benedict
Dorothy A. Bennett
Carl H. Berendt
Lee Berger
Brent Berlin
Catherine Helen Webb Berndt
Catherine L. Besteman
Theodore C. Bestor
Lewis Binford
Evelyn Blackwood
Wilhelm Bleek
Maurice Bloch
Anton Blok
Franz Boas
Tom Boellstorff
Paul Bohannan
Dmitri Bondarenko
Pere Bosch-Gimpera
Pierre Bourdieu
Philippe Bourgois
Charles L. Briggs
Paul Broca
Christian Bromberger
Kari Bruwelheide
Peter Buck (Te Rangi Hīroa)
C
Julio Caro Baroja
Edmund Carpenter
Napoleon Chagnon
Pierre Clastres
Mabel Cook Cole
Malcolm Carr Collier
Harold C. Conklin
Carleton S. Coon
Frank Hamilton Cushing
D
Regna Darnell
Raymond Dart
Emma Lou Davis
Wade Davis
Ernesto de Martino
Ella Cara Deloria
Raymond J. DeMallie
Philippe Descola
Stanley Diamond
Mary Douglas
Cora Du Bois
Eugene Dubois
Robin Dunbar
Ann Dunham
Katherine Dunham
Elizabeth Cullen Dunn
Émile Durkheim
E
Mary Lindsay Elmendolf
Verrier Elwin
Matthew Engelke
Friedrich Engels
Arturo Escobar
E. E. Evans-Pritchard
F
James Ferguson
Raymond Firth
Raymond D. Fogelson
Meyer Fortes
Gregory Forth
Dian Fossey
Kate Fox
Robin Fox
James Frazer
Lina Fruzzetti
G
Clifford Geertz
Alfred Gell
Ernest Gellner
Herb Di Gioia
Max Gluckman
Maurice Godelier
Jane Goodall
Marjorie Harness Goodwin
Igor Gorevich
Harold A. Gould
David Graeber
Hilma Granqvist
J. Patrick Gray
Marcel Griaule
Jacob Grimm
Wilhelm Grimm
H
Abdellah Hammoudi
Michael Harkin
Michael Harner
John P. Harrington
Marvin Harris
K. David Harrison
Kirsten Hastrup
Jacquetta Hawkes
Brian Douglas Hayden
Rose Oldfield Hayes
Stephen C. Headley
Thor Heyerdahl
Arthur Maurice Hocart
Ian Hodder
E. Adamson Hoebel
Earnest Hooton
Robin W.G. Horton
Aleš Hrdlička
Eva Verbitsky Hunt
Dell Hymes
I
Miyako Inoue
Bill Irons
J
Ira Jacknis
John M. Janzen
Thomas Des Jean
F. Landa Jocano
Alfred E. Johnson
William Jones
Michal Josephy
Jeffrey S. Juris
K
Sergei Kan
Jomo Kenyatta
David Kertzer
Alice Beck Kehoe
Anatoly Khazanov
Dolly Kikon
Richard G. Klein
Chris Knight
Eduardo Kohn
Dorinne K. Kondo
Andrey Korotayev
Conrad Kottak
Charles H. Kraft
Grover Krantz
Alfred L. Kroeber
Theodora Kroeber
Lars Krutak
Adam Kuper
L
William Labov
George Lakoff
Harold E. Lambert
Edmund Leach
Eleanor Leacock
Murray Leaf
Louis Leakey
Mary Leakey
Richard Leakey
Richard Borshay Lee
Charles Miller Leslie
Claude Lévi-Strauss
Ellen Lewin
C. Scott Littleton
Albert Buell Lewis
Oscar Lewis
Phillip Harold Lewis
Roland Littlewood
Robert Lowie
Nancy Lurie
M
Alan Macfarlane
Saba Mahmood
Bronisław Malinowski
George Marcus
Jonathan M. Marks
Karl Marx
John Alden Mason
Michael Atwood Mason
Marcel Mauss
Phillip McArthur
Irma McClaurin
Charles Harrison McNutt
Margaret Mead
Mervyn Meggitt
Josef Mengele
Nicholas Miklouho-Maclay
Emily Martin
Horace Mitchell Miner
Sidney Mintz
Ashley Montagu
James Mooney
Henrietta L. Moore
John H. Moore
Lewis H. Morgan
Desmond Morris
George Murdock
Yolanda Murphy
N
Laura Nader
Moni Nag
Jeremy Narby
Raoul Naroll
Josiah Nott
Erland Nordenskiöld
O
Gananath Obeyesekere
Kaori O'Connor
Aihwa Ong
Marvin Opler
Morris Opler
Sherry Ortner
Keith F. Otterbein
Evelia Edith Oyhenart
P
Elsie Clews Parsons
Bronislav Pilsudski
Thomas J. Pluckhahn
Hortense Powdermaker
A.H.J. Prins
Harald E.L. Prins
Q
Buell Quain
James Quesada
R
Paul Rabinow
Wilhelm Radloff
Laurence Ralph
Lucinda Ramberg
Roy Rappaport
Hans Ras
Alfred Reginald Radcliffe-Brown
Margaret Read
Gerardo Reichel-Dolmatoff
Kathy Reichs
Audrey Richards
W. H. R. Rivers
Paul Rivet
Uzma Z. Rizvi
Joel Robbins
Renato Rosaldo
Gayle Rubin
Robert A. Rubinstein
S
Marshall Sahlins
Noel B. Salazar
Roger Sandall
Edward Sapir
Patricia Sawin
Nancy Scheper-Hughes
Wilhelm Schmidt
Tobias Schneebaum
James C. Scott
Thayer Scudder
Elman Service
Afanasy Shchapov
Gerald F. Schroedl
Florence Connolly Shipek
Sydel Silverman
Audra Simpson
Cathy Small
Christen A. Smith
Jacques Soustelle
Melford Spiro
James Spradley
Julian Steward
Herbert Spencer
Marilyn Strathern
William Sturtevant
Niara Sudarkasa
T
Michael Taussig
Sharika Thiranagama
Edward Burnett Tylor
Colin Turnbull
Victor Turner
Bruce Trigger
V
Karl Verner
L. P. Vidyarthi
Eduardo Viveiros de Castro
Christoph von Fürer-Haimendorf
W
Anthony F. C. Wallace
Lee Henderson Watkins
Camilla Wedgwood
Hank Wesselman
Kath Weston
Douglas R. White
Isobel Mary White
Leslie White
Tim White
Benjamin Whorf
Unni Wikan
Clark Wissler
Eric Wolf
Alvin Wolfe
Sol Worth
Y
Nur Yalman
Kim Yeshi
Z
Jarrett Zigon
R. Tom Zuidema
Fictional anthropologists
Mary Albright (Jane Curtin) in the sitcom 3rd Rock from the Sun
Temperance "Bones" Brennan (Emily Deschanel) in the television series Bones
Temperance Brennan in the novel series Temperance Brennan by Kathy Reichs
Chakotay (Robert Beltran) in the television series Star Trek: Voyager
Michael Burnham (Sonequa Martin-Green) in the television series Star Trek: Discovery
Daniel Jackson (Michael Shanks, James Spader) in the television series and film Stargate SG-1
Charlotte Lewis (Rebecca Mader) in the television series Lost
Korekiyo Shinguji
See also
List of female anthropologists
List of Black Anthropologists
List of Chinese sociologists and anthropologists
References
Anthropologists |
734 | https://en.wikipedia.org/wiki/Actinopterygii | Actinopterygii | Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin supported by radially extended thin bony spines called lepidotrichia, as opposed to the bulkier, fleshy lobed fins of the sister class Sarcopterygii (lobe-finned fish). Resembling folding fans, the actinopterygian fins can easily change shape and wetted area, providing superior thrust-to-weight ratios per movement compared to sarcopterygian and chondrichthyian fins. The fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the articulation between these fins and the internal skeleton (e.g., pelvic and pectoral girdles).
The vast majority of actinopterygians are teleosts. By species count, they dominate the subphylum Vertebrata, and constitute nearly 99% of the over 30,000 extant species of fish. They are the most abundant nektonic aquatic animals and are ubiquitous throughout freshwater and marine environments from the deep sea to subterranean waters to the highest mountain streams. Extant species can range in size from Paedocypris, at ; to the massive ocean sunfish, at ; and to the giant oarfish, at . The largest ever known ray-finned fish, the extinct Leedsichthys from the Jurassic, has been estimated to have grown to .
Characteristics
Ray-finned fishes occur in many variant forms. The main features of typical ray-finned fish are shown in the adjacent diagram.
The swim bladder is a more derived structure and used for buoyancy. Except from the bichirs, which just like the lungs of lobe-finned fish have retained the ancestral condition of ventral budding from the foregut, the swim bladder in ray-finned fishes derives from a dorsal bud above the foregut. In early forms the swim bladder could still be used for breathing, a trait still present in Holostei (bowfins and gars). In some fish like the arapaima, the swim bladder has been modified for breathing air again, and in other lineages it have been completely lost.
Ray-finned fishes have many different types of scales; but all teleosts have leptoid scales. The outer part of these scales fan out with bony ridges, while the inner part is crossed with fibrous connective tissue. Leptoid scales are thinner and more transparent than other types of scales, and lack the hardened enamel- or dentine-like layers found in the scales of many other fish. Unlike ganoid scales, which are found in non-teleost actinopterygians, new scales are added in concentric layers as the fish grows.
Teleosts and chondrosteans (sturgeons and paddlefish) also differ from the bichirs and holosteans (bowfin and gars) in having gone through a whole-genome duplication (paleopolyploidy). The WGD is estimated to have happened about 320 million years ago in the teleosts, which on average has retained about 17% of the gene duplicates, and around 180 (124–225) million years ago in the chondrosteans . It has since happened again in some teleost lineages, like Salmonidae (80–100 million years ago) and several times independently within the Cyprinidae (in goldfish and common carp as recently as 14 million years ago).
Body shapes and fin arrangements
Ray-finned fish vary in size and shape, in their feeding specializations, and in the number and arrangement of their ray-fins.
Reproduction
In nearly all ray-finned fish, the sexes are separate, and in most species the females spawn eggs that are fertilized externally, typically with the male inseminating the eggs after they are laid. Development then proceeds with a free-swimming larval stage. However other patterns of ontogeny exist, with one of the commonest being sequential hermaphroditism. In most cases this involves protogyny, fish starting life as females and converting to males at some stage, triggered by some internal or external factor. Protandry, where a fish converts from male to female, is much less common than protogyny.
Most families use external rather than internal fertilization. Of the oviparous teleosts, most (79%) do not provide parental care. Viviparity, ovoviviparity, or some form of parental care for eggs, whether by the male, the female, or both parents is seen in a significant fraction (21%) of the 422 teleost families; no care is likely the ancestral condition. The oldest case of viviparity in ray-finned fish is found in Middle Triassic species of Saurichthys. Viviparity is relatively rare and is found in about 6% of living teleost species; male care is far more common than female care. Male territoriality "preadapts" a species for evolving male parental care.
There are a few examples of fish that self-fertilise. The mangrove rivulus is an amphibious, simultaneous hermaphrodite, producing both eggs and spawn and having internal fertilisation. This mode of reproduction may be related to the fish's habit of spending long periods out of water in the mangrove forests it inhabits. Males are occasionally produced at temperatures below and can fertilise eggs that are then spawned by the female. This maintains genetic variability in a species that is otherwise highly inbred.
Classification and fossil record
Actinopterygii is divided into the classes Cladistia and Actinopteri. The latter comprises the subclasses Chondrostei and Neopterygii. The Neopterygii, in turn, is divided into the infraclasses Holostei and Teleostei. During the Mesozoic (Triassic, Jurassic, Cretaceous) and Cenozoic the teleosts in particular diversified widely. As a result, 96% of living fish species are teleosts (40% of all fish species belong to the teleost subgroup Acanthomorpha), while all other groups of actinopterygians represent depauperate lineages.
The classification of ray-finned fishes can be summarized as follows:
Cladistia, which include bichirs and reedfish
Actinopteri, which include:
Chondrostei, which include Acipenseriformes (paddlefishes and sturgeons)
Neopterygii, which include:
Teleostei (most living fishes)
Holostei, which include:
Lepisosteiformes (gars)
Amiiformes (bowfin)
The cladogram below shows the main clades of living actinopterygians and their evolutionary relationships to other extant groups of fishes and the four-limbed vertebrates (tetrapods). The latter include mostly terrestrial species but also groups that became secondarily aquatic (e.g. whales and dolphins). Tetrapods evolved from a group of bony fish during the Devonian period. Approximate divergence dates for the different actinopterygian clades (in millions of years, mya) are from Near et al., 2012.
The polypterids (bichirs and reedfish) are the sister lineage of all other actinopterygians, the Acipenseriformes (sturgeons and paddlefishes) are the sister lineage of Neopterygii, and Holostei (bowfin and gars) are the sister lineage of teleosts. The Elopomorpha (eels and tarpons) appear to be the most basal teleosts.
The earliest known fossil actinopterygian is Andreolepis hedei, dating back 420 million years (Late Silurian), remains of which have been found in Russia, Sweden, and Estonia. Crown group actinopterygians most likely originated near the Devonian-Carboniferous boundary. The earliest fossil relatives of modern teleosts are from the Triassic period (Prohalecites, Pholidophorus), although it is suspected that teleosts originated already during the Paleozoic Era.
Taxonomy
The listing below is a summary of all extinct (indicated by a dagger, †) and living groups of Actinopterygii with their respective taxonomic rank. The taxonomy follows Phylogenetic Classification of Bony Fishes with notes when this differs from Nelson, ITIS and FishBase and extinct groups from Van der Laan 2016 and Xu 2021.
Order †?Asarotiformes Schaeffer 1968
Order †?Discordichthyiformes Minikh 1998
Order †?Paphosisciformes Grogan & Lund 2015
Order †?Scanilepiformes Selezneya 1985
Order †Cheirolepidiformes Kazantseva-Selezneva 1977
Order †Paramblypteriformes Heyler 1969
Order †Rhadinichthyiformes
Order †Palaeonisciformes Hay 1902
Order †Tarrasiiformes sensu Lund & Poplin 2002
Order †Ptycholepiformes Andrews et al. 1967
Order †Haplolepidiformes Westoll 1944
Order †Aeduelliformes Heyler 1969
Order †Platysomiformes Aldinger 1937
Order †Dorypteriformes Cope 1871
Order †Eurynotiformes Sallan & Coates 2013
Class Cladistia Pander 1860
Order †Guildayichthyiformes Lund 2000
Order Polypteriformes Bleeker 1859 (bichirs and reedfishes)
Class Actinopteri Cope 1972 s.s.
Order †Elonichthyiformes Kazantseva-Selezneva 1977
Order †Phanerorhynchiformes
Order †Bobasatraniiformes Berg 1940
Order †Saurichthyiformes Aldinger 1937
Subclass Chondrostei Müller, 1844
Order †Birgeriiformes Heyler 1969
Order †Chondrosteiformes Aldinger, 1937
Order Acipenseriformes Berg 1940 (includes sturgeons and paddlefishes)
Subclass Neopterygii Regan 1923 sensu Xu & Wu 2012
Order †Pholidopleuriformes Berg 1937
Order †Redfieldiiformes Berg 1940
Order †Platysiagiformes Brough 1939
Order †Polzbergiiformes Griffith 1977
Order †Perleidiformes Berg 1937
Order †Louwoichthyiformes Xu 2021
Order †Peltopleuriformes Lehman 1966
Order †Luganoiiformes Lehman 1958
Order †Pycnodontiformes Berg 1937
Infraclass Holostei Müller 1844
Division Halecomorphi Cope 1872 sensu Grande & Bemis 1998
Order †Parasemionotiformes Lehman 1966
Order †Ionoscopiformes Grande & Bemis 1998
Order Amiiformes Huxley 1861 sensu Grande & Bemis 1998 (bowfins)
Division Ginglymodi Cope 1871
Order †Dapediiformes Thies & Waschkewitz 2015
Order †Semionotiformes Arambourg & Bertin 1958
Order Lepisosteiformes Hay 1929 (gars)
Clade Teleosteomorpha Arratia 2000 sensu Arratia 2013
Order †Prohaleciteiformes Arratia 2017
Division Aspidorhynchei Nelson, Grand & Wilson 2016
Order †Aspidorhynchiformes Bleeker 1859
Order †Pachycormiformes Berg 1937
Infraclass Teleostei Müller 1844 sensu Arratia 2013
Order †?Araripichthyiformes
Order †?Ligulelliiformes Taverne 2011
Order †?Tselfatiiformes Nelson 1994
Order †Pholidophoriformes Berg 1940
Order †Dorsetichthyiformes Nelson, Grand & Wilson 2016
Order †Leptolepidiformes
Order †Crossognathiformes Taverne 1989
Order †Ichthyodectiformes Bardeck & Sprinkle 1969
Teleocephala de Pinna 1996 s.s.
Megacohort Elopocephalai Patterson 1977 sensu Arratia 1999 (Elopomorpha Greenwood et al. 1966)
Order Elopiformes Gosline 1960 (ladyfishes and tarpon)
Order Albuliformes Greenwood et al. 1966 sensu Forey et al. 1996 (bonefishes)
Order Notacanthiformes Goodrich 1909 (halosaurs and spiny eels)
Order Anguilliformes Jarocki 1822 sensu Goodrich 1909 (true eels)
Megacohort Osteoglossocephalai sensu Arratia 1999
Supercohort Osteoglossocephala sensu Arratia 1999 (Osteoglossomorpha Greenwood et al. 1966)
Order †Lycopteriformes Chang & Chou 1977
Order Hiodontiformes McAllister 1968 sensu Taverne 1979 (mooneye and goldeye)
Order Osteoglossiformes Regan 1909 sensu Zhang 2004 (bony-tongued fishes)
Supercohort Clupeocephala Patterson & Rosen 1977 sensu Arratia 2010
Cohort Otomorpha Wiley & Johnson 2010 (Otocephala; Ostarioclupeomorpha)
Subcohort Clupei Wiley & Johnson 2010 (Clupeomorpha Greenwood et al. 1966)
Order †Ellimmichthyiformes Grande 1982
Order Clupeiformes Bleeker 1859 (herrings and anchovies)
Subcohort Alepocephali
Order Alepocephaliformes Marshall 1962
Subcohort Ostariophysi Sagemehl 1885
Section Anotophysa (Rosen & Greenwood 1970) Sagemehl 1885
Order †Sorbininardiformes Taverne 1999
Order Gonorynchiformes Regan 1909 (milkfishes)
Section Otophysa Garstang 1931
Order Cypriniformes Bleeker 1859 sensu Goodrich 1909 (barbs, carp, danios, goldfishes, loaches, minnows, rasboras)
Order Characiformes Goodrich 1909 (characins, pencilfishes, hatchetfishes, piranhas, tetras, dourado / golden (genus Salminus) and pacu)
Order Gymnotiformes Berg 1940 (electric eels and knifefishes)
Order Siluriformes Cuvier 1817 sensu Hay 1929 (catfishes)
Cohort Euteleosteomorpha (Greenwood et al. 1966) (Euteleostei Greenwood 1967 sensu Johnson & Patterson 1996)
Subcohort Lepidogalaxii
Lepidogalaxiiformes Betancur-Rodriguez et al. 2013 (salamanderfish)
Subcohort Protacanthopterygii Greenwood et al. 1966 sensu Johnson & Patterson 1996
Order Argentiniformes (barreleyes and slickheads) (formerly in Osmeriformes)
Order Galaxiiformes
Order Salmoniformes Bleeker 1859 sensu Nelson 1994 (salmon and trout)
Order Esociformes Bleeker 1859 (pike)
Subcohort Stomiati
Order Osmeriformes (smelts)
Order Stomiatiformes Regan 1909 (bristlemouths and marine hatchetfishes)
Subcohort Neoteleostei Nelson 1969
Infracohort Ateleopodia
Order Ateleopodiformes (jellynose fish)
Infracohort Eurypterygia Rosen 1973
Section Aulopa [Cyclosquamata Rosen 1973]
Order Aulopiformes Rosen 1973 (Bombay duck and lancetfishes)
Section Ctenosquamata Rosen 1973
Subsection Myctophata [Scopelomorpha]
Order Myctophiformes Regan 1911 (lanternfishes)
Subsection Acanthomorpha Betancur-Rodriguez et al. 2013
Division Lampridacea Betancur-Rodriguez et al. 2013 [Lampridomorpha; Lampripterygii]
Order Lampriformes Regan 1909 (oarfish, opah and ribbonfishes)
Division Paracanthomorphacea sensu Grande et al. 2013 (Paracanthopterygii Greenwood 1937)
Order Percopsiformes Berg 1937 (cavefishes and trout-perches)
Order †Sphenocephaliformes Rosen & Patterson 1969
Order Zeiformes Regan 1909 (dories)
Order Stylephoriformes Miya et al. 2007
Order Gadiformes Goodrich 1909 (cods)
Division Polymixiacea Betancur-Rodriguez et al. 2013 (Polymyxiomorpha; Polymixiipterygii)
Order †Pattersonichthyiformes Gaudant 1976
Order †Ctenothrissiformes Berg 1937
Order Polymixiiformes Lowe 1838 (beardfishes)
Division Euacanthomorphacea Betancur-Rodriguez et al. 2013 (Euacanthomorpha sensu Johnson & Patterson 1993; Acanthopterygii Gouan 1770 sensu])
Subdivision Berycimorphaceae Betancur-Rodriguez et al. 2013
Order Beryciformes (fangtooths and pineconefishes) (incl. Stephanoberyciformes; Cetomimiformes)
Subdivision Holocentrimorphaceae Betancur-Rodriguez et al. 2013
Order Holocentriformes (Soldierfishes)
Subdivision Percomorphaceae Betancur-Rodriguez et al. 2013 (Percomorpha sensu Miya et al. 2003; Acanthopteri)
Series Ophidiimopharia Betancur-Rodriguez et al. 2013
Order Ophidiiformes (pearlfishes)
Series Batrachoidimopharia Betancur-Rodriguez et al. 2013
Order Batrachoidiformes (toadfishes)
Series Gobiomopharia Betancur-Rodriguez et al. 2013
Order Kurtiformes(Nurseryfishes and cardinalfishes)
Order Gobiiformes(Sleepers and gobies)
Series Scombrimopharia Betancur-Rodriguez et al. 2013
Order Syngnathiformes (seahorses, pipefishes, sea moths, cornetfishes and flying gurnards)
Order Scombriformes (Tunas and (mackerels)
Series Carangimopharia Betancur-Rodriguez et al. 2013
Subseries Anabantaria Betancur-Rodriguez et al. 2014
Order Synbranchiformes (swamp eels)
Order Anabantiformes (Labyrinthici) (gouramies, snakeheads, )
Subseries Carangaria Betancur-Rodriguez et al. 2014
Carangaria incertae sedis
Order Istiophoriformes Betancur-Rodriguez 2013 (Marlins, swordfishes, billfishes)
Order Carangiformes (Jack mackerels, pompanos)
Order Pleuronectiformes Bleeker 1859 (flatfishes)
Subseries Ovalentaria Smith & Near 2012 (Stiassnyiformes sensu Li et al. 2009)
Ovalentaria incertae sedis
Order Cichliformes Betancur-Rodriguez et al. 2013 (Cichlids, Convict blenny, leaf fishes)
Order Atheriniformes Rosen 1964 (silversides and rainbowfishes)
Order Cyprinodontiformes Berg 1940 (livebearers, killifishes)
Order Beloniformes Berg 1940 (flyingfishes and ricefishes)
Order Mugiliformes Berg 1940 (mullets)
Order Blenniiformes Springer 1993 (Blennies)
Order Gobiesociformes Gill 1872 (Clingfishes)
Series Eupercaria Betancur-Rodriguez et al. 2014 (Percomorpharia Betancur-Rodriguez et al. 2013)
Eupercaria incertae sedis
Order Gerreiformes (Mojarras)
Order Labriformes (Wrasses and Parrotfishes)
Order Caproiformes (Boarfishes)
Order Lophiiformes Garman 1899 (Anglerfishes)
Order Tetraodontiformes Regan 1929 (Filefishes and pufferfish)
Order Centrarchiformes Bleeker 1859 (Sunfishes and mandarin fishes)
Order Gasterosteiformes (Sticklebacks and relatives)
Order Scorpaeniformes (Lionfishes and relatives)
Order Perciformes Bleeker 1859
References
External links
Ray-finned fish
Fish classes
Silurian bony fish
Extant Silurian first appearances |
742 | https://en.wikipedia.org/wiki/Algorithms%20%28journal%29 | Algorithms (journal) | Algorithms is a monthly peer-reviewed open-access scientific journal of mathematics, covering design, analysis, and experiments on algorithms. The journal is published by MDPI and was established in 2008. The founding editor-in-chief was Kazuo Iwama (Kyoto University). From May 2014 to September 2019, the editor-in-chief was Henning Fernau (Universität Trier). The current editor-in-chief is Frank Werner (Otto-von-Guericke-Universität Magdeburg).
Abstracting and indexing
According to the Journal Citation Reports, the journal has a 2022 impact factor of 2.3.
The journal is abstracted and indexed in:
See also
Journals with similar scope include:
ACM Transactions on Algorithms
Algorithmica
Journal of Algorithms (Elsevier)
References
External links
Theoretical computer science journals
Open access journals
MDPI academic journals
English-language journals
Academic journals established in 2008
Monthly journals |
748 | https://en.wikipedia.org/wiki/Amateur%20astronomy | Amateur astronomy | Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, double stars, sunspots, or occultations of stars by the Moon or asteroids, or by discovering transient astronomical events, such as comets, galactic novae or supernovae in other galaxies.
Amateur astronomers do not use the field of astronomy as their primary source of income or support, and usually have no professional degree in astrophysics or advanced academic training in the subject. Most amateurs are hobbyists, while others have a high degree of experience in astronomy and may often assist and work alongside professional astronomers. Many astronomers have studied the sky throughout history in an amateur framework; however, since the beginning of the twentieth century, professional astronomy has become an activity clearly distinguished from amateur astronomy and associated activities.
Amateur astronomers typically view the sky at night, when most celestial objects and astronomical events are visible, but others observe during the daytime by viewing the Sun and solar eclipses. Some just look at the sky using nothing more than their eyes or binoculars, but more dedicated amateurs often use portable telescopes or telescopes situated in their private or club observatories. Amateurs also join amateur astronomical societies, which can advise, educate or guide them towards ways of finding and observing celestial objects. They also promote the science of astronomy among the general public.
Objectives
Collectively, amateur astronomers observe a variety of celestial objects and phenomena. Common targets of amateur astronomers include the Sun, the Moon, planets, stars, comets, meteor showers, and a variety of deep sky objects such as star clusters, galaxies, and nebulae. Many amateurs like to specialise in observing particular objects, types of objects, or types of events which interest them. One branch of amateur astronomy, amateur astrophotography, involves the taking of photos of the night sky. Astrophotography has become more popular with the introduction of far easier to use equipment including, digital cameras, DSLR cameras and relatively sophisticated purpose built high quality CCD cameras and CMOS cameras.
Most amateur astronomers work at visible wavelengths, but a small minority experiment with wavelengths outside the visible spectrum. An early pioneer of radio astronomy was Grote Reber, an amateur astronomer who constructed the first purpose built radio telescope in the late 1930s to follow up on the discovery of radio wavelength emissions from space by Karl Jansky. Non-visual amateur astronomy includes the use of infrared filters on conventional telescopes, and also the use of radio telescopes. Some amateur astronomers use home-made radio telescopes, while others use radio telescopes that were originally built for astronomical research but have since been made available for use by amateurs. The One-Mile Telescope is one such example.
Common tools
Amateur astronomers use a range of instruments to study the sky, depending on a combination of their interests and resources. Methods include simply looking at the night sky with the naked eye, using binoculars, and using a variety of optical telescopes of varying power and quality, as well as additional sophisticated equipment, such as cameras, to study light from the sky in both the visual and non-visual parts of the spectrum. To further improve studying the visual and non-visual part of the spectrum, amateur astronomers go to rural areas to get away from light pollution. Commercial telescopes are available, new and used, but it is also common for amateur astronomers to build (or commission the building of) their own custom telescopes. Some people even focus on amateur telescope making as their primary interest within the hobby of amateur astronomy.
Although specialized and experienced amateur astronomers tend to acquire more specialized and more powerful equipment over time, relatively simple equipment is often preferred for certain tasks. Binoculars, for instance, although generally of lower power than the majority of telescopes, also tend to provide a wider field of view, which is preferable for looking at some objects in the night sky. Recent models of iPhones have introduced a “night mode” option when taking pictures as well, that allows you to increase exposure, which is a period of time the picture is being taken for. This optimizes focus on light in the frame which is why it is used primarily at night.
Amateur astronomers also use star charts that, depending on experience and intentions, may range from simple planispheres through to detailed charts of very specific areas of the night sky. A range of astronomy software is available and used by amateur astronomers, including software that generates maps of the sky, software to assist with astrophotography, observation scheduling software, and software to perform various calculations pertaining to astronomical phenomena.
Amateur astronomers often like to keep records of their observations, which usually takes the form of an observing log. Observing logs typically record details about which objects were observed and when, as well as describing the details that were seen. Sketching is sometimes used within logs, and photographic records of observations have also been used in recent times. The information gathered is used to help studies and interactions between amateur astronomers in yearly gatherings. Although not professional information or credible, it is a way for the hobby lovers to share their new sightings and experiences.
The popularity of imaging among amateurs has led to large numbers of web sites being written by individuals about their images and equipment. Much of the social interaction of amateur astronomy occurs on mailing lists or discussion groups. Discussion group servers host numerous astronomy lists. A great deal of the commerce of amateur astronomy, the buying and selling of equipment, occurs online. Many amateurs use online tools to plan their nightly observing sessions, using tools such as the Clear Sky Chart.
Common techniques
While a number of interesting celestial objects are readily identified by the naked eye, sometimes with the aid of a star chart, many others are so faint or inconspicuous that technical means are necessary to locate them. Although many methods are used in amateur astronomy, most are variations of a few specific techniques.
Star hopping
Star hopping is a method often used by amateur astronomers with low-tech equipment such as binoculars or a manually driven telescope. It involves the use of maps (or memory) to locate known landmark stars, and "hopping" between them, often with the aid of a finderscope. Because of its simplicity, star hopping is a very common method for finding objects that are close to naked-eye stars.
More advanced methods of locating objects in the sky include telescope mounts with setting circles, which assist with pointing telescopes to positions in the sky that are known to contain objects of interest, and GOTO telescopes, which are fully automated telescopes that are capable of locating objects on demand (having first been calibrated).
Mobile apps
The advent of mobile applications for use in smartphones has led to the creation of many dedicated apps. These apps allow any user to easily locate celestial objects of interest by simply pointing the smartphone device in that direction in the sky. These apps make use of the inbuilt hardware in the phone, such as GPS location and gyroscope. Useful information about the pointed object like celestial coordinates, the name of the object, its constellation, etc. are provided for a quick reference. Some paid versions give more information. These apps are gradually getting into regular use during observing, for the alignment process of telescopes.
Setting circles
Setting circles are angular measurement scales that can be placed on the two main rotation axes of some telescopes. Since the widespread adoption of digital setting circles, any classical engraved setting circle is now specifically identified as an "analog setting circle" (ASC). By knowing the coordinates of an object (usually given in equatorial coordinates), the telescope user can use the setting circle to align (i.e., point) the telescope in the appropriate direction before looking through its eyepiece. A computerized setting circle is called a "digital setting circle" (DSC). Although digital setting circles can be used to display a telescope's RA and Dec coordinates, they are not simply a digital read-out of what can be seen on the telescope's analog setting circles. As with go-to telescopes, digital setting circle computers (commercial names include Argo Navis, Sky Commander, and NGC Max) contain databases of tens of thousands of celestial objects and projections of planet positions.
To find a celestial object in a telescope equipped with a DSC computer, one does not need to look up the specific RA and Dec coordinates in a book or other resource, and then adjust the telescope to those numerical readings. Rather, the object is chosen from the electronic database, which causes distance values and arrow markers to appear in the display that indicate the distance and direction to move the telescope. The telescope is moved until the two angular distance values reach zero, indicating that the telescope is properly aligned. When both the RA and Dec axes are thus "zeroed out", the object should be in the eyepiece. Many DSCs, like go-to systems, can also work in conjunction with laptop sky programs.
Computerized systems provide the further advantage of computing coordinate precession. Traditional printed sources are subtitled by the epoch year, which refers to the positions of celestial objects at a given time to the nearest year (e.g., J2005, J2007). Most such printed sources have been updated for intervals of only about every fifty years (e.g., J1900, J1950, J2000). Computerized sources, on the other hand, are able to calculate the right ascension and declination of the "epoch of date" to the exact instant of observation.
GoTo telescopes
GOTO telescopes have become more popular since the 1980s as technology has improved and prices have been reduced. With these computer-driven telescopes, the user typically enters the name of the item of interest and the mechanics of the telescope point the telescope towards that item automatically. They have several notable advantages for amateur astronomers intent on research. For example, GOTO telescopes tend to be faster for locating items of interest than star hopping, allowing more time for studying of the object. GOTO also allows manufacturers to add equatorial tracking to mechanically simpler alt-azimuth telescope mounts, allowing them to produce an overall less expensive product. GOTO telescopes usually have to be calibrated using alignment stars in order to provide accurate tracking and positioning. However, several telescope manufacturers have recently developed telescope systems that are calibrated with the use of built-in GPS, decreasing the time it takes to set up a telescope at the start of an observing session.
Remote-controlled telescopes
With the development of fast Internet in the last part of the 20th century along with advances in computer controlled telescope mounts and CCD cameras "Remote Telescope" astronomy is now a viable means for amateur astronomers not aligned with major telescope facilities to partake in research and deep sky imaging. This enables anyone to control a telescope a great distance away in a dark location. The observer can image through the telescope using CCD cameras. The digital data collected by the telescope is then transmitted and displayed to the user by means of the Internet. An example of a digital remote telescope operation for public use via the Internet is the Bareket observatory, and there are telescope farms in New Mexico, Australia and Atacama in Chile.
Imaging techniques
Amateur astronomers engage in many imaging techniques including film, DSLR, LRGB, and CCD astrophotography. Because CCD imagers are linear, image processing may be used to subtract away the effects of light pollution, which has increased the popularity of astrophotography in urban areas. Narrowband filters may also be used to minimize light pollution.
Scientific research
Scientific research is most often not the main goal for many amateur astronomers, unlike professional astronomers. Work of scientific merit is possible, however, and many amateurs successfully contribute to the knowledge base of professional astronomers. Astronomy is sometimes promoted as one of the few remaining sciences for which amateurs can still contribute useful data. To recognize this, the Astronomical Society of the Pacific annually gives Amateur Achievement Awards for significant contributions to astronomy by amateurs.
The majority of scientific contributions by amateur astronomers are in the area of data collection. In particular, this applies where large numbers of amateur astronomers with small telescopes are more effective than the relatively small number of large telescopes that are available to professional astronomers. Several organizations, such as the American Association of Variable Star Observers and the British Astronomical Association, exist to help coordinate these contributions.
Amateur astronomers often contribute toward activities such as monitoring the changes in brightness of variable stars and supernovae, helping to track asteroids, and observing occultations to determine both the shape of asteroids and the shape of the terrain on the apparent edge of the Moon as seen from Earth. With more advanced equipment, but still cheap in comparison to professional setups, amateur astronomers can measure the light spectrum emitted from astronomical objects, which can yield high-quality scientific data if the measurements are performed with due care. A relatively recent role for amateur astronomers is searching for overlooked phenomena (e.g., Kreutz Sungrazers) in the vast libraries of digital images and other data captured by Earth and space based observatories, much of which is available over the Internet.
In the past and present, amateur astronomers have played a major role in discovering new comets. Recently however, funding of projects such as the Lincoln Near-Earth Asteroid Research and Near Earth Asteroid Tracking projects has meant that most comets are now discovered by automated systems long before it is possible for amateurs to see them.
Societies
There are a large number of amateur astronomical societies around the world, that serve as a meeting point for those interested in amateur astronomy. Members range from active observers with their own equipment to "armchair astronomers" who are simply interested in the topic. Societies range widely in their goals and activities, which may depend on a variety of factors such as geographic spread, local circumstances, size, and membership. For example, a small local society located in dark countryside may focus on practical observing and star parties, whereas a large one based in a major city might have numerous members but be limited by light pollution and thus hold regular indoor meetings with guest speakers instead. Major national or international societies generally publish their own journal or newsletter, and some hold large multi-day meetings akin to a scientific conference or convention. They may also have sections devoted to particular topics, such as lunar observation or amateur telescope making.
Notable amateur astronomers
George Alcock, discovered several comets and novae.
Thomas Bopp, shared the discovery of Comet Hale-Bopp in 1995 with unemployed PhD physicist Alan Hale.
Robert Burnham Jr. (1931–1993), author of the Celestial Handbook.
Andrew Ainslie Common (1841–1903), built his own very large reflecting telescopes and demonstrated that photography could record astronomical features invisible to the human eye.
Robert E. Cox (1917–1989) who conducted the "Gleanings for ATMs" column in Sky & Telescope magazine for 21 years.
John Dobson (1915–2014), whose name is associated with the Dobsonian telescope.
Robert Owen Evans (1937-2022) was an amateur astronomer who currently holds the all-time record for visual discoveries of supernovae.
Clinton B. Ford (1913–1992), who specialized in the observation of variable stars.
John Ellard Gore (1845–1910), who specialized in the observation of variable stars.
Edward Halbach (1909–2011), who specialized in the observation of variable stars.
Will Hay, the famous comedian and actor, who discovered a white spot on Saturn.
Walter Scott Houston (1912–1993) who wrote the "Deep-Sky Wonders" column in Sky & Telescope magazine for almost 50 years.
Albert G. Ingalls (1888–1958), editor of Amateur Telescope Making, Vols. 1–3 and "The Amateur Scientist".
Peter Jalowiczor (born in 1966) discovered four exoplanets.
David H. Levy discovered or co-discovered 22 comets including Comet Shoemaker-Levy 9, the most for any individual.
Terry Lovejoy discovered five comets in the 21st century and developed modifications to DSLR cameras for astrophotography.
Sir Patrick Moore (1923–2012), presenter of the BBC's long-running The Sky at Night and author of many books on astronomy.
Leslie Peltier (1900–1980), a prolific discoverer of comets and well-known observer of variable stars.
John M. Pierce (1886–1958) was one of the founders of the Springfield Telescope Makers.
Russell W. Porter (1871–1949) founded Stellafane and has been referred to as the "founder".
Grote Reber (1911–2002), pioneer of radio astronomy constructing the first purpose built radio telescope and conducted the first sky survey in the radio frequency.
Isaac Roberts (1829–1904), early experimenter in astronomical photography.
Discoveries with major contributions by amateur astronomers
Cygnus A (1939) is a radio galaxy and one of the strongest radio sources on the sky.
Dramatic period decrease in T Ursae Minoris using AAVSO observations (1995).
McNeil's Nebula (2004) is a variable nebula.
XO-1b (2006) is an exoplanet.
Tidal streams around NGC 5907 (2008).
Voorwerpjes (2009) is a type of quasar ionization echo.
Pea Galaxies (2009) are a type of galaxy.
Most recent (2010) outburst of U Scorpii.
Kronberger 61 (2011) is a planetary nebula.
Speca (2011) is a spiral galaxy containing contain DRAGNs (Double Radio-source Associated with Galactic Nucleus).
2011 HM102 (2013) is a Neptune Trojan.
PH1b (2013) is an extrasolar planet in a circumbinary orbit in a quadruple star system.
PH2b (2013) is an extrasolar gas giant planet located in its parent star's habitable zone.
J1649+2635 (2014) is a spiral galaxy containing contain DRAGNs (Double Radio-source Associated with Galactic Nucleus).
Yellowballs (2015) are a type of compact star-forming region.
9Spitch (2015) is a distant gravitationally lensed galaxy with high star-forming rate.
NGC 253-dw2 (2016) is a dwarf spheroidal (dSph) galaxy candidate undergoing tidal disruption around the nearby galaxy NGC 253. The galaxy was discovered by an amateur astronomer with a small-aperture amateur telescope.
KIC 8462852 (2016) is an F-type star showing unusual dimming events.
HD 74389 (2016) contains a debris disk. It is the first debris disk discovered around a star with a companion white dwarf.
AWI0005x3s (2016) is the oldest M-dwarf with a debris disk detected in a moving group at the time of the discovery.
PSR J1913+1102 (2016) is a binary neutron star with the highest total mass at the time of the discovery.
Donatiello I (2016) a nearby spheroidal dwarf galaxy discovered by the Italian amateur astronomer Giuseppe Donatiello. It is also the first galaxy to be named after an amateur astronomer.
Transiting Exocomets (2017) are comets in an extrasolar system blocking some of the starlight while transiting in front of the extra-solar star.
K2-138 (2018) is a planetary system with five confirmed planets in an unbroken 3:2-resonance chain.
Supernova 2016gkg (2018) was observed by an amateur astronomer shortly after it began to erupt.
PSR J1744−7619 (2018) is the first Pulsar to be detected only in gamma-rays and not in radio-waves.
STEVE (2018) is an atmospheric phenomenon.
K2-288Bb (2019) is an extrasolar planet in the habitable zone around a M-star, which belongs to a binary system.
LSPM J0207+3331 (2019) is an old white dwarf containing a debris disk with two components.
Interstellar Comet 2I/Borisov (2019) is the first interstellar comet.
Kojima-1Lb (confirmed in 2019) is a Neptune-sized exoplanet discovered by an amateur astronomer with the microlensing method. Kojima-1 is the brightest microlensing host discovered.
WISE2150-7520AB (2019/2020) is a pair of brown dwarfs with the lowest binding energy at a total mass smaller than 0.1 solar masses not associated with a young cluster.
GJ 3470 c (2020) is the first exoplanet candidate completely discovered by amateurs. Unlike Peter Jalowiczor, Kojima-1Lb and XO-1b, GJ 3470 c was fully discovered by an amateur in a project led by amateur astronomers.
Pisces VII/Triangulum IIII (Psc VIII/Tri III) is an ultrafaint dwarf galaxy in Messier 31 system, a possible satellite of Messier 33. It is the second discovery credited to the Italian amateur astronomer Giuseppe Donatiello, already discoverer of the dwarf galaxy Donatiello I.
Donatiello II, Donatiello III and Donatiello IV, three new satellites of the nearby galaxy NGC 253, discovered in 2021 by the Italian amateur astronomer Giuseppe Donatiello. With these three new dwarf galaxies, Donatiello I and Pisces VII, his total discoveries in this topic are five.
Pegasus V/Andromeda XXXIV (Peg V/And XXXIV) an ultrafaint dwarf in the constellation of Pegasus located ~260 kpc from Messier 31 (Andromeda Galaxy) in the outskirts of its halo. Peg V was initially identified in the DESI Legacy Imaging Surveys by the Italian amateur astronomer Giuseppe Donatiello.
Prizes recognizing amateur astronomers
Amateur Achievement Award of Astronomical Society of the Pacific
Chambliss Amateur Achievement Award
See also
Astronomical object
Caldwell catalogue A list of astronomical objects for observation by amateur astronomers compiled by Sir Patrick Caldwell-Moore.
Clear Sky Chart Weather forecasts designed for amateur astronomers.
List of astronomical societies
List of telescope parts and construction
Messier catalogue A set of astronomical objects catalogued by the French astronomer Charles Messier in 1771, which is still used by many amateurs as an observing list.
Observation
Observational astronomy
School Astronomical Olympiad by Correspondence
Sidewalk astronomy
Skygazing
Star party
References
Further reading
External links
Amateur Astronomy Magazine
Articles containing video clips
Citizen science |
752 | https://en.wikipedia.org/wiki/Art | Art | Art is a diverse range of human activity and its resulting product that involves creative or imaginative talent generally expressive of technical proficiency, beauty, emotional power, or conceptual ideas.
There is no generally agreed definition of what constitutes art, and its interpretation has varied greatly throughout history and across cultures. In the Western tradition, the three classical branches of visual art are painting, sculpture, and architecture. Theatre, dance, and other performing arts, as well as literature, music, film and other media such as interactive media, are included in a broader definition of the arts. Until the 17th century, art referred to any skill or mastery and was not differentiated from crafts or sciences. In modern usage after the 17th century, where aesthetic considerations are paramount, the fine arts are separated and distinguished from acquired skills in general, such as the decorative or applied arts.
The nature of art and related concepts, such as creativity and interpretation, are explored in a branch of philosophy known as aesthetics. The resulting artworks are studied in the professional fields of art criticism and the history of art.
Overview
In the perspective of the history of art, artistic works have existed for almost as long as humankind: from early prehistoric art to contemporary art; however, some theorists think that the typical concept of "artistic works" does not fit well outside modern Western societies. One early sense of the definition of art is closely related to the older Latin meaning, which roughly translates to "skill" or "craft", as associated with words such as "artisan". English words derived from this meaning include artifact, artificial, artifice, medical arts, and military arts. However, there are many other colloquial uses of the word, all with some relation to its etymology.
Over time, philosophers like Plato, Aristotle, Socrates and Immanuel Kant, among others, questioned the meaning of art. Several dialogues in Plato tackle questions about art: Socrates says that poetry is inspired by the muses, and is not rational. He speaks approvingly of this, and other forms of divine madness (drunkenness, eroticism, and dreaming) in the Phaedrus (265a–c), and yet in the Republic wants to outlaw Homer's great poetic art, and laughter as well. In Ion, Socrates gives no hint of the disapproval of Homer that he expresses in the Republic. The dialogue Ion suggests that Homer's Iliad functioned in the ancient Greek world as the Bible does today in the modern Christian world: as divinely inspired literary art that can provide moral guidance, if only it can be properly interpreted.
With regards to the literary art and the musical arts, Aristotle considered epic poetry, tragedy, comedy, Dithyrambic poetry and music to be mimetic or imitative art, each varying in imitation by medium, object, and manner. For example, music imitates with the media of rhythm and harmony, whereas dance imitates with rhythm alone, and poetry with language. The forms also differ in their object of imitation. Comedy, for instance, is a dramatic imitation of men worse than average; whereas tragedy imitates men slightly better than average. Lastly, the forms differ in their manner of imitation—through narrative or character, through change or no change, and through drama or no drama. Aristotle believed that imitation is natural to mankind and constitutes one of mankind's advantages over animals.
The more recent and specific sense of the word art as an abbreviation for creative art or fine art emerged in the early 17th century. Fine art refers to a skill used to express the artist's creativity, or to engage the audience's aesthetic sensibilities, or to draw the audience towards consideration of more refined or finer works of art.
Within this latter sense, the word art may refer to several things: (i) a study of a creative skill, (ii) a process of using the creative skill, (iii) a product of the creative skill, or (iv) the audience's experience with the creative skill. The creative arts (art as discipline) are a collection of disciplines which produce artworks (art as objects) that are compelled by a personal drive (art as activity) and convey a message, mood, or symbolism for the perceiver to interpret (art as experience). Art is something that stimulates an individual's thoughts, emotions, beliefs, or ideas through the senses. Works of art can be explicitly made for this purpose or interpreted on the basis of images or objects. For some scholars, such as Kant, the sciences and the arts could be distinguished by taking science as representing the domain of knowledge and the arts as representing the domain of the freedom of artistic expression.
Often, if the skill is being used in a common or practical way, people will consider it a craft instead of art. Likewise, if the skill is being used in a commercial or industrial way, it may be considered commercial art instead of fine art. On the other hand, crafts and design are sometimes considered applied art. Some art followers have argued that the difference between fine art and applied art has more to do with value judgments made about the art than any clear definitional difference. However, even fine art often has goals beyond pure creativity and self-expression. The purpose of works of art may be to communicate ideas, such as in politically, spiritually, or philosophically motivated art; to create a sense of beauty (see aesthetics); to explore the nature of perception; for pleasure; or to generate strong emotions. The purpose may also be seemingly nonexistent.
The nature of art has been described by philosopher Richard Wollheim as "one of the most elusive of the traditional problems of human culture". Art has been defined as a vehicle for the expression or communication of emotions and ideas, a means for exploring and appreciating formal elements for their own sake, and as mimesis or representation. Art as mimesis has deep roots in the philosophy of Aristotle. Leo Tolstoy identified art as a use of indirect means to communicate from one person to another. Benedetto Croce and R. G. Collingwood advanced the idealist view that art expresses emotions, and that the work of art therefore essentially exists in the mind of the creator. The theory of art as form has its roots in the philosophy of Kant, and was developed in the early 20th century by Roger Fry and Clive Bell. More recently, thinkers influenced by Martin Heidegger have interpreted art as the means by which a community develops for itself a medium for self-expression and interpretation. George Dickie has offered an institutional theory of art that defines a work of art as any artifact upon which a qualified person or persons acting on behalf of the social institution commonly referred to as "the art world" has conferred "the status of candidate for appreciation". Larry Shiner has described fine art as "not an essence or a fate but something we have made. Art as we have generally understood it is a European invention barely two hundred years old."
Art may be characterized in terms of mimesis (its representation of reality), narrative (storytelling), expression, communication of emotion, or other qualities. During the Romantic period, art came to be seen as "a special faculty of the human mind to be classified with religion and science".
History
A shell engraved by Homo erectus was determined to be between 430,000 and 540,000 years old. A set of eight 130,000 years old white-tailed eagle talons bear cut marks and abrasion that indicate manipulation by neanderthals, possibly for using it as jewelry. A series of tiny, drilled snail shells about 75,000 years old—were discovered in a South African cave. Containers that may have been used to hold paints have been found dating as far back as 100,000 years.
The oldest piece of art found in Europe is the Riesenhirschknochen der Einhornhöhle, dating back 51,000 years and made by Neanderthals.
Sculptures, cave paintings, rock paintings and petroglyphs from the Upper Paleolithic dating to roughly 40,000 years ago have been found, but the precise meaning of such art is often disputed because so little is known about the cultures that produced them.
The first undisputed sculptures and similar art pieces, like the Venus of Hohle Fels, are the numerous objects found at the Caves and Ice Age Art in the Swabian Jura UNESCO World Heritage Site, where the oldest non-stationary works of human art yet discovered were found, in the form of carved animal and humanoid figurines, in addition to the oldest musical instruments unearthed so far, with the artifacts dating between 43,000 and 35,000 BC, so being the first centre of human art.
Many great traditions in art have a foundation in the art of one of the great ancient civilizations: Ancient Egypt, Mesopotamia, Persia, India, China, Ancient Greece, Rome, as well as Inca, Maya, and Olmec. Each of these centers of early civilization developed a unique and characteristic style in its art. Because of the size and duration of these civilizations, more of their art works have survived and more of their influence has been transmitted to other cultures and later times. Some also have provided the first records of how artists worked. For example, this period of Greek art saw a veneration of the human physical form and the development of equivalent skills to show musculature, poise, beauty, and anatomically correct proportions.
In Byzantine and Medieval art of the Western Middle Ages, much art focused on the expression of subjects about biblical and religious culture, and used styles that showed the higher glory of a heavenly world, such as the use of gold in the background of paintings, or glass in mosaics or windows, which also presented figures in idealized, patterned (flat) forms. Nevertheless, a classical realist tradition persisted in small Byzantine works, and realism steadily grew in the art of Catholic Europe.
Renaissance art had a greatly increased emphasis on the realistic depiction of the material world, and the place of humans in it, reflected in the corporeality of the human body, and development of a systematic method of graphical perspective to depict recession in a three-dimensional picture space.
In the east, Islamic art's rejection of iconography led to emphasis on geometric patterns, calligraphy, and architecture. Further east, religion dominated artistic styles and forms too. India and Tibet saw emphasis on painted sculptures and dance, while religious painting borrowed many conventions from sculpture and tended to bright contrasting colors with emphasis on outlines. China saw the flourishing of many art forms: jade carving, bronzework, pottery (including the stunning terracotta army of Emperor Qin), poetry, calligraphy, music, painting, drama, fiction, etc. Chinese styles vary greatly from era to era and each one is traditionally named after the ruling dynasty. So, for example, Tang dynasty paintings are monochromatic and sparse, emphasizing idealized landscapes, but Ming dynasty paintings are busy and colorful, and focus on telling stories via setting and composition. Japan names its styles after imperial dynasties too, and also saw much interplay between the styles of calligraphy and painting. Woodblock printing became important in Japan after the 17th century.
The western Age of Enlightenment in the 18th century saw artistic depictions of physical and rational certainties of the clockwork universe, as well as politically revolutionary visions of a post-monarchist world, such as Blake's portrayal of Newton as a divine geometer, or David's propagandistic paintings. This led to Romantic rejections of this in favor of pictures of the emotional side and individuality of humans, exemplified in the novels of Goethe. The late 19th century then saw a host of artistic movements, such as academic art, Symbolism, impressionism and fauvism among others.
The history of 20th-century art is a narrative of endless possibilities and the search for new standards, each being torn down in succession by the next. Thus the parameters of Impressionism, Expressionism, Fauvism, Cubism, Dadaism, Surrealism, etc. cannot be maintained very much beyond the time of their invention. Increasing global interaction during this time saw an equivalent influence of other cultures into Western art. Thus, Japanese woodblock prints (themselves influenced by Western Renaissance draftsmanship) had an immense influence on impressionism and subsequent development. Later, African sculptures were taken up by Picasso and to some extent by Matisse. Similarly, in the 19th and 20th centuries the West has had huge impacts on Eastern art with originally western ideas like Communism and Post-Modernism exerting a powerful influence.
Modernism, the idealistic search for truth, gave way in the latter half of the 20th century to a realization of its unattainability. Theodor W. Adorno said in 1970, "It is now taken for granted that nothing which concerns art can be taken for granted any more: neither art itself, nor art in relationship to the whole, nor even the right of art to exist." Relativism was accepted as an unavoidable truth, which led to the period of contemporary art and postmodern criticism, where cultures of the world and of history are seen as changing forms, which can be appreciated and drawn from only with skepticism and irony. Furthermore, the separation of cultures is increasingly blurred and some argue it is now more appropriate to think in terms of a global culture, rather than of regional ones.
In The Origin of the Work of Art, Martin Heidegger, a German philosopher and seminal thinker, describes the essence of art in terms of the concepts of being and truth. He argues that art is not only a way of expressing the element of truth in a culture, but the means of creating it and providing a springboard from which "that which is" can be revealed. Works of art are not merely representations of the way things are, but actually produce a community's shared understanding. Each time a new artwork is added to any culture, the meaning of what it is to exist is inherently changed.
Historically, art and artistic skills and ideas have often been spread through trade. An example of this is the Silk Road, where Hellenistic, Iranian, Indian and Chinese influences could mix. Greco Buddhist art is one of the most vivid examples of this interaction. The meeting of different cultures and worldviews also influenced artistic creation. An example of this is the multicultural port metropolis of Trieste at the beginning of the 20th century, where James Joyce met writers from Central Europe and the artistic development of New York City as a cultural melting pot.
Forms, genres, media, and styles
The creative arts are often divided into more specific categories, typically along perceptually distinguishable categories such as media, genre, styles, and form. Art form refers to the elements of art that are independent of its interpretation or significance. It covers the methods adopted by the artist and the physical composition of the artwork, primarily non-semantic aspects of the work (i.e., figurae), such as color, contour, dimension, medium, melody, space, texture, and value. Form may also include Design principles, such as arrangement, balance, contrast, emphasis, harmony, proportion, proximity, and rhythm.
In general there are three schools of philosophy regarding art, focusing respectively on form, content, and context. Extreme Formalism is the view that all aesthetic properties of art are formal (that is, part of the art form). Philosophers almost universally reject this view and hold that the properties and aesthetics of art extend beyond materials, techniques, and form. Unfortunately, there is little consensus on terminology for these informal properties. Some authors refer to subject matter and content—i.e., denotations and connotations—while others prefer terms like meaning and significance.
Extreme Intentionalism holds that authorial intent plays a decisive role in the meaning of a work of art, conveying the content or essential main idea, while all other interpretations can be discarded. It defines the subject as the persons or idea represented, and the content as the artist's experience of that subject. For example, the composition of Napoleon I on his Imperial Throne is partly borrowed from the Statue of Zeus at Olympia. As evidenced by the title, the subject is Napoleon, and the content is Ingres's representation of Napoleon as "Emperor-God beyond time and space". Similarly to extreme formalism, philosophers typically reject extreme intentionalism, because art may have multiple ambiguous meanings and authorial intent may be unknowable and thus irrelevant. Its restrictive interpretation is "socially unhealthy, philosophically unreal, and politically unwise".
Finally, the developing theory of post-structuralism studies art's significance in a cultural context, such as the ideas, emotions, and reactions prompted by a work. The cultural context often reduces to the artist's techniques and intentions, in which case analysis proceeds along lines similar to formalism and intentionalism. However, in other cases historical and material conditions may predominate, such as religious and philosophical convictions, sociopolitical and economic structures, or even climate and geography. Art criticism continues to grow and develop alongside art.
Skill and craft
Art can connote a sense of trained ability or mastery of a medium. Art can also refer to the developed and efficient use of a language to convey meaning with immediacy or depth. Art can be defined as an act of expressing feelings, thoughts, and observations.
There is an understanding that is reached with the material as a result of handling it, which facilitates one's thought processes.
A common view is that the epithet art, particular in its elevated sense, requires a certain level of creative expertise by the artist, whether this be a demonstration of technical ability, an originality in stylistic approach, or a combination of these two. Traditionally skill of execution was viewed as a quality inseparable from art and thus necessary for its success; for Leonardo da Vinci, art, neither more nor less than his other endeavors, was a manifestation of skill. Rembrandt's work, now praised for its ephemeral virtues, was most admired by his contemporaries for its virtuosity. At the turn of the 20th century, the adroit performances of John Singer Sargent were alternately admired and viewed with skepticism for their manual fluency, yet at nearly the same time the artist who would become the era's most recognized and peripatetic iconoclast, Pablo Picasso, was completing a traditional academic training at which he excelled.
A common contemporary criticism of some modern art occurs along the lines of objecting to the apparent lack of skill or ability required in the production of the artistic object. In conceptual art, Marcel Duchamp's Fountain is among the first examples of pieces wherein the artist used found objects ("ready-made") and exercised no traditionally recognised set of skills. Tracey Emin's My Bed, or Damien Hirst's The Physical Impossibility of Death in the Mind of Someone Living follow this example and also manipulate the mass media. Emin slept (and engaged in other activities) in her bed before placing the result in a gallery as work of art. Hirst came up with the conceptual design for the artwork but has left most of the eventual creation of many works to employed artisans. Hirst's celebrity is founded entirely on his ability to produce shocking concepts. The actual production in many conceptual and contemporary works of art is a matter of assembly of found objects. However, there are many modernist and contemporary artists who continue to excel in the skills of drawing and painting and in creating hands-on works of art.
Purpose
Art has had a great number of different functions throughout its history, making its purpose difficult to abstract or quantify to any single concept. This does not imply that the purpose of art is "vague", but that it has had many unique, different reasons for being created. Some of these functions of art are provided in the following outline. The different purposes of art may be grouped according to those that are non-motivated, and those that are motivated (Lévi-Strauss).
Non-motivated functions
The non-motivated purposes of art are those that are integral to being human, transcend the individual, or do not fulfill a specific external purpose. In this sense, Art, as creativity, is something humans must do by their very nature (i.e., no other species creates art), and is therefore beyond utility.
Basic human instinct for harmony, balance, rhythm. Art at this level is not an action or an object, but an internal appreciation of balance and harmony (beauty), and therefore an aspect of being human beyond utility.Imitation, then, is one instinct of our nature. Next, there is the instinct for 'harmony' and rhythm, meters being manifestly sections of rhythm. Persons, therefore, starting with this natural gift developed by degrees their special aptitudes, till their rude improvisations gave birth to Poetry. – Aristotle
Experience of the mysterious. Art provides a way to experience one's self in relation to the universe. This experience may often come unmotivated, as one appreciates art, music or poetry.The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. – Albert Einstein
Expression of the imagination. Art provides a means to express the imagination in non-grammatic ways that are not tied to the formality of spoken or written language. Unlike words, which come in sequences and each of which have a definite meaning, art provides a range of forms, symbols and ideas with meanings that are malleable.Jupiter's eagle [as an example of art] is not, like logical (aesthetic) attributes of an object, the concept of the sublimity and majesty of creation, but rather something else—something that gives the imagination an incentive to spread its flight over a whole host of kindred representations that provoke more thought than admits of expression in a concept determined by words. They furnish an aesthetic idea, which serves the above rational idea as a substitute for logical presentation, but with the proper function, however, of animating the mind by opening out for it a prospect into a field of kindred representations stretching beyond its ken. – Immanuel Kant
Ritualistic and symbolic functions. In many cultures, art is used in rituals, performances and dances as a decoration or symbol. While these often have no specific utilitarian (motivated) purpose, anthropologists know that they often serve a purpose at the level of meaning within a particular culture. This meaning is not furnished by any one individual, but is often the result of many generations of change, and of a cosmological relationship within the culture.Most scholars who deal with rock paintings or objects recovered from prehistoric contexts that cannot be explained in utilitarian terms and are thus categorized as decorative, ritual or symbolic, are aware of the trap posed by the term 'art'. – Silva Tomaskova
Motivated functions
Motivated purposes of art refer to intentional, conscious actions on the part of the artists or creator. These may be to bring about political change, to comment on an aspect of society, to convey a specific emotion or mood, to address personal psychology, to illustrate another discipline, to (with commercial arts) sell a product, or used as a form of communication.
Communication. Art, at its simplest, is a form of communication. As most forms of communication have an intent or goal directed toward another individual, this is a motivated purpose. Illustrative arts, such as scientific illustration, are a form of art as communication. Maps are another example. However, the content need not be scientific. Emotions, moods and feelings are also communicated through art.[Art is a set of] artefacts or images with symbolic meanings as a means of communication. – Steve Mithen
Art as entertainment. Art may seek to bring about a particular emotion or mood, for the purpose of relaxing or entertaining the viewer. This is often the function of the art industries of motion pictures and video games.
The Avant-Garde. Art for political change. One of the defining functions of early 20th-century art has been to use visual images to bring about political change. Art movements that had this goal—Dadaism, Surrealism, Russian constructivism, and Abstract Expressionism, among others—are collectively referred to as the avant-garde arts.By contrast, the realistic attitude, inspired by positivism, from Saint Thomas Aquinas to Anatole France, clearly seems to me to be hostile to any intellectual or moral advancement. I loathe it, for it is made up of mediocrity, hate, and dull conceit. It is this attitude which today gives birth to these ridiculous books, these insulting plays. It constantly feeds on and derives strength from the newspapers and stultifies both science and art by assiduously flattering the lowest of tastes; clarity bordering on stupidity, a dog's life. – André Breton (Surrealism)
Art as a "free zone", removed from the action of the social censure. Unlike the avant-garde movements, which wanted to erase cultural differences in order to produce new universal values, contemporary art has enhanced its tolerance towards cultural differences as well as its critical and liberating functions (social inquiry, activism, subversion, deconstruction, etc.), becoming a more open place for research and experimentation.
Art for social inquiry, subversion or anarchy. While similar to art for political change, subversive or deconstructivist art may seek to question aspects of society without any specific political goal. In this case, the function of art may be used to criticize some aspect of society. Graffiti art and other types of street art are graphics and images that are spray-painted or stencilled on publicly viewable walls, buildings, buses, trains, and bridges, usually without permission. Certain art forms, such as graffiti, may also be illegal when they break laws (in this case vandalism).
Art for social causes. Art can be used to raise awareness for a large variety of causes. A number of art activities were aimed at raising awareness of autism, cancer, human trafficking, and a variety of other topics, such as ocean conservation, human rights in Darfur, murdered and missing Aboriginal women, elder abuse, and pollution. Trashion, using trash to make fashion, practiced by artists such as Marina DeBris is one example of using art to raise awareness about pollution.
Art for psychological and healing purposes. Art is also used by art therapists, psychotherapists and clinical psychologists as art therapy. The Diagnostic Drawing Series, for example, is used to determine the personality and emotional functioning of a patient. The end product is not the principal goal in this case, but rather a process of healing, through creative acts, is sought. The resultant piece of artwork may also offer insight into the troubles experienced by the subject and may suggest suitable approaches to be used in more conventional forms of psychiatric therapy.
Art for propaganda, or commercialism. Art is often used as a form of propaganda, and thus can be used to subtly influence popular conceptions or mood. In a similar way, art that tries to sell a product also influences mood and emotion. In both cases, the purpose of art here is to subtly manipulate the viewer into a particular emotional or psychological response toward a particular idea or object.
Art as a fitness indicator. It has been argued that the ability of the human brain by far exceeds what was needed for survival in the ancestral environment. One evolutionary psychology explanation for this is that the human brain and associated traits (such as artistic ability and creativity) are the human equivalent of the peacock's tail. The purpose of the male peacock's extravagant tail has been argued to be to attract females (see also Fisherian runaway and handicap principle). According to this theory superior execution of art was evolutionarily important because it attracted mates.
The functions of art described above are not mutually exclusive, as many of them may overlap. For example, art for the purpose of entertainment may also seek to sell a product, i.e. the movie or video game.
Steps
Art can be divided into any number of steps one can make an argument for. This section divides the creative process into broad three steps, but there is no consensus on an exact number.
Preparation
In the first step, the artist envisions the art in their mind. By imagining what their art would look like, the artist begins the process of bringing the art into existence. Preparation of art may involve approaching and researching the subject matter. Artistic inspiration is one of the main drivers of art, and may be considered to stem from instinct, impressions, and feelings.
Creation
In the second step, the artist executes the creation of their work. The creation of a piece can be affected by factors such as the artist's mood, surroundings, and mental state. For example, The Black Paintings by Francisco de Goya, created in the elder years of his life, are thought to be so bleak because he was in isolation and because of his experience with war. He painted them directly on the walls of his apartment in Spain, and most likely never discussed them with anyone. The Beatles stated drugs such as LSD and cannabis influenced some of their greatest hits, such as Revolver. Trial and error are considered an integral part of the creation process.
Appreciation
The last step is art appreciation, which has the sub-topic of critique. In one study, over half of visual arts students agreed that reflection is an essential step of the art process. According to education journals, the reflection of art is considered an essential part of the experience. However an important aspect of art is that others may view and appreciate it as well. While many focus on whether those viewing/listening/etc. believe the art to be good/successful or not, art has profound value beyond its commercial success as a provider of information and health in society. Art enjoyment can bring about a wide spectrum of emotion due to beauty. Some art is meant to be practical, with its analysis studious, meant to stimulate discourse.
Public access
Since ancient times, much of the finest art has represented a deliberate display of wealth or power, often achieved by using massive scale and expensive materials. Much art has been commissioned by political rulers or religious establishments, with more modest versions only available to the most wealthy in society.
Nevertheless, there have been many periods where art of very high quality was available, in terms of ownership, across large parts of society, above all in cheap media such as pottery, which persists in the ground, and perishable media such as textiles and wood. In many different cultures, the ceramics of indigenous peoples of the Americas are found in such a wide range of graves that they were clearly not restricted to a social elite, though other forms of art may have been. Reproductive methods such as moulds made mass-production easier, and were used to bring high-quality Ancient Roman pottery and Greek Tanagra figurines to a very wide market. Cylinder seals were both artistic and practical, and very widely used by what can be loosely called the middle class in the Ancient Near East. Once coins were widely used, these also became an art form that reached the widest range of society.
Another important innovation came in the 15th century in Europe, when printmaking began with small woodcuts, mostly religious, that were often very small and hand-colored, and affordable even by peasants who glued them to the walls of their homes. Printed books were initially very expensive, but fell steadily in price until by the 19th century even the poorest could afford some with printed illustrations. Popular prints of many different sorts have decorated homes and other places for centuries.
In 1661, the city of Basel, in Switzerland, opened the first public museum of art in the world, the Kunstmuseum Basel. Today, its collection is distinguished by an impressively wide historic span, from the early 15th century up to the immediate present. Its various areas of emphasis give it international standing as one of the most significant museums of its kind. These encompass: paintings and drawings by artists active in the Upper Rhine region between 1400 and 1600, and on the art of the 19th to 21st centuries.
Public buildings and monuments, secular and religious, by their nature normally address the whole of society, and visitors as viewers, and display to the general public has long been an important factor in their design. Egyptian temples are typical in that the most largest and most lavish decoration was placed on the parts that could be seen by the general public, rather than the areas seen only by the priests. Many areas of royal palaces, castles and the houses of the social elite were often generally accessible, and large parts of the art collections of such people could often be seen, either by anybody, or by those able to pay a small price, or those wearing the correct clothes, regardless of who they were, as at the Palace of Versailles, where the appropriate extra accessories (silver shoe buckles and a sword) could be hired from shops outside.
Special arrangements were made to allow the public to see many royal or private collections placed in galleries, as with the Orleans Collection mostly housed in a wing of the Palais Royal in Paris, which could be visited for most of the 18th century. In Italy the art tourism of the Grand Tour became a major industry from the Renaissance onwards, and governments and cities made efforts to make their key works accessible. The British Royal Collection remains distinct, but large donations such as the Old Royal Library were made from it to the British Museum, established in 1753. The Uffizi in Florence opened entirely as a gallery in 1765, though this function had been gradually taking the building over from the original civil servants' offices for a long time before. The building now occupied by the Prado in Madrid was built before the French Revolution for the public display of parts of the royal art collection, and similar royal galleries open to the public existed in Vienna, Munich and other capitals. The opening of the Musée du Louvre during the French Revolution (in 1793) as a public museum for much of the former French royal collection certainly marked an important stage in the development of public access to art, transferring ownership to a republican state, but was a continuation of trends already well established.
Most modern public museums and art education programs for children in schools can be traced back to this impulse to have art available to everyone. However, museums do not only provide availability to art, but do also influence the way art is being perceived by the audience, as studies found. Thus, the museum itself is not only a blunt stage for the presentation of art, but plays an active and vital role in the overall perception of art in modern society.
Museums in the United States tend to be gifts from the very rich to the masses. (The Metropolitan Museum of Art in New York City, for example, was created by John Taylor Johnston, a railroad executive whose personal art collection seeded the museum.) But despite all this, at least one of the important functions of art in the 21st century remains as a marker of wealth and social status.
There have been attempts by artists to create art that can not be bought by the wealthy as a status object. One of the prime original motivators of much of the art of the late 1960s and 1970s was to create art that could not be bought and sold. It is "necessary to present something more than mere objects" said the major post war German artist Joseph Beuys. This time period saw the rise of such things as performance art, video art, and conceptual art. The idea was that if the artwork was a performance that would leave nothing behind, or was an idea, it could not be bought and sold. "Democratic precepts revolving around the idea that a work of art is a commodity impelled the aesthetic innovation which germinated in the mid-1960s and was reaped throughout the 1970s. Artists broadly identified under the heading of Conceptual art ... substituting performance and publishing activities for engagement with both the material and materialistic concerns of painted or sculptural form ... [have] endeavored to undermine the art object qua object."
In the decades since, these ideas have been somewhat lost as the art market has learned to sell limited edition DVDs of video works, invitations to exclusive performance art pieces, and the objects left over from conceptual pieces. Many of these performances create works that are only understood by the elite who have been educated as to why an idea or video or piece of apparent garbage may be considered art. The marker of status becomes understanding the work instead of necessarily owning it, and the artwork remains an upper-class activity. "With the widespread use of DVD recording technology in the early 2000s, artists, and the gallery system that derives its profits from the sale of artworks, gained an important means of controlling the sale of video and computer artworks in limited editions to collectors."
Controversies
Art has long been controversial, that is to say disliked by some viewers, for a wide variety of reasons, though most pre-modern controversies are dimly recorded, or completely lost to a modern view. Iconoclasm is the destruction of art that is disliked for a variety of reasons, including religious ones. Aniconism is a general dislike of either all figurative images, or often just religious ones, and has been a thread in many major religions. It has been a crucial factor in the history of Islamic art, where depictions of Muhammad remain especially controversial. Much art has been disliked purely because it depicted or otherwise stood for unpopular rulers, parties or other groups. Artistic conventions have often been conservative and taken very seriously by art critics, though often much less so by a wider public. The iconographic content of art could cause controversy, as with late medieval depictions of the new motif of the Swoon of the Virgin in scenes of the Crucifixion of Jesus. The Last Judgment by Michelangelo was controversial for various reasons, including breaches of decorum through nudity and the Apollo-like pose of Christ.
The content of much formal art through history was dictated by the patron or commissioner rather than just the artist, but with the advent of Romanticism, and economic changes in the production of art, the artists' vision became the usual determinant of the content of his art, increasing the incidence of controversies, though often reducing their significance. Strong incentives for perceived originality and publicity also encouraged artists to court controversy. Théodore Géricault's Raft of the Medusa (), was in part a political commentary on a recent event. Édouard Manet's Le Déjeuner sur l'Herbe (1863), was considered scandalous not because of the nude woman, but because she is seated next to men fully dressed in the clothing of the time, rather than in robes of the antique world. John Singer Sargent's Madame Pierre Gautreau (Madam X) (1884), caused a controversy over the reddish pink used to color the woman's ear lobe, considered far too suggestive and supposedly ruining the high-society model's reputation.
The gradual abandonment of naturalism and the depiction of realistic representations of the visual appearance of subjects in the 19th and 20th centuries led to a rolling controversy lasting for over a century.
In the 20th century, Pablo Picasso's Guernica (1937) used arresting cubist techniques and stark monochromatic oils, to depict the harrowing consequences of a contemporary bombing of a small, ancient Basque town. Leon Golub's Interrogation III (1981), depicts a female nude, hooded detainee strapped to a chair, her legs open to reveal her sexual organs, surrounded by two tormentors dressed in everyday clothing. Andres Serrano's Piss Christ (1989) is a photograph of a crucifix, sacred to the Christian religion and representing Christ's sacrifice and final suffering, submerged in a glass of the artist's own urine. The resulting uproar led to comments in the United States Senate about public funding of the arts.
Theory
Before Modernism, aesthetics in Western art was greatly concerned with achieving the appropriate balance between different aspects of realism or truth to nature and the ideal; ideas as to what the appropriate balance is have shifted to and fro over the centuries. This concern is largely absent in other traditions of art. The aesthetic theorist John Ruskin, who championed what he saw as the naturalism of J. M. W. Turner, saw art's role as the communication by artifice of an essential truth that could only be found in nature.
The definition and evaluation of art has become especially problematic since the 20th century. Richard Wollheim distinguishes three approaches to assessing the aesthetic value of art: the Realist, whereby aesthetic quality is an absolute value independent of any human view; the Objectivist, whereby it is also an absolute value, but is dependent on general human experience; and the Relativist position, whereby it is not an absolute value, but depends on, and varies with, the human experience of different humans.
Arrival of Modernism
The arrival of Modernism in the late 19th century led to a radical break in the conception of the function of art, and then again in the late 20th century with the advent of postmodernism. Clement Greenberg's 1960 article "Modernist Painting" defines modern art as "the use of characteristic methods of a discipline to criticize the discipline itself". Greenberg originally applied this idea to the Abstract Expressionist movement and used it as a way to understand and justify flat (non-illusionistic) abstract painting:
Realistic, naturalistic art had dissembled the medium, using art to conceal art; modernism used art to call attention to art. The limitations that constitute the medium of painting—the flat surface, the shape of the support, the properties of the pigment—were treated by the Old Masters as negative factors that could be acknowledged only implicitly or indirectly. Under Modernism these same limitations came to be regarded as positive factors, and were acknowledged openly. After Greenberg, several important art theorists emerged, such as Michael Fried, T. J. Clark, Rosalind Krauss, Linda Nochlin and Griselda Pollock among others. Though only originally intended as a way of understanding a specific set of artists, Greenberg's definition of modern art is important to many of the ideas of art within the various art movements of the 20th century and early 21st century.
Pop artists like Andy Warhol became both noteworthy and influential through work including and possibly critiquing popular culture, as well as the art world. Artists of the 1980s, 1990s, and 2000s expanded this technique of self-criticism beyond high art to all cultural image-making, including fashion images, comics, billboards and pornography.
Duchamp once proposed that art is any activity of any kind-everything. However, the way that only certain activities are classified today as art is a social construction. There is evidence that there may be an element of truth to this. In The Invention of Art: A Cultural History, Larry Shiner examines the construction of the modern system of the arts, i.e. fine art. He finds evidence that the older system of the arts before our modern system (fine art) held art to be any skilled human activity; for example, Ancient Greek society did not possess the term art, but techne. Techne can be understood neither as art or craft, the reason being that the distinctions of art and craft are historical products that came later on in human history. Techne included painting, sculpting and music, but also cooking, medicine, horsemanship, geometry, carpentry, prophecy, and farming, etc.
New Criticism and the "intentional fallacy"
Following Duchamp during the first half of the 20th century, a significant shift to general aesthetic theory took place which attempted to apply aesthetic theory between various forms of art, including the literary arts and the visual arts, to each other. This resulted in the rise of the New Criticism school and debate concerning the intentional fallacy. At issue was the question of whether the aesthetic intentions of the artist in creating the work of art, whatever its specific form, should be associated with the criticism and evaluation of the final product of the work of art, or, if the work of art should be evaluated on its own merits independent of the intentions of the artist.
In 1946, William K. Wimsatt and Monroe Beardsley published a classic and controversial New Critical essay entitled "The Intentional Fallacy", in which they argued strongly against the relevance of an author's intention, or "intended meaning" in the analysis of a literary work. For Wimsatt and Beardsley, the words on the page were all that mattered; importation of meanings from outside the text was considered irrelevant, and potentially distracting.
In another essay, "The Affective Fallacy", which served as a kind of sister essay to "The Intentional Fallacy" Wimsatt and Beardsley also discounted the reader's personal/emotional reaction to a literary work as a valid means of analyzing a text. This fallacy would later be repudiated by theorists from the reader-response school of literary theory. Ironically, one of the leading theorists from this school, Stanley Fish, was himself trained by New Critics. Fish criticizes Wimsatt and Beardsley in his 1970 essay "Literature in the Reader".
As summarized by Berys Gaut and Paisley Livingston in their essay "The Creation of Art": "Structuralist and post-structuralists theorists and critics were sharply critical of many aspects of New Criticism, beginning with the emphasis on aesthetic appreciation and the so-called autonomy of art, but they reiterated the attack on biographical criticisms' assumption that the artist's activities and experience were a privileged critical topic." These authors contend that: "Anti-intentionalists, such as formalists, hold that the intentions involved in the making of art are irrelevant or peripheral to correctly interpreting art. So details of the act of creating a work, though possibly of interest in themselves, have no bearing on the correct interpretation of the work."
Gaut and Livingston define the intentionalists as distinct from formalists stating that: "Intentionalists, unlike formalists, hold that reference to intentions is essential in fixing the correct interpretation of works." They quote Richard Wollheim as stating that, "The task of criticism is the reconstruction of the creative process, where the creative process must in turn be thought of as something not stopping short of, but terminating on, the work of art itself."
"Linguistic turn" and its debate
The end of the 20th century fostered an extensive debate known as the linguistic turn controversy, or the "innocent eye debate" in the philosophy of art. This debate discussed the encounter of the work of art as being determined by the relative extent to which the conceptual encounter with the work of art dominates over the perceptual encounter with the work of art.
Decisive for the linguistic turn debate in art history and the humanities were the works of yet another tradition, namely the structuralism of Ferdinand de Saussure and the ensuing movement of poststructuralism. In 1981, the artist Mark Tansey created a work of art titled The Innocent Eye as a criticism of the prevailing climate of disagreement in the philosophy of art during the closing decades of the 20th century. Influential theorists include Judith Butler, Luce Irigaray, Julia Kristeva, Michel Foucault and Jacques Derrida. The power of language, more specifically of certain rhetorical tropes, in art history and historical discourse was explored by Hayden White. The fact that language is a transparent medium of thought had been stressed by a very different form of philosophy of language which originated in the works of Johann Georg Hamann and Wilhelm von Humboldt. Ernst Gombrich and Nelson Goodman in his book Languages of Art: An Approach to a Theory of Symbols came to hold that the conceptual encounter with the work of art predominated exclusively over the perceptual and visual encounter with the work of art during the 1960s and 1970s. He was challenged on the basis of research done by the Nobel prize winning psychologist Roger Sperry who maintained that the human visual encounter was not limited to concepts represented in language alone (the linguistic turn) and that other forms of psychological representations of the work of art were equally defensible and demonstrable. Sperry's view eventually prevailed by the end of the 20th century with aesthetic philosophers such as Nick Zangwill strongly defending a return to moderate aesthetic formalism among other alternatives.
Classification disputes
Disputes as to whether or not to classify something as a work of art are referred to as classificatory disputes about art. Classificatory disputes in the 20th century have included cubist and impressionist paintings, Duchamp's Fountain, the movies, J. S. G. Boggs' superlative imitations of banknotes, conceptual art, and video games. Philosopher David Novitz has argued that disagreement about the definition of art are rarely the heart of the problem. Rather, "the passionate concerns and interests that humans vest in their social life" are "so much a part of all classificatory disputes about art." According to Novitz, classificatory disputes are more often disputes about societal values and where society is trying to go than they are about theory proper. For example, when the Daily Mail criticized Hirst's and Emin's work by arguing "For 1,000 years art has been one of our great civilising forces. Today, pickled sheep and soiled beds threaten to make barbarians of us all" they are not advancing a definition or theory about art, but questioning the value of Hirst's and Emin's work. In 1998, Arthur Danto, suggested a thought experiment showing that "the status of an artifact as work of art results from the ideas a culture applies to it, rather than its inherent physical or perceptible qualities. Cultural interpretation (an art theory of some kind) is therefore constitutive of an object's arthood."
Anti-art is a label for art that intentionally challenges the established parameters and values of art; it is a term associated with Dadaism and attributed to Marcel Duchamp just before World War I, when he was making art from found objects. One of these, Fountain (1917), an ordinary urinal, has achieved considerable prominence and influence on art. Anti-art is a feature of work by Situationist International, the lo-fi Mail art movement, and the Young British Artists, though it is a form still rejected by the Stuckists, who describe themselves as anti-anti-art.
Architecture is often included as one of the visual arts; however, like the decorative arts, or advertising, it involves the creation of objects where the practical considerations of use are essential in a way that they usually are not in a painting, for example.
Value judgment
Somewhat in relation to the above, the word art is also used to apply judgments of value, as in such expressions as "that meal was a work of art" (the cook is an artist), or "the art of deception" (the highly attained level of skill of the deceiver is praised). It is this use of the word as a measure of high quality and high value that gives the term its flavor of subjectivity. Making judgments of value requires a basis for criticism. At the simplest level, a way to determine whether the impact of the object on the senses meets the criteria to be considered art is whether it is perceived to be attractive or repulsive. Though perception is always colored by experience, and is necessarily subjective, it is commonly understood that what is not somehow aesthetically satisfying cannot be art. However, "good" art is not always or even regularly aesthetically appealing to a majority of viewers. In other words, an artist's prime motivation need not be the pursuit of the aesthetic. Also, art often depicts terrible images made for social, moral, or thought-provoking reasons. For example, Francisco Goya's painting depicting the Spanish shootings of 3 May 1808 is a graphic depiction of a firing squad executing several pleading civilians. Yet at the same time, the horrific imagery demonstrates Goya's keen artistic ability in composition and execution and produces fitting social and political outrage. Thus, the debate continues as to what mode of aesthetic satisfaction, if any, is required to define 'art'.
The assumption of new values or the rebellion against accepted notions of what is aesthetically superior need not occur concurrently with a complete abandonment of the pursuit of what is aesthetically appealing. Indeed, the reverse is often true, that the revision of what is popularly conceived of as being aesthetically appealing allows for a re-invigoration of aesthetic sensibility, and a new appreciation for the standards of art itself. Countless schools have proposed their own ways to define quality, yet they all seem to agree in at least one point: once their aesthetic choices are accepted, the value of the work of art is determined by its capacity to transcend the limits of its chosen medium to strike some universal chord by the rarity of the skill of the artist or in its accurate reflection in what is termed the zeitgeist. Art is often intended to appeal to and connect with human emotion. It can arouse aesthetic or moral feelings, and can be understood as a way of communicating these feelings. Artists express something so that their audience is aroused to some extent, but they do not have to do so consciously. Art may be considered an exploration of the human condition; that is, what it is to be human. By extension, it has been argued by Emily L. Spratt that the development of artificial intelligence, especially in regard to its uses with images, necessitates a re-evaluation of aesthetic theory in art history today and a reconsideration of the limits of human creativity.
Art and law
An essential legal issue are art forgeries, plagiarism, replicas and works that are strongly based on other works of art.
Intellectual property law plays a significant role in the art world. Copyright protection is granted to artists for their original works, providing them with exclusive rights to reproduce, distribute, and display their creations. This safeguard empowers artists to govern the usage of their work and safeguard against unauthorized copying or infringement.
The trade in works of art or the export from a country may be subject to legal regulations. Internationally there are also extensive efforts to protect the works of art created. The UN, UNESCO and Blue Shield International try to ensure effective protection at the national level and to intervene directly in the event of armed conflicts or disasters. This can particularly affect museums, archives, art collections and excavation sites. This should also secure the economic basis of a country, especially because works of art are often of tourist importance. The founding president of Blue Shield International, Karl von Habsburg, explained an additional connection between the destruction of cultural property and the cause of flight during a mission in Lebanon in April 2019: "Cultural goods are part of the identity of the people who live in a certain place. If you destroy their culture, you also destroy their identity. Many people are uprooted, often no longer have any prospects and as a result flee from their homeland." In order to preserve the diversity of cultural identity, UNESCO protects the living human treasure through the Convention for the Safeguarding of the Intangible Cultural Heritage.
See also
Artist-in-residence
Artistic freedom
Cultural tourism
Craftivism
List of art media
List of art techniques
Mathematics and art
Outline of the visual arts, a guide to the subject of art presented as a tree structured list of its subtopics.
Visual impairment in art
References
Works cited
Bibliography
Oscar Wilde, Intentions, 1891
Katharine Everett Gilbert and Helmut Kuhn, A History of Esthetics. Edition 2, revised. Indiana: Indiana University Press, 1953.
Stephen Davies, Definitions of Art, 1991
Nina Felshin, ed. But is it Art?, 1995
Catherine de Zegher (ed.). Inside the Visible. MIT Press, 1996
Evelyn Hatcher, ed. Art as Culture: An Introduction to the Anthropology of Art, 1999
Noel Carroll, Theories of Art Today, 2000
John Whitehead. Grasping for the Wind, 2001
Michael Ann Holly and Keith Moxey (eds.) Art History Aesthetics Visual Studies. New Haven: Yale University Press, 2002.
Shiner, Larry. The Invention of Art: A Cultural History. Chicago: University of Chicago Press, 2003.
Arthur Danto, The Abuse of Beauty: Aesthetics and the Concept of Art. 2003
Dana Arnold and Margaret Iversen, eds. Art and Thought. London: Blackwell, 2003.
Jean Robertson and Craig McDaniel, Themes of Contemporary Art, Visual Art after 1980, 2005
Further reading
Antony Briant and Griselda Pollock, eds. Digital and Other Virtualities: Renegotiating the image. London and NY: I.B. Tauris, 2010.
Augros, Robert M., Stanciu, George N. The New Story of Science: mind and the universe, Lake Bluff, Ill.: Regnery Gateway, 1984. (this book has significant material on art and science)
Benedetto Croce. Aesthetic as Science of Expression and General Linguistic, 2002
Botar, Oliver A.I. Technical Detours: The Early Moholy-Nagy Reconsidered. Art Gallery of The Graduate Center, The City University of New York and The Salgo Trust for Education, 2006.
Burguete, Maria, and Lam, Lui, eds. (2011). Arts: A Science Matter. World Scientific: Singapore.
Carol Armstrong and Catherine de Zegher, eds. Women Artists at the Millennium. Massachusetts: October Books/The MIT Press, 2006.
Carl Jung, Man and His Symbols. London: Pan Books, 1978.
E.H. Gombrich, The Story of Art. London: Phaidon Press, 1995.
Florian Dombois, Ute Meta Bauer, Claudia Mareis and Michael Schwab, eds. Intellectual Birdhouse. Artistic Practice as Research. London: Koening Books, 2012.
Kristine Stiles and Peter Selz, eds. Theories and Documents of Contemporary Art. Berkeley: University of California Press, 1986
Kleiner, Gardner, Mamiya and Tansey. Art Through the Ages, Twelfth Edition (2 volumes) Wadsworth, 2004. (vol 1) and (vol 2)
Richard Wollheim, Art and its Objects: An introduction to aesthetics. New York: Harper & Row, 1968.
Will Gompertz. What Are You Looking At?: 150 Years of Modern Art in the Blink of an Eye. New York: Viking, 2012.
Władysław Tatarkiewicz, A History of Six Ideas: an Essay in Aesthetics, translated from the Polish by Christopher Kasparek, The Hague, Martinus Nijhoff, 1980
External links
Art and Play from the Dictionary of the History of ideas
In-depth directory of art
Art and Artist Files in the Smithsonian Libraries Collection (2005) Smithsonian Digital Libraries
Visual Arts Data Service (VADS) – online collections from UK museums, galleries, universities
RevolutionArt – Art magazines with worldwide exhibitions, callings and competitions
Concepts in aesthetics
The arts
Visual arts |
764 | https://en.wikipedia.org/wiki/Agnostida | Agnostida | Agnostida are an order of extinct arthropods which have classically been seen as a group of highly modified trilobites, though some recent research has doubted this placement. Regardless, they appear to be close relatives as part of the Artiopoda. They are present in the Lower Cambrian fossil record along with trilobites from the Redlichiida, Corynexochida, and Ptychopariida orders, and were highly diverse throughout the Cambrian. Agnostidan diversity severely declined during the Cambrian-Ordovician transition, and the last agnostidans went extinct in the Late Ordovician.
Systematics
The Agnostida are divided into two suborders — Agnostina and Eodiscina — which are then subdivided into a number of families. As a group, agnostids are isopygous, meaning their pygidium is similar in size and shape to their cephalon. Most agnostid species were eyeless.
The systematic position of the order Agnostida within the class Trilobita remains uncertain, and there has been continuing debate whether they are trilobites or a stem group. The challenge to the status has focused on Agnostina partly due to the juveniles of one genus have been found with legs differing dramatically from those of adult trilobites, suggesting they are not members of the lamellipedian clade, of which trilobites are a part. Instead, the limbs of agnostids closely resemble those of stem group crustaceans, although they lack the proximal endite, which defines that group. The study suggested that they were likely the sister taxon to the crustacean stem lineage, and, as such, part of the clade, Crustaceomorpha. Other researchers have suggested, based on a cladistic analyses of dorsal exoskeletal features, that Eodiscina and Agnostida are closely united, and the Eodiscina descended from the trilobite order Ptychopariida. A 2019 study of adult specimens with preserved soft tissue from the Burgess Shale found that agnostidans shared morphological similarities to trilobites and other related artiopodans like nektaspids, and their placement as stem-crustaceans was unsupported. The study recovered agnostidans as the sister group to other trilobites within the Artiopoda.
Ecology
Scientists have long debated whether the agnostids lived a pelagic or a benthic lifestyle. Their lack of eyes, a morphology not well-suited for swimming, and their fossils found in association with other benthic trilobites suggest a benthic (bottom-dwelling) mode of life. They are likely to have lived on areas of the ocean floor which received little or no light and fed on detritus which descended from upper layers of the sea to the bottom. Their wide geographic dispersion in the fossil record is uncharacteristic of benthic animals, suggesting a pelagic existence. The thoracic segment appears to form a hinge between the head and pygidium allowing for a bivalved ostracodan-type lifestyle. The orientation of the thoracic appendages appears ill-suited for benthic living. Recent work suggests that some agnostids were benthic predators, engaging in cannibalism and possibly pack-hunting behavior.
They are sometimes preserved within the voids of other organisms, for instance within empty hyolith conchs, within sponges, worm tubes and under the carapaces of bivalved arthropods, presumably in order to hide from predators or strong storm currents; or maybe whilst scavenging for food. In the case of the tapering worm tubes Selkirkia, trilobites are always found with their heads directed towards the opening of the tube, suggesting that they reversed in; the absence of any moulted carapaces suggests that moulting was not their primary reason for seeking shelter.
References
External links
Order Agnostida by Sam Gon III.
The Virtual Fossil Museum – Trilobite Order Agnostida
Agnostida fact sheet by Sam Gon III.
"Earth's Early Cannibals Caught in the Act", by Larry O'Hanlon, news.discovery.com.
Trilobite orders
Cambrian trilobites
Ordovician trilobites
Fossil taxa described in 1864
Cambrian first appearances
Late Ordovician extinctions
Taxa named by John William Salter |
766 | https://en.wikipedia.org/wiki/Abstract%20%28law%29 | Abstract (law) | In law, an abstract is a brief statement that contains the most important points of a long legal document or of several related legal papers.
Types of legislation
The abstract of title, used in real estate transactions, is the more common form of abstract. An abstract of title lists all the owners of a piece of land, a house, or a building before it came into possession of the present owner. The abstract also records all deeds, wills, mortgages, and other documents that affect ownership of the property. An abstract describes a chain of transfers from owner to owner and any agreements by former owners that are binding on later owners.
Patent law
In the context of patent law and specifically in prior art searches, searching through abstracts is a common way to find relevant prior art document to question to novelty or inventive step (or non-obviousness in United States patent law) of an invention. Under United States patent law, the abstract may be called "Abstract of the Disclosure".
References
External links
, defining the requirements regarding the abstract in an international application filed under Patent Cooperation Treaty (PCT)
and (previously ), defining the abstract-related requirements in a European patent application
Legal research |
772 | https://en.wikipedia.org/wiki/Ampere | Ampere | The ampere ( , ; symbol: A), often shortened to amp, is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 coulomb (C) moving past a point per second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagnetism along with Danish physicist Hans Christian Ørsted.
As of the 2019 redefinition of the SI base units, the ampere is defined by fixing the elementary charge to be exactly , which means an ampere is an electric current equivalent to elementary charges moving every seconds or elementary charges moving in a second. Prior to the redefinition the ampere was defined as the current passing through two parallel wires 1 metre apart that produces a magnetic force of newtons per metre.
The earlier CGS system has two units of current, one structured similarly to the SI's and the other using Coulomb's law as a fundamental relationship, with the CGS unit of charge defined by measuring the force between two charged metal plates. The CGS unit of current is then defined as one unit of charge per second.
History
The ampere is named for French physicist and mathematician André-Marie Ampère (1775–1836), who studied electromagnetism and laid the foundation of electrodynamics. In recognition of Ampère's contributions to the creation of modern electrical science, an international convention, signed at the 1881 International Exposition of Electricity, established the ampere as a standard unit of electrical measurement for electric current.
The ampere was originally defined as one tenth of the unit of electric current in the centimetre–gram–second system of units. That unit, now known as the abampere, was defined as the amount of current that generates a force of two dynes per centimetre of length between two wires one centimetre apart. The size of the unit was chosen so that the units derived from it in the MKSA system would be conveniently sized.
The "international ampere" was an early realization of the ampere, defined as the current that would deposit of silver per second from a silver nitrate solution. Later, more accurate measurements revealed that this current is .
Since power is defined as the product of current and voltage, the ampere can alternatively be expressed in terms of the other units using the relationship , and thus 1 A = 1 W/V. Current can be measured by a multimeter, a device that can measure electrical voltage, current, and resistance.
Former definition in the SI
Until 2019, the SI defined the ampere as follows:
The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed one metre apart in vacuum, would produce between these conductors a force equal to newtons per metre of length.
Ampère's force law states that there is an attractive or repulsive force between two parallel wires carrying an electric current. This force is used in the formal definition of the ampere.
The SI unit of charge, the coulomb, was then defined as "the quantity of electricity carried in 1 second by a current of 1 ampere". Conversely, a current of one ampere is one coulomb of charge going past a given point per second:
In general, charge was determined by steady current flowing for a time as .
This definition of the ampere was most accurately realised using a Kibble balance, but in practice the unit was maintained via Ohm's law from the units of electromotive force and resistance, the volt and the ohm, since the latter two could be tied to physical phenomena that are relatively easy to reproduce, the Josephson effect and the quantum Hall effect, respectively.
Techniques to establish the realisation of an ampere had a relative uncertainty of approximately a few parts in 10, and involved realisations of the watt, the ohm and the volt.
Present definition
The 2019 redefinition of the SI base units defined the ampere by taking the fixed numerical value of the elementary charge to be when expressed in the unit C, which is equal to A⋅s, where the second is defined in terms of , the unperturbed ground state hyperfine transition frequency of the caesium-133 atom.
The SI unit of charge, the coulomb, "is the quantity of electricity carried in 1 second by a current of 1 ampere". Conversely, a current of one ampere is one coulomb of charge going past a given point per second:
In general, charge is determined by steady current flowing for a time as .
Constant, instantaneous and average current are expressed in amperes (as in "the charging current is 1.2 A") and the charge accumulated (or passed through a circuit) over a period of time is expressed in coulombs (as in "the battery charge is "). The relation of the ampere (C/s) to the coulomb is the same as that of the watt (J/s) to the joule.
Units derived from the ampere
The international system of units (SI) is based on seven SI base units the second, metre, kilogram, kelvin, ampere, mole, and candela representing seven fundamental types of physical quantity, or "dimensions", (time, length, mass, temperature, electric current, amount of substance, and luminous intensity respectively) with all other SI units being defined using these. These SI derived units can either be given special names e.g. watt, volt, lux, etc. or defined in terms of others, e.g. metre per second. The units with special names derived from the ampere are:
There are also some SI units that are frequently used in the context of electrical engineering and electrical appliances, but are defined independently of the ampere, notably the hertz, joule, watt, candela, lumen, and lux.
SI prefixes
Like other SI units, the ampere can be modified by adding a prefix that multiplies it by a power of 10.
See also
Ammeter
Ampacity (current-carrying capacity)
Electric current
Electric shock
Hydraulic analogy
Magnetic constant
Orders of magnitude (current)
References
External links
The NIST Reference on Constants, Units, and Uncertainty
NIST Definition of ampere and μ0
SI base units
Units of electric current |
775 | https://en.wikipedia.org/wiki/Algorithm | Algorithm | In mathematics and computer science, an algorithm () is a finite sequence of mathematically rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing calculations and data processing. More advanced algorithms can use conditionals to divert the code execution through various routes (referred to as automated decision-making) and deduce valid inferences (referred to as automated reasoning), achieving automation eventually. Using human characteristics as descriptors of machines in metaphorical ways was already practiced by Alan Turing with terms such as "memory", "search" and "stimulus".
In contrast, a heuristic is an approach to problem solving that may not be fully specified or may not guarantee correct or optimal results, especially in problem domains where there is no well-defined correct or optimal result. For example, social media recommender systems rely on heuristics in such a way that, although widely characterized as "algorithms" in 21st century popular media, cannot deliver correct results due to the nature of the problem.
As an effective method, an algorithm can be expressed within a finite amount of space and time and in a well-defined formal language for calculating a function. Starting from an initial state and initial input (perhaps empty), the instructions describe a computation that, when executed, proceeds through a finite number of well-defined successive states, eventually producing "output" and terminating at a final ending state. The transition from one state to the next is not necessarily deterministic; some algorithms, known as randomized algorithms, incorporate random input.
Etymology
Around 825 AD, Persian scientist and polymath Muḥammad ibn Mūsā al-Khwārizmī wrote kitāb al-ḥisāb al-hindī ("Book of Indian computation") and kitab al-jam' wa'l-tafriq al-ḥisāb al-hindī ("Addition and subtraction in Indian arithmetic"). Both of these texts are lost in the original Arabic at this time. However, his other book on algebra remains.
In the early 12th century, Latin translations of said al-Khwarizmi texts involving the Hindu–Arabic numeral system and arithmetic appeared: Liber Alghoarismi de practica arismetrice (attributed to John of Seville) and Liber Algorismi de numero Indorum (attributed to Adelard of Bath). Hereby, alghoarismi or algorismi is the Latinization of Al-Khwarizmi's name; the text starts with the phrase Dixit Algorismi ("Thus spoke Al-Khwarizmi").
Around 1230, the English word algorism is attested and then by Chaucer in 1391, English adopted the French term. In the 15th century, under the influence of the Greek word ἀριθμός (arithmos, "number"; cf. "arithmetic"), the Latin word was altered to algorithmus.
Definition
One informal definition is "a set of rules that precisely defines a sequence of operations", which would include all computer programs (including programs that do not perform numeric calculations), and (for example) any prescribed bureaucratic procedure
or cook-book recipe. In general, a program is an algorithm only if it stops eventually—even though infinite loops may sometimes prove desirable. define an algorithm to be a set of instructions for determining an output, given explicitly, in a form that can be followed by either a computing machine, or a human who could only carry out specific elementary operations on symbols.
The concept of algorithm is also used to define the notion of decidability—a notion that is central for explaining how formal systems come into being starting from a small set of axioms and rules. In logic, the time that an algorithm requires to complete cannot be measured, as it is not apparently related to the customary physical dimension. From such uncertainties, that characterize ongoing work, stems the unavailability of a definition of algorithm that suits both concrete (in some sense) and abstract usage of the term.
Most algorithms are intended to be implemented as computer programs. However, algorithms are also implemented by other means, such as in a biological neural network (for example, the human brain implementing arithmetic or an insect looking for food), in an electrical circuit, or in a mechanical device.
History
Ancient algorithms
Since antiquity, step-by-step procedures for solving mathematical problems have been attested. This includes Babylonian mathematics (around 2500 BC), Egyptian mathematics (around 1550 BC), Indian mathematics (around 800 BC and later; e.g. Shulba Sutras, Kerala School, and Brāhmasphuṭasiddhānta), The Ifa Oracle (around 500 BC), Greek mathematics (around 240 BC, e.g. sieve of Eratosthenes and Euclidean algorithm), and Arabic mathematics (9th century, e.g. cryptographic algorithms for code-breaking based on frequency analysis). The first cryptographic algorithm for deciphering encrypted code was developed by Al-Kindi, a 9th-century Arab mathematician, in A Manuscript On Deciphering Cryptographic Messages. He gave the first description of cryptanalysis by frequency analysis, the earliest codebreaking algorithm.
Ancient Near East
The earliest evidence of algorithms is found in the Babylonian mathematics of ancient Mesopotamia (modern Iraq). A Sumerian clay tablet found in Shuruppak near Baghdad and dated to described the earliest division algorithm. During the Hammurabi dynasty , Babylonian clay tablets described algorithms for computing formulas. Algorithms were also used in Babylonian astronomy. Babylonian clay tablets describe and employ algorithmic procedures to compute the time and place of significant astronomical events.
Algorithms for arithmetic are also found in ancient Egyptian mathematics, dating back to the Rhind Mathematical Papyrus . Algorithms were later used in ancient Hellenistic mathematics. Two examples are the Sieve of Eratosthenes, which was described in the Introduction to Arithmetic by Nicomachus, and the Euclidean algorithm, which was first described in Euclid's Elements ().
Computers
Weight-driven clocks
Bolter credits the invention of the weight-driven clock as "The key invention [of Europe in the Middle Ages]", in particular, the verge escapement that provides us with the tick and tock of a mechanical clock. "The accurate automatic machine" led immediately to "mechanical automata" beginning in the 13th century and finally to "computational machines"—the difference engine and analytical engines of Charles Babbage and Countess Ada Lovelace, mid-19th century. Lovelace is credited with the first creation of an algorithm intended for processing on a computer—Babbage's analytical engine, the first device considered a real Turing-complete computer instead of just a calculator—and is sometimes called "history's first programmer" as a result, though a full implementation of Babbage's second device would not be realized until decades after her lifetime.
Electromechanical relay
Bell and Newell (1971) indicate that the Jacquard loom (1801), precursor to Hollerith cards (punch cards, 1887), and "telephone switching technologies" were the roots of a tree leading to the development of the first computers. By the mid-19th century the telegraph, the precursor of the telephone, was in use throughout the world, its discrete and distinguishable encoding of letters as "dots and dashes" a common sound. By the late 19th century, the ticker tape () was in use, as was the use of Hollerith cards in the 1890 U.S. census. Then came the teleprinter () with its punched-paper use of Baudot code on tape.
Telephone-switching networks of electromechanical relays (invented 1835) was behind the work of George Stibitz (1937), the inventor of the digital adding device. As he worked in Bell Laboratories, he observed the "burdensome' use of mechanical calculators with gears. "He went home one evening in 1937 intending to test his idea... When the tinkering was over, Stibitz had constructed a binary adding device". The mathematician Martin Davis supported the particular importance of the electromechanical relay.
Formalization
In 1928, a partial formalization of the modern concept of algorithms began with attempts to solve the Entscheidungsproblem (decision problem) posed by David Hilbert. Later formalizations were framed as attempts to define "effective calculability" or "effective method". Those formalizations included the Gödel–Herbrand–Kleene recursive functions of 1930, 1934 and 1935, Alonzo Church's lambda calculus of 1936, Emil Post's Formulation 1 of 1936, and Alan Turing's Turing machines of 1936–37 and 1939.
Representations
Algorithms can be expressed in many kinds of notation, including natural languages, pseudocode, flowcharts, drakon-charts, programming languages or control tables (processed by interpreters). Natural language expressions of algorithms tend to be verbose and ambiguous and are rarely used for complex or technical algorithms. Pseudocode, flowcharts, drakon-charts and control tables are structured ways to express algorithms that avoid many of the ambiguities common in statements based on natural language. Programming languages are primarily intended for expressing algorithms in a form that can be executed by a computer, but they are also often used as a way to define or document algorithms.
Turing machines
There is a wide variety of representations possible and one can express a given Turing machine program as a sequence of machine tables (see finite-state machine, state-transition table and control table for more), as flowcharts and drakon-charts (see state diagram for more), or as a form of rudimentary machine code or assembly code called "sets of quadruples" (see Turing machine for more). Representations of algorithms can also be classified into three accepted levels of Turing machine description: high level description, implementation description, and formal description. A high level description describes qualities of the algorithm itself, ignoring how it is implemented on the Turing machine. An implementation description describes the general manner in which the machine moves its head and stores data in order to carry out the algorithm, but doesn't give exact states. In the most detail, a formal description gives the exact state table and list of transitions of the Turing machine.
Flowchart representation
The graphical aid called a flowchart offers a way to describe and document an algorithm (and a computer program corresponding to it). Like the program flow of a Minsky machine, a flowchart always starts at the top of a page and proceeds down. Its primary symbols are only four: the directed arrow showing program flow, the rectangle (SEQUENCE, GOTO), the diamond (IF-THEN-ELSE), and the dot (OR-tie). The Böhm–Jacopini canonical structures are made of these primitive shapes. Sub-structures can "nest" in rectangles, but only if a single exit occurs from the superstructure. The symbols and their use to build the canonical structures are shown in the diagram.
Algorithmic analysis
It is frequently important to know how much of a particular resource (such as time or storage) is theoretically required for a given algorithm. Methods have been developed for the analysis of algorithms to obtain such quantitative answers (estimates); for example, an algorithm which adds up the elements of a list of n numbers would have a time requirement of , using big O notation. At all times the algorithm only needs to remember two values: the sum of all the elements so far, and its current position in the input list. Therefore, it is said to have a space requirement of , if the space required to store the input numbers is not counted, or if it is counted.
Different algorithms may complete the same task with a different set of instructions in less or more time, space, or 'effort' than others. For example, a binary search algorithm (with cost ) outperforms a sequential search (cost ) when used for table lookups on sorted lists or arrays.
Formal versus empirical
The analysis, and study of algorithms is a discipline of computer science, and is often practiced abstractly without the use of a specific programming language or implementation. In this sense, algorithm analysis resembles other mathematical disciplines in that it focuses on the underlying properties of the algorithm and not on the specifics of any particular implementation. Usually, pseudocode is used for analysis as it is the simplest and most general representation. However, ultimately, most algorithms are usually implemented on particular hardware/software platforms and their algorithmic efficiency is eventually put to the test using real code. For the solution of a "one off" problem, the efficiency of a particular algorithm may not have significant consequences (unless n is extremely large) but for algorithms designed for fast interactive, commercial or long life scientific usage it may be critical. Scaling from small n to large n frequently exposes inefficient algorithms that are otherwise benign.
Empirical testing is useful because it may uncover unexpected interactions that affect performance. Benchmarks may be used to compare before/after potential improvements to an algorithm after program optimization.
Empirical tests cannot replace formal analysis, though, and are not trivial to perform in a fair manner.
Execution efficiency
To illustrate the potential improvements possible even in well-established algorithms, a recent significant innovation, relating to FFT algorithms (used heavily in the field of image processing), can decrease processing time up to 1,000 times for applications like medical imaging. In general, speed improvements depend on special properties of the problem, which are very common in practical applications. Speedups of this magnitude enable computing devices that make extensive use of image processing (like digital cameras and medical equipment) to consume less power.
Design
Algorithm design refers to a method or a mathematical process for problem-solving and engineering algorithms. The design of algorithms is part of many solution theories, such as divide-and-conquer or dynamic programming within operation research. Techniques for designing and implementing algorithm designs are also called algorithm design patterns, with examples including the template method pattern and the decorator pattern. One of the most important aspects of algorithm design is resource (run-time, memory usage) efficiency; the big O notation is used to describe e.g., an algorithm's run-time growth as the size of its input increases.
Structured programming
Per the Church–Turing thesis, any algorithm can be computed by a model known to be Turing complete. In fact, it has been demonstrated that Turing completeness requires only four instruction types—conditional GOTO, unconditional GOTO, assignment, HALT. However, Kemeny and Kurtz observe that, while "undisciplined" use of unconditional GOTOs and conditional IF-THEN GOTOs can result in "spaghetti code", a programmer can write structured programs using only these instructions; on the other hand "it is also possible, and not too hard, to write badly structured programs in a structured language". Tausworthe augments the three Böhm-Jacopini canonical structures: SEQUENCE, IF-THEN-ELSE, and WHILE-DO, with two more: DO-WHILE and CASE. An additional benefit of a structured program is that it lends itself to proofs of correctness using mathematical induction.
Classification
There are various ways to classify algorithms, each with its own merits.
By implementation
One way to classify algorithms is by implementation means.
Recursion
A recursive algorithm is one that invokes (makes reference to) itself repeatedly until a certain condition (also known as termination condition) matches, which is a method common to functional programming. Iterative algorithms use repetitive constructs like loops and sometimes additional data structures like stacks to solve the given problems. Some problems are naturally suited for one implementation or the other. For example, towers of Hanoi is well understood using recursive implementation. Every recursive version has an equivalent (but possibly more or less complex) iterative version, and vice versa.
Serial, parallel or distributed
Algorithms are usually discussed with the assumption that computers execute one instruction of an algorithm at a time. Those computers are sometimes called serial computers. An algorithm designed for such an environment is called a serial algorithm, as opposed to parallel algorithms or distributed algorithms. Parallel algorithms are algorithms that take advantage of computer architectures where multiple processors can work on a problem at the same time. Distributed algorithms are algorithms that use multiple machines connected with a computer network. Parallel and distributed algorithms divide the problem into more symmetrical or asymmetrical subproblems and collect the results back together. For example, a CPU would be an example of a parallel algorithm. The resource consumption in such algorithms is not only processor cycles on each processor but also the communication overhead between the processors. Some sorting algorithms can be parallelized efficiently, but their communication overhead is expensive. Iterative algorithms are generally parallelizable, but some problems have no parallel algorithms and are called inherently serial problems.
Deterministic or non-deterministic
Deterministic algorithms solve the problem with exact decision at every step of the algorithm whereas non-deterministic algorithms solve problems via guessing although typical guesses are made more accurate through the use of heuristics.
Exact or approximate
While many algorithms reach an exact solution, approximation algorithms seek an approximation that is closer to the true solution. The approximation can be reached by either using a deterministic or a random strategy. Such algorithms have practical value for many hard problems. One of the examples of an approximate algorithm is the Knapsack problem, where there is a set of given items. Its goal is to pack the knapsack to get the maximum total value. Each item has some weight and some value. Total weight that can be carried is no more than some fixed number X. So, the solution must consider weights of items as well as their value.
Quantum algorithm
Quantum algorithms run on a realistic model of quantum computation. The term is usually used for those algorithms which seem inherently quantum, or use some essential feature of Quantum computing such as quantum superposition or quantum entanglement.
By design paradigm
Another way of classifying algorithms is by their design methodology or paradigm. There is a certain number of paradigms, each different from the other. Furthermore, each of these categories includes many different types of algorithms. Some common paradigms are:
Brute-force or exhaustive search
Brute force is a method of problem-solving that involves systematically trying every possible option until the optimal solution is found. This approach can be very time consuming, as it requires going through every possible combination of variables. However, it is often used when other methods are not available or too complex. Brute force can be used to solve a variety of problems, including finding the shortest path between two points and cracking passwords.
Divide and conquer
A divide-and-conquer algorithm repeatedly reduces an instance of a problem to one or more smaller instances of the same problem (usually recursively) until the instances are small enough to solve easily. One such example of divide and conquer is merge sorting. Sorting can be done on each segment of data after dividing data into segments and sorting of entire data can be obtained in the conquer phase by merging the segments. A simpler variant of divide and conquer is called a decrease-and-conquer algorithm, which solves an identical subproblem and uses the solution of this subproblem to solve the bigger problem. Divide and conquer divides the problem into multiple subproblems and so the conquer stage is more complex than decrease and conquer algorithms. An example of a decrease and conquer algorithm is the binary search algorithm.
Search and enumeration
Many problems (such as playing chess) can be modeled as problems on graphs. A graph exploration algorithm specifies rules for moving around a graph and is useful for such problems. This category also includes search algorithms, branch and bound enumeration and backtracking.
Randomized algorithm
Such algorithms make some choices randomly (or pseudo-randomly). They can be very useful in finding approximate solutions for problems where finding exact solutions can be impractical (see heuristic method below). For some of these problems, it is known that the fastest approximations must involve some randomness. Whether randomized algorithms with polynomial time complexity can be the fastest algorithm for some problems is an open question known as the P versus NP problem. There are two large classes of such algorithms:
Monte Carlo algorithms return a correct answer with high-probability. E.g. RP is the subclass of these that run in polynomial time.
Las Vegas algorithms always return the correct answer, but their running time is only probabilistically bound, e.g. ZPP.
Reduction of complexity
This technique involves solving a difficult problem by transforming it into a better-known problem for which we have (hopefully) asymptotically optimal algorithms. The goal is to find a reducing algorithm whose complexity is not dominated by the resulting reduced algorithm's. For example, one selection algorithm for finding the median in an unsorted list involves first sorting the list (the expensive portion) and then pulling out the middle element in the sorted list (the cheap portion). This technique is also known as transform and conquer.
Back tracking
In this approach, multiple solutions are built incrementally and abandoned when it is determined that they cannot lead to a valid full solution.
Optimization problems
For optimization problems there is a more specific classification of algorithms; an algorithm for such problems may fall into one or more of the general categories described above as well as into one of the following:
Linear programming
When searching for optimal solutions to a linear function bound to linear equality and inequality constraints, the constraints of the problem can be used directly in producing the optimal solutions. There are algorithms that can solve any problem in this category, such as the popular simplex algorithm. Problems that can be solved with linear programming include the maximum flow problem for directed graphs. If a problem additionally requires that one or more of the unknowns must be an integer then it is classified in integer programming. A linear programming algorithm can solve such a problem if it can be proved that all restrictions for integer values are superficial, i.e., the solutions satisfy these restrictions anyway. In the general case, a specialized algorithm or an algorithm that finds approximate solutions is used, depending on the difficulty of the problem.
Dynamic programming
When a problem shows optimal substructures—meaning the optimal solution to a problem can be constructed from optimal solutions to subproblems—and overlapping subproblems, meaning the same subproblems are used to solve many different problem instances, a quicker approach called dynamic programming avoids recomputing solutions that have already been computed. For example, Floyd–Warshall algorithm, the shortest path to a goal from a vertex in a weighted graph can be found by using the shortest path to the goal from all adjacent vertices. Dynamic programming and memoization go together. The main difference between dynamic programming and divide and conquer is that subproblems are more or less independent in divide and conquer, whereas subproblems overlap in dynamic programming. The difference between dynamic programming and straightforward recursion is in caching or memoization of recursive calls. When subproblems are independent and there is no repetition, memoization does not help; hence dynamic programming is not a solution for all complex problems. By using memoization or maintaining a table of subproblems already solved, dynamic programming reduces the exponential nature of many problems to polynomial complexity.
The greedy method
A greedy algorithm is similar to a dynamic programming algorithm in that it works by examining substructures, in this case not of the problem but of a given solution. Such algorithms start with some solution, which may be given or have been constructed in some way, and improve it by making small modifications. For some problems they can find the optimal solution while for others they stop at local optima, that is, at solutions that cannot be improved by the algorithm but are not optimum. The most popular use of greedy algorithms is for finding the minimal spanning tree where finding the optimal solution is possible with this method. Huffman Tree, Kruskal, Prim, Sollin are greedy algorithms that can solve this optimization problem.
The heuristic method
In optimization problems, heuristic algorithms can be used to find a solution close to the optimal solution in cases where finding the optimal solution is impractical. These algorithms work by getting closer and closer to the optimal solution as they progress. In principle, if run for an infinite amount of time, they will find the optimal solution. Their merit is that they can find a solution very close to the optimal solution in a relatively short time. Such algorithms include local search, tabu search, simulated annealing, and genetic algorithms. Some of them, like simulated annealing, are non-deterministic algorithms while others, like tabu search, are deterministic. When a bound on the error of the non-optimal solution is known, the algorithm is further categorized as an approximation algorithm.
Legal status
Algorithms, by themselves, are not usually patentable. In the United States, a claim consisting solely of simple manipulations of abstract concepts, numbers, or signals does not constitute "processes" (USPTO 2006), so algorithms are not patentable (as in Gottschalk v. Benson). However practical applications of algorithms are sometimes patentable. For example, in Diamond v. Diehr, the application of a simple feedback algorithm to aid in the curing of synthetic rubber was deemed patentable. The patenting of software is controversial, and there are criticized patents involving algorithms, especially data compression algorithms, such as Unisys's LZW patent. Additionally, some cryptographic algorithms have export restrictions (see export of cryptography).
Examples
One of the simplest algorithms is to find the largest number in a list of numbers of random order. Finding the solution requires looking at every number in the list. From this follows a simple algorithm, which can be stated in a high-level description in English prose, as:
High-level description:
If there are no numbers in the set, then there is no highest number.
Assume the first number in the set is the largest number in the set.
For each remaining number in the set: if this number is larger than the current largest number, consider this number to be the largest number in the set.
When there are no numbers left in the set to iterate over, consider the current largest number to be the largest number of the set.
(Quasi-)formal description:
Written in prose but much closer to the high-level language of a computer program, the following is the more formal coding of the algorithm in pseudocode or pidgin code:
Input: A list of numbers L.
Output: The largest number in the list L.
if L.size = 0 return null
largest ← L[0]
for each item in L, do
if item > largest, then
largest ← item
return largest
See also
Abstract machine
ALGOL
Algorithm aversion
Algorithm engineering
Algorithm characterizations
Algorithmic bias
Algorithmic composition
Algorithmic entities
Algorithmic synthesis
Algorithmic technique
Algorithmic topology
Garbage in, garbage out
Introduction to Algorithms (textbook)
Government by algorithm
List of algorithms
List of algorithm general topics
Regulation of algorithms
Theory of computation
Computability theory
Computational complexity theory
Computational mathematics
Notes
Bibliography
Bell, C. Gordon and Newell, Allen (1971), Computer Structures: Readings and Examples, McGraw–Hill Book Company, New York. .
Includes a bibliography of 56 references.
,
: cf. Chapter 3 Turing machines where they discuss "certain enumerable sets not effectively (mechanically) enumerable".
Campagnolo, M.L., Moore, C., and Costa, J.F. (2000) An analog characterization of the subrecursive functions. In Proc. of the 4th Conference on Real Numbers and Computers, Odense University, pp. 91–109
Reprinted in The Undecidable, p. 89ff. The first expression of "Church's Thesis". See in particular page 100 (The Undecidable) where he defines the notion of "effective calculability" in terms of "an algorithm", and he uses the word "terminates", etc.
Reprinted in The Undecidable, p. 110ff. Church shows that the Entscheidungsproblem is unsolvable in about 3 pages of text and 3 pages of footnotes.
Davis gives commentary before each article. Papers of Gödel, Alonzo Church, Turing, Rosser, Kleene, and Emil Post are included; those cited in the article are listed here by author's name.
Davis offers concise biographies of Leibniz, Boole, Frege, Cantor, Hilbert, Gödel and Turing with von Neumann as the show-stealing villain. Very brief bios of Joseph-Marie Jacquard, Babbage, Ada Lovelace, Claude Shannon, Howard Aiken, etc.
,
Yuri Gurevich, Sequential Abstract State Machines Capture Sequential Algorithms, ACM Transactions on Computational Logic, Vol 1, no 1 (July 2000), pp. 77–111. Includes bibliography of 33 sources.
, 3rd edition 1976[?], (pbk.)
, . Cf. Chapter "The Spirit of Truth" for a history leading to, and a discussion of, his proof.
Presented to the American Mathematical Society, September 1935. Reprinted in The Undecidable, p. 237ff. Kleene's definition of "general recursion" (known now as mu-recursion) was used by Church in his 1935 paper An Unsolvable Problem of Elementary Number Theory that proved the "decision problem" to be "undecidable" (i.e., a negative result).
Reprinted in The Undecidable, p. 255ff. Kleene refined his definition of "general recursion" and proceeded in his chapter "12. Algorithmic theories" to posit "Thesis I" (p. 274); he would later repeat this thesis (in Kleene 1952:300) and name it "Church's Thesis"(Kleene 1952:317) (i.e., the Church thesis).
Kosovsky, N.K. Elements of Mathematical Logic and its Application to the theory of Subrecursive Algorithms, LSU Publ., Leningrad, 1981
A.A. Markov (1954) Theory of algorithms. [Translated by Jacques J. Schorr-Kon and PST staff] Imprint Moscow, Academy of Sciences of the USSR, 1954 [i.e., Jerusalem, Israel Program for Scientific Translations, 1961; available from the Office of Technical Services, U.S. Dept. of Commerce, Washington] Description 444 p. 28 cm. Added t.p. in Russian Translation of Works of the Mathematical Institute, Academy of Sciences of the USSR, v. 42. Original title: Teoriya algerifmov. [QA248.M2943 Dartmouth College library. U.S. Dept. of Commerce, Office of Technical Services, number OTS .]
Minsky expands his "...idea of an algorithm – an effective procedure..." in chapter 5.1 Computability, Effective Procedures and Algorithms. Infinite machines.
Reprinted in The Undecidable, pp. 289ff. Post defines a simple algorithmic-like process of a man writing marks or erasing marks and going from box to box and eventually halting, as he follows a list of simple instructions. This is cited by Kleene as one source of his "Thesis I", the so-called Church–Turing thesis.
Reprinted in The Undecidable, p. 223ff. Herein is Rosser's famous definition of "effective method": "...a method each step of which is precisely predetermined and which is certain to produce the answer in a finite number of steps... a machine which will then solve any problem of the set with no human intervention beyond inserting the question and (later) reading the answer" (p. 225–226, The Undecidable)
Cf. in particular the first chapter titled: Algorithms, Turing Machines, and Programs. His succinct informal definition: "...any sequence of instructions that can be obeyed by a robot, is called an algorithm" (p. 4).
. Corrections, ibid, vol. 43(1937) pp. 544–546. Reprinted in The Undecidable, p. 116ff. Turing's famous paper completed as a Master's dissertation while at King's College Cambridge UK.
Reprinted in The Undecidable, pp. 155ff. Turing's paper that defined "the oracle" was his PhD thesis while at Princeton.
United States Patent and Trademark Office (2006), 2106.02 **>Mathematical Algorithms: 2100 Patentability, Manual of Patent Examining Procedure (MPEP). Latest revision August 2006
Zaslavsky, C. (1970). Mathematics of the Yoruba People and of Their Neighbors in Southern Nigeria. The Two-Year College Mathematics Journal, 1(2), 76–99. https://doi.org/10.2307/3027363
Further reading
Knuth, Donald E. (2000). Selected Papers on Analysis of Algorithms . Stanford, California: Center for the Study of Language and Information.
Knuth, Donald E. (2010). Selected Papers on Design of Algorithms . Stanford, California: Center for the Study of Language and Information.
External links
Dictionary of Algorithms and Data Structures – National Institute of Standards and Technology
Algorithm repositories
The Stony Brook Algorithm Repository – State University of New York at Stony Brook
Collected Algorithms of the ACM – Associations for Computing Machinery
The Stanford GraphBase – Stanford University
Articles with example pseudocode
Mathematical logic
Theoretical computer science |
777 | https://en.wikipedia.org/wiki/Annual%20plant | Annual plant | An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, only 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are annuals. The annual life cycle has independently emerged in over 120 different plant families throughout the entire angiosperm phylogeny.
The evolutionary and ecological drivers of the annual life cycle
Traditionally, there has been a prevailing assumption that annuals have evolved from perennial ancestors. However, recent research challenges this notion, revealing instances where perennials have evolved from annual ancestors. Intriguingly, models propose that transition rates from an annual to a perennial life cycle are twice as fast as the reverse transition.
The life-history theory posits that annual plants are favored when adult mortality is higher than seedling (or seed) mortality, i.e., annuals will dominate environments with disturbances or high temporal variability, reducing adult survival. This hypothesis finds support in observations of increased prevalence of annuals in regions with hot-dry summers, with elevated adult mortality and high seed persistence. Furthermore, the evolution of the annual life cycle under hot-dry summer in different families makes it one of the best examples of convergent evolution. Additionally, annual prevalence is also positively affected by year-to-year variability.
Globally, the prevalence of annual plants shows an upward trend with an increasing human footprint. Moreover, domestic grazing has been identified as contributing to the heightened abundance of annuals in grasslands. Disturbances linked to activities like grazing and agriculture, particularly following European settlement, have facilitated the invasion of annual species from Europe and Asia into the New World.
In various ecosystems, the dominance of annual plants is often a temporary phase during secondary succession, particularly in the aftermath of disturbances. For instance, after fields are abandoned, annuals may initially colonize them but are eventually replaced by long-lived species. However, in certain Mediterranean systems, a unique scenario unfolds: when annuals establish dominance, perennials do not necessarily supplant them. This peculiarity is attributed to alternative stable states in the system—both annual dominance and perennial states prove stable, with the ultimate system state dependent on the initial conditions.
Traits of annuals and their implication for agriculture
Annual plants commonly exhibit a higher growth rate, allocate more resources to seeds, and allocate fewer resources to roots than perennials. In contrast to perennials, which feature long-lived plants and short-lived seeds, annual plants compensate for their lower longevity by maintaining a higher persistence of soil seed banks. These differences in life history strategies profoundly affect ecosystem functioning and services. For instance, annuals, by allocating less resources belowground, play a minor role in reducing erosion, storing organic carbon, and achieving lower nutrient- and water-use efficiencies than perennials.
The distinctions between annual and perennial plants are notably evident in agricultural contexts. Despite constituting a minor part of global biomass, annual species stand out as the primary food source for humankind, likely owing to their greater allocation of resources to seed production, thereby enhancing agricultural productivity. In the Anthropocene epoch, marked by human impact on the environment, there has been a substantial increase in the global cover of annuals. This shift is primarily attributed to the conversion of natural systems, often dominated by perennials, into annual cropland . Currently, annual plants cover approximately 70% of croplands and contribute to around 80% of worldwide food consumption.
Molecular genetics
In 2008, it was discovered that the inactivation of only two genes in one species of annual plant leads to its conversion into a perennial plant. Researchers deactivated the SOC1 and FUL genes (which control flowering time) of Arabidopsis thaliana. This switch established phenotypes common in perennial plants, such as wood formation.
See also
- Plant that flowers & sets seeds once, then dies.
Ephemeral plant
References
External links |
779 | https://en.wikipedia.org/wiki/Anthophyta | Anthophyta | The anthophytes are a paraphyletic grouping of plant taxa bearing flower-like reproductive structures. The group, once thought to be a clade, contained the angiosperms – the extant flowering plants, such as roses and grasses – as well as the Gnetales and the extinct Bennettitales.
Detailed morphological and molecular studies have shown that the group is not actually monophyletic, with proposed floral homologies of the gnetophytes and the angiosperms having evolved in parallel. This makes it easier to reconcile molecular clock data that suggests that the angiosperms diverged from the gymnosperms around 320-300 mya.
Some more recent studies have used the word anthophyte to describe a hypothetical group which includes the angiosperms and a variety of extinct seed plant groups (with various suggestions including at least some of the following groups: glossopterids, corystosperms, Petriellales Pentoxylales, Bennettitales and Caytoniales), but not the Gnetales.
References
Historically recognized plant taxa |
780 | https://en.wikipedia.org/wiki/Atlas%20%28disambiguation%29 | Atlas (disambiguation) | An atlas is a collection of maps.
Atlas may also refer to:
Mythology
Atlas (mythology), an Ancient Greek Titanic deity
Atlas of Atlantis, the first legendary king of Atlantis
Atlas of Mauretania, a legendary king
Places
United States
Atlas, Illinois
Atlas, Texas
Atlas, West Virginia
Atlas, Wisconsin
Atlas District, in Washington, D.C.
Atlas Peak AVA, a California wine region
Atlas Township, Michigan
Other places
Atlas Cinema, a historic movie theatre in Istanbul, Turkey
Atlas Mountains, a set of mountain ranges in northwestern Africa
Atlas, Nilüfer, a village in Bursa Province, Turkey
People with the name
Atlas (given name)
Atlas (graffiti artist)
Atlas DaBone, American wrestler and football player
Charles Atlas (1892–1972), Italian-American bodybuilder
Charles Atlas (artist)
David Atlas (born 1924), American meteorologist
James Atlas (1949-2019), American writer, editor and publisher
Meir Atlas (1848–1926), Lithuanian rabbi
Natacha Atlas (born 1964), Belgian singer
Nava Atlas, American book artist and author
Omar Atlas (born 1938), former Venezuelan professional wrestler
Scott Atlas (born 1955), American conservative health care policy advisor
Teddy Atlas (born 1956), American boxing trainer and commentator
Tony Atlas (born 1954), American wrestler and bodybuilder
Arts, entertainment, and media
Comics
Atlas (comic book series), by Dylan Horrocks
Agents of Atlas, a Marvel Comics mini-series
Atlas Comics (1950s), a publisher
Atlas/Seaboard Comics, a 1970s line of comics
Fictional characters
Atlas (DC Comics), any of several fictional characters
Atlas (Teen Titans)
Atlas, an Astro Boy (1980) character
Atlas (BioShock)
Atlas, a BattleMech in the BattleTech universe
Atlas, an antagonist in Mega Man ZX Advent
Atlas, a Portal 2 character
Atlas, a PS238 character
Erik Josten, a.k.a. Atlas, a Marvel Comics supervillain
The Atlas, a strong driving force from No Man's Sky
Literature
Atlas, a photography book by Gerhard Richter
ATLAS of Finite Groups, a group theory book
Atlas Shrugged, a novel by Ayn Rand
The Atlas (novel), by William T. Vollmann
Music
Groups
Atlas (band), a New Zealand rock band
Atlas Sound, the solo musical project of Deerhunter lead singer and guitarist Bradford Cox
Musicians
Black Atlass, a Canadian musician
Albums
Atlas (Kinky album)
Atlas (Laurel Halo album)
Atlas (Parkway Drive album)
Atlas (Real Estate album)
Atlas (RÜFÜS album)
Atlas (The Score album)
Operas
Atlas (opera), 1991, by Meredith Monk
Atlas: An Opera in Three Parts, a 1993 recording of Monk's opera
Songs
"Atlas" (Battles song), 2007
"Atlas" (Bicep song), 2020
"Atlas" (Coldplay song), 2013
"Atlas", a song by Caligula's Horse from the album The Tide, the Thief & River's End
"Atlas", by Parkway Drive
"Atlas", a song by Man Overboard from Man Overboard
"Atlas", a song by Jake Chudnow, used as the main theme in the YouTube series Mind Field
“Atlas”, a song by Coheed and Cambria
“Atlas”, a song by Good Kid
Periodicals
Atlas (magazine)
The Atlas (newspaper), published in England from 1826 to 1869
Other uses in arts, entertainment, and media
Atlas (1961 film), an action-adventure film
Atlas (2024 film), an upcoming American science fiction thriller film
Atlas (statue), iconic statue by Lee Lawrie in Rockefeller Center
Atlas, a book about flora and/or fauna of a region, such as atlases of the flora and fauna of Britain and Ireland
Atlas Entertainment, a film production company
Atlas folio, a book size
Atlas Media Corp., a non-fiction entertainment company
Atlas Press, a UK publisher
RTV Atlas, a broadcaster in Montenegro
The Atlas (video game), a 1991 multiplatform strategy video game
Atlas (video game), a massively-multiplayer online video game released for early access in 2018
Atlas Corporation, a fictional arms manufacturer in the video game series Borderlands
Atlas Corporation, a fictional private military company in the game Call of Duty: Advanced Warfare
Brands and enterprises
Atlas (appliance company), in Belarus
Atlas (restaurant), a Michelin-starred restaurant in Atlanta
Atlas Consortium, a group of technology companies
Atlas Copco, a Swedish company founded in 1873
Atlas Corporation, an investment company
Atlas Elektronik, a German naval/marine electronics and systems business
Atlas Group, a Pakistani business group
Atlas Mara Limited, formerly Atlas Mara Co-Nvest Limited, a financial holding company that owns banks in Africa
Atlas Model Railroad, American maker of model trains and accessories
Atlas Network, formerly Atlas Economic Research Foundation
Atlas Press (tool company)
Atlas Solutions, an online advertising subsidiary of Meta Platforms
Atlas Van Lines, a moving company
Atlas-Imperial, an American diesel engine manufacturer
Dresser Atlas, a provider of oilfield and factory automation services
Tele Atlas, a Dutch mapping company
Western Atlas, an oilfield services company
Atlas Powder Company, American explosives and chemicals company
Computing and technology
Atlas (computer), a 1960s supercomputer
Atlas Supervisor, its operating system
Atlas (robot)
ATLAS (software), a tool to scan American citizenship records for candidates for denaturalization
Atlas, a computer used at the Lawrence Livermore National Laboratory in 2006
Abbreviated Test Language for All Systems (ATLAS), a computer language for equipment testing
Advanced Technology Leisure Application Simulator (ATLAS), a hydraulic motion simulator used in theme parks
ASP.NET AJAX (formerly "Atlas"), a set of ASP.NET extensions
ATLAS Transformation Language, a programming language for model transformation
Atlas.ti, a qualitative analysis program
Automatically Tuned Linear Algebra Software (ATLAS)
Texture atlas, in computer graphics, a large image containing multiple smaller images
UNIVAC 1101, a 1950s American computer
Science
Astronomy
Atlas (comet) (C/2019 Y4)
Atlas (crater), on the near side of the Moon
Atlas (moon), a satellite of Saturn
Atlas (star), a triple star system in the constellation of Taurus and a member of the Pleiades
Advanced Topographic Laser Altimeter System (ATLAS), a space-based lidar instrument on ICESat-2
Asteroid Terrestrial-impact Last Alert System (ATLAS)
Mathematics
Atlas (topology), a set of charts
A set of charts which covers a manifold
A smooth structure, a maximal smooth atlas for a topological manifold
Physics
Argonne Tandem Linear Accelerator System (ATLAS), at the Argonne National Laboratory
ATLAS experiment, a particle detector for the Large Hadron Collider at CERN
Atomic-terrace low-angle shadowing (ATLAS), a nanofabrication technique
Biology and healthcare
Atlas (anatomy), a vertebra in the cervical spine
Atlas personality, the personality of someone whose childhood was characterized by excessive responsibilities
Brain atlas, a neuroanatomical map of the brain of a human or other animal
Animals and plants
Atlas bear
Atlas beetle
Atlas cedar
Atlas moth
Atlas pied flycatcher, a bird
Atlas turtle
Sport
Atlas Delmenhorst, a German association football club
Atlas F.C., a Mexican professional football club
Club Atlético Atlas, an Argentine amateur football club
KK Atlas, a former Serbian men's professional basketball club
Transport
Aerospace
Atlas (rocket family)
SM-65 Atlas intercontinental ballistic missile (ICBM)
AeroVelo Atlas, a human-powered helicopter
Airbus A400M Atlas, a military aircraft produced from 2007–present
Armstrong Whitworth Atlas, a British military aeroplane produced 1927–1933
Atlas Air, an American cargo airline
Atlas Aircraft, a 1940s aircraft manufacturer
Atlas Aircraft Corporation, a South African military aircraft manufacturer
Atlas Aviation, an aircraft maintenance firm
Atlas Blue, a Moroccan low-cost airline
Atlasjet, a Turkish airline
Birdman Atlas, an ultralight aircraft
HMLAT-303, U.S. Marine Corps helicopter training squadron
La Mouette Atlas, a French hang glider design
Automotive
Atlas (1951 automobile), a French mini-car
Atlas (light trucks), a Greek motor vehicle manufacturer
Atlas (Pittsburgh automobile), produced 1906–1907
Atlas (Springfield automobile), produced 1907–1913
Atlas, a British van by the Standard Motor Company produced 1958–1962
Atlas Drop Forge Company, a parts subsidiary of REO Motor Car Company
Atlas Motor Buggy, an American highwheeler produced in 1909
Ford Atlas, a concept pickup truck that previewed the then-new 2015 F-150
General Motors Atlas engine
Honda Atlas Cars Pakistan, a car manufacturer
Nissan Atlas, a Japanese light truck
Volkswagen Atlas, a sport utility vehicle
Geely Atlas, a sport utility vehicle
Ships and boats
Atlas Werke, a defunct German shipbuilding company
Atlas (ship), any of several merchant ships
French ship Atlas, any of several French Navy ships
HMS Atlas, any of several Royal Navy ships
ST Atlas, a Swedish tugboat
USS Atlas, any of several U.S. Navy ships
Trains
Atlas, an 1863–1885 South Devon Railway Dido class locomotive
Atlas, a 1927–1962 LMS Royal Scot Class locomotive
Atlas Car and Manufacturing Company, a locomotive manufacturer
Atlas Model Railroad
Other uses
Atlas (architecture)
ATLAS (simulation) (Army Tactical Level Advanced Simulation), a Thai military system
Atlas (storm), which hit the Midwestern United States in October 2013, named by The Weather Channel
Agrupación de Trabajadores Latinoamericanos Sindicalistas (ATLAS), a 1950s Latin American trade union confederation
Atlas languages, Berber languages spoken in the Atlas Mountains of Morocco
ATLAS Network, a network of European special police units
Atlas Uranium Mill
Atlas Corporation, a private military company by Call of Duty: Advanced Warfare
See also
Advanced Technology Large-Aperture Space Telescope (ATLAST)
Altas (disambiguation)
Atlant (disambiguation) () |
782 | https://en.wikipedia.org/wiki/Mouthwash | Mouthwash | Mouthwash, mouth rinse, oral rinse, or mouth bath is a liquid which is held in the mouth passively or swirled around the mouth by contraction of the perioral muscles and/or movement of the head, and may be gargled, where the head is tilted back and the liquid bubbled at the back of the mouth.
Usually mouthwashes are antiseptic solutions intended to reduce the microbial load in the mouth, although other mouthwashes might be given for other reasons such as for their analgesic, anti-inflammatory or anti-fungal action. Additionally, some rinses act as saliva substitutes to neutralize acid and keep the mouth moist in xerostomia (dry mouth). Cosmetic mouthrinses temporarily control or reduce bad breath and leave the mouth with a pleasant taste.
Rinsing with water or mouthwash after brushing with a fluoride toothpaste can reduce the availability of salivary fluoride. This can lower the anti-cavity re-mineralization and antibacterial effects of fluoride. Fluoridated mouthwash may mitigate this effect or in high concentrations increase available fluoride, but is not as cost-effective as leaving the fluoride toothpaste on the teeth after brushing. A group of experts discussing post brushing rinsing in 2012 found that although there was clear guidance given in many public health advice publications to "spit, avoid rinsing with water/excessive rinsing with water" they believed there was a limited evidence base for best practice.
Use
Common use involves rinsing the mouth with about 20–50 ml (2/3 fl oz) of mouthwash. The wash is typically swished or gargled for about half a minute and then spat out. Most companies suggest not drinking water immediately after using mouthwash. In some brands, the expectorate is stained, so that one can see the bacteria and debris.
Mouthwash should not be used immediately after brushing the teeth so as not to wash away the beneficial fluoride residue left from the toothpaste. Similarly, the mouth should not be rinsed out with water after brushing. Patients were told to "spit don't rinse" after toothbrushing as part of a National Health Service campaign in the UK. A fluoride mouthrinse can be used at a different time of the day to brushing.
Gargling is where the head is tilted back, allowing the mouthwash to sit in the back of the mouth while exhaling, causing the liquid to bubble. Gargling is practiced in Japan for perceived prevention of viral infection. One commonly used way is with infusions or tea. In some cultures, gargling is usually done in private, typically in a bathroom at a sink so the liquid can be rinsed away.
Dangerous misuse
If one drinks mouthwash, serious harm and even death can quickly result from the high alcohol content and other substances harmful to ingestion present in mouthwash. It is a common cause of death among homeless people during winter months, because a person can feel warmer after drinking it.
Effects
The most-commonly-used mouthwashes are commercial antiseptics, which are used at home as part of an oral hygiene routine. Mouthwashes combine ingredients to treat a variety of oral conditions. Variations are common, and mouthwash has no standard formulation, so its use and recommendation involves concerns about patient safety. Some manufacturers of mouthwash state that their antiseptic and antiplaque mouthwashes kill the bacterial plaque that causes cavities, gingivitis, and bad breath. It is, however, generally agreed that the use of mouthwash does not eliminate the need for both brushing and flossing. The American Dental Association asserts that regular brushing and proper flossing are enough in most cases, in addition to regular dental check-ups, although they approve many mouthwashes.
For many patients, however, the mechanical methods could be tedious and time-consuming, and, additionally, some local conditions may render them especially difficult. Chemotherapeutic agents, including mouthwashes, could have a key role as adjuncts to daily home care, preventing and controlling supragingival plaque, gingivitis and oral malodor.
Minor and transient side effects of mouthwashes are very common, such as taste disturbance, tooth staining, sensation of a dry mouth, etc. Alcohol-containing mouthwashes may make dry mouth and halitosis worse, as they dry out the mouth. Soreness, ulceration and redness may sometimes occur (e.g., aphthous stomatitis or allergic contact stomatitis) if the person is allergic or sensitive to mouthwash ingredients, such as preservatives, coloring, flavors and fragrances. Such effects might be reduced or eliminated by diluting the mouthwash with water, using a different mouthwash (e.g. saltwater), or foregoing mouthwash entirely.
Prescription mouthwashes are used prior to and after oral surgery procedures, such as tooth extraction, or to treat the pain associated with mucositis caused by radiation therapy or chemotherapy. They are also prescribed for aphthous ulcers, other oral ulcers, and other mouth pain. "Magic mouthwashes" are prescription mouthwashes compounded in a pharmacy from a list of ingredients specified by a doctor. Despite a lack of evidence that prescription mouthwashes are more effective in decreasing the pain of oral lesions, many patients and prescribers continue to use them. There has been only one controlled study to evaluate the efficacy of magic mouthwash; it shows no difference in efficacy between the most common magic-mouthwash formulation, on the one hand, and commercial mouthwashes (such as chlorhexidine) or a saline/baking soda solution, on the other. Current guidelines suggest that saline solution is just as effective as magic mouthwash in pain relief and in shortening the healing time of oral mucositis from cancer therapies.
History
The first known references to mouth rinsing is in Ayurveda for treatment of gingivitis. Later, in the Greek and Roman periods, mouth rinsing following mechanical cleansing became common among the upper classes, and Hippocrates recommended a mixture of salt, alum, and vinegar. The Jewish Talmud, dating back about 1,800 years, suggests a cure for gum ailments containing "dough water" and olive oil. The ancient Chinese had also gargled salt water, tea and wine as a form of mouthwash after meals, due to the antiseptic properties of those liquids.
Before Europeans came to the Americas, Native North American and Mesoamerican cultures used mouthwashes, often made from plants such as Coptis trifolia. Peoples of the Americas used salt water mouthwashes for sore throats, and other mouthwashes for problems such as teething and mouth ulcers.
Anton van Leeuwenhoek, the famous 17th century microscopist, discovered living organisms (living, because they were mobile) in deposits on the teeth (what we now call dental plaque). He also found organisms in water from the canal next to his home in Delft. He experimented with samples by adding vinegar or brandy and found that this resulted in the immediate immobilization or killing of the organisms suspended in water. Next he tried rinsing the mouth of himself and somebody else with a mouthwash containing vinegar or brandy and found that living organisms remained in the dental plaque. He concluded—correctly—that the mouthwash either did not reach, or was not present long enough, to kill the plaque organisms.
In 1892, German Richard Seifert invented mouthwash product Odol, which was produced by company founder Karl August Lingner (1861–1916) in Dresden.
That remained the state of affairs until the late 1960s when Harald Loe (at the time a professor at the Royal Dental College in Aarhus, Denmark) demonstrated that a chlorhexidine compound could prevent the build-up of dental plaque. The reason for chlorhexidine's effectiveness is that it strongly adheres to surfaces in the mouth and thus remains present in effective concentrations for many hours.
Since then commercial interest in mouthwashes has been intense and several newer products claim effectiveness in reducing the build-up in dental plaque and the associated severity of gingivitis, in addition to fighting bad breath. Many of these solutions aim to control the volatile sulfur compound–creating anaerobic bacteria that live in the mouth and excrete substances that lead to bad breath and unpleasant mouth taste. For example, the number of mouthwash variants in the United States of America has grown from 15 (1970) to 66 (1998) to 113 (2012).
Research
Research in the field of microbiotas shows that only a limited set of microbes cause tooth decay, with most of the bacteria in the human mouth being harmless. Focused attention on cavity-causing bacteria such as Streptococcus mutans has led research into new mouthwash treatments that prevent these bacteria from initially growing. While current mouthwash treatments must be used with a degree of frequency to prevent this bacteria from regrowing, future treatments could provide a viable long-term solution.
A clinical trial and laboratory studies have shown that alcohol-containing mouthwash could reduce the growth of Neisseria gonorrhoeae in the pharynx. However, subsequent trials have found that there was no difference in gonorrhoea cases among men using daily mouthwash compared to those who did not use mouthwash for 12 weeks.
Ingredients
Alcohol
Alcohol is added to mouthwash not to destroy bacteria but to act as a carrier agent for essential active ingredients such as menthol, eucalyptol and thymol, which help to penetrate plaque. Sometimes a significant amount of alcohol (up to 27% vol) is added, as a carrier for the flavor, to provide "bite". Because of the alcohol content, it is possible to fail a breathalyzer test after rinsing, although breath alcohol levels return to normal after 10 minutes. In addition, alcohol is a drying agent, which encourages bacterial activity in the mouth, releasing more malodorous volatile sulfur compounds. Therefore, alcohol-containing mouthwash may temporarily worsen halitosis in those who already have it, or, indeed, be the sole cause of halitosis in other individuals.
It is hypothesized that alcohol in mouthwashes acts as a carcinogen (cancer-inducing agent). Generally, there is no scientific consensus about this. One review stated:
The same researchers also state that the risk of acquiring oral cancer rises almost five times for users of alcohol-containing mouthwash who neither smoke nor drink (with a higher rate of increase for those who do). In addition, the authors highlight side effects from several mainstream mouthwashes that included dental erosion and accidental poisoning of children. The review garnered media attention and conflicting opinions from other researchers. Yinka Ebo of Cancer Research UK disputed the findings, concluding that "there is still not enough evidence to suggest that using mouthwash that contains alcohol will increase the risk of mouth cancer". Studies conducted in 1985, 1995, 2003, and 2012 did not support an association between alcohol-containing mouth rinses and oral cancer. Andrew Penman, chief executive of The Cancer Council New South Wales, called for further research on the matter. In a March 2009 brief, the American Dental Association said "the available evidence does not support a connection between oral cancer and alcohol-containing mouthrinse". Many newer brands of mouthwash are alcohol-free, not just in response to consumer concerns about oral cancer, but also to cater for religious groups who abstain from alcohol consumption.
Benzydamine (analgesic)
In painful oral conditions such as aphthous stomatitis, analgesic mouthrinses (e.g. benzydamine mouthwash, or "Difflam") are sometimes used to ease pain, commonly used before meals to reduce discomfort while eating.
Benzoic acid
Benzoic acid acts as a buffer.
Betamethasone
Betamethasone is sometimes used as an anti-inflammatory, corticosteroid mouthwash. It may be used for severe inflammatory conditions of the oral mucosa such as the severe forms of aphthous stomatitis.
Cetylpyridinium chloride (antiseptic, antimalodor)
Cetylpyridinium chloride containing mouthwash (e.g. 0.05%) is used in some specialized mouthwashes for halitosis. Cetylpyridinium chloride mouthwash has less anti-plaque effect than chlorhexidine and may cause staining of teeth, or sometimes an oral burning sensation or ulceration.
Chlorhexidine digluconate and hexetidine (antiseptic)
Chlorhexidine digluconate is a chemical antiseptic and is used in a 0.05–0.2% solution as a mouthwash. There is no evidence to support that higher concentrations are more effective in controlling dental plaque and gingivitis. A randomized clinical trial conducted in Rabat University in Morocco found better results in plaque inhibition when chlorohexidine with alcohol base 0.12% was used, when compared to an alcohol-free 0.1% chlorhexidine mouthrinse.
Chlorhexidine has good substantivity (the ability of a mouthwash to bind to hard and soft tissues in the mouth). It has anti-plaque action, and also some anti-fungal action. It is especially effective against Gram-negative rods. The proportion of Gram-negative rods increase as gingivitis develops, so it is also used to reduce gingivitis. It is sometimes used as an adjunct to prevent dental caries and to treat periodontal disease, although it does not penetrate into periodontal pockets well. Chlorhexidine mouthwash alone is unable to prevent plaque, so it is not a substitute for regular toothbrushing and flossing. Instead, chlorhexidine mouthwash is more effective when used as an adjunctive treatment with toothbrushing and flossing. In the short term, if toothbrushing is impossible due to pain, as may occur in primary herpetic gingivostomatitis, chlorhexidine mouthwash is used as a temporary substitute for other oral hygiene measures. It is not suited for use in acute necrotizing ulcerative gingivitis, however. Rinsing with chlorhexidine mouthwash before and after a tooth extraction may reduce the risk of a dry socket. Other uses of chlorhexidine mouthwash include prevention of oral candidiasis in immunocompromised persons, treatment of denture-related stomatitis, mucosal ulceration/erosions and oral mucosal lesions, general burning sensation and many other uses.
Chlorhexidine mouthwash is known to have minor adverse effects. Chlorhexidine binds to tannins, meaning that prolonged use in persons who consume coffee, tea or red wine is associated with extrinsic staining (i.e. removable staining) of teeth. A systematic review of commercial chlorhexidine products with anti-discoloration systems (ADSs) found that the ADSs were able to reduce tooth staining without affecting the beneficial effects of chlorhexidine. Chlorhexidine mouthwash can also cause taste disturbance or alteration. Chlorhexidine is rarely associated with other issues like overgrowth of enterobacteria in persons with leukemia, desquamation, irritation, and stomatitis of oral mucosa, salivary gland pain and swelling, and hypersensitivity reactions including anaphylaxis.
Hexetidine also has anti-plaque, analgesic, astringent and anti-malodor properties, but is considered an inferior alternative to chlorhexidine.
Chlorine dioxide
In dilute concentrations, chlorine dioxide is an ingredient that acts as an antiseptic agent in some mouthwashes.
Edible oils
In traditional Ayurvedic medicine, the use of oil mouthwashes is called "Kavala" ("oil swishing") or "Gandusha", and this practice has more recently been re-marketed by the complementary and alternative medicine industry as "oil pulling". Its promoters claim it works by "pulling out" "toxins", which are known as ama in Ayurvedic medicine, and thereby reducing inflammation. Ayurvedic literature claims that oil pulling is capable of improving oral and systemic health, including a benefit in conditions such as headaches, migraines, diabetes mellitus, asthma, and acne, as well as whitening teeth.
Oil pulling has received little study and there is little evidence to support claims made by the technique's advocates. When compared with chlorhexidine in one small study, it was found to be less effective at reducing oral bacterial load, and the other health claims of oil pulling have failed scientific verification or have not been investigated. There is a report of lipid pneumonia caused by accidental inhalation of the oil during oil pulling.
The mouth is rinsed with approximately one tablespoon of oil for 10–20 minutes then spat out. Sesame oil, coconut oil and ghee are traditionally used, but newer oils such as sunflower oil are also used.
Essential oils
Phenolic compounds and monoterpenes include essential oil constituents that have some antibacterial properties, such as eucalyptol, eugenol, hinokitiol, menthol, phenol, or thymol.
Essential oils are oils which have been extracted from plants. Mouthwashes based on essential oils could be more effective than traditional mouthcare as anti-gingival treatments. They have been found effective in reducing halitosis, and are being used in several commercial mouthwashes.
Fluoride (anticavity)
Anti-cavity mouthwashes use sodium fluoride to protect against tooth decay. Fluoride-containing mouthwashes are used as prevention for dental caries for individuals who are considered at higher risk for tooth decay, whether due to xerostomia related to salivary dysfunction or side effects of medication, to not drinking fluoridated water, or to being physically unable to care for their oral needs (brushing and flossing), and as treatment for those with dentinal hypersensitivity, gingival recession/ root exposure.
Flavoring agents and Xylitol
Flavoring agents include sweeteners such as sorbitol, sucralose, sodium saccharin, and xylitol, which stimulate salivary function due to their sweetness and taste and helps restore the mouth to a neutral level of acidity.
Xylitol rinses double as a bacterial inhibitor, and have been used as substitute for alcohol to avoid dryness of mouth associated with alcohol.
Hydrogen peroxide
Hydrogen peroxide can be used as an oxidizing mouthwash (e.g. Peroxyl, 1.5%). It kills anaerobic bacteria, and also has a mechanical cleansing action when it froths as it comes into contact with debris in mouth. It is often used in the short term to treat acute necrotising ulcerative gingivitis. Side effects can occur with prolonged use, including hypertrophy of the lingual papillae.
Lactoperoxidase (saliva substitute)
Enzymes and non-enzymatic proteins, such as lactoperoxidase, lysozyme, and lactoferrin, have been used in mouthwashes (e.g., Biotene) to reduce levels of oral bacteria, and, hence, of the acids produced by these bacteria.
Lidocaine/xylocaine
Oral lidocaine is useful for the treatment of mucositis symptoms (inflammation of mucous membranes) induced by radiation or chemotherapy. There is evidence that lidocaine anesthetic mouthwash has the potential to be systemically absorbed, when it was tested in patients with oral mucositis who underwent a bone marrow transplant.
Methyl salicylate
Methyl salicylate functions as an antiseptic, antiinflammatory, and analgesic agent, a flavoring, and a fragrance. Methyl salicylate has some anti-plaque action, but less than chlorhexidine. Methyl salicylate does not stain teeth.
Nystatin
Nystatin suspension is an antifungal ingredient used for the treatment of oral candidiasis.
Potassium oxalate
A randomized clinical trial found promising results in controlling and reducing dentine hypersensitivity when potassium oxalate mouthwash was used in conjugation with toothbrushing.
Povidone/iodine (PVP-I)
A 2005 study found that gargling three times a day with simple water or with a povidone-iodine solution was effective in preventing upper respiratory infection and decreasing the severity of symptoms if contracted. Other sources attribute the benefit to a simple placebo effect.
PVP-I in general covers "a wider virucidal spectrum, covering both enveloped and nonenveloped viruses, than the other commercially available antiseptics", which also includes the novel SARS-CoV-2 Virus.
Sanguinarine
Sanguinarine-containing mouthwashes are marketed as anti-plaque and anti-malodor treatments. Sanguinarine is a toxic alkaloid herbal extract, obtained from plants such as Sanguinaria canadensis (bloodroot), Argemone mexicana (Mexican prickly poppy), and others. However, its use is strongly associated with the development of leukoplakia (a white patch in the mouth), usually in the buccal sulcus. This type of leukoplakia has been termed "sanguinaria-associated keratosis", and more than 80% of people with leukoplakia in the vestibule of the mouth have used this substance. Upon stopping contact with the causative substance, the lesions may persist for years. Although this type of leukoplakia may show dysplasia, the potential for malignant transformation is unknown. Ironically, elements within the complementary and alternative medicine industry promote the use of sanguinaria as a therapy for cancer.
Sodium bicarbonate (baking soda)
Sodium bicarbonate is sometimes combined with salt to make a simple homemade mouthwash, indicated for any of the reasons that a saltwater mouthwash might be used. Pre-mixed mouthwashes of 1% sodium bicarbonate and 1.5% sodium chloride in aqueous solution are marketed, although pharmacists will easily be able to produce such a formulation from the base ingredients when required. Sodium bicarbonate mouthwash is sometimes used to remove viscous saliva and to aid visualization of the oral tissues during examination of the mouth.
Sodium chloride (salt)
Saline has a mechanical cleansing action and an antiseptic action, as it is a hypertonic solution in relation to bacteria, which undergo lysis. The heat of the solution produces a therapeutic increase in blood flow (hyperemia) to the surgical site, promoting healing. Hot saltwater mouthwashes also encourage the draining of pus from dental abscesses. In contrast, if heat is applied on the side of the face (e.g., hot water bottle) rather than inside the mouth, it may cause a dental abscess to drain extra-orally, which is later associated with an area of fibrosis on the face (see cutaneous sinus of dental origin).
Saltwater mouthwashes are also routinely used after oral surgery, to keep food debris out of healing wounds and to prevent infection. Some oral surgeons consider saltwater mouthwashes the mainstay of wound cleanliness after surgery. In dental extractions, hot saltwater mouthbaths should start about 24 hours after a dental extraction. The term mouth bath implies that the liquid is passively held in the mouth, rather than vigorously swilled around (which could dislodge a blood clot). Once the blood clot has stabilized, the mouthwash can be used more vigorously. These mouthwashes tend to be advised for use about 6 times per day, especially after meals (to remove food from the socket).
Sodium lauryl sulfate (foaming agent)
Sodium lauryl sulfate (SLS) is used as a foaming agent in many oral hygiene products, including many mouthwashes. Some may suggest that it is probably advisable to use mouthwash at least an hour after brushing with toothpaste when the toothpaste contains SLS, since the anionic compounds in the SLS toothpaste can deactivate cationic agents present in the mouthwash.
Sucralfate
Sucralfate is a mucosal coating agent, composed of an aluminum salt of sulfated sucrose. It is not recommended for use in the prevention of oral mucositis in head and neck cancer patients receiving radiotherapy or chemoradiation, due to a lack of efficacy found in a well-designed, randomized controlled trial.
Tetracycline (antibiotic)
Tetracycline is an antibiotic which may sometimes be used as a mouthwash in adults (it causes red staining of teeth in children). It is sometimes use for herpetiforme ulceration (an uncommon type of aphthous stomatitis), but prolonged use may lead to oral candidiasis, as the fungal population of the mouth overgrows in the absence of enough competing bacteria. Similarly, minocycline mouthwashes of 0.5% concentrations can relieve symptoms of recurrent aphthous stomatitis. Erythromycin is similar.
Tranexamic acid
A 4.8% tranexamic acid solution is sometimes used as an antifibrinolytic mouthwash to prevent bleeding during and after oral surgery in persons with coagulopathies (clotting disorders) or who are taking anticoagulants (blood thinners such as warfarin).
Triclosan
Triclosan is a non-ionic chlorinate bisphenol antiseptic found in some mouthwashes. When used in mouthwash (e.g. 0.03%), there is moderate substantivity, broad spectrum anti-bacterial action, some anti-fungal action, and significant anti-plaque effect, especially when combined with a copolymer or zinc citrate. Triclosan does not cause staining of the teeth. The safety of triclosan has been questioned.
Zinc
Astringents like zinc chloride provide a pleasant-tasting sensation and shrink tissues. Zinc, when used in combination with other antiseptic agents, can limit the buildup of tartar.
See also
Sodium fluoride/malic acid
Virucide
References
External links
Article on Bad-Breath Prevention Products – from MSNBC
Mayo Clinic Q&A on Magic Mouthwash for chemotherapy sores
American Dental Association article on mouthwash
Dentifrices
Oral hygiene
Drug delivery devices
Dosage forms |
784 | https://en.wikipedia.org/wiki/Alfred%20Korzybski | Alfred Korzybski | Alfred Habdank Skarbek Korzybski (, ; July 3, 1879 – March 1, 1950) was a Polish-American independent scholar who developed a field called general semantics, which he viewed as both distinct from, and more encompassing than, the field of semantics. He argued that human knowledge of the world is limited both by the human nervous system and the languages humans have developed, and thus no one can have direct access to reality, given that the most we can know is that which is filtered through the brain's responses to reality. His best known dictum is "The map is not the territory".
Early life and career
Born in Warsaw, Vistula Country, which was then part of the Russian Empire, Korzybski belonged to an aristocratic Polish family whose members had worked as mathematicians, scientists, and engineers for generations. He learned the Polish language at home and the Russian language in schools, and having a French and German governess, he became fluent in four languages as a child.
Korzybski studied engineering at the Warsaw University of Technology. During the First World War (1914–1918) Korzybski served as an intelligence officer in the Russian Army. After being wounded in a leg and suffering other injuries, he moved to North America in 1916 (first to Canada, then to the United States) to coordinate the shipment of artillery to Russia. He also lectured to Polish-American audiences about the conflict, promoting the sale of war bonds. After the war he decided to remain in the United States, becoming a naturalized citizen in 1940. He met Mira Edgerly, a painter of portraits on ivory, shortly after the 1918 Armistice; They married in January 1919; the marriage lasted until his death.
E. P. Dutton published Korzybski's first book, Manhood of Humanity, in 1921. In this work he proposed and explained in detail a new theory of humankind: mankind as a "time-binding" class of life (humans perform time binding by the transmission of knowledge and abstractions through time which become accreted in cultures).
In 1925 and 1926, Korzybski observed psychiatric patients at St. Elizabeth's hospital in D.C. under the supervision of William Alanson White.
General semantics
Korzybski's work culminated in the initiation of a discipline that he named general semantics (GS). This should not be confused with semantics. The basic principles of general semantics, which include time-binding, are described in the publication Science and Sanity, published in 1933. In 1938, Korzybski founded the Institute of General Semantics in Chicago. The post-World War II housing shortage in Chicago cost him the institute's building lease, so in 1946 he moved the institute to Lakeville, Connecticut, U.S., where he directed it until his death in 1950.
Korzybski maintained that humans are limited in what they know by (1) the structure of their nervous systems, and (2) the structure of their languages. Humans cannot experience the world directly, but only through their "abstractions" (nonverbal impressions or "gleanings" derived from the nervous system, and verbal indicators expressed and derived from language). These sometimes mislead us about what is the truth. Our understanding sometimes lacks similarity of structure with what is actually happening.
He sought to train our awareness of abstracting, using techniques he had derived from his study of mathematics and science. He called this awareness, this goal of his system, "consciousness of abstracting". His system included the promotion of attitudes such as "I don't know; let's see," in order that we may better discover or reflect on its realities as revealed by modern science. Another technique involved becoming inwardly and outwardly quiet, an experience he termed, "silence on the objective levels".
"To be"
Many devotees and critics of Korzybski reduced his rather complex system to a simple matter of what he said about the verb form "is" of the general verb "to be." His system, however, is based primarily on such terminology as the different "orders of abstraction," and formulations such as "consciousness of abstracting." The contention that Korzybski opposed the use of the verb "to be" would be a profound exaggeration.
He thought that certain uses of the verb "to be", called the "is of identity" and the "is of predication", were faulty in structure, e.g., a statement such as, "Elizabeth is a fool" (said of a person named "Elizabeth" who has done something that we regard as foolish). In Korzybski's system, one's assessment of Elizabeth belongs to a higher order of abstraction than Elizabeth herself. Korzybski's remedy was to deny identity; in this example, to be aware continually that "Elizabeth" is not what we call her. We find Elizabeth not in the verbal domain, the world of words, but the nonverbal domain (the two, he said, amount to different orders of abstraction). This was expressed by Korzybski's most famous premise, "the map is not the territory". Note that this premise uses the phrase "is not", a form of "to be"; this and many other examples show that he did not intend to abandon "to be" as such. In fact, he said explicitly that there were no structural problems with the verb "to be" when used as an auxiliary verb or when used to state existence or location. It was even acceptable at times to use the faulty forms of the verb "to be," as long as one was aware of their structural limitations.
Anecdotes
One day, Korzybski was giving a lecture to a group of students, and he interrupted the lesson suddenly in order to retrieve a packet of biscuits, wrapped in white paper, from his briefcase. He muttered that he just had to eat something, and he asked the students on the seats in the front row if they would also like a biscuit. A few students took a biscuit. "Nice biscuit, don't you think," said Korzybski, while he took a second one. The students were chewing vigorously. Then he tore the white paper from the biscuits, in order to reveal the original packaging. On it was a big picture of a dog's head and the words "Dog Cookies." The students looked at the package, and were shocked. Two of them wanted to vomit, put their hands in front of their mouths, and ran out of the lecture hall to the toilet. "You see," Korzybski remarked, "I have just demonstrated that people don't just eat food, but also words, and that the taste of the former is often outdone by the taste of the latter."
William Burroughs went to a Korzybski workshop in the autumn of 1939. He was 25 years old, and paid $40. His fellow students—there were 38 in all—included young Samuel I. Hayakawa (later to become a Republican member of the U.S. Senate) and Wendell Johnson (founder of the Monster Study).
Influence
Korzybski's work received positive reactions from a variety of individuals in the 1940s and 1950s. Robert A. Heinlein named a character after him in his 1940 short story "Blowups Happen", and science fiction writer A. E. van Vogt in his novel "The World of Null-A", published in 1948. On March 8, 1949, fellow science-fiction author L. Ron Hubbard wrote to Heinlein referencing Korzybski as an influence on what would become Dianetics:
Korzybski's ideas influenced philosopher Alan Watts who used his phrase "the map is not the territory" in lectures. Writer Robert Anton Wilson was also deeply influenced by Korzybski's ideas.
As reported in the third edition of Science and Sanity, in World War II the US Army used Korzybski's system to treat battle fatigue in Europe, under the supervision of Dr. Douglas M. Kelley, who went on to become the psychiatrist in charge of the Nazi war criminals at Nuremberg.
Some of the General Semantics tradition was continued by Samuel I. Hayakawa.
Publications
1921 Manhood of Humanity: The Science and Art of Human Engineering, E.P. Dutton, New York, USA
1933 Science and Sanity: An Introduction to Non-Aristotelian Systems and General Semantics, Science Press Printing Co., Lancaster, Pa., USA
See also
Alfred Korzybski Memorial Lecture
Concept and object
E-Prime
Robert Pula
Structural differential
Neuro-linguistic Programming
References
Further reading
Kodish, Bruce. 2011. Korzybski: A Biography. Pasadena, CA: Extensional Publishing. softcover, 978-09700664-28 hardcover.
Kodish, Bruce and Susan Presby Kodish. 2011. Drive Yourself Sane: Using the Uncommon Sense of General Semantics, Third Edition. Pasadena, CA: Extensional Publishing.
Alfred Korzybski, Manhood of Humanity, foreword by Edward Kasner, notes by M. Kendig, Institute of General Semantics, 1950, hardcover, 2nd edition, 391 pages, . (Copy of the first edition.)
Science and Sanity: An Introduction to Non-Aristotelian Systems and General Semantics, Alfred Korzybski, preface by Robert P. Pula, Institute of General Semantics, 1994, hardcover, 5th edition, . (Full text online.)
Alfred Korzybski, Collected Writings 1920-1950, Institute of General Semantics, 1990, hardcover,
Montagu, M. F. A. (1953). Time-binding and the concept of culture. The Scientific Monthly, Vol. 77, No. 3 (Sep., 1953), pp. 148–155.
Murray, E. (1950). In memoriam: Alfred H. Korzybski. Sociometry, Vol. 13, No. 1 (Feb., 1950), pp. 76–77.
External links
Alfred Korzybski and Gestalt Therapy Website
Australian General Semantics Society
Institute of General Semantics
Finding aid to Alfred Korzybski papers at Columbia University. Rare Book & Manuscript Library.
1879 births
1950 deaths
Writers from Warsaw
Clan Abdank
Polish emigrants to the United States
Polish engineers
20th-century Polish philosophers
Polish mathematicians
Linguists from Poland
General semantics
People from Lakeville, Connecticut |
786 | https://en.wikipedia.org/wiki/Asparagales | Asparagales | Asparagales (asparagoid lilies) is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group (APG) and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in the monocots amongst the lilioid monocots. The order has only recently been recognized in classification systems. It was first put forward by Huber in 1977 and later taken up in the Dahlgren system of 1985 and then the APG in 1998, 2003 and 2009. Before this, many of its families were assigned to the old order Liliales, a very large order containing almost all monocots with colorful tepals and lacking starch in their endosperm. DNA sequence analysis indicated that many of the taxa previously included in Liliales should actually be redistributed over three orders, Liliales, Asparagales, and Dioscoreales. The boundaries of the Asparagales and of its families have undergone a series of changes in recent years; future research may lead to further changes and ultimately greater stability. In the APG circumscription, Asparagales is the largest order of monocots with 14 families, 1,122 genera, and about 36,000 species.
The order is clearly circumscribed on the basis of molecular phylogenetics, but it is difficult to define morphologically since its members are structurally diverse. Most species of Asparagales are herbaceous perennials, although some are climbers and some are trees or shrubs. The order also contains many geophytes (bulbs, corms, and various kinds of tuber). According to telomere sequence, at least two evolutionary switch-points happened within the order. The basal sequence is formed by TTTAGGG like in the majority of higher plants. Basal motif was changed to vertebrate-like TTAGGG and finally, the most divergent motif CTCGGTTATGGG appears in Allium. One of the defining characteristics (synapomorphies) of the order is the presence of phytomelanin, a black pigment present in the seed coat, creating a dark crust. Phytomelanin is found in most families of the Asparagales (although not in Orchidaceae, thought to be the sister-group of the rest of the order).
The leaves of almost all species form a tight rosette, either at the base of the plant or at the end of the stem, but occasionally along the stem. The flowers are not particularly distinctive, being 'lily type', with six tepals and up to six stamina.
The order is thought to have first diverged from other related monocots some 120–130 million years ago (early in the Cretaceous period), although given the difficulty in classifying the families involved, estimates are likely to be uncertain.
From an economic point of view, the order Asparagales is second in importance within the monocots only to the order Poales (which includes grasses and cereals). Species are used as food and flavourings (e.g. onion, garlic, leek, asparagus, vanilla, saffron), in medicinal or cosmetic applications (Aloe), as cut flowers (e.g. freesia, gladiolus, iris, orchids), and as garden ornamentals (e.g. day lilies, lily of the valley, Agapanthus).
Description
Although most species in the order are herbaceous, some no more than 15 cm high, there are a number of climbers (e.g., some species of Asparagus), as well as several genera forming trees (e.g. Agave, Cordyline, Yucca, Dracaena, Aloe ), which can exceed 10 m in height. Succulent genera occur in several families (e.g. Aloe).
Almost all species have a tight cluster of leaves (a rosette), either at the base of the plant or at the end of a more-or-less woody stem as with Yucca. In some cases, the leaves are produced along the stem. The flowers are in the main not particularly distinctive, being of a general 'lily type', with six tepals, either free or fused from the base and up to six stamina. They are frequently clustered at the end of the plant stem.
The Asparagales are generally distinguished from the Liliales by the lack of markings on the tepals, the presence of septal nectaries in the ovaries, rather than the bases of the tepals or stamen filaments, and the presence of secondary growth. They are generally geophytes, but with linear leaves, and a lack of fine reticular venation.
The seeds characteristically have the external epidermis either obliterated (in most species bearing fleshy fruit), or if present, have a layer of black carbonaceous phytomelanin in species with dry fruits (nuts). The inner part of the seed coat is generally collapsed, in contrast to Liliales whose seeds have a well developed outer epidermis, lack phytomelanin, and usually display a cellular inner layer.
The orders which have been separated from the old Liliales are difficult to characterize. No single morphological character appears to be diagnostic of the order Asparagales.
The flowers of Asparagales are of a general type among the lilioid monocots. Compared to Liliales, they usually have plain tepals without markings in the form of dots. If nectaries are present, they are in the septa of the ovaries rather than at the base of the tepals or stamens.
Those species which have relatively large dry seeds have a dark, crust-like (crustose) outer layer containing the pigment phytomelan. However, some species with hairy seeds (e.g. Eriospermum, family Asparagaceae s.l.), berries (e.g. Maianthemum, family Asparagaceae s.l.), or highly reduced seeds (e.g. orchids) lack this dark pigment in their seed coats. Phytomelan is not unique to Asparagales (i.e. it is not a synapomorphy) but it is common within the order and rare outside it. The inner portion of the seed coat is usually completely collapsed. In contrast, the morphologically similar seeds of Liliales have no phytomelan, and usually retain a cellular structure in the inner portion of the seed coat.
Most monocots are unable to thicken their stems once they have formed, since they lack the cylindrical meristem present in other angiosperm groups. Asparagales have a method of secondary thickening which is otherwise only found in Dioscorea (in the monocot order Disoscoreales). In a process called 'anomalous secondary growth', they are able to create new vascular bundles around which thickening growth occurs. Agave, Yucca, Aloe, Dracaena, Nolina and Cordyline can become massive trees, albeit not of the height of the tallest dicots, and with less branching. Other genera in the order, such as Lomandra and Aphyllanthes, have the same type of secondary growth but confined to their underground stems.
Microsporogenesis (part of pollen formation) distinguishes some members of Asparagales from Liliales. Microsporogenesis involves a cell dividing twice (meiotically) to form four daughter cells. There are two kinds of microsporogenesis: successive and simultaneous (although intermediates exist). In successive microsporogenesis, walls are laid down separating the daughter cells after each division. In simultaneous microsporogenesis, there is no wall formation until all four cell nuclei are present. Liliales all have successive microsporogenesis, which is thought to be the primitive condition in monocots. It seems that when the Asparagales first diverged they developed simultaneous microsporogenesis, which the 'lower' Asparagales families retain. However, the 'core' Asparagales (see Phylogenetics ) have reverted to successive microsporogenesis.
The Asparagales appear to be unified by a mutation affecting their telomeres (a region of repetitive DNA at the end of a chromosome). The typical 'Arabidopsis-type' sequence of bases has been fully or partially replaced by other sequences, with the 'human-type' predominating.
Other apomorphic characters of the order according to Stevens are: the presence of chelidonic acid, anthers longer than wide, tapetal cells bi- to tetra-nuclear, tegmen not persistent, endosperm helobial, and loss of mitochondrial gene sdh3.
Taxonomy
As circumscribed within the Angiosperm Phylogeny Group system Asparagales is the largest order within the monocotyledons, with 14 families, 1,122 genera and about 25,000–42,000 species, thus accounting for about 50% of all monocots and 10–15% of the flowering plants (angiosperms). The attribution of botanical authority for the name Asparagales belongs to Johann Heinrich Friedrich Link (1767–1851) who coined the word 'Asparaginae' in 1829 for a higher order taxon that included Asparagus although Adanson and Jussieau had also done so earlier (see History). Earlier circumscriptions of Asparagales attributed the name to Bromhead (1838), who had been the first to use the term 'Asparagales'.
History
Pre-Darwinian
The type genus, Asparagus, from which the name of the order is derived, was described by Carl Linnaeus in 1753, with ten species. He placed Asparagus within the Hexandria Monogynia (six stamens, one carpel) in his sexual classification in the Species Plantarum. The majority of taxa now considered to constitute Asparagales have historically been placed within the very large and diverse family, Liliaceae. The family Liliaceae was first described by Michel Adanson in 1763, and in his taxonomic scheme he created eight sections within it, including the Asparagi with Asparagus and three other genera. The system of organising genera into families is generally credited to Antoine Laurent de Jussieu who formally described both the Liliaceae and the type family of Asparagales, the Asparagaceae, as Lilia and Asparagi, respectively, in 1789. Jussieu established the hierarchical system of taxonomy (phylogeny), placing Asparagus and related genera within a division of Monocotyledons, a class (III) of Stamina Perigynia and 'order' Asparagi, divided into three subfamilies. The use of the term Ordo (order) at that time was closer to what we now understand as Family, rather than Order. In creating his scheme he used a modified form of Linnaeus' sexual classification but using the respective topography of stamens to carpels rather than just their numbers. While De Jussieu's Stamina Perigynia also included a number of 'orders' that would eventually form families within the Asparagales such as the Asphodeli (Asphodelaceae), Narcissi (Amaryllidaceae) and Irides (Iridaceae), the remainder are now allocated to other orders. Jussieu's Asparagi soon came to be referred to as Asparagacées in the French literature (Latin: Asparagaceae). Meanwhile, the 'Narcissi' had been renamed as the 'Amaryllidées' (Amaryllideae) in 1805, by Jean Henri Jaume Saint-Hilaire, using Amaryllis as the type species rather than Narcissus, and thus has the authority attribution for Amaryllidaceae. In 1810, Brown proposed that a subgroup of Liliaceae be distinguished on the basis of the position of the ovaries and be referred to as Amaryllideae and in 1813 de Candolle described Liliacées Juss. and Amaryllidées Brown as two quite separate families.
The literature on the organisation of genera into families and higher ranks became available in the English language with Samuel Frederick Gray's A natural arrangement of British plants (1821). Gray used a combination of Linnaeus' sexual classification and Jussieu's natural classification to group together a number of families having in common six equal stamens, a single style and a perianth that was simple and petaloid, but did not use formal names for these higher ranks. Within the grouping he separated families by the characteristics of their fruit and seed. He treated groups of genera with these characteristics as separate families, such as Amaryllideae, Liliaceae, Asphodeleae and Asparageae.
The circumscription of Asparagales has been a source of difficulty for many botanists from the time of John Lindley (1846), the other important British taxonomist of the early nineteenth century. In his first taxonomic work, An Introduction to the Natural System of Botany (1830) he partly followed Jussieu by describing a subclass he called Endogenae, or Monocotyledonous Plants (preserving de Candolle's Endogenæ phanerogamæ) divided into two tribes, the Petaloidea and Glumaceae. He divided the former, often referred to as petaloid monocots, into 32 orders, including the Liliaceae (defined narrowly), but also most of the families considered to make up the Asparagales today, including the Amaryllideae.
By 1846, in his final scheme Lindley had greatly expanded and refined the treatment of the monocots, introducing both an intermediate ranking (Alliances) and tribes within orders (i.e. families). Lindley placed the Liliaceae within the Liliales, but saw it as a paraphyletic ("catch-all") family, being all Liliales not included in the other orders, but hoped that the future would reveal some characteristic that would group them better. The order Liliales was very large and included almost all monocotyledons with colourful tepals and without starch in their endosperm (the lilioid monocots). The Liliales was difficult to divide into families because morphological characters were not present in patterns that clearly demarcated groups. This kept the Liliaceae separate from the Amaryllidaceae (Narcissales). Of these, Liliaceae was divided into eleven tribes (with 133 genera) and Amaryllidaceae into four tribes (with 68 genera), yet both contained many genera that would eventually segregate to each other's contemporary orders (Liliales and Asparagales respectively). The Liliaceae would be reduced to a small 'core' represented by the tribe Tulipae, while large groups such Scilleae and Asparagae would become part of Asparagales either as part of the Amaryllidaceae or as separate families. While of the Amaryllidaceae, the Agaveae would be part of Asparagaceae but the Alstroemeriae would become a family within the Liliales.
The number of known genera (and species) continued to grow and by the time of the next major British classification, that of the Bentham & Hooker system in 1883 (published in Latin) several of Lindley's other families had been absorbed into the Liliaceae. They used the term 'series' to indicate suprafamilial rank, with seven series of monocotyledons (including Glumaceae), but did not use Lindley's terms for these. However, they did place the Liliaceous and Amaryllidaceous genera into separate series. The Liliaceae were placed in series Coronariae, while the Amaryllideae were placed in series Epigynae. The Liliaceae now consisted of twenty tribes (including Tulipeae, Scilleae and Asparageae), and the Amaryllideae of five (including Agaveae and Alstroemerieae). An important addition to the treatment of the Liliaceae was the recognition of the Allieae as a distinct tribe that would eventually find its way to the Asparagales as the subfamily Allioideae of the Amaryllidaceae.
Post-Darwinian
The appearance of Charles Darwin's Origin of Species in 1859 changed the way that taxonomists considered plant classification, incorporating evolutionary information into their schemata. The Darwinian approach led to the concept of phylogeny (tree-like structure) in assembling classification systems, starting with Eichler. Eichler, having established a hierarchical system in which the flowering plants (angiosperms) were divided into monocotyledons and dicotyledons, further divided into former into seven orders. Within the Liliiflorae were seven families, including Liliaceae and Amaryllidaceae. Liliaceae included Allium and Ornithogalum (modern Allioideae) and Asparagus.
Engler, in his system developed Eichler's ideas into a much more elaborate scheme which he treated in a number of works including Die Natürlichen Pflanzenfamilien (Engler and Prantl 1888) and Syllabus der Pflanzenfamilien (1892–1924). In his treatment of Liliiflorae the Liliineae were a suborder which included both families Liliaceae and Amaryllidaceae. The Liliaceae had eight subfamilies and the Amaryllidaceae four. In this rearrangement of Liliaceae, with fewer subdivisions, the core Liliales were represented as subfamily Lilioideae (with Tulipae and Scilleae as tribes), the Asparagae were represented as Asparagoideae and the Allioideae was preserved, representing the alliaceous genera. Allieae, Agapantheae and Gilliesieae were the three tribes within this subfamily. In the Amaryllidaceae, there was little change from the Bentham & Hooker. A similar approach was adopted by Wettstein.
Twentieth century
In the twentieth century the Wettstein system (1901–1935) placed many of the taxa in an order called 'Liliiflorae'. Next Johannes Paulus Lotsy (1911) proposed dividing the Liliiflorae into a number of smaller families including Asparagaceae. Then Herbert Huber (1969, 1977), following Lotsy's example, proposed that the Liliiflorae be split into four groups including the 'Asparagoid' Liliiflorae.
The widely used Cronquist system (1968–1988) used the very broadly defined order Liliales.
These various proposals to separate small groups of genera into more homogeneous families made little impact till that of Dahlgren (1985) incorporating new information including synapomorphy. Dahlgren developed Huber's ideas further and popularised them, with a major deconstruction of existing families into smaller units. They created a new order, calling it Asparagales. This was one of five orders within the superorder Liliiflorae. Where Cronquist saw one family, Dahlgren saw forty distributed over three orders (predominantly Liliales and Asparagales). Over the 1980s, in the context of a more general review of the classification of angiosperms, the Liliaceae were subjected to more intense scrutiny. By the end of that decade, the Royal Botanic Gardens at Kew, the British Museum of Natural History and the Edinburgh Botanical Gardens formed a committee to examine the possibility of separating the family at least for the organization of their herbaria. That committee finally recommended that 24 new families be created in the place of the original broad Liliaceae, largely by elevating subfamilies to the rank of separate families.
Phylogenetics
The order Asparagales as currently circumscribed has only recently been recognized in classification systems, through the advent of phylogenetics. The 1990s saw considerable progress in plant phylogeny and phylogenetic theory, enabling a phylogenetic tree to be constructed for all of the flowering plants. The establishment of major new clades necessitated a departure from the older but widely used classifications such as Cronquist and Thorne based largely on morphology rather than genetic data. This complicated the discussion about plant evolution and necessitated a major restructuring. rbcL gene sequencing and cladistic analysis of monocots had redefined the Liliales in 1995. from four morphological orders sensu Dahlgren. The largest clade representing the Liliaceae, all previously included in Liliales, but including both the Calochortaceae and Liliaceae sensu Tamura. This redefined family, that became referred to as core Liliales, but corresponded to the emerging circumscription of the Angiosperm Phylogeny Group (1998).
Phylogeny and APG system
The 2009 revision of the Angiosperm Phylogeny Group system, APG III, places the order in the clade monocots.
From the Dahlgren system of 1985 onwards, studies based mainly on morphology had identified the Asparagales as a distinct group, but had also included groups now located in Liliales, Pandanales and Zingiberales. Research in the 21st century has supported the monophyly of Asparagales, based on morphology, 18S rDNA, and other DNA sequences, although some phylogenetic reconstructions based on molecular data have suggested that Asparagales may be paraphyletic, with Orchidaceae separated from the rest. Within the monocots, Asparagales is the sister group of the commelinid clade.
This cladogram shows the placement of Asparagales within the orders of Lilianae sensu Chase & Reveal (monocots) based on molecular phylogenetic evidence. The lilioid monocot orders are bracketed, namely Petrosaviales, Dioscoreales, Pandanales, Liliales and Asparagales. These constitute a paraphyletic assemblage, that is groups with a common ancestor that do not include all direct descendants (in this case commelinids as the sister group to Asparagales); to form a clade, all the groups joined by thick lines would need to be included. While Acorales and Alismatales have been collectively referred to as "alismatid monocots" (basal or early branching monocots), the remaining clades (lilioid and commelinid monocots) have been referred to as the "core monocots". The relationship between the orders (with the exception of the two sister orders) is pectinate, that is diverging in succession from the line that leads to the commelinids. Numbers indicate crown group (most recent common ancestor of the sampled species of the clade of interest) divergence times in mya (million years ago).
Subdivision
A phylogenetic tree for the Asparagales, generally to family level, but including groups which were recently and widely treated as families but which are now reduced to subfamily rank, is shown below.
The tree shown above can be divided into a basal paraphyletic group, the 'lower Asparagales (asparagoids)', from Orchidaceae to Asphodelaceae, and a well-supported monophyletic group of 'core Asparagales' (higher asparagoids), comprising the two largest families, Amaryllidaceae sensu lato and Asparagaceae sensu lato.
Two differences between these two groups (although with exceptions) are: the mode of microsporogenesis and the position of the ovary. The 'lower Asparagales' typically have simultaneous microsporogenesis (i.e. cell walls develop only after both meiotic divisions), which appears to be an apomorphy within the monocots, whereas the 'core Asparagales' have reverted to successive microsporogenesis (i.e. cell walls develop after each division). The 'lower Asparagales' typically have an inferior ovary, whereas the 'core Asparagales' have reverted to a superior ovary. A 2002 morphological study by Rudall treated possessing an inferior ovary as a synapomorphy of the Asparagales, stating that reversions to a superior ovary in the 'core Asparagales' could be associated with the presence of nectaries below the ovaries. However, Stevens notes that superior ovaries are distributed among the 'lower Asparagales' in such a way that it is not clear where to place the evolution of different ovary morphologies. The position of the ovary seems a much more flexible character (here and in other angiosperms) than previously thought.
Changes to family structure in APG III
The APG III system when it was published in 2009, greatly expanded the families Xanthorrhoeaceae, Amaryllidaceae, and Asparagaceae. Thirteen of the families of the earlier APG II system were thereby reduced to subfamilies within these three families. The expanded Xanthorrhoeaceae is now called "Asphodelaceae". The APG II families (left) and their equivalent APG III subfamilies (right) are as follows:
Structure of Asparagales
Orchid clade
Orchidaceae is possibly the largest family of all angiosperms (only Asteraceae might - or might not - be more speciose) and hence by far the largest in the order. The Dahlgren system recognized three families of orchids, but DNA sequence analysis later showed that these families are polyphyletic and so should be combined. Several studies suggest (with high bootstrap support) that Orchidaceae is the sister of the rest of the Asparagales. Other studies have placed the orchids differently in the phylogenetic tree, generally among the Boryaceae-Hypoxidaceae clade. The position of Orchidaceae shown above seems the best current hypothesis, but cannot be taken as confirmed.
Orchids have simultaneous microsporogenesis and inferior ovaries, two characters that are typical of the 'lower Asparagales'. However, their nectaries are rarely in the septa of the ovaries, and most orchids have dust-like seeds, atypical of the rest of the order. (Some members of Vanilloideae and Cypripedioideae have crustose seeds, probably associated with dispersal by birds and mammals that are attracted by fermenting fleshy fruit releasing fragrant compounds, e.g. vanilla.)
In terms of the number of species, Orchidaceae diversification is remarkable, with recent estimations suggesting that despite the old origin of the family dating back to the late cretaceous, modern orchid diversity originated mostly during the last 5 million years. However, although the other Asparagales may be less rich in species, they are more variable morphologically, including tree-like forms.
Boryaceae to Hypoxidaceae
The four families excluding Boryaceae form a well-supported clade in studies based on DNA sequence analysis. All four contain relatively few species, and it has been suggested that they be combined into one family under the name Hypoxidaceae sensu lato. The relationship between Boryaceae (which includes only two genera, Borya and Alania), and other Asparagales has remained unclear for a long time. The Boryaceae are mycorrhizal, but not in the same way as orchids. Morphological studies have suggested a close relationship between Boryaceae and Blandfordiaceae. There is relatively low support for the position of Boryaceae in the tree shown above.
Ixioliriaceae to Xeronemataceae
The relationship shown between Ixioliriaceae and Tecophilaeaceae is still unclear. Some studies have supported a clade of these two families, others have not. The position of Doryanthaceae has also varied, with support for the position shown above, but also support for other positions.
The clade from Iridaceae upwards appears to have stronger support. All have some genetic characteristics in common, having lost Arabidopsis-type telomeres. Iridaceae is distinctive among the Asparagales in the unique structure of the inflorescence (a rhipidium), the combination of an inferior ovary and three stamens, and the common occurrence of unifacial leaves whereas bifacial leaves are the norm in other Asparagales.
Members of the clade from Iridaceae upwards have infra-locular septal nectaries, which Rudall interpreted as a driver towards secondarily superior ovaries.
Asphodelaceae + 'core Asparagales'
The next node in the tree (Xanthorrhoeaceae sensu lato + the 'core Asparagales') has strong support. 'Anomalous' secondary thickening occurs among this clade, e.g. in Xanthorrhoea (family Asphodelaceae) and Dracaena (family Asparagaceae sensu lato), with species reaching tree-like proportions.
The 'core Asparagales', comprising Amaryllidaceae sensu lato and Asparagaceae sensu lato, are a strongly supported clade, as are clades for each of the families. Relationships within these broadly defined families appear less clear, particularly within the Asparagaceae sensu lato. Stevens notes that most of its subfamilies are difficult to recognize, and that significantly different divisions have been used in the past, so that the use of a broadly defined family to refer to the entire clade is justified. Thus the relationships among subfamilies shown above, based on APWeb , is somewhat uncertain.
Evolution
Several studies have attempted to date the evolution of the Asparagales, based on phylogenetic evidence. Earlier studies generally give younger dates than more recent studies, which have been preferred in the table below.
A 2009 study suggests that the Asparagales have the highest diversification rate in the monocots, about the same as the order Poales, although in both orders the rate is little over half that of the eudicot order Lamiales, the clade with the highest rate.
Comparison of family structures
The taxonomic diversity of the monocotyledons is described in detail by Kubitzki. Up-to-date information on the Asparagales can be found on the Angiosperm Phylogeny Website.
The APG III system's family circumscriptions are being used as the basis of the Kew-hosted World Checklist of Selected Plant Families. With this circumscription, the order consists of 14 families (Dahlgren had 31) with approximately 1120 genera and 26000 species.
Order Asparagales Link
Family Amaryllidaceae J.St.-Hil. (including Agapanthaceae F.Voigt, Alliaceae Borkh.)
Family Asparagaceae Juss. (including Agavaceae Dumort. [which includes Anemarrhenaceae, Anthericaceae, Behniaceae and Herreriaceae], Aphyllanthaceae Burnett, Hesperocallidaceae Traub, Hyacinthaceae Batsch ex Borkh., Laxmanniaceae Bubani, Ruscaceae M.Roem. [which includes Convallariaceae] and Themidaceae Salisb.)
Family Asteliaceae Dumort.
Family Blandfordiaceae R.Dahlgren & Clifford
Family Boryaceae M.W. Chase, Rudall & Conran
Family Doryanthaceae R.Dahlgren & Clifford
Family Hypoxidaceae R.Br.
Family Iridaceae Juss.
Family Ixioliriaceae Nakai
Family Lanariaceae R.Dahlgren & A.E.van Wyk
Family Orchidaceae Juss.
Family Tecophilaeaceae Leyb.
Family Xanthorrhoeaceae Dumort. (including Asphodelaceae Juss. and Hemerocallidaceae R.Br.), now Asphodelaceae Juss.
Family Xeronemataceae M.W.Chase, Rudall & M.F.Fay
The earlier 2003 version, APG II, allowed 'bracketed' families, i.e. families which could either be segregated from more comprehensive families or could be included in them. These are the families given under "including" in the list above. APG III does not allow bracketed families, requiring the use of the more comprehensive family; otherwise the circumscription of the Asparagales is unchanged. A separate paper accompanying the publication of the 2009 APG III system provided subfamilies to accommodate the families which were discontinued. The first APG system of 1998 contained some extra families, included in square brackets in the list above.
Two older systems which use the order Asparagales are the Dahlgren system and the Kubitzki system. The families included in the circumscriptions of the order in these two systems are shown in the first and second columns of the table below. The equivalent family in the modern APG III system (see below) is shown in the third column. Note that although these systems may use the same name for a family, the genera which it includes may be different, so the equivalence between systems is only approximate in some cases.
Uses
The Asparagales include many important crop plants and ornamental plants. Crops include Allium, Asparagus and Vanilla, while ornamentals include irises, hyacinths and orchids.
See also
Taxonomy of Liliaceae
Notes
References
Bibliography
Books
contents
*
Chapters
in
in
in
in
Articles
APG
Historical sources
digital edition by the University and State Library Düsseldorf
1st ed. 1901–1908; 2nd ed. 1910–1911; 3rd ed. 1923–1924; 4th ed. 1933–1935
Websites
: Families included in the checklist
Reference materials
External links
Biodiversity Heritage Library
Angiosperm orders
Extant Late Cretaceous first appearances |
787 | https://en.wikipedia.org/wiki/Alismatales | Alismatales | The Alismatales (alismatids) are an order of flowering plants including about 4,500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Perhaps the most important food crop in the order is the corm of the taro plant, Colocasia esculenta.
Description
The Alismatales comprise herbaceous flowering plants of often aquatic and marshy habitats, and the only monocots known to have green embryos other than the Amaryllidaceae. They also include the only marine angiosperms growing completely submerged, the seagrasses. The flowers are usually arranged in inflorescences, and the mature seeds lack endosperm.
Both marine and freshwater forms include those with staminate flowers that detach from the parent plant and float to the surface. There they can pollinate carpellate flowers floating on the surface via long pedicels. In others, pollination occurs underwater, where pollen may form elongated strands, increasing chance of success. Most aquatic species have a totally submerged juvenile phase, and flowers are either floating or emerge above the water's surface. Vegetation may be totally submersed, have floating leaves, or protrude from the water. Collectively, they are commonly known as "water plantain".
Taxonomy
The Alismatales contain about 165 genera in 13 families, with a cosmopolitan distribution. Phylogenetically, they are basal monocots, diverging early in evolution relative to the lilioid and commelinid monocot lineages. Together with the Acorales, the Alismatales are referred to informally as the alismatid monocots.
Early systems
The Cronquist system (1981) places the Alismatales in subclass Alismatidae, class Liliopsida [= monocotyledons] and includes only three families as shown:
Alismataceae
Butomaceae
Limnocharitaceae
Cronquist's subclass Alismatidae conformed fairly closely to the order Alismatales as defined by APG, minus the Araceae.
The Dahlgren system places the Alismatales in the superorder Alismatanae in the subclass Liliidae [= monocotyledons] in the class Magnoliopsida [= angiosperms] with the following families included:
Alismataceae
Aponogetonaceae
Butomaceae
Hydrocharitaceae
Limnocharitaceae
In Tahktajan's classification (1997), the order Alismatales contains only the Alismataceae and Limnocharitaceae, making it equivalent to the Alismataceae as revised in APG-III. Other families included in the Alismatates as currently defined are here distributed among 10 additional orders, all of which are assigned, with the following exception, to the Subclass Alismatidae. Araceae in Tahktajan 1997 is assigned to the Arales and placed in the Subclass Aridae; Tofieldiaceae to the Melanthiales and placed in the Liliidae.
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group system (APG) of 1998 and APG II (2003) assigned the Alismatales to the monocots, which may be thought of as an unranked clade containing the families listed below. The biggest departure from earlier systems (see below) is the inclusion of family Araceae. By its inclusion, the order has grown enormously in number of species. The family Araceae alone accounts for about a hundred genera, totaling over two thousand species. The rest of the families together contain only about five hundred species, many of which are in very small families.
The APG III system (2009) differs only in that the Limnocharitaceae are combined with the Alismataceae; it was also suggested that the genus Maundia (of the Juncaginaceae) could be separated into a monogeneric family, the Maundiaceae, but the authors noted that more study was necessary before the Maundiaceae could be recognized.
order Alismatales sensu APG III
family Alismataceae (including Limnocharitaceae)
family Aponogetonaceae
family Araceae
family Butomaceae
family Cymodoceaceae
family Hydrocharitaceae
family Juncaginaceae
family Posidoniaceae
family Potamogetonaceae
family Ruppiaceae
family Scheuchzeriaceae
family Tofieldiaceae
family Zosteraceae
In APG IV (2016), it was decided that evidence was sufficient to elevate Maundia to family level as the monogeneric Maundiaceae. The authors considered including a number of the smaller orders within the Juncaginaceae, but an online survey of botanists and other users found little support for this "lumping" approach. Consequently, the family structure for APG IV is:
family Alismataceae (including Limnocharitaceae)
family Aponogetonaceae
family Araceae
family Butomaceae
family Cymodoceaceae
family Hydrocharitaceae
family Juncaginaceae
family Maundiaceae
family Posidoniaceae
family Potamogetonaceae
family Ruppiaceae
family Scheuchzeriaceae
family Tofieldiaceae
family Zosteraceae
Phylogeny
Cladogram showing the orders of monocots (Lilianae sensu Chase & Reveal) based on molecular phylogenetic evidence:
References
Further reading
B. C. J. du Mortier 1829. Analyse des Familles de Plantes : avec l'indication des principaux genres qui s'y rattachent. Imprimerie de J. Casterman, Tournay
W. S. Judd, C. S. Campbell, E. A. Kellogg, P. F. Stevens, M. J. Donoghue, 2002. Plant Systematics: A Phylogenetic Approach, 2nd edition. Sinauer Associates, Sunderland, Massachusetts .
, in
External links
Angiosperm orders |
788 | https://en.wikipedia.org/wiki/Apiales | Apiales | The Apiales are an order of flowering plants. The families are those recognized in the APG III system. This is typical of the newer classifications, though there is some slight variation and in particular, the Torriceliaceae may also be divided.
Under this definition, well-known members include carrots, celery, parsley, and Hedera helix (English ivy).
The order Apiales is placed within the asterid group of eudicots as circumscribed by the APG III system. Within the asterids, Apiales belongs to an unranked group called the campanulids, and within the campanulids, it belongs to a clade known in phylogenetic nomenclature as Apiidae. In 2010, a subclade of Apiidae named Dipsapiidae was defined to consist of the three orders: Apiales, Paracryphiales, and Dipsacales.
Taxonomy
Under the Cronquist system, only the Apiaceae and Araliaceae were included here, and the restricted order was placed among the rosids rather than the asterids. The Pittosporaceae were placed within the Rosales, and many of the other forms within the family Cornaceae. Pennantia was in the family Icacinaceae. In the classification system of Dahlgren the families Apiaceae and Araliaceae were placed in the order Ariales, in the superorder Araliiflorae (also called Aralianae).
The present understanding of the Apiales is fairly recent and is based upon comparison of DNA sequences by phylogenetic methods. The circumscriptions of some of the families have changed. In 2009, one of the subfamilies of Araliaceae was shown to be polyphyletic.
Gynoecia
The largest and obviously closely related families of Apiales are Araliaceae, Myodocarpaceae and
Apiaceae, which resemble each other in the structure of their gynoecia. In this respect however, the Pittosporaceae is notably distinct from them.
Typical syncarpous gynoecia exhibit four vertical zones, determined by the extent of fusion of the carpels. In most plants, the synascidiate (i.e. "united bottle-shaped") and symplicate zones are fertile and bear the ovules. Each of the first three families possess mainly bi- or multilocular ovaries in a gynoecium with a long synascidiate, but very short symplicate zone, where the ovules are inserted at their transition, the so-called cross-zone (or "Querzone").
In gynoecia of the Pittosporaceae, the symplicate is much longer than the synascidiate zone, and the ovules are arranged along the first. Members of the latter family consequently have unilocular ovaries with a single cavity between adjacent carpels.
References
Angiosperm orders
Taxa named by Takenoshin Nakai |
789 | https://en.wikipedia.org/wiki/Asterales | Asterales | Asterales () is an order of dicotyledonous flowering plants that includes the large family Asteraceae (or Compositae) known for composite flowers made of florets, and ten families related to the Asteraceae. While asterids in general are characterized by fused petals, composite flowers consisting of many florets create the false appearance of separate petals (as found in the rosids).
The order is cosmopolitan (plants found throughout most of the world including desert and frigid zones), and includes mostly herbaceous species, although a small number of trees (such as the Lobelia deckenii, the giant lobelia, and Dendrosenecio, giant groundsels) and shrubs are also present.
Asterales are organisms that seem to have evolved from one common ancestor. Asterales share characteristics on morphological and biochemical levels. Synapomorphies (a character that is shared by two or more groups through evolutionary development) include the presence in the plants of oligosaccharide inulin, a nutrient storage molecule used instead of starch; and unique stamen morphology. The stamens are usually found around the style, either aggregated densely or fused into a tube, probably an adaptation in association with the plunger (brush; or secondary) pollination that is common among the families of the order, wherein pollen is collected and stored on the length of the pistil.
Taxonomy
The name and order Asterales is botanically venerable, dating back to at least 1926 in the Hutchinson system of plant taxonomy when it contained only five families, of which only two are retained in the APG III classification. Under the Cronquist system of taxonomic classification of flowering plants, Asteraceae was the only family in the group, but newer systems (such as APG II and APG III) have expanded it to 11. In the classification system of Rolf Dahlgren the Asterales were in the superorder Asteriflorae (also called Asteranae).
The order Asterales currently includes 11 families, the largest of which are the Asteraceae, with about 25,000 species, and the Campanulaceae (bellflowers), with about 2,000 species. The remaining families count together for less than 1500 species. The two large families are cosmopolitan, with many of their species found in the Northern Hemisphere, and the smaller families are usually confined to Australia and the adjacent areas, or sometimes South America.
Only the Asteraceae have composite flower heads; the other families do not, but share other characteristics such as storage of inulin that define the 11 families as more closely related to each other than to other plant families or orders such as the rosids.
The phylogenetic tree according to APG III for the Campanulid clade is as below.
Phylogeny
Although most extant species of Asteraceae are herbaceous, the examination of the basal members in the family suggests that the common ancestor of the family was an arborescent plant, a tree or shrub, perhaps adapted to dry conditions, radiating from South America. Less can be said about the Asterales themselves with certainty, although since several families in Asterales contain trees, the ancestral member is most likely to have been a tree or shrub.
Because all clades are represented in the Southern Hemisphere but many not in the Northern Hemisphere, it is natural to conjecture that there is a common southern origin to them. Asterales are angiosperms, flowering plants that appeared about 140 million years ago. The Asterales order probably originated in the Cretaceous (145 – 66 Mya) on the supercontinent Gondwana which broke up from 184 – 80 Mya, forming the area that is now Australia, South America, Africa, India and Antarctica.
Asterales contain about 14% of eudicot diversity. From an analysis of relationships and diversities within the Asterales and with their superorders, estimates of the age of the beginning of the Asterales have been made, which range from 116 Mya to 82Mya. However few fossils have been found, of the Menyanthaceae-Asteraceae clade in the Oligocene, about 29 Mya.
Fossil evidence of the Asterales is rare and belongs to rather recent epochs, so the precise estimation of the order's age is quite difficult. An Oligocene (34 – 23 Mya) pollen is known for Asteraceae and Goodeniaceae, and seeds from Oligocene and Miocene (23 – 5.3 Mya) are known for Menyanthaceae and Campanulaceae respectively.
Biogeography
The core Asterales are Stylidiaceae (six genera), APA clade (Alseuosmiaceae, Phellinaceae and Argophyllaceae, together seven genera), MGCA clade (Menyanthaceae, Goodeniaceae, Calyceraceae, in total twenty genera), and Asteraceae (about sixteen hundred genera). Other Asterales are Rousseaceae (four genera), Campanulaceae (eighty-four genera) and Pentaphragmataceae (one genus).
All Asterales families are represented in the Southern Hemisphere; however, Asteraceae and Campanulaceae are cosmopolitan and Menyanthaceae nearly so.
Uses
The Asterales, by dint of being a super-set of the family Asteraceae, include some species grown for food, including the sunflower (Helianthus annuus), lettuce (Lactuca sativa) and chicory (Cichorium). Many are also used as spices and traditional medicines.
Asterales are common plants and have many known uses. For example, pyrethrum (derived from Old World members of the genus Chrysanthemum) is a natural insecticide with minimal environmental impact. Wormwood, derived from a genus that includes the sagebrush, is used as a source of flavoring for absinthe, a bitter classical liquor of European origin.
References
Further reading
W. S. Judd, C. S. Campbell, E. A. Kellogg, P. F. Stevens, M. J. Donoghue (2002). Plant Systematics: A Phylogenetic Approach, 2nd edition. pp. 476–486 (Asterales). Sinauer Associates, Sunderland, Massachusetts. .
External links
Angiosperm orders |
794 | https://en.wikipedia.org/wiki/Allocution | Allocution | An allocution, or allocutus, is a formal statement made to the court by the defendant who has been found guilty prior to being sentenced. It is part of the criminal procedure in some jurisdictions using common law.
Concept
An allocution allows the defendant to explain why the sentence should be lenient. In plea bargains, an allocution may be required of the defendant. The defendant explicitly admits specifically and in detail the actions and their reasons in exchange for a reduced sentence.
In principle, that removes any doubt as to the exact nature of the defendant's guilt in the matter.
The term allocution is used generally only in jurisdictions in the United States, but there are vaguely similar processes in other common law countries. In many other jurisdictions, it is for the defense lawyer to mitigate on their client's behalf, and the defendant rarely has the opportunity to speak.
Australia
In Australia, the term allocutus is used by the Clerk of Arraigns or another formal associate of the court.
It is generally phrased as: "Prisoner at the Bar, you have been found Guilty by a jury of your peers of the offence of XYZ. Do you have anything to say as to why the sentence of this Court should not now be passed upon you?"
The defense counsel will then make a plea in mitigation (also called submissions on penalty) in an attempt to mitigate the relative seriousness of the offense, and heavily refer to and rely upon the defendant's previous good character and good works, if any.
The right to make a plea in mitigation is absolute: if a judge or magistrate refuses to hear such a plea or does not properly consider it, the sentence can be overturned on appeal.
United States
In most of the United States, defendants are allowed the opportunity to allocute before a sentence is passed. Some jurisdictions hold that as an absolute right. In its absence, a sentence but not the conviction may be overturned, resulting in the need for a new sentencing hearing. In the federal system, Federal Rules of Criminal Procedure 32(i)(4) provides that the court must "address the defendant personally in order to permit the defendant to speak or present any information to mitigate the sentence".
The federal public defender recommends that defendants speak in terms of how a lenient sentence will be sufficient but not greater than necessary to comply with the statutory directives set forth in .
See also
Confession (law)
References
Criminal procedure
Evidence law |
795 | https://en.wikipedia.org/wiki/Affidavit | Affidavit | An ( ; Medieval Latin for "he has declared under oath") is a written statement voluntarily made by an affiant or deponent under an oath or affirmation which is administered by a person who is authorized to do so by law. Such a statement is witnessed as to the authenticity of the affiant's signature by a taker of oaths, such as a notary public or commissioner of oaths. An affidavit is a type of verified statement or showing, or in other words, it contains a verification, which means that it is made under oath on penalty of perjury, and this serves as evidence for its veracity and is required in court proceedings.
Definition
An affidavit is typically defined as a written declaration or statement that is sworn or affirmed before a person who has authority to administer an oath. There is no general defined form for an affidavit, although for some proceedings an affidavit must satisfy legal or statutory requirements in order to be considered. An affidavit may include,
a commencement which identifies the affiant;
an attestation clause, usually a jurat, at the end certifying that the affiant made the statement under oath on the specified date;
signatures of the affiant and person who administered the oath.
In some cases, an introductory clause, called a preamble, is added attesting that the affiant personally appeared before the authenticating authority. An affidavit may also recite that the statement it records was made under penalty of perjury.
An affidavit that is prepared for use within the context of litigation may also include a caption that identifies the venue and parties to the relevant judicial proceedings.
Worldwide
Australia
On 2 March 2016, the High Court of Australia held that the ACT Uniform Evidence Legislation is neutral in the way sworn evidence and unsworn evidence is treated as being of equal weight.
United Kingdom
The term "affidavit" is used in the UK. According the UK government website, "The affidavit can be sworn or affirmed by a solicitor, notary or commissioner for oaths (for a charge) or by an authorised member of court staff."
India
In Indian law, although an affidavit may be taken as proof of the facts stated therein, the courts have no jurisdiction to admit evidence by way of affidavit. Affidavit is not treated as "evidence" within the meaning of Section 3 of the Evidence Act. However, it was held by the Supreme Court that an affidavit can be used as evidence only if the court so orders for sufficient reasons, namely, the right of the opposite party to have the deponent produced for cross-examination. Therefore, an affidavit cannot ordinarily be used as evidence in absence of a specific order of the court.
Sri Lanka
In Sri Lanka, under the Oaths Ordinance, with the exception of a court-martial, a person may submit an affidavit signed in the presence of a commissioner for oaths or a justice of the peace.
Ireland
Affidavits are made in a similar way as to England and Wales, although "make oath" is sometimes omitted. An affirmed affidavit may be substituted for an sworn affidavit in most cases for those opposed to swearing oaths. The person making the affidavit is known as the deponent and signs the affidavit. The affidavit concludes in the standard format "sworn/affirmed (declared) before me, [name of commissioner for oaths/solicitor], a commissioner for oaths (solicitor), on the [date] at [location] in the county/city of [county/city], and I know the deponent", and it is signed and stamped by the commissioner for oaths. It is important that the Commissioner states his/her name clearly, sometimes documents are rejected when the name cannot be ascertained.
In August 2020, a new method of filing affidavits came into force. Under Section 21 of the Civil Law and Criminal Law (Miscellaneous Provisions) Act 2020 witnesses are no longer required to swear before God or make an affirmation when filing an affidavit. Instead, witnesses will make a non-religious "statement of truth" and, if it is breached, will be liable for up to one year in prison if convicted summarily or, upon conviction on indictment, to a maximum fine of €250,000 or imprisonment for a term not exceeding 5 years, or both.
This is designed to replace affidavits and statutory declarations in situations where the electronic means of lodgement or filing of documents with the Court provided for in Section 20 is utilised. As of January 2022, it has yet to be adopted widely, and it is expected it will not be used for some time by lay litigants who will still lodge papers in person.
United States
In American jurisprudence, under the rules for hearsay, admission of an unsupported affidavit as evidence is unusual (especially if the affiant is not available for cross-examination) with regard to material facts which may be dispositive of the matter at bar. Affidavits from persons who are dead or otherwise incapacitated, or who cannot be located or made to appear, may be accepted by the court, but usually only in the presence of corroborating evidence. An affidavit which reflected a better grasp of the facts close in time to the actual events may be used to refresh a witness's recollection. Materials used to refresh recollection are admissible as evidence. If the affiant is a party in the case, the affiant's opponent may be successful in having the affidavit admitted as evidence, as statements by a party-opponent are admissible through an exception to the hearsay rule.
Affidavits are typically included in the response to interrogatories. Requests for admissions under Federal Rule of Civil Procedure 36, however, are not required to be sworn.
When a person signs an affidavit, that person is eligible to take the stand at a trial or evidentiary hearing. One party may wish to summon the affiant to verify the contents of the affidavit, while the other party may want to cross-examine the affiant about the affidavit.
Some types of motions will not be accepted by the court unless accompanied by an independent sworn statement or other evidence in support of the need for the motion. In such a case, a court will accept an affidavit from the filing attorney in support of the motion, as certain assumptions are made, to wit: The affidavit in place of sworn testimony promotes judicial economy. The lawyer is an officer of the court and knows that a false swearing by them, if found out, could be grounds for severe penalty up to and including disbarment. The lawyer if called upon would be able to present independent and more detailed evidence to prove the facts set forth in his affidavit.
Affidavits should not be confused with unsworn declarations under penalty of perjury. In federal courts and about 20 states as of 2006, unsworn declarations under penalty of perjury are authorized by statute as acceptable in lieu of affidavits. The key differences are that an unsworn declaration does not bear the jurat of a notary public and the declarant is not required to swear an oath or affirmation. Rather, the signature of the declarant under a carefully worded phrase binding them to the truth of their statements "under penalty of perjury" is deemed as a matter of law to be sufficiently solemn to remind the declarant of their duty to tell the truth, the whole truth, and nothing but the truth. The point of such affidavit substitution statutes is that unsworn declarations can be prepared and executed far more quickly and economically than affidavits, in that the witness need not meet personally with a notary public for the notarization process.
The acceptance of an affidavit by one society does not confirm its acceptance as a legal document in other jurisdictions. Equally, the acceptance that a lawyer is an officer of the court (for swearing the affidavit) is not a given. This matter is addressed by the use of the apostille, a means of certifying the legalization of a document for international use under the terms of the 1961 Hague Convention Abolishing the Requirement of Legalization for Foreign Public Documents. Documents which have been notarized by a notary public, and certain other documents, and then certified with a conformant apostille, are accepted for legal use in all the nations that have signed the Hague Convention. Thus most affidavits now require to be apostilled if used for cross border issues.
See also
Declaration (law)
Deposition (law)
Fishman Affidavit, a well-known example of an affidavit
Performativity
Statutory declaration
Sworn declaration
References
Evidence law
Legal documents
Notary |
799 | https://en.wikipedia.org/wiki/Aquarius%20%28constellation%29 | Aquarius (constellation) | Aquarius is an equatorial constellation of the zodiac, between Capricornus and Pisces. Its name is Latin for "water-carrier" or "cup-carrier", and its old astronomical symbol is (♒︎), a representation of water. Aquarius is one of the oldest of the recognized constellations along the zodiac (the Sun's apparent path). It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is found in a region often called the Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus the river.
At apparent magnitude 2.9, Beta Aquarii is the brightest star in the constellation.
History and mythology
Aquarius is identified as "The Great One" in the Babylonian star catalogues and represents the god Ea himself, who is commonly depicted holding an overflowing vase. The Babylonian star-figure appears on entitlement stones and cylinder seals from the second millennium. It contained the winter solstice in the Early Bronze Age. In Old Babylonian astronomy, Ea was the ruler of the southernmost quarter of the Sun's path, the "Way of Ea", corresponding to the period of 45 days on either side of winter solstice. Aquarius was also associated with the destructive floods that the Babylonians regularly experienced, and thus was negatively connoted. In Ancient Egypt astronomy, Aquarius was associated with the annual flood of the Nile; the banks were said to flood when Aquarius put his jar into the river, beginning spring.
In the Greek tradition, the constellation came to be represented simply as a single vase from which a stream poured down to Piscis Austrinus. The name in the Hindu zodiac is likewise kumbha "water-pitcher".
In Greek mythology, Aquarius is sometimes associated with Deucalion, the son of Prometheus who built a ship with his wife Pyrrha to survive an imminent flood. They sailed for nine days before washing ashore on Mount Parnassus. Aquarius is also sometimes identified with beautiful Ganymede, a youth in Greek mythology and the son of Trojan king Tros, who was taken to Mount Olympus by Zeus to act as cup-carrier to the gods. Neighboring Aquila represents the eagle, under Zeus' command, that snatched the young boy; some versions of the myth indicate that the eagle was in fact Zeus transformed. One tradition, stated that he was carried off by Eos. Yet another figure associated with the water bearer is Cecrops I, a king of Athens who sacrificed water instead of wine to the gods.
Depictions
In the first century, Ptolemy's Almagest established the common Western depiction of Aquarius. His water jar, an asterism itself, consists of Gamma, Pi, Eta, and Zeta Aquarii; it pours water in a stream of more than 20 stars terminating with Fomalhaut, now assigned solely to Piscis Austrinus. The water bearer's head is represented by 5th magnitude 25 Aquarii while his left shoulder is Beta Aquarii; his right shoulder and forearm are represented by Alpha and Gamma Aquarii respectively.
In Eastern astronomy
In Chinese astronomy, the stream of water flowing from the Water Jar was depicted as the "Army of Yu-Lin" (Yu-lim-kiun or Yulinjun, Hanzi: 羽林君). The name "Yu-lin" means "feathers and forests", referring to the numerous light-footed soldiers from the northern reaches of the empire represented by these faint stars. The constellation's stars were the most numerous of any Chinese constellation, numbering 45, the majority of which were located in modern Aquarius. The celestial army was protected by the wall Leibizhen (垒壁阵), which counted Iota, Lambda, Phi, and Sigma Aquarii among its 12 stars. 88, 89, and 98 Aquarii represent Fou-youe, the axes used as weapons and for hostage executions. Also in Aquarius is Loui-pi-tchin, the ramparts that stretch from 29 and 27 Piscium and 33 and 30 Aquarii through Phi, Lambda, Sigma, and Iota Aquarii to Delta, Gamma, Kappa, and Epsilon Capricorni.
Near the border with Cetus, the axe Fuyue was represented by three stars; its position is disputed and may have instead been located in Sculptor. Tienliecheng also has a disputed position; the 13-star castle replete with ramparts may have possessed Nu and Xi Aquarii but may instead have been located south in Piscis Austrinus. The Water Jar asterism was seen to the ancient Chinese as the tomb, Fenmu. Nearby, the emperors' mausoleum Xiuliang stood, demarcated by Kappa Aquarii and three other collinear stars. Ku ("crying") and Qi ("weeping"), each composed of two stars, were located in the same region.
Three of the Chinese lunar mansions shared their name with constellations. Nu, also the name for the 10th lunar mansion, was a handmaiden represented by Epsilon, Mu, 3, and 4 Aquarii. The 11th lunar mansion shared its name with the constellation Xu ("emptiness"), formed by Beta Aquarii and Alpha Equulei; it represented a bleak place associated with death and funerals. Wei, the rooftop and 12th lunar mansion, was a V-shaped constellation formed by Alpha Aquarii, Theta Pegasi, and Epsilon Pegasi; it shared its name with two other Chinese constellations, in modern-day Scorpius and Aries.
Features
Stars
Despite both its prominent position on the zodiac and its large size, Aquarius has no particularly bright stars, its four brightest stars being less than However, recent research has shown that there are several stars lying within its borders that possess planetary systems.
The two brightest stars, α Aquarii and β Aquarii, are luminous yellow supergiants, of spectral types G0Ib and G2Ib respectively, that were once hot blue-white B-class main sequence stars 5 to 9 times as massive as the Sun. The two are also moving through space perpendicular to the plane of the Milky Way. Just shading α, β Aquarii is the brightest star in Aquarius with apparent It also has the proper name of Sadalsuud. Having cooled and swollen to around 50 times the Sun's diameter, it is around 2200 times as luminous as the Sun. It is around 6.4 times as massive as the Sun and around 56 million years old. Sadalsuud is from Earth. α Aquarii, also known as Sadalmelik, has apparent It is distant from Earth, and is around 6.5 times as massive as the Sun, and 3000 times as luminous. It is 53 million years old.
γ Aquarii, also called Sadachbia, is a white main sequence star of spectral type star of spectral type A0V that is between 158 and 315 million years old and is around 2.5 times the Sun's mass (), and double its radius. Its magnitude is 3.85, and it is away, hence its luminosity is . The name Sadachbia comes from the Arabic for "lucky stars of the tents", sa'd al-akhbiya.
δ Aquarii, also known as Skat or Scheat is a blue-white spectral type A2 star with apparent magnitude 3.27 and luminosity .
ε Aquarii, also known as Albali, is a blue-white spectral type A1 star with apparent magnitude 3.77, absolute magnitude 1.2, and a luminosity of .
ζ Aquarii is a spectral type F2 double star; both stars are white. In combination, they appear to be magnitude 3.6 with luminosity . The primary has magnitude 4.53 and the secondary's magnitude is 4.31, but both have absolute The system's orbital period is 760 years; currently the two components are moving farther apart.
θ Aquarii, sometimes called Ancha, is spectral type G8 with apparent magnitude 4.16 and an absolute
κ Aquarii, also called Situla, has an apparent
λ Aquarii, also called Hudoor or Ekchusis, is spectral type M2 with magnitude 3.74 and luminosity .
ξ Aquarii, also called Bunda, is spectral type A7 with an apparent magnitude 4.69 and an absolute
π Aquarii, also called Seat, is spectral type B0 with apparent magnitude 4.66 and absolute
Planetary systems
Twelve exoplanet systems have been found in Aquarius as of 2013. Gliese 876, one of the nearest stars to Earth at a distance of 15 light-years, was the first red dwarf star to be found to possess a planetary system. It is orbited by four planets, including one terrestrial planet 6.6 times the mass of Earth. The planets vary in orbital period from 2 days to 124 days. 91 Aquarii is an orange giant star orbited by one planet, 91 Aquarii b. The planet's mass is 2.9 times the mass of Jupiter, and its orbital period is 182 days. Gliese 849 is a red dwarf star orbited by the first known long-period Jupiter-like planet, Gliese 849 b. The planet's mass is 0.99 times that of Jupiter and its orbital period is 1,852 days.
There are also less-prominent systems in Aquarius. WASP-6, a type G8 star of magnitude 12.4, is host to one exoplanet, WASP-6 b. The star is 307 parsecs from Earth and has a mass of 0.888 solar masses and a radius of 0.87 solar radii. WASP-6 b was discovered in 2008 by the transit method. It orbits its parent star every 3.36 days at a distance of 0.042 astronomical units (AU). It is 0.503 Jupiter masses but has a proportionally larger radius of 1.224 Jupiter radii. HD 206610, a K0 star located 194 parsecs from Earth, is host to one planet, HD 206610 b. The host star is larger than the Sun; more massive at 1.56 solar masses and larger at 6.1 solar radii. The planet was discovered by the radial velocity method in 2010 and has a mass of 2.2 Jupiter masses. It orbits every 610 days at a distance of 1.68 AU. Much closer to its sun is WASP-47 b, which orbits every 4.15 days only 0.052 AU from its sun, yellow dwarf (G9V) WASP-47. WASP-47 is close in size to the Sun, having a radius of 1.15 solar radii and a mass even closer at 1.08 solar masses. WASP-47 b was discovered in 2011 by the transit method, like WASP-6 b. It is slightly larger than Jupiter with a mass of 1.14 Jupiter masses and a radius of 1.15 Jupiter masses.
There are several more single-planet systems in Aquarius. HD 210277, a magnitude 6.63 yellow star located 21.29 parsecs from Earth, is host to one known planet: HD 210277 b. The 1.23 Jupiter mass planet orbits at nearly the same distance as Earth orbits the Sun1.1 AU, though its orbital period is significantly longer at around 442 days. HD 210277 b was discovered earlier than most of the other planets in Aquarius, detected by the radial velocity method in 1998. The star it orbits resembles the Sun beyond their similar spectral class; it has a radius of 1.1 solar radii and a mass of 1.09 solar masses. HD 212771 b, a larger planet at 2.3 Jupiter masses, orbits host star HD 212771 at a distance of 1.22 AU. The star itself, barely below the threshold of naked-eye visibility at magnitude 7.6, is a G8IV (yellow subgiant) star located 131 parsecs from Earth. Though it has a similar mass to the Sun1.15 solar massesit is significantly less dense with its radius of 5 solar radii. Its lone planet was discovered in 2010 by the radial velocity method, like several other exoplanets in the constellation.
As of 2013, there were only two known multiple-planet systems within the bounds of Aquarius: the Gliese 876 and HD 215152 systems. The former is quite prominent; the latter has only two planets and has a host star farther away at 21.5 parsecs. The HD 215152 system consists of the planets HD 215152 b and HD 215152 c orbiting their K0-type, magnitude 8.13 sun. Both discovered in 2011 by the radial velocity method, the two tiny planets orbit very close to their host star. HD 215152 c is the larger at 0.0097 Jupiter masses (still significantly larger than the Earth, which weighs in at 0.00315 Jupiter masses); its smaller sibling is barely smaller at 0.0087 Jupiter masses. The error in the mass measurements (0.0032 and respectively) is large enough to make this discrepancy statistically insignificant. HD 215152 c also orbits further from the star than HD 215152 b, 0.0852 AU compared to 0.0652.
On 23 February 2017, NASA announced that ultracool dwarf star TRAPPIST-1 in Aquarius has seven Earth-like rocky planets. Of these, as many as four may lie within the system's habitable zone, and may have liquid water on their surfaces. The discovery of the TRAPPIST-1 system is seen by astronomers as a significant step toward finding life beyond Earth.
Deep sky objects
Because of its position away from the galactic plane, the majority of deep-sky objects in Aquarius are galaxies, globular clusters, and planetary nebulae. Aquarius contains three deep sky objects that are in the Messier catalog: the globular clusters Messier 2, Messier 72, and the asterism Messier 73. While M73 was originally catalogued as a sparsely populated open cluster, modern analysis indicates the 6 main stars are not close enough together to fit this definition, reclassifying M73 as an asterism. Two well-known planetary nebulae are also located in Aquarius: the Saturn Nebula (NGC 7009), to the southeast of μ Aquarii; and the famous Helix Nebula (NGC 7293), southwest of δ Aquarii.
M2, also catalogued as NGC 7089, is a rich globular cluster located approximately 37,000 light-years from Earth. At magnitude 6.5, it is viewable in small-aperture instruments, but a 100 mm aperture telescope is needed to resolve any stars. M72, also catalogued as NGC 6981, is a small 9th magnitude globular cluster located approximately 56,000 light-years from Earth. M73, also catalogued as NGC 6994, is an open cluster with highly disputed status.
Aquarius is also home to several planetary nebulae. NGC 7009, also known as the Saturn Nebula, is an 8th magnitude planetary nebula located 3,000 light-years from Earth. It was given its moniker by the 19th century astronomer Lord Rosse for its resemblance to the planet Saturn in a telescope; it has faint protrusions on either side that resemble Saturn's rings. It appears blue-green in a telescope and has a central star of magnitude 11.3. Compared to the Helix Nebula, another planetary nebula in Aquarius, it is quite small. NGC 7293, also known as the Helix Nebula, is the closest planetary nebula to Earth at a distance of 650 light-years. It covers 0.25 square degrees, making it also the largest planetary nebula as seen from Earth. However, because it is so large, it is only viewable as a very faint object, though it has a fairly high integrated magnitude of 6.0.
One of the visible galaxies in Aquarius is NGC 7727, of particular interest for amateur astronomers who wish to discover or observe supernovae. A spiral galaxy (type S), it has an integrated magnitude of 10.7 and is 3 by 3 arcseconds. NGC 7252 is a tangle of stars resulting from the collision of two large galaxies and is known as the Atoms-for-Peace galaxy because of its resemblance to a cartoon atom.
Meteor showers
There are three major meteor showers with radiants in Aquarius: the Eta Aquariids, the Delta Aquariids, and the Iota Aquariids.
The Eta Aquariids are the strongest meteor shower radiating from Aquarius. It peaks between 5 and 6 May with a rate of approximately 35 meteors per hour. Originally discovered by Chinese astronomers in 401, Eta Aquariids can be seen coming from the Water Jar beginning on 21 April and as late as 12 May. The parent body of the shower is Halley's Comet, a periodic comet. Fireballs are common shortly after the peak, approximately between 9 May and 11 May. The normal meteors appear to have yellow trails.
The Delta Aquariids is a double radiant meteor shower that peaks first on 29 July and second on 6 August. The first radiant is located in the south of the constellation, while the second radiant is located in the northern circlet of Pisces asterism. The southern radiant's peak rate is about 20 meteors per hour, while the northern radiant's peak rate is about 10 meteors per hour.
The Iota Aquariids is a fairly weak meteor shower that peaks on 6 August, with a rate of approximately 8 meteors per hour.
Astrology
, the Sun appears in the constellation Aquarius from 16 February to 12 March. In tropical astrology, the Sun is considered to be in the sign Aquarius from 20 January to 19 February, and in sidereal astrology, from 15 February to 14 March.
Aquarius is also associated with the Age of Aquarius, a concept popular in 1960s counterculture and Medieval Alchemy. The date of the start of The Age of Aquarius is a topic of much debate.
Notes
See also
Aquarius (Chinese astronomy)
References
External links
The Deep Photographic Guide to the Constellations: Aquarius
The clickable Aquarius
Warburg Institute Iconographic Database (medieval and early modern images of Aquarius)
Constellations
Equatorial constellations
Constellations listed by Ptolemy |
801 | https://en.wikipedia.org/wiki/Asterism | Asterism | Asterism may refer to:
Asterism (astronomy), a pattern of stars
Asterism (band), a Japanese rock band
Asterism (gemology), an optical phenomenon in gemstones
Asterism (typography), (⁂) a moderately rare typographical symbol denoting a break in passages
See also
Aster (disambiguation)
Asterisk (disambiguation) |
809 | https://en.wikipedia.org/wiki/Anaconda | Anaconda | Anacondas or water boas are a group of large boas of the genus Eunectes. They are a semiaquatic group of snakes found in tropical South America. Three to five extant and one extinct species are currently recognized, including one of the largest snakes in the world, E. murinus, the green anaconda.
Description
Although the name applies to a group of snakes, it is often used to refer only to one species, in particular, the common or green anaconda (Eunectes murinus), which is the largest snake in the world by weight, and the second longest after the reticulated python.
Origin
The recent fossil record of Eunectes is relatively sparse compared to other vertebrates and other genera of snakes. The fossil record of this group is effected by an artifact called the Pull of the Recent. Fossils of recent ancestors are not known, so the living species 'pull' the historical range of the genus to the present.
Etymology
The name Eunectes is derived from .
The South American names anacauchoa and anacaona were suggested in an account by Peter Martyr d'Anghiera. The idea of a South American origin was questioned by Henry Walter Bates who, in his travels in South America, failed to find any similar name in use. The word anaconda is derived from the name of a snake from Ceylon (Sri Lanka) that John Ray described in Latin in his (1693) as .
Ray used a catalogue of snakes from the Leyden museum supplied by Dr. Tancred Robinson. The description of its habit was based on Andreas Cleyer, who in 1684 described a gigantic snake that crushed large animals by coiling around their bodies and crushing their bones. Henry Yule in his 1886 work Hobson-Jobson, notes that the word became more popular due to a piece of fiction published in 1768 in the Scots Magazine by a certain R. Edwin. Edwin described a 'tiger' being crushed to death by an anaconda, when there were never any tigers in Sri Lanka.
Yule and Frank Wall noted that the snake was a python and suggested a Tamil origin meaning elephant killer. A Sinhalese origin was also suggested by Donald Ferguson who pointed out that the word ( lightning/large and stem/trunk) was used in Sri Lanka for the small whip snake (Ahaetulla pulverulenta) and somehow got misapplied to the python before myths were created.
The name commonly used for the anaconda in Brazil is sucuri, sucuriju or sucuriuba.
Distribution and habitat
Found in tropical South America from Ecuador, Brazil, Colombia and Venezuela south to Argentina.
Feeding
All five species are aquatic snakes that prey on other aquatic animals, including fish, river fowl, and caiman. Videos exist of anacondas preying on domestic animals such as goats and sometimes even jaguars that venture too close to the water.
Relationship with humans
While encounters between people and anacondas may be dangerous, they do not regularly hunt humans. Nevertheless, threat from anacondas is a familiar trope in comics, movies, and adventure stories (often published in pulp magazines or adventure magazines) set in the Amazon jungle. Local communities and some European explorers have given accounts of giant anacondas, legendary snakes of much greater proportion than any confirmed specimen.
Although charismatic, there is little known on the biology of wild anacondas. Most of our knowledge comes from the work of Dr. Jesús A. Rivas and his team working in the Venezuelan Llanos.
Species
Rivas et al. revised the taxonomy of Eunectes, describing a new species of green anaconda (Eunectes akayima) and merging E. deschauenseei and E. beniensis with E. notaeus, which resulted in the recognition of only three species of anaconda. The result of their phylogenetic analysis is represented below:
In a response paper, Dubois et al. questioned the results of the mtDNA analysis above and the validity of Eunectes akayima. The name of the new species was considered a nomen nudum.
Mating system
The mating seasons in Eunectes varies both between species and within species depending on locality, although the trend appears to be the dry season. The green anaconda (E. murinus) is the most well-studied species of Eunectes in terms of their mating system, followed by the yellow anaconda (E. notaeus); unfortunately E. deschauenseei and E. beniensis are much less common, making the specific details of their mating systems less well understood.
Sexual dimorphism
Sexual size dimorphism in Eunectes is the opposite of most other vertebrates. Females are larger than males in most snakes, and green anacondas (E. murinus) have one of the most extreme size differences, where females average roughly and males average only around . This size difference has several benefits for both sexes. Large size in females leads to higher fecundity and larger offspring; as a result male mate choice favours larger females. Large size is also favoured in males because larger males tend to be more successful at reproducing, both because of their size advantage in endurance rivalry and their advantage in sperm competition because larger males are able to produce more sperm. One reason that males are so much smaller in Eunectes is that large males can be confused for females, which interferes with their ability to mate when smaller males mistakenly coil them in breeding balls; as a result, there is an optimum size for males where they are large enough to successfully compete, but not large enough to risk other males trying to mate with them.
Breeding balls
During the mating season female anacondas release pheromones to attract males for breeding, which can result in polyandrous breeding balls; these breeding balls have been observed in E. murinus, E. notaeus, and E. deschauenseei, and likely also occur in E. beniensis. In the green anaconda (E. murinus), up to 13 males have been observed in a breeding ball, which have been recorded to last two weeks on average. In anaconda breeding balls, several males coil around one female and attempt to position themselves as close to her cloaca as possible where they use their pelvic spurs to "tickle" and encourage her to allow penetration. Since there are often many males present and only one male can mate with the female at a time, the success of a male often depends on his persistence and endurance, because physical combat is not a part of the Eunectes mating ritual, apart from firmly pushing against other males in an attempt to secure the best position on the female.
Sexual cannibalism
Cannibalism is quite easy in anacondas since females are so much larger than males, but sexual cannibalism has only been confirmed in E. murinus. Females gain the direct benefit of a post-copulatory high-protein meal when they consume their mates, along with the indirect benefit of additional resources to use for the formation of offspring; cannibalism in general (outside of the breeding season) has been confirmed in all but E. deschauenseei, although it is likely that it occurs in all Eunectes species.
Asexual reproduction
Although sexual reproduction is by far the most common in Eunectes, E. murinus has been observed to undergo facultative parthenogenesis. In both cases, the females had lived in isolation from other anacondas for over eight years, and DNA analysis showed that the few fully formed offspring were genetically identical to the mothers; although this is not commonly observed, it is likely possible in all species of Eunectes and several other species of Boidae.
Indigenous mythology
According to the founding myth of the Huni Kuin, a man named Yube fell in love with an anaconda woman and was turned into an anaconda as well. He began to live with her in the deep world of waters. In this world, Yube discovered a hallucinogenic drink with healing powers and access to knowledge. One day, without telling his anaconda wife, Yube decided to return to the land of men and resume his old human form. The myth also explains the origin of cipó or ayahuasca — a hallucinogenic drink taken ritualistically by the Huni Kuin.
See also
Jaguar, a competitor or predator
Notes
References
Further reading
External links
Snakes of South America
Reptiles of Trinidad and Tobago
Taxa named by Johann Georg Wagler |
825 | https://en.wikipedia.org/wiki/Austrian%20German | Austrian German | Austrian German (), Austrian Standard German (ASG), Standard Austrian German (), Austrian High German (), or simply just Austrian (), is the variety of Standard German written and spoken in Austria and South Tyrol. It has the highest sociolinguistic prestige locally, as it is the variation used in the media and for other formal situations. In less formal situations, Austrians use Bavarian and Alemannic dialects, which are traditionally spoken but rarely written in Austria. It has been standardized with the publishing of the Österreichisches Wörterbuch in 1951.
History
Austrian German has its beginning in the mid-18th century, when Empress Maria Theresa and her son Joseph II introduced compulsory schooling in 1774, and several reforms of administration in their multilingual Habsburg Empire. At the time, the written standard was Oberdeutsche Schreibsprache (Upper German written language), which was highly influenced by the Bavarian and Alemannic dialects of Austria. Another option was to create a new standard based on the Southern German dialects, as proposed by the linguist Johann Siegmund Popowitsch. Instead they decided for pragmatic reasons to adopt the already-standardized chancellery language of Saxony (Sächsische Kanzleisprache or Meißner Kanzleideutsch), which was based on the administrative language of the non-Austrian area of Meißen and Dresden.
Austria High German (Hochdeutsch in Österreich, not to be confused with the Bavarian Austria German dialects) has the same geographic origin as the Swiss High German (Schweizer Hochdeutsch, not to be confused with the Alemannic Swiss German dialects).
The process of introducing the new written standard was led by Joseph von Sonnenfels.
Since 1951, the standardized form of Austrian German for official governmental use and in schools has been defined by the ("Austrian Dictionary"), published originally at the behest of the Austrian Federal Ministry of Education, Arts and Culture (in the 1950s the "Unterrichtsministerium", under minister Felix Hurdes) with Verlag Jugend & Volk, then by the Österreichischer Bundesverlag.
Standard Austrian German
The official Austrian dictionary, , prescribes spelling rules that define the official language.
Austrian delegates participated in the international working group that drafted the German spelling reform of 1996 and several conferences leading up to the reform were hosted in Vienna at the invitation of the Austrian federal government. Austria adopted it as a signatory, along with Germany, Switzerland, and Liechtenstein, of an international memorandum of understanding () signed in Vienna in 1996.
The eszett or "sharp s" (ß) is used in Austria, as in Germany but unlike in Switzerland.
Distinctions in vocabulary persist, for example, in culinary terms, for which communication with Germans is frequently difficult, and administrative and legal language because of Austria's exclusion from the development of a German nation-state in the late 19th century and its manifold particular traditions. A comprehensive collection of Austrian-German legal, administrative and economic terms is offered in Markhardt, Heidemarie: Wörterbuch der österreichischen Rechts-, Wirtschafts- und Verwaltungsterminologie (Peter Lang, 2006).
Because of German's pluricentric nature, German dialects in Austria should not be confused with the variety of Standard Austrian German spoken by most Austrians, which is distinct from that of Germany or Switzerland. In the field of German dialectology, the notion of Standard Austrian German has been both debated and defended by German linguists since the 1970s. A One Standard German Axiom, effectively preventing the development of newer standards of German, has recently been offered as a characteristic of the field.
Former spoken standard
Until 1918, the spoken standard in Austria was the , a sociolect spoken by the imperial Habsburg family and the nobility of Austria-Hungary. The sociolect, a variety of Standard German, is influenced by Viennese German and other Austro-Bavarian dialects spoken in eastern Austria but is slightly nasalized.
Special written forms
For many years, Austria had a special form of the language for official government documents that is known as , or "Austrian chancellery language". It is a very traditional form of the language, probably derived from medieval deeds and documents, and has a very complex structure and vocabulary generally reserved for such documents. For most speakers (even native speakers), this form of the language is generally difficult to understand, as it contains many highly-specialised terms for diplomatic, internal, official, and military matters. There are no regional variations because the special written form has been used mainly by a government that has now for centuries been based in Vienna.
is now used less and less because of various administrative reforms that reduced the number of traditional civil servants (). As a result, Standard Austrian German is replacing it in government and administrative texts.
European Union
When Austria became a member of the European Union, 23 food-related terms were listed in its accession agreement as having the same legal status as the equivalent terms used in Germany,
for example, the words for "potato", "tomato", and "Brussels sprouts". (Examples in "Vocabulary")
Austrian German is the only variety of a pluricentric language recognized under international law or EU primary law.
Grammar
Verbs
In Austria, as in the German-speaking parts of Switzerland and in southern Germany, verbs that express a state tend to use as the auxiliary verb in the perfect, as well as verbs of movement. Verbs which fall into this category include (to sit), (to lie) and, in parts of Styria and Carinthia, (to sleep). Therefore, the perfect of these verbs would be , and , respectively.
In Germany, the words (to stand) and (to confess) are identical in the present perfect: . The Austrian variant avoids that potential ambiguity ( from , "to stand"; and from , "to confess": ).
In addition, the preterite (simple past) is very rarely used in Austria, especially in the spoken language, with the exception of some modal verbs (, ).
Vocabulary
There are many official terms that differ in Austrian German from their usage in most parts of Germany. Words used in Austria are (January) rather than , (seldom, February) along with , (this year) along with , (stairs) along with , (chimney) instead of , many administrative, legal and political terms, and many food terms, including the following:
There are, however, some false friends between the two regional varieties:
(wardrobe) along with or instead of (and, similarly, along with , fridge), as opposed to (box) instead of . in Germany means both "box" and "chest".
(chair) instead of . means "" in Germany and means "stool (faeces)" in both varieties.
Dialects
Classification
Dialects of the Austro-Bavarian group, which also comprises dialects from Bavaria
Central Austro-Bavarian (along the main rivers Isar and Danube, spoken in the northern parts of the State of Salzburg, Upper Austria, Lower Austria, and northern Burgenland)
Viennese German
Southern Austro-Bavarian (in Tyrol, South Tyrol, Carinthia, Styria, and the southern parts of Salzburg and Burgenland)
Vorarlbergerisch, spoken in Vorarlberg, is a High Alemannic dialect.
Regional accents
In addition to the standard variety, in everyday life most Austrians speak one of a number of Upper German dialects.
While strong forms of the various dialects are not fully mutually intelligible to northern Germans, communication is much easier in Bavaria, especially rural areas, where the Bavarian dialect still predominates as the mother tongue. The Central Austro-Bavarian dialects are more intelligible to speakers of Standard German than the Southern Austro-Bavarian dialects of Tyrol.
Viennese, the Austro-Bavarian dialect of Vienna, is seen for many in Germany as quintessentially Austrian. The people of Graz, the capital of Styria, speak yet another dialect which is not very Styrian and more easily understood by people from other parts of Austria than other Styrian dialects, for example from western Styria.
Simple words in the various dialects are very similar, but pronunciation is distinct for each and, after listening to a few spoken words, it may be possible for an Austrian to realise which dialect is being spoken. However, in regard to the dialects of the deeper valleys of the Tyrol, other Tyroleans are often unable to understand them. Speakers from the different provinces of Austria can easily be distinguished from each other by their particular accents (probably more so than Bavarians), those of Carinthia, Styria, Vienna, Upper Austria, and the Tyrol being very characteristic. Speakers from those regions, even those speaking Standard German, can usually be easily identified by their accent, even by an untrained listener.
Several of the dialects have been influenced by contact with non-Germanic linguistic groups, such as the dialect of Carinthia, where, in the past, many speakers were bilingual (and, in the southeastern portions of the state, many still are even today) with Slovene, and the dialect of Vienna, which has been influenced by immigration during the Austro-Hungarian period, particularly from what is today the Czech Republic. The German dialects of South Tyrol have been influenced by local Romance languages, particularly noticeable with the many loanwords from Italian and Ladin.
The geographic borderlines between the different accents (isoglosses) coincide strongly with the borders of the states and also with the border with Bavaria, with Bavarians having a markedly different rhythm of speech in spite of the linguistic similarities.
References
Notes
Citations
Works cited
Further reading
Ammon, Ulrich: Die deutsche Sprache in Deutschland, Österreich und der Schweiz: Das Problem der nationalen Varietäten. de Gruyter, Berlin/New York 1995.
Ammon, Ulrich / Hans Bickel, Jakob Ebner u. a.: Variantenwörterbuch des Deutschen. Die Standardsprache in Österreich, der Schweiz und Deutschland sowie in Liechtenstein, Luxemburg, Ostbelgien und Südtirol. Berlin/New York 2004, .
Dollinger, Stefan: Österreichisches Deutsch oder Deutsch in Österreich? Identitäten im 21. Jahrhundert. New Academic Press, 2021. Available online, 3rd ed.:https://www.nid-library.com/Home/BookDetail/512
Grzega, Joachim: „Deutschländisch und Österreichisches Deutsch: Mehr Unterschiede als nur in Wortschatz und Aussprache.“ In: Joachim Grzega: Sprachwissenschaft ohne Fachchinesisch. Shaker, Aachen 2001, S. 7–26. .
Grzega, Joachim: "On the Description of National Varieties: Examples from (German and Austrian) German and (English and American) English". In: Linguistik Online 7 (2000).
Grzega, Joachim: "Nonchalance als Merkmal des Österreichischen Deutsch". In: Muttersprache 113 (2003): 242–254.
Muhr, Rudolf / Schrodt, Richard: Österreichisches Deutsch und andere nationale Varietäten plurizentrischer Sprachen in Europa. Wien, 1997
Muhr, Rudolf/Schrodt, Richard/Wiesinger, Peter (eds.): Österreichisches Deutsch: Linguistische, sozialpsychologische und sprachpolitische Aspekte einer nationalen Variante des Deutschen. Wien, 1995.
Pohl, Heinz Dieter: „Österreichische Identität und österreichisches Deutsch“ aus dem „Kärntner Jahrbuch für Politik 1999“ Wiesinger, Peter: Die deutsche Sprache in Österreich. Eine Einführung, In: Wiesinger (Hg.): Das österreichische Deutsch. Schriften zur deutschen Sprache. Band 12.'' (Wien, Köln, Graz, 1988, Verlag, Böhlau)
External links
Austrian German – German Dictionary
Das Österreichische Volkswörterbuch
Bavarian language
German dialects
German
National varieties of German |
840 | https://en.wikipedia.org/wiki/Axiom%20of%20choice | Axiom of choice | In mathematics, the axiom of choice, abbreviated AC or AoC, is an axiom of set theory equivalent to the statement that a Cartesian product of a collection of non-empty sets is non-empty. Informally put, the axiom of choice says that given any collection of sets, each containing at least one element, it is possible to construct a new set by choosing one element from each set, even if the collection is infinite. Formally, it states that for every indexed family of nonempty sets, there exists an indexed set such that for every . The axiom of choice was formulated in 1904 by Ernst Zermelo in order to formalize his proof of the well-ordering theorem.
In many cases, a set created by choosing elements can be made without invoking the axiom of choice, particularly if the number of sets from which to choose the elements is finite, or if a canonical rule on how to choose the elements is available — some distinguishing property that happens to hold for exactly one element in each set. An illustrative example is sets picked from the natural numbers. From such sets, one may always select the smallest number, e.g. given the sets {{4, 5, 6}, {10, 12}, {1, 400, 617, 8000}}, the set containing each smallest element is {4, 10, 1}. In this case, "select the smallest number" is a choice function. Even if infinitely many sets are collected from the natural numbers, it will always be possible to choose the smallest element from each set to produce a set. That is, the choice function provides the set of chosen elements. But no definite choice function is known for the collection of all non-empty subsets of the real numbers. In that case, the axiom of choice must be invoked.
Bertrand Russell coined an analogy: for any (even infinite) collection of pairs of shoes, one can pick out the left shoe from each pair to obtain an appropriate collection (i.e. set) of shoes; this makes it possible to define a choice function directly. For an infinite collection of pairs of socks (assumed to have no distinguishing features), there is no obvious way to make a function that forms a set out of selecting one sock from each pair without invoking the axiom of choice.
Although originally controversial, the axiom of choice is now used without reservation by most mathematicians, and is included in the standard form of axiomatic set theory, Zermelo–Fraenkel set theory with the axiom of choice (ZFC). One motivation for this is that a number of generally accepted mathematical results, such as Tychonoff's theorem, require the axiom of choice for their proofs. Contemporary set theorists also study axioms that are not compatible with the axiom of choice, such as the axiom of determinacy. The axiom of choice is avoided in some varieties of constructive mathematics, although there are varieties of constructive mathematics in which the axiom of choice is embraced.
Statement
A choice function (also called selector or selection) is a function f, defined on a collection X of nonempty sets, such that for every set A in X, f(A) is an element of A. With this concept, the axiom can be stated:
Formally, this may be expressed as follows:
Thus, the negation of the axiom may be expressed as the existence of a collection of nonempty sets which has no choice function. Formally, this may be derived making use of the logical equivalence of to .
Each choice function on a collection X of nonempty sets is an element of the Cartesian product of the sets in X. This is not the most general situation of a Cartesian product of a family of sets, where a given set can occur more than once as a factor; however, one can focus on elements of such a product that select the same element every time a given set appears as factor, and such elements correspond to an element of the Cartesian product of all distinct sets in the family. The axiom of choice asserts the existence of such elements; it is therefore equivalent to:
Given any family of nonempty sets, their Cartesian product is a nonempty set.
Nomenclature
In this article and other discussions of the Axiom of Choice the following abbreviations are common:
AC – the Axiom of Choice. More rarely, AoC is used.
ZF – Zermelo–Fraenkel set theory omitting the Axiom of Choice.
ZFC – Zermelo–Fraenkel set theory, extended to include the Axiom of Choice.
Variants
There are many other equivalent statements of the axiom of choice. These are equivalent in the sense that, in the presence of other basic axioms of set theory, they imply the axiom of choice and are implied by it.
One variation avoids the use of choice functions by, in effect, replacing each choice function with its range:
Given any set X, if the empty set is not an element of X and the elements of X are disjoint, then there exists a set C such that its intersection with any of the elements of X contains exactly one element.
This can be formalized in first-order logic as:
∀x (
∃o (o ∈ x ∧ ¬∃n (n ∈ o)) ∨
∃a ∃b ∃c (a ∈ x ∧ b ∈ x ∧ c ∈ a ∧ c ∈ b ∧ ¬(a = b)) ∨
∃c ∀e (e ∈ x → ∃a (a ∈ e ∧ a ∈ c ∧ ∀b ((b ∈ e ∧ b ∈ c) → a = b))))
Note that P ∨ Q ∨ R is logically equivalent to (¬P ∧ ¬Q) → R.
In English, this first-order sentence reads:
Given any set X,
X contains the empty set as an element or
the elements of X are not pairwise disjoint or
there exists a set C such that its intersection with any of the elements of X contains exactly one element.
This guarantees for any partition of a set X the existence of a subset C of X containing exactly one element from each part of the partition.
Another equivalent axiom only considers collections X that are essentially powersets of other sets:
For any set A, the power set of A (with the empty set removed) has a choice function.
Authors who use this formulation often speak of the choice function on A, but this is a slightly different notion of choice function. Its domain is the power set of A (with the empty set removed), and so makes sense for any set A, whereas with the definition used elsewhere in this article, the domain of a choice function on a collection of sets is that collection, and so only makes sense for sets of sets. With this alternate notion of choice function, the axiom of choice can be compactly stated as
Every set has a choice function.
which is equivalent to
For any set A there is a function f such that for any non-empty subset B of A, f(B) lies in B.
The negation of the axiom can thus be expressed as:
There is a set A such that for all functions f (on the set of non-empty subsets of A), there is a B such that f(B) does not lie in B.
Restriction to finite sets
The usual statement of the axiom of choice does not specify whether the collection of nonempty sets is finite or infinite, and thus implies that every finite collection of nonempty sets has a choice function. However, that particular case is a theorem of the Zermelo–Fraenkel set theory without the axiom of choice (ZF); it is easily proved by the principle of finite induction. In the even simpler case of a collection of one set, a choice function just corresponds to an element, so this instance of the axiom of choice says that every nonempty set has an element; this holds trivially. The axiom of choice can be seen as asserting the generalization of this property, already evident for finite collections, to arbitrary collections.
Usage
Until the late 19th century, the axiom of choice was often used implicitly, although it had not yet been formally stated. For example, after having established that the set X contains only non-empty sets, a mathematician might have said "let F(s) be one of the members of s for all s in X" to define a function F. In general, it is impossible to prove that F exists without the axiom of choice, but this seems to have gone unnoticed until Zermelo.
Examples
The nature of the individual nonempty sets in the collection may make it possible to avoid the axiom of choice even for certain infinite collections. For example, suppose that each member of the collection X is a nonempty subset of the natural numbers. Every such subset has a smallest element, so to specify our choice function we can simply say that it maps each set to the least element of that set. This gives us a definite choice of an element from each set, and makes it unnecessary to add the axiom of choice to our axioms of set theory.
The difficulty appears when there is no natural choice of elements from each set. If we cannot make explicit choices, how do we know that our selection forms a legitimate set (as defined by the other ZF axioms of set theory)? For example, suppose that X is the set of all non-empty subsets of the real numbers. First we might try to proceed as if X were finite. If we try to choose an element from each set, then, because X is infinite, our choice procedure will never come to an end, and consequently we shall never be able to produce a choice function for all of X. Next we might try specifying the least element from each set. But some subsets of the real numbers do not have least elements. For example, the open interval (0,1) does not have a least element: if x is in (0,1), then so is x/2, and x/2 is always strictly smaller than x. So this attempt also fails.
Additionally, consider for instance the unit circle S, and the action on S by a group G consisting of all rational rotations, that is, rotations by angles which are rational multiples of π. Here G is countable while S is uncountable. Hence S breaks up into uncountably many orbits under G. Using the axiom of choice, we could pick a single point from each orbit, obtaining an uncountable subset X of S with the property that all of its translates by G are disjoint from X. The set of those translates partitions the circle into a countable collection of disjoint sets, which are all pairwise congruent. Since X is not measurable for any rotation-invariant countably additive finite measure on S, finding an algorithm to form a set from selecting a point in each orbit requires that one add the axiom of choice to our axioms of set theory. See non-measurable set for more details.
In classical arithmetic, the natural numbers are well-ordered: for every nonempty subset of the natural numbers, there is a unique least element under the natural ordering. In this way, one may specify a set from any given subset. One might say, "Even though the usual ordering of the real numbers does not work, it may be possible to find a different ordering of the real numbers which is a well-ordering. Then our choice function can choose the least element of every set under our unusual ordering." The problem then becomes that of constructing a well-ordering, which turns out to require the axiom of choice for its existence; every set can be well-ordered if and only if the axiom of choice holds.
Criticism and acceptance
A proof requiring the axiom of choice may establish the existence of an object without explicitly defining the object in the language of set theory. For example, while the axiom of choice implies that there is a well-ordering of the real numbers, there are models of set theory with the axiom of choice in which no individual well-ordering of the reals is definable. Similarly, although a subset of the real numbers that is not Lebesgue measurable can be proved to exist using the axiom of choice, it is consistent that no such set is definable.
The axiom of choice proves the existence of these intangibles (objects that are proved to exist, but which cannot be explicitly constructed), which may conflict with some philosophical principles. Because there is no canonical well-ordering of all sets, a construction that relies on a well-ordering may not produce a canonical result, even if a canonical result is desired (as is often the case in category theory). This has been used as an argument against the use of the axiom of choice.
Another argument against the axiom of choice is that it implies the existence of objects that may seem counterintuitive. One example is the Banach–Tarski paradox, which says that it is possible to decompose the 3-dimensional solid unit ball into finitely many pieces and, using only rotations and translations, reassemble the pieces into two solid balls each with the same volume as the original. The pieces in this decomposition, constructed using the axiom of choice, are non-measurable sets.
Moreover, paradoxical consequences of the axiom of choice for the no-signaling principle in physics have recently been pointed out.
Despite these seemingly paradoxical results, most mathematicians accept the axiom of choice as a valid principle for proving new results in mathematics. But the debate is interesting enough that it is considered notable when a theorem in ZFC (ZF plus AC) is logically equivalent (with just the ZF axioms) to the axiom of choice, and mathematicians look for results that require the axiom of choice to be false, though this type of deduction is less common than the type that requires the axiom of choice to be true.
Theorems of ZF hold true in any model of that theory, regardless of the truth or falsity of the axiom of choice in that particular model. The implications of choice below, including weaker versions of the axiom itself, are listed because they are not theorems of ZF. The Banach–Tarski paradox, for example, is neither provable nor disprovable from ZF alone: it is impossible to construct the required decomposition of the unit ball in ZF, but also impossible to prove there is no such decomposition. Such statements can be rephrased as conditional statements—for example, "If AC holds, then the decomposition in the Banach–Tarski paradox exists." Such conditional statements are provable in ZF when the original statements are provable from ZF and the axiom of choice.
In constructive mathematics
As discussed above, in the classical theory of ZFC, the axiom of choice enables nonconstructive proofs in which the existence of a type of object is proved without an explicit instance being constructed. In fact, in set theory and topos theory, Diaconescu's theorem shows that the axiom of choice implies the law of excluded middle. The principle is thus not available in constructive set theory, where non-classical logic is employed.
The situation is different when the principle is formulated in Martin-Löf type theory. There and higher-order Heyting arithmetic, the appropriate statement of the axiom of choice is (depending on approach) included as an axiom or provable as a theorem. A cause for this difference is that the axiom of choice in type theory does not have the extensionality properties that the axiom of choice in constructive set theory does. The type theoretical context is discussed further below.
Different choice principles have been thoroughly studied in the constructive contexts and the principles' status varies between different school and varieties of the constructive mathematics.
Some results in constructive set theory use the axiom of countable choice or the axiom of dependent choice, which do not imply the law of the excluded middle. Errett Bishop, who is notable for developing a framework for constructive analysis, argued that an axiom of choice was constructively acceptable, saying
Although the axiom of countable choice in particular is commonly used in constructive mathematics, its use has also been questioned.
Independence
In 1938, Kurt Gödel showed that the negation of the axiom of choice is not a theorem of ZF by constructing an inner model (the constructible universe) that satisfies ZFC, thus showing that ZFC is consistent if ZF itself is consistent. In 1963, Paul Cohen employed the technique of forcing, developed for this purpose, to show that, assuming ZF is consistent, the axiom of choice itself is not a theorem of ZF. He did this by constructing a much more complex model that satisfies ZF¬C (ZF with the negation of AC added as axiom) and thus showing that ZF¬C is consistent.
Together these results establish that the axiom of choice is logically independent of ZF. The assumption that ZF is consistent is harmless because adding another axiom to an already inconsistent system cannot make the situation worse. Because of independence, the decision whether to use the axiom of choice (or its negation) in a proof cannot be made by appeal to other axioms of set theory. It must be made on other grounds.
One argument in favor of using the axiom of choice is that it is convenient because it allows one to prove some simplifying propositions that otherwise could not be proved. Many theorems provable using choice are of an elegant general character: the cardinalities of any two sets are comparable, every nontrivial ring with unity has a maximal ideal, every vector space has a basis, every connected graph has a spanning tree, and every product of compact spaces is compact, among many others. Frequently, the axiom of choice allows generalizing a theorem to "larger" objects. For example, it is provable without the axiom of choice that every vector space of finite dimension has a basis, but the generalization to all vector spaces requires the axiom of choice. Likewise, a finite product of compact spaces can be proven to be compact without the axiom of choice, but the generalization to infinite products (Tychonoff's theorem) requires the axiom of choice.
The proof of the independence result also shows that a wide class of mathematical statements, including all statements that can be phrased in the language of Peano arithmetic, are provable in ZF if and only if they are provable in ZFC. Statements in this class include the statement that P = NP, the Riemann hypothesis, and many other unsolved mathematical problems. When attempting to solve problems in this class, it makes no difference whether ZF or ZFC is employed if the only question is the existence of a proof. It is possible, however, that there is a shorter proof of a theorem from ZFC than from ZF.
The axiom of choice is not the only significant statement that is independent of ZF. For example, the generalized continuum hypothesis (GCH) is not only independent of ZF, but also independent of ZFC. However, ZF plus GCH implies AC, making GCH a strictly stronger claim than AC, even though they are both independent of ZF.
Stronger axioms
The axiom of constructibility and the generalized continuum hypothesis each imply the axiom of choice and so are strictly stronger than it. In class theories such as Von Neumann–Bernays–Gödel set theory and Morse–Kelley set theory, there is an axiom called the axiom of global choice that is stronger than the axiom of choice for sets because it also applies to proper classes. The axiom of global choice follows from the axiom of limitation of size. Tarski's axiom, which is used in Tarski–Grothendieck set theory and states (in the vernacular) that every set belongs to Grothendieck universe, is stronger than the axiom of choice.
Equivalents
There are important statements that, assuming the axioms of ZF but neither AC nor ¬AC, are equivalent to the axiom of choice. The most important among them are Zorn's lemma and the well-ordering theorem. In fact, Zermelo initially introduced the axiom of choice in order to formalize his proof of the well-ordering theorem.
Set theory
Tarski's theorem about choice: For every infinite set A, there is a bijective map between the sets A and A×A.
Trichotomy: If two sets are given, then either they have the same cardinality, or one has a smaller cardinality than the other.
Given two non-empty sets, one has a surjection to the other.
Every surjective function has a right inverse.
The Cartesian product of any family of nonempty sets is nonempty. In other words, every family of nonempty sets has a choice function (i.e. a function which maps each of the nonempty sets to one of its elements).
König's theorem: Colloquially, the sum of a sequence of cardinals is strictly less than the product of a sequence of larger cardinals. (The reason for the term "colloquially" is that the sum or product of a "sequence" of cardinals cannot itself be defined without some aspect of the axiom of choice.)
Well-ordering theorem: Every set can be well-ordered. Consequently, every cardinal has an initial ordinal.
Every element of a partially ordered set S is the minimal element of a well-ordered subset having no strict upper bound in S.
Zorn's lemma: Every non-empty partially ordered set in which every chain (i.e., totally ordered subset) has an upper bound contains at least one maximal element.
Hausdorff maximal principle: Every partially ordered set has a maximal chain. Equivalently, in any partially ordered set, every chain can be extended to a maximal chain.
Tukey's lemma: Every non-empty collection of finite character has a maximal element with respect to inclusion.
Antichain principle: Every partially ordered set has a maximal antichain. Equivalently, in any partially ordered set, every antichain can be extended to a maximal antichain.
Abstract algebra
Every vector space has a basis (i.e., a linearly independent spanning subset). In other words, vector spaces are equivalent to free modules.
Krull's theorem: Every unital ring (other than the trivial ring) contains a maximal ideal. Equivalently, in any nontrivial unital ring, every ideal can be extended to a maximal ideal.
For every non-empty set S there is a binary operation defined on S that gives it a group structure. (A cancellative binary operation is enough, see group structure and the axiom of choice.)
Every free abelian group is projective.
Baer's criterion: Every divisible abelian group is injective.
Every set is a projective object in the category Set of sets.
Functional analysis
The closed unit ball of the dual of a normed vector space over the reals has an extreme point.
Point-set topology
The Cartesian product of any family of connected topological spaces is connected.
Tychonoff's theorem: The Cartesian product of any family of compact topological spaces is compact.
In the product topology, the closure of a product of subsets is equal to the product of the closures.
Mathematical logic
If S is a set of sentences of first-order logic and B is a consistent subset of S, then B is included in a set that is maximal among consistent subsets of S. The special case where S is the set of all first-order sentences in a given signature is weaker, equivalent to the Boolean prime ideal theorem; see the section "Weaker forms" below.
Algebraic topology
Every connected graph has a spanning tree. Equivalently, every nonempty graph has a spanning forest.
Category theory
Several results in category theory invoke the axiom of choice for their proof. These results might be weaker than, equivalent to, or stronger than the axiom of choice, depending on the strength of the technical foundations. For example, if one defines categories in terms of sets, that is, as sets of objects and morphisms (usually called a small category), or even locally small categories, whose hom-objects are sets, then there is no category of all sets, and so it is difficult for a category-theoretic formulation to apply to all sets. On the other hand, other foundational descriptions of category theory are considerably stronger, and an identical category-theoretic statement of choice may be stronger than the standard formulation, à la class theory, mentioned above.
Examples of category-theoretic statements which require choice include:
Every small category has a skeleton.
If two small categories are weakly equivalent, then they are equivalent.
Every continuous functor on a small-complete category which satisfies the appropriate solution set condition has a left-adjoint (the Freyd adjoint functor theorem).
Weaker forms
There are several weaker statements that are not equivalent to the axiom of choice but are closely related. One example is the axiom of dependent choice (DC). A still weaker example is the axiom of countable choice (ACω or CC), which states that a choice function exists for any countable set of nonempty sets. These axioms are sufficient for many proofs in elementary mathematical analysis, and are consistent with some principles, such as the Lebesgue measurability of all sets of reals, that are disprovable from the full axiom of choice.
Given an ordinal parameter α ≥ ω+2 — for every set S with rank less than α, S is well-orderable. Given an ordinal parameter α ≥ 1 — for every set S with Hartogs number less than ωα, S is well-orderable. As the ordinal parameter is increased, these approximate the full axiom of choice more and more closely.
Other choice axioms weaker than axiom of choice include the Boolean prime ideal theorem and the axiom of uniformization. The former is equivalent in ZF to Tarski's 1930 ultrafilter lemma: every filter is a subset of some ultrafilter.
Results requiring AC (or weaker forms) but weaker than it
One of the most interesting aspects of the axiom of choice is the large number of places in mathematics where it shows up. Here are some statements that require the axiom of choice in the sense that they are not provable from ZF but are provable from ZFC (ZF plus AC). Equivalently, these statements are true in all models of ZFC but false in some models of ZF.
Set theory
The ultrafilter lemma (with ZF) can be used to prove the Axiom of choice for finite sets: Given and a collection of non-empty sets, their product is not empty.
The union of any countable family of countable sets is countable (this requires countable choice but not the full axiom of choice).
If the set A is infinite, then there exists an injection from the natural numbers N to A (see Dedekind infinite).
Eight definitions of a finite set are equivalent.
Every infinite game in which is a Borel subset of Baire space is determined.
Measure theory
The Vitali theorem on the existence of non-measurable sets, which states that there exists a subset of the real numbers that is not Lebesgue measurable.
There exist Lebesgue-measurable subsets of the real numbers that are not Borel sets. That is, the Borel σ-algebra on the real numbers (which is generated by all real intervals) is distinct from the Lebesgue-measure σ-algebra on the real numbers.
The Hausdorff paradox.
The Banach–Tarski paradox.
Algebra
Every field has an algebraic closure.
Every field extension has a transcendence basis.
Every infinite-dimensional vector space contains an infinite linearly independent subset (this requires dependent choice, but not the full axiom of choice).
Stone's representation theorem for Boolean algebras needs the Boolean prime ideal theorem.
The Nielsen–Schreier theorem, that every subgroup of a free group is free.
The additive groups of R and C are isomorphic.
Functional analysis
The Hahn–Banach theorem in functional analysis, allowing the extension of linear functionals.
The theorem that every Hilbert space has an orthonormal basis.
The Banach–Alaoglu theorem about compactness of sets of functionals.
The Baire category theorem about complete metric spaces, and its consequences, such as the open mapping theorem and the closed graph theorem.
On every infinite-dimensional topological vector space there is a discontinuous linear map.
General topology
A uniform space is compact if and only if it is complete and totally bounded.
Every Tychonoff space has a Stone–Čech compactification.
Mathematical logic
Gödel's completeness theorem for first-order logic: every consistent set of first-order sentences has a completion. That is, every consistent set of first-order sentences can be extended to a maximal consistent set.
The compactness theorem: If is a set of first-order (or alternatively, zero-order) sentences such that every finite subset of has a model, then has a model.
Possibly equivalent implications of AC
There are several historically important set-theoretic statements implied by AC whose equivalence to AC is open. Zermelo cited the partition principle, which was formulated before AC itself, as a justification for believing AC. In 1906, Russell declared PP to be equivalent, but whether the partition principle implies AC is the oldest open problem in set theory, and the equivalences of the other statements are similarly hard old open problems. In every known model of ZF where choice fails, these statements fail too, but it is unknown whether they can hold without choice.
Set theory
Partition principle: if there is a surjection from A to B, there is an injection from B to A. Equivalently, every partition P of a set S is less than or equal to S in size.
Converse Schröder–Bernstein theorem: if two sets have surjections to each other, they are equinumerous.
Weak partition principle: if there is a injection and a surjection from A to B, then A and B are equinumerous. Equivalently, a partition of a set S cannot be strictly larger than S. If WPP holds, this already implies the existence of a non-measurable set. Each of the previous three statements is implied by the preceding one, but it is unknown if any of these implications can be reversed.
There is no infinite decreasing sequence of cardinals. The equivalence was conjectured by Schoenflies in 1905.
Abstract algebra
Hahn embedding theorem: Every ordered abelian group G order-embeds as a subgroup of the additive group endowed with a lexicographical order, where Ω is the set of Archimedean equivalence classes of G. This equivalence was conjectured by Hahn in 1907.
Stronger forms of the negation of AC
If we abbreviate by BP the claim that every set of real numbers has the property of Baire, then BP is stronger than ¬AC, which asserts the nonexistence of any choice function on perhaps only a single set of nonempty sets. Strengthened negations may be compatible with weakened forms of AC. For example, ZF + DC + BP is consistent, if ZF is.
It is also consistent with ZF + DC that every set of reals is Lebesgue measurable, but this consistency result, due to Robert M. Solovay, cannot be proved in ZFC itself, but requires a mild large cardinal assumption (the existence of an inaccessible cardinal). The much stronger axiom of determinacy, or AD, implies that every set of reals is Lebesgue measurable, has the property of Baire, and has the perfect set property (all three of these results are refuted by AC itself). ZF + DC + AD is consistent provided that a sufficiently strong large cardinal axiom is consistent (the existence of infinitely many Woodin cardinals).
Quine's system of axiomatic set theory, New Foundations (NF), takes its name from the title ("New Foundations for Mathematical Logic") of the 1937 article that introduced it. In the NF axiomatic system, the axiom of choice can be disproved.
Statements consistent with the negation of AC
There are models of Zermelo-Fraenkel set theory in which the axiom of choice is false. We shall abbreviate "Zermelo-Fraenkel set theory plus the negation of the axiom of choice" by ZF¬C. For certain models of ZF¬C, it is possible to validate the negation of some standard ZFC theorems. As any model of ZF¬C is also a model of ZF, it is the case that for each of the following statements, there exists a model of ZF in which that statement is true.
There is a set that can be partitioned into strictly more equivalence classes than the original set has elements, and a function whose domain is strictly smaller than its range. In fact, this is the case in all known models.
There is a function f from the real numbers to the real numbers such that f is not continuous at a, but f is sequentially continuous at a, i.e., for any sequence {xn} converging to a, limn f(xn)=f(a).
There is an infinite set of real numbers without a countably infinite subset.
The real numbers are a countable union of countable sets. This does not imply that the real numbers are countable: As pointed out above, to show that a countable union of countable sets is itself countable requires the Axiom of countable choice.
There is a field with no algebraic closure.
In all models of ZF¬C there is a vector space with no basis.
There is a vector space with two bases of different cardinalities.
There is a free complete Boolean algebra on countably many generators.
There is a set that cannot be linearly ordered.
There exists a model of ZF¬C in which every set in Rn is measurable. Thus it is possible to exclude counterintuitive results like the Banach–Tarski paradox which are provable in ZFC. Furthermore, this is possible whilst assuming the Axiom of dependent choice, which is weaker than AC but sufficient to develop most of real analysis.
In all models of ZF¬C, the generalized continuum hypothesis does not hold.
For proofs, see .
Additionally, by imposing definability conditions on sets (in the sense of descriptive set theory) one can often prove restricted versions of the axiom of choice from axioms incompatible with general choice. This appears, for example, in the Moschovakis coding lemma.
Axiom of choice in type theory
In type theory, a different kind of statement is known as the axiom of choice. This form begins with two types, σ and τ, and a relation R between objects of type σ and objects of type τ. The axiom of choice states that if for each x of type σ there exists a y of type τ such that R(x,y), then there is a function f from objects of type σ to objects of type τ such that R(x,f(x)) holds for all x of type σ:
Unlike in set theory, the axiom of choice in type theory is typically stated as an axiom scheme, in which R varies over all formulas or over all formulas of a particular logical form.
Quotations
This is a joke: although the three are mathematically equivalent, many mathematicians find the axiom of choice intuitive, the well-ordering principle counterintuitive, and Zorn's lemma too complex for any intuition.
The observation here is that one can define a function to select from an infinite number of pairs of shoes, for example by choosing the left shoe from each pair. Without the axiom of choice, one cannot assert that such a function exists for pairs of socks, because left and right socks are (presumably) indistinguishable.
Polish-American mathematician Jan Mycielski relates this anecdote in a 2006 article in the Notices of the AMS.
This quote comes from the famous April Fools' Day article in the computer recreations column of the Scientific American, April 1989.
Notes
References
Per Martin-Löf, "100 years of Zermelo's axiom of choice: What was the problem with it?", in Logicism, Intuitionism, and Formalism: What Has Become of Them?, Sten Lindström, Erik Palmgren, Krister Segerberg, and Viggo Stoltenberg-Hansen, editors (2008).
, available as a Dover Publications reprint, 2013, .
Herman Rubin, Jean E. Rubin: Equivalents of the axiom of choice. North Holland, 1963. Reissued by Elsevier, April 1970. .
Herman Rubin, Jean E. Rubin: Equivalents of the Axiom of Choice II. North Holland/Elsevier, July 1985, .
George Tourlakis, Lectures in Logic and Set Theory. Vol. II: Set Theory, Cambridge University Press, 2003.
Ernst Zermelo, "Untersuchungen über die Grundlagen der Mengenlehre I," Mathematische Annalen 65: (1908) pp. 261–81. PDF download via digizeitschriften.de
Translated in: Jean van Heijenoort, 2002. From Frege to Gödel: A Source Book in Mathematical Logic, 1879–1931. New edition. Harvard University Press.
1904. "Proof that every set can be well-ordered," 139-41.
1908. "Investigations in the foundations of set theory I," 199–215.
External links
Axiom of Choice entry in the Springer Encyclopedia of Mathematics.
Axiom of Choice and Its Equivalents entry at ProvenMath. Includes formal statement of the Axiom of Choice, Hausdorff's Maximal Principle, Zorn's Lemma and formal proofs of their equivalence down to the finest detail.
Consequences of the Axiom of Choice , based on the book by Paul Howard and Jean Rubin.
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843 | https://en.wikipedia.org/wiki/A%20Clockwork%20Orange%20%28novel%29 | A Clockwork Orange (novel) | A Clockwork Orange is a dystopian satirical black comedy novella by English writer Anthony Burgess, published in 1962. It is set in a near-future society that has a youth subculture of extreme violence. The teenage protagonist, Alex, narrates his violent exploits and his experiences with state authorities intent on reforming him. The book is partially written in a Russian-influenced argot called "Nadsat", which takes its name from the Russian suffix that is equivalent to '-teen' in English. According to Burgess, the novel was a jeu d'esprit written in just three weeks.
In 2005, A Clockwork Orange was included on Time magazine's list of the 100 best English-language novels written since 1923, and it was named by Modern Library and its readers as one of the 100 best English-language novels of the 20th century. The original manuscript of the book has been kept at McMaster University's William Ready Division of Archives and Research Collections in Hamilton, Ontario, Canada since the institution purchased the documents in 1971.
It is considered one of the most influential dystopian books.
In 2022, the novel was included on the "Big Jubilee Read" list of 70 books by Commonwealth authors selected to celebrate the Platinum Jubilee of Elizabeth II.
Plot summary
Part 1: Alex's world
Alex is a 15-year-old gang leader living in a near-future dystopian city. His friends ("droogs" in the novel's Anglo-Russian slang, "Nadsat") and fellow gang members are Dim, a slow-witted bruiser, who is the gang's muscle; Georgie, an ambitious second-in-command; and Pete, who mostly plays along as the droogs indulge their taste for "ultra-violence" (random, violent mayhem). Characterised as a sociopath and hardened juvenile delinquent, Alex is also intelligent, quick-witted, and enjoys classical music; he is particularly fond of Beethoven, whom he calls "Lovely Ludwig Van".
The droogs sit in their favourite hangout, the Korova Milk Bar, drinking "milk-plus" (milk laced with the customer's drug of choice) to prepare for a night of ultra-violence. They assault a scholar walking home from the public library; rob a shop, leaving the owner and his wife bloodied and unconscious; beat up a beggar; then scuffle with a rival gang. Joyriding through the countryside in a stolen car, they break into an isolated cottage and terrorise the young couple living there, beating the husband and gang-raping his wife. The husband is a writer working on a manuscript entitled A Clockwork Orange, and Alex contemptuously reads out a paragraph that states the novel's main theme before shredding the manuscript. At the Korova, Alex strikes Dim for his crude response to a woman's singing of an operatic passage, and strains within the gang become apparent. At home in his parents' flat, Alex plays classical music at top volume, which he describes as giving him orgasmic bliss before falling asleep.
Alex feigns illness to his parents to stay out of school the next day. Following an unexpected visit from P.R. Deltoid, his "post-corrective adviser", Alex visits a record store, where he meets two pre-teen girls. He invites them back to the flat, where he drugs and rapes them. That night after a nap, Alex finds his droogs in a mutinous mood, waiting downstairs in the torn-up and graffitied lobby. Georgie challenges Alex for leadership of the gang, demanding that they focus on higher-value targets in their robberies. Alex quells the rebellion by slashing Dim's hand and fighting with Georgie, then soothes the gang by agreeing to Georgie's plan to rob the home of a wealthy elderly woman. Alex breaks in and knocks the woman unconscious, but when he hears sirens and opens the door to flee, Dim strikes him as revenge for the earlier fight. The gang abandons Alex on the front step to be arrested by the police; while in custody, he learns that the woman has died from her injuries.
Part 2: The Ludovico Technique
Alex is convicted of murder and sentenced to 14 years in prison. His parents visit one day to inform him that Georgie has been killed in a botched robbery. Two years into his term, he has obtained a job in one of the prison chapels, playing music on the stereo to accompany the Sunday Christian services. The chaplain mistakes Alex's Bible studies for stirrings of faith; in reality, Alex only reads Scripture for the violent or sexual passages. After his fellow cellmates blame him for beating a troublesome cellmate to death, he is chosen to undergo an experimental behaviour modification treatment called the Ludovico Technique in exchange for having the remainder of his sentence commuted. The technique is a form of aversion therapy in which Alex is injected with nausea-inducing drugs while watching graphically violent films, eventually conditioning him to become severely ill at the mere thought of violence. As an unintended consequence, the soundtrack to one of the films, Beethoven's Ninth Symphony, renders Alex unable to enjoy his beloved classical music as before.
The technique's effectiveness is demonstrated to a group of VIPs, who watch as Alex collapses before a man who slaps him and abases himself before a scantily clad young woman. Although the prison chaplain accuses the state of stripping Alex of free will, the government officials on the scene are pleased with the results, and Alex is released from prison.
Part 3: After prison
Alex returns to his parents' flat, only to find that they are letting his room to a lodger. Now homeless, he wanders the streets and enters a public library, hoping to learn of a painless method for committing suicide. The old scholar whom Alex had assaulted in Part 1 finds him and beats him with the help of several friends. Two policemen come to Alex's rescue, but they turn out to be Dim and Billyboy, a former rival gang leader. They take Alex outside town, brutalise him, and abandon him there. Alex collapses at the door of an isolated cottage, realising too late that it is the one he and his droogs invaded in Part 1.
The writer, F. Alexander, still lives here, but his wife has since died of what he believes to be injuries she sustained in the rape. He does not recognise Alex but gives him shelter and questions him about the conditioning he has undergone. Alexander and his colleagues, all highly critical of the government, plan to use Alex as a symbol of state brutality and thus prevent the incumbent government from being re-elected. Alex inadvertently reveals that he was the ringleader of the home invasion; he is removed from the cottage and locked in an upper-storey bedroom as a relentless barrage of classical music plays over speakers. He attempts suicide by leaping from the window.
Alex wakes up in a hospital, where he is courted by government officials, anxious to counter the bad publicity created by his suicide attempt. He is informed that F. Alexander has been "put away" for Alex's protection and his own. Alex is offered a well-paying job if he agrees to side with the government once discharged. A round of tests reveals that his old violent impulses have returned, indicating that the hospital doctors have undone the effects of his conditioning. As photographers snap pictures, Alex daydreams of orgiastic violence and reflects, "I was cured all right."
In the final chapter, Alex—now 18 years old and working for the nation's musical recording archives—finds himself halfheartedly preparing for another night of crime with a new gang (Len, Rick, and Bully). After a chance encounter with Pete, who has reformed and married, Alex finds himself taking less and less pleasure in acts of senseless violence. He begins contemplating giving up crime himself to become a productive member of society and start a family of his own while reflecting on the notion that his children could end up being just as destructive as he has been, if not more so.
Omission of the final chapter in the US
The book has three parts, each with seven chapters. Burgess has stated that the total of 21 chapters was an intentional nod to the age of 21 being recognised as a milestone in human maturation. The 21st chapter was omitted from the editions published in the United States prior to 1986. In the introduction to the updated American text (these newer editions include the missing 21st chapter), Burgess explains that when he first brought the book to an American publisher, he was told that US audiences would never go for the final chapter, in which Alex sees the error of his ways, decides he has lost his taste for violence and resolves to turn his life around.
At the American publisher's insistence, Burgess allowed its editors to cut the redeeming final chapter from the US version, so that the tale would end on a darker note, with Alex becoming his old, ultraviolent self again – an ending which the publisher insisted would be "more realistic" and appealing to a US audience. The film adaptation, directed by Stanley Kubrick, is based on the American edition of the book, and is considered to be "badly flawed" by Burgess. Kubrick called Chapter 21 "an extra chapter" and claimed that he had not read the original version until he had virtually finished the screenplay and that he had never given serious consideration to using it. In Kubrick's opinion – as in the opinion of other readers, including the original American editor – the final chapter was unconvincing and inconsistent with the book. Kubrick's stance was unusual when compared to the standard Hollywood practice of producing films with the familiar tropes of resolving moral messages and good triumphing over evil before the film's end.
Characters
Alex: The novel's protagonist and leader among his droogs. He often refers to himself as "Your Humble Narrator". Having coaxed two ten-year-old girls into his bedroom, Alex refers to himself as "Alexander the Large" while raping them; this was later the basis for Alex's claimed surname DeLarge in the 1971 film.
George, Georgie or Georgie Boy: Effectively Alex's greedy second-in-command. Georgie attempts to undermine Alex's status as leader of the gang and take over their gang as the new leader. He is later killed during a botched robbery while Alex is in prison.
Pete: The only one who does not take particular sides when the droogs fight among themselves. He later meets and marries a girl named Georgina, renouncing his violent ways and even losing his former (Nadsat) speech patterns. A chance encounter with Pete in the final chapter influences Alex to realise that he has grown bored with violence and recognise that human energy is better expended on creation than destruction.
Dim: An idiotic and thoroughly gormless member of the gang, persistently condescended to by Alex, but respected to some extent by his droogs for his formidable fighting abilities, his weapon of choice being a length of bike chain. He later becomes a police officer, exacting his revenge on Alex for the abuse he once suffered under his command.
P. R. Deltoid: A criminal rehabilitation social worker assigned the task of keeping Alex on the straight and narrow. He seemingly has no clue about dealing with young people, and is devoid of empathy or understanding for his troublesome charge. Indeed, when Alex is arrested for murdering an old woman and then ferociously beaten by several police officers, Deltoid simply spits on him.
Prison Chaplain: The character who first questions whether it is moral to turn a violent person into a behavioural automaton who can make no choice in such matters. This is the only character who is truly concerned about Alex's welfare; he is not taken seriously by Alex, though. He is nicknamed by Alex "prison charlie" or "chaplin", a pun on Charlie Chaplin.
Billyboy: A rival of Alex's. Early on in the story, Alex and his droogs battle Billyboy and his droogs, which ends abruptly when the police arrive. Later, after Alex is released from prison, Billyboy (along with Dim, who like Billyboy has become a police officer) rescues Alex from a mob, then subsequently beats him in a location out of town.
Prison Governor: The man who decides to let Alex "choose" to be the first reformed by the Ludovico technique.
The Minister of the Interior: The government high-official who determined that the Ludovico's technique will be used to cut recidivism. He is referred to as the Minister of Interior or Inferior by Alex.
Dr Branom: A scientist, co-developer of the Ludovico technique. He appears friendly and almost paternal towards Alex at first, before forcing him into the theatre and what Alex calls the "chair of torture".
Dr Brodsky: Branom's colleague and co-developer of the Ludovico technique. He seems much more passive than Branom and says considerably less.
F. Alexander: An author who was in the process of typing his magnum opus A Clockwork Orange when Alex and his droogs broke into his house, beat him, tore up his work and then brutally gang-raped his wife, which caused her subsequent death. He is left deeply scarred by these events and when he encounters Alex two years later, he uses him as a guinea pig in a sadistic experiment intended to prove the Ludovico technique unsound. The government imprisons him afterwards. He is given the name Frank Alexander in the film.
Cat Woman: An indirectly named woman who blocks Alex's gang's entrance scheme, and threatens to shoot Alex and set her cats on him if he does not leave. After Alex breaks into her house, she fights with him, ordering her cats to join the melee, but reprimands Alex for fighting them off. She sustains a fatal blow to the head during the scuffle. She is given the name Miss Weathers in the film.
Analysis
Background
A Clockwork Orange was written in Hove, then a senescent English seaside town. Burgess had arrived back in Britain after his stint abroad to see that much had changed. A youth culture had developed, based around coffee bars, pop music and teenage gangs. England was gripped by fears over juvenile delinquency. Burgess stated that the novel's inspiration was his first wife Lynne's beating by a gang of drunk American servicemen stationed in England during World War II. She subsequently miscarried. In its investigation of free will, the book's target is ostensibly the concept of behaviourism, pioneered by such figures as B. F. Skinner. Burgess later stated that he wrote the book in three weeks.
Title
Burgess has offered several clarifications about the meaning and origin of its title:
He had overheard the phrase "as queer as a clockwork orange" in a London pub in 1945 and assumed it was a Cockney expression. In Clockwork Marmalade, an essay published in the Listener in 1972, he said that he had heard the phrase several times since that occasion. He also explained the title in response to a question from William Everson on the television programme Camera Three in 1972, "Well, the title has a very different meaning but only to a particular generation of London Cockneys. It's a phrase which I heard many years ago and so fell in love with, I wanted to use it, the title of the book. But the phrase itself I did not make up. The phrase "as queer as a clockwork orange" is good old East London slang and it didn't seem to me necessary to explain it. Now, obviously, I have to give it an extra meaning. I've implied an extra dimension. I've implied the junction of the organic, the lively, the sweet – in other words, life, the orange – and the mechanical, the cold, the disciplined. I've brought them together in this kind of oxymoron, this sour-sweet word." No other record of the expression being used before 1962 has ever appeared, with Kingsley Amis going so far as to note in his Memoirs (1991) that no trace of it appears in Eric Partridge's Dictionary of Historical Slang. However, saying "as queer as ..." followed by an improbable object: "... a clockwork orange", or "... a four-speed walking stick" or "... a left-handed corkscrew" etc. predates Burgess's novel. An early example, "as queer as Dick's hatband", appeared in 1796, and was alluded to in 1757.
His second explanation was that it was a pun on the Malay word orang, meaning "man". The novella contains no other Malay words or links.
In a prefatory note to A Clockwork Orange: A Play with Music, he wrote that the title was a metaphor for "an organic entity, full of juice and sweetness and agreeable odour, being turned into a mechanism".
In his essay Clockwork Oranges, Burgess asserts that "this title would be appropriate for a story about the application of Pavlovian or mechanical laws to an organism which, like a fruit, was capable of colour and sweetness".
While addressing the reader in a letter before some editions of the book, the author says that when a man ceases to have free will, they are no longer a man. "Just a clockwork orange", a shiny, appealing object, but "just a toy to be wound-up by either God or the Devil, or (what is increasingly replacing both) the State."
This title alludes to the protagonist's negative emotional responses to feelings of evil which prevent the exercise of his free will subsequent to the administration of the Ludovico Technique. To induce this conditioning, Alex is forced to watch scenes of violence on a screen that are systematically paired with negative physical stimulation. The negative physical stimulation takes the form of nausea and "feelings of terror", which are caused by an emetic medicine administered just before the presentation of the films.
In its original drafts, Burgess used the working title 'The Ludovico Technique,' as he himself described in the foreword in the April 1995 publication. Along with removing the 21st chapter as insisted by his publisher in the original 1962 edition, he would also change the finished product's name to its current title.
Use of slang
The book, narrated by Alex, contains many words in a slang argot which Burgess invented for the book, called Nadsat. It is a mix of modified Slavic words, Cockney rhyming slang and derived Russian (like baboochka). For instance, these terms have the following meanings in Nadsat: droog (друг) = friend; moloko (молоко) = milk; gulliver (голова) = head; malchick (мальчик) or malchickiwick = boy; soomka (сумка) = sack or bag; Bog (Бог) = God; horrorshow (хорошо) = good; prestoopnick (преступник) = criminal; rooker (рука) = hand; cal (кал) = crap; veck (человек) = man or guy; litso (лицо) = face; malenky (маленький) = little; and so on. Some words Burgess invented himself or just adapted from existing languages. Compare Polari.
One of Alex's doctors explains the language to a colleague as "odd bits of old rhyming slang; a bit of gypsy talk, too. But most of the roots are Slav propaganda. Subliminal penetration." Some words are not derived from anything, but merely easy to guess, e.g. "in-out, in-out" or "the old in-out" means sexual intercourse. Cutter, however, means "money", because "cutter" rhymes with "bread-and-butter"; this is rhyming slang, which is intended to be impenetrable to outsiders (especially eavesdropping policemen). Additionally, slang like appypolly loggy ("apology") seems to derive from school boy slang. This reflects Alex's age of 15.
In the first edition of the book, no key was provided, and the reader was left to interpret the meaning from the context. In his appendix to the restored edition, Burgess explained that the slang would keep the book from seeming dated, and served to muffle "the raw response of pornography" from the acts of violence.
The term "ultraviolence", referring to excessive or unjustified violence, was coined by Burgess in the book, which includes the phrase "do the ultra-violent". The term's association with aesthetic violence has led to its use in the media.
Banning and censorship history in the US
The first major incident of censorship of A Clockwork Orange took place in 1973, when a bookseller was arrested for selling the novel (although the charges were later dropped). In 1976, A Clockwork Orange was removed from an Aurora, Colorado high school because of "objectionable language". A year later in 1977 it was removed from high school classrooms in Westport, Massachusetts over similar concerns with "objectionable" language. In 1982, it was removed from two Anniston, Alabama libraries, later to be reinstated on a restricted basis. However, each of these instances came after the release of Stanley Kubrick's popular 1971 film adaptation of A Clockwork Orange, itself the subject of much controversy after exposing a much larger part of the populace to the themes of the novel.
Reception
Initial response
The Sunday Telegraph review was positive, and described the book as "entertaining ... even profound". Kingsley Amis in The Observer acclaimed the novel as "cheerful horror", writing "Mr Burgess has written a fine farrago of outrageousness, one which incidentally suggests a view of juvenile violence I can't remember having met before". Malcolm Bradbury wrote "All of Mr Burgess's powers as a comic writer, which are considerable, have gone into the rich language of his inverted Utopia. If you can stomach the horrors, you'll enjoy the manner". Roald Dahl called it "a terrifying and marvellous book". Many reviewers praised the inventiveness of the language, but expressed unease at the violent subject matter. The Spectator praised Burgess's "extraordinary technical feat" but was uncomfortable with "a certain arbitrariness about the plot which is slightly irritating". New Statesman acclaimed Burgess for addressing "acutely and savagely the tendencies of our time" but called the book "a great strain to read". The Sunday Times review was negative, and described the book as "a very ordinary, brutal and psychologically shallow story". The Times also reviewed the book negatively, describing it as "a somewhat clumsy experiment with science fiction [with] clumsy cliches about juvenile delinquency". The violence was criticised as "unconvincing in detail".
Writer's appraisal
Burgess dismissed A Clockwork Orange as "too didactic to be artistic". He said that the violent content of the novel "nauseated" him.
In 1985, Burgess published Flame into Being: The Life and Work of D. H. Lawrence and while discussing Lady Chatterley's Lover in his biography, Burgess compared the notoriety of D. H. Lawrence's novel with A Clockwork Orange: "We all suffer from the popular desire to make the known notorious. The book I am best known for, or only known for, is a novel I am prepared to repudiate: written a quarter of a century ago, a jeu d'esprit knocked off for money in three weeks, it became known as the raw material for a film which seemed to glorify sex and violence. The film made it easy for readers of the book to misunderstand what it was about, and the misunderstanding will pursue me until I die. I should not have written the book because of this danger of misinterpretation, and the same may be said of Lawrence and Lady Chatterley's Lover."
Awards and nominations and rankings
1983 – Prometheus Award (Preliminary Nominee)
1999 – Prometheus Award (Nomination)
2002 – Prometheus Award (Nomination)
2003 – Prometheus Award (Nomination)
2006 – Prometheus Award (Nomination)
2008 – Prometheus Award (Hall of Fame Award)
A Clockwork Orange was chosen by Time magazine as one of the 100 best English-language books from 1923 to 2005.
Adaptations
A 1965 film by Andy Warhol entitled Vinyl was an adaptation of Burgess's novel.
The best known adaptation of the novella is the 1971 film A Clockwork Orange by Stanley Kubrick, with Malcolm McDowell as Alex. In 1987, Burgess published a stage play titled A Clockwork Orange: A Play with Music. The play includes songs, written by Burgess, which are inspired by Beethoven and Nadsat slang.
A manga anthology by Osamu Tezuka entitled Tokeijikake no Ringo (Clockwork Apple) was released in 1983.
In 1988, a German adaptation of A Clockwork Orange at the intimate theatre of Bad Godesberg featured a musical score by the German punk rock band Die Toten Hosen which, combined with orchestral clips of Beethoven's Ninth Symphony and "other dirty melodies" (so stated by the subtitle), was released on the album Ein kleines bisschen Horrorschau. The track Hier kommt Alex became one of the band's signature songs.
In February 1990, another musical version was produced at the Barbican Theatre in London by the Royal Shakespeare Company. Titled A Clockwork Orange: 2004, it received mostly negative reviews, with John Peter of The Sunday Times of London calling it "only an intellectual Rocky Horror Show", and John Gross of The Sunday Telegraph calling it "a clockwork lemon". Even Burgess himself, who wrote the script based on his novel, was disappointed. According to The Evening Standard, he called the score, written by Bono and The Edge of the rock group U2, "neo-wallpaper". Burgess had originally worked alongside the director of the production, Ron Daniels, and envisioned a musical score that was entirely classical. Unhappy with the decision to abandon that score, he heavily criticised the band's experimental mix of hip hop, liturgical, and gothic music. Lise Hand of The Irish Independent reported The Edge as saying that Burgess's original conception was "a score written by a novelist rather than a songwriter". Calling it "meaningless glitz", Jane Edwardes of 20/20 magazine said that watching this production was "like being invited to an expensive French Restaurant – and being served with a Big Mac."
In 1994, Chicago's Steppenwolf Theater put on a production of A Clockwork Orange directed by Terry Kinney. The American premiere of novelist Anthony Burgess's own adaptation of his A Clockwork Orange starred K. Todd Freeman as Alex. In 2001, UNI Theatre (Mississauga, Ontario) presented the Canadian premiere of the play under the direction of Terry Costa.
In 2002, Godlight Theatre Company presented the New York Premiere adaptation of A Clockwork Orange at Manhattan Theatre Source. The production went on to play at the SoHo Playhouse (2002), Ensemble Studio Theatre (2004), 59E59 Theaters (2005) and the Edinburgh Festival Fringe (2005). While at Edinburgh, the production received rave reviews from the press while playing to sold-out audiences. The production was directed by Godlight's artistic director, Joe Tantalo.
In 2003, Los Angeles director Brad Mays and the ARK Theatre Company staged a multi-media adaptation of A Clockwork Orange, which was named "Pick of the Week" by the LA Weekly and nominated for three of the 2004 LA Weekly Theater Awards: Direction, Revival Production (of a 20th-century work), and Leading Female Performance. Vanessa Claire Smith won Best Actress for her gender-bending portrayal of Alex, the music-loving teenage sociopath. This production utilised three separate video streams outputted to seven onstage video monitors – six 19-inch and one 40-inch. In order to preserve the first-person narrative of the book, a pre-recorded video stream of Alex, "your humble narrator", was projected onto the 40-inch monitor, thereby freeing the onstage character during passages which would have been awkward or impossible to sustain in the breaking of the fourth wall.
An adaptation of the work, based on the original novel, the film and Burgess's own stage version, was performed by the SiLo Theatre in Auckland, New Zealand in early 2007.
In 2021, the International Anthony Burgess Foundation premiered a webpage cataloging various productions of A Clockwork Orange from around the world.
See also
Classical conditioning
List of cultural references to A Clockwork Orange
List of stories set in a future now in the past
MKUltra
Violence in art
References
Further reading
A Clockwork Orange: A Play With Music. Century Hutchinson Ltd. (1987). An extract is quoted on several web sites: Anthony Burgess from A Clockwork Orange: A Play With Music (Century Hutchinson Ltd, 1987), , A Clockwork Orange - From A Clockwork Orange: A Play With Music
Burgess, Anthony (1978). "Clockwork Oranges". In 1985. London: Hutchinson. (extracts quoted here)
External links
A Clockwork Orange at SparkNotes
A Clockwork Orange at Literapedia
A Clockwork Orange (1962) |Last chapter |Anthony Burgess (1917–1993)
Comparisons with the Kubrick film adaptation
Dalrymple, Theodore. "A Prophetic and Violent Masterpiece", City Journal
Giola, Ted. "A Clockwork Orange by Anthony Burgess" at Conceptual Fiction
Priestley, Brenton. "Of Clockwork Apples and Oranges: Burgess and Kubrick (2002)"
1962 British novels
1962 science fiction novels
Novel
Books written in fictional dialects
British novellas
British novels adapted into films
British novels adapted into plays
British philosophical novels
British science fiction novels
Censored books
Crime novels
Counterculture of the 1960s
Dystopian novels
English-language novels
Fiction about mind control
Fiction with unreliable narrators
Fiction about gang rape
Heinemann (publisher) books
Metafictional novels
Novels about music
Novels about rape
Novels by Anthony Burgess
Obscenity controversies in literature
Science fiction novels adapted into films |
844 | https://en.wikipedia.org/wiki/Amsterdam | Amsterdam | Amsterdam ( , , ; literally, "The Dam on the River Amstel") is the capital and most populated city of the Netherlands. It has a population of 921,402 within the city proper, 1,457,018 in the urban area and 2,480,394 in the metropolitan area. Located in the Dutch province of North Holland, Amsterdam is colloquially referred to as the "Venice of the North", for its large number of canals, now a UNESCO World Heritage Site.
Amsterdam was founded at the mouth of the Amstel River, which was dammed to control flooding. Originally a small fishing village in the 12th century, Amsterdam became a major world port during the Dutch Golden Age of the 17th century, when the Netherlands was an economic powerhouse. Amsterdam was the leading centre for finance and trade, as well as a hub of secular art production. In the 19th and 20th centuries, the city expanded and new neighborhoods and suburbs were built. The city has a long tradition of openness, liberalism, and tolerance. Cycling is key to the city's modern character, and there are numerous biking paths and lanes spread throughout.
Amsterdam's main attractions include its historic canals; the , the state museum with Dutch Golden Age art; the Van Gogh Museum; the Dam Square, where the Royal Palace of Amsterdam and former city hall are located; the Amsterdam Museum; Stedelijk Museum, with modern art; the concert hall; the Anne Frank House; the , the ; Hortus Botanicus, NEMO, the red-light district and cannabis coffee shops. The city is known for its nightlife and festival activity, with several nightclubs among the world's most famous. Its artistic heritage, canals and narrow canal houses with gabled façades, well-preserved legacies of the city's 17th-century Golden Age, have attracted millions of visitors annually.
The Amsterdam Stock Exchange, founded in 1602, is considered the oldest "modern" securities market stock exchange in the world. As the commercial capital of the Netherlands and one of the top financial centres in Europe, Amsterdam is considered an alpha world city. The city is the cultural capital of the Netherlands. Many large Dutch institutions have their headquarters in the city. Many of the world's largest companies are based here or have established their European headquarters in the city, such as technology companies Uber, Netflix and Tesla. In 2022, Amsterdam was ranked the ninth-best city to live in by the Economist Intelligence Unit and 12th on quality of living for environment and infrastructure by Mercer. The city was ranked 4th place globally as top tech hub in 2019. The Port of Amsterdam is the fifth largest in Europe. The KLM hub and Amsterdam's main airport, Schiphol, is the busiest airport in the Netherlands, third in Europe, and 11th in the world. The Dutch capital is one of the most multicultural cities in the world, with about 180 nationalities represented. Immigration and ethnic segregation in Amsterdam is a current issue.
Amsterdam's notable residents throughout its history include painters Rembrandt and Vincent van Gogh, 17th-century philosophers Baruch Spinoza, John Locke, René Descartes, and the Holocaust victim and diarist Anne Frank.
History
Prehistory
Due to its geographical location in what used to be wet peatland, the founding of Amsterdam is later than other urban centres in the Low Countries. However, around the area of what later became Amsterdam, farmers settled as early as three millennia ago. They lived along the prehistoric IJ river and upstream of its tributary Amstel. The prehistoric IJ was a shallow and quiet stream in peatland behind beach ridges. This secluded area was able to grow into an important local settlement centre, especially in the late Bronze Age, the Iron Age and the Roman Age. Neolithic and Roman artefacts have also been found in the prehistoric Amstel bedding under Amsterdam's Damrak and Rokin, such as shards of Bell Beaker culture pottery (2200-2000 BC) and a granite grinding stone (2700-2750 BC), but the location of these artefacts around the river banks of the Amstel probably point to a presence of a modest semi-permanent or seasonal settlement. Until water issues were controlled, a permanent settlement would not have been possible, since the river mouth and the banks of the Amstel in this period in time were too wet for permanent habitation.
Founding
The origins of Amsterdam are linked to the development of a dam on the Amstel River called Amestelle, meaning 'watery area', from Aa(m) 'river' + stelle 'site at a shoreline', 'river bank'. In this area, land reclamation started as early as the late 10th century. Amestelle was located along a side arm of the IJ. This side arm took the name from the eponymous land: Amstel. Amestelle was inhabited by farmers, who lived more inland and more upstream, where the land was not as wet as at the banks of the downstream river mouth. These farmers were starting the reclamation around upstream Ouderkerk aan de Amstel, and later at the other side of the river at Amstelveen. The Van Amstel family, known in documents by this name since 1019, held the stewardship in this northwestern nook of the ecclesiastical district of the bishop of Utrecht. The family later served also under the count of Holland.
A major turning point in the development of the Amstel river mouth was the All Saint's Flood of 1170. In an extremely short period of time, the shallow river IJ turned into a wide estuary, which from then on offered the Amstel an open connection to the Zuiderzee, IJssel and waterways further afield. This made the water flow of the Amstel more active, so excess water could be drained better. With drier banks, the downstream Amstel mouth became attractive for permanent habitation. Moreover, the river had grown from an insignificant peat stream into a junction of international waterways. A settlement was built here immediately after the landscape change of 1170. Right from the start of its foundation it focused on traffic, production and trade; not on farming, as opposed to how communities had lived further upstream for the past 200 years and northward for thousands of years. The construction of a dam at the mouth of the Amstel, eponymously named Dam, is historically estimated to have occurred between 1264 and 1275. The settlement first appeared in a document from 1275, concerning a road toll granted by the count of Holland Floris V to the residents apud Amestelledamme 'at the dam in the Amstel' or 'at the dam of Amstelland'. This allowed the inhabitants of the village to travel freely through the County of Holland, paying no tolls at bridges, locks and dams. This was a move in a years-long struggle for power in the area between the count of Holland and the Amstel family who governed the area on behalf of the bishop of Utrecht. By 1327, the name had developed into Aemsterdam.
Middle Ages
The bishop of Utrecht granted Amsterdam zone rights in either 1300 or 1306. The in 1345 rendered the city an important place of pilgrimage. During the heyday of the Stille Omgang, which became the expression of the pilgrimage after the Protestant Reformation, up to 90,000 pilgrims came to Amsterdam.
From the 14th century on, Amsterdam flourished, largely from trade with the Hanseatic League. From the 15th century on the city established an independent trade route with the Baltic Sea in grain and timber, cutting out the Hanseatic League as middlemen. The city became the staple market of Europe for bulk cargo. This was made possible due to innovations in the herring fishery, from which Amsterdam reaped great wealth. Herring had demand in markets all around Europe. Inventions of on-board gibbing and the haringbuis in 1415, made longer voyages feasible, and hence enabled Dutch fishermen to follow the herring shoals far from the coasts, giving them a monopoly in the industry.
The herring industry relied on international trade cooperation and large initial investments in ships, which needed many highly skilled and unskilled workers cooperating, which required the import of the necessary raw materials to turn an unfinished product into a marketable one, which required merchants to then sell it throughout the continent and book-keepers and accountants to divide the profit. In short, the herring industry was setting up the foundations for what would later become the transcontinental trade system and the Dutch Golden Age, with Amsterdam at its centre, hence the saying "Amsterdam is built on Herring bones".
Conflict with Spain
The Low Countries were part of the Hapsburg inheritance and came under the Spanish monarchy in the early sixteenth century. The Dutch rebelled against Philip II of Spain, who led a defense of Catholicism during the Protestant Reformation. The main reasons for the uprising were the imposition of new taxes, the tenth penny, and the religious persecution of Protestants by the newly introduced Inquisition. The revolt escalated into the Eighty Years' War, which ultimately led to Dutch independence. Strongly pushed by Dutch Revolt leader William the Silent, the Dutch Republic became known for its relative religious tolerance. Jews from the Iberian Peninsula, Protestant Huguenots from France, prosperous merchants and printers from Flanders, and economic and religious refugees from the Spanish-controlled parts of the Low Countries found safety in Amsterdam. The influx of Flemish printers and the city's intellectual tolerance made Amsterdam a centre for the European free press.
Centre of the Dutch Golden Age
During the 17th century, Amsterdam experienced what is considered its Golden Age, during which it became the wealthiest city in the Western world. Ships sailed from Amsterdam to the Baltic Sea, the Caribbean, North America, and Africa, as well as present-day Indonesia, India, Sri Lanka, and Brazil, forming the basis of a worldwide trading network. Amsterdam's merchants had the largest share in both the Dutch East India Company (VOC) and the Dutch West India Company. These companies acquired overseas possessions that later became Dutch colonies.
Amsterdam was Europe's most important hub for the shipment of goods and was the leading financial centre of the Western world. In 1602, the Amsterdam office of the Dutch East India Company became the world's first stock exchange by trading in its own shares. The Bank of Amsterdam started operations in 1609, acting as a full-service bank for Dutch merchant bankers and as a reserve bank.
From the 17th century onwards, Amsterdam also became involved in the Atlantic slave trade. The city was a major destination port for Dutch slave ships participating in the triangular trade, which lasted until the United Netherlands abolished the Netherlands' involvement in the trade in 1814 at the request of the British government. Amsterdam was also a member of the Society of Suriname, an organisation founded to oversee the management of the Dutch colony of Surinam, which was economically dependent on slave plantations. On 1 July 2021, the mayor of Amsterdam, Femke Halsema, apologised for the city's involvement in the slave trade.
Decline and modernization
Amsterdam's prosperity declined during the 18th and early 19th centuries. The wars of the Dutch Republic with England (latterly, Great Britain) and France took their toll on the city. During the Napoleonic Wars, Amsterdam's significance reached its lowest point, with Holland being absorbed into the French Empire. However, the later establishment of the United Kingdom of the Netherlands in 1815 marked a turning point.
The end of the 19th century is sometimes called Amsterdam's second Golden Age. New museums, a railway station, and the were built; At the same time, the Industrial Revolution reached the city. The Amsterdam–Rhine Canal was dug to give Amsterdam a direct connection to the Rhine, and the North Sea Canal was dug to give the port a shorter connection to the North Sea. Both projects dramatically improved commerce with the rest of Europe and the world. In 1906, Joseph Conrad gave a brief description of Amsterdam as seen from the seaside, in The Mirror of the Sea.
20th century – present
Shortly before the First World War, the city started to expand again, and new suburbs were built. Even though the Netherlands remained neutral in this war, Amsterdam suffered a food shortage, and heating fuel became scarce. The shortages sparked riots in which several people were killed. These riots are known as the Aardappeloproer (Potato rebellion). People started looting stores and warehouses in order to get supplies, mainly food.
On 1 January 1921, after a flood in 1916, the depleted municipalities of Durgerdam, Holysloot, Zunderdorp and Schellingwoude, all lying north of Amsterdam, were, at their own request, annexed to the city. Between the wars, the city continued to expand, most notably to the west of the Jordaan district in the Frederik Hendrikbuurt and surrounding neighbourhoods.
Nazi Germany invaded the Netherlands on 10 May 1940 and took control of the country. Some Amsterdam citizens sheltered Jews, thereby exposing themselves and their families to a high risk of being imprisoned or sent to concentration camps. More than 100,000 Dutch Jews were deported to Nazi concentration camps, of whom some 60,000 lived in Amsterdam. In response, the Dutch Communist Party organized the February strike attended by 300,000 people to protest against the raids. The most famous deportee was the young Jewish girl Anne Frank, who died in the Bergen-Belsen concentration camp. At the end of the Second World War, communication with the rest of the country broke down, and food and fuel became scarce. Many citizens traveled to the countryside to forage. Dogs, cats, raw sugar beets, and tulip bulbs—cooked to a pulp—were consumed to stay alive. Many trees in Amsterdam were cut down for fuel, and wood was taken from the houses, apartments and other buildings of deported Jews. The city was finally liberated by Canadian forces on 5 May 1945, shortly before the end of the war in Europe.
Many new suburbs, such as Osdorp, Slotervaart, Slotermeer and Geuzenveld, were built in the years after the Second World War. These suburbs contained many public parks and wide-open spaces, and the new buildings provided improved housing conditions with larger and brighter rooms, gardens, and balconies. Because of the war and other events of the 20th century, almost the entire city centre had fallen into disrepair. As society was changing, politicians and other influential figures made plans to redesign large parts of it. There was an increasing demand for office buildings, and also for new roads, as the automobile became available to most people. A metro started operating in 1977 between the new suburb of Bijlmermeer in the city's Zuidoost (southeast) exclave and the centre of Amsterdam. Further plans were to build a new highway above the metro to connect Amsterdam Centraal and the city centre with other parts of the city.
The required large-scale demolitions began in Amsterdam's former Jewish neighborhood. Smaller streets, such as the Jodenbreestraat and Weesperstraat, were widened and almost all houses and buildings were demolished. At the peak of the demolition, the Nieuwmarktrellen (Nieuwmarkt Riots) broke out; the rioters expressed their fury about the demolition caused by the restructuring of the city.
As a result, the demolition was stopped and the highway into the city's centre was never fully built; only the metro was completed. Only a few streets remained widened. The new city hall was built on the almost completely demolished Waterlooplein. Meanwhile, large private organizations, such as Stadsherstel Amsterdam, were founded to restore the entire city centre. Although the success of this struggle is visible today, efforts for further restoration are still ongoing. The entire city centre has reattained its former splendour and, as a whole, is now a protected area. Many of its buildings have become monuments, and in July 2010 the Grachtengordel (the three concentric canals: Herengracht, Keizersgracht, and Prinsengracht) was added to the UNESCO World Heritage List.
In the 21st century, the Amsterdam city centre has attracted large numbers of tourists: between 2012 and 2015, the annual number of visitors rose from 10 to 17 million. Real estate prices have surged, and local shops are making way for tourist-oriented ones, making the centre unaffordable for the city's inhabitants. These developments have evoked comparisons with Venice, a city thought to be overwhelmed by the tourist influx.
Construction of a new metro line connecting the part of the city north of the IJ to its southern part was started in 2003. The project was controversial because its cost had exceeded its budget by a factor of three by 2008, because of fears of damage to buildings in the centre, and because construction had to be halted and restarted multiple times. The new metro line was completed in 2018.
Since 2014, renewed focus has been given to urban regeneration and renewal, especially in areas directly bordering the city centre, such as Frederik Hendrikbuurt. This urban renewal and expansion of the traditional centre of the city—with the construction on artificial islands of the new eastern IJburg neighbourhood—is part of the Structural Vision Amsterdam 2040 initiative.
Geography
Amsterdam is located in the Western Netherlands, in the province of North Holland, the capital of which is not Amsterdam, but rather Haarlem. The river Amstel ends in the city centre and connects to a large number of canals that eventually terminate in the IJ. Amsterdam's elevation is about below sea level. The surrounding land is flat as it is formed of large polders. An artificial forest, Amsterdamse Bos, is in the southwest. Amsterdam is connected to the North Sea through the long North Sea Canal.
Amsterdam is intensely urbanised, as is the Amsterdam metropolitan area surrounding the city. Comprising of land, the city proper has 4,457 inhabitants per km2 and 2,275 houses per km2. Parks and nature reserves make up 12% of Amsterdam's land area.
Water
Amsterdam has more than of canals, most of which are navigable by boat. The city's three main canals are the Prinsengracht, the Herengracht and the Keizersgracht.
In the Middle Ages, Amsterdam was surrounded by a moat, called the Singel, which now forms the innermost ring in the city, and gives the city centre a horseshoe shape. The city is also served by a seaport. It has been compared with Venice, due to its division into about 90 islands, which are linked by more than 1,200 bridges.
Climate
Amsterdam has an oceanic climate (Köppen: Cfb) strongly influenced by its proximity to the North Sea to the west, with prevailing westerly winds.
Amsterdam, as well as most of the North Holland province, lies in USDA Hardiness zone 8b. Frosts mainly occur during spells of easterly or northeasterly winds from the inner European continent. Even then, because Amsterdam is surrounded on three sides by large bodies of water, as well as having a significant heat-island effect, nights rarely fall below , while it could easily be in Hilversum, southeast.
Summers are moderately warm with a number of hot and humid days with occasional rain every month. The average daily high in August is , and or higher is only measured on average on 2.5 days, placing Amsterdam in AHS Heat Zone 2. The record extremes range from to .
Days with more than of precipitation are common, on average 133 days per year.
Amsterdam's average annual precipitation is . A large part of this precipitation falls as light rain or brief showers. Cloudy and damp days are common during the cooler months of October through March.
Demographics
Historical population
In 1300, Amsterdam's population was around 1,000 people. While many towns in Holland experienced population decline during the 15th and 16th centuries, Amsterdam's population grew, mainly due to the rise of the profitable Baltic maritime trade especially in grain after the Burgundian victory in the Dutch–Hanseatic War in 1441. The population of Amsterdam was only modest compared to the towns and cities of Flanders and Brabant, which comprised the most urbanized area of the Low Countries.
This changed when, during the Dutch Revolt, many people from the Southern Netherlands fled to the North, especially after Antwerp fell to Spanish forces in 1585. Jews from Spain, Portugal and Eastern Europe similarly settled in Amsterdam, as did Germans and Scandinavians. In thirty years, Amsterdam's population more than doubled between 1585 and 1610. By 1600, its population was around 50,000. During the 1660s, Amsterdam's population reached 200,000. The city's growth levelled off and the population stabilized around 240,000 for most of the 18th century.
In 1750, Amsterdam was the fourth largest city in Western Europe, behind London (676,000), Paris (560,000) and Naples (324,000). This was all the more remarkable as Amsterdam was neither the capital city nor the seat of government of the Dutch Republic, which itself was a much smaller state than Great Britain, France or the Ottoman Empire. In contrast to those other metropolises, Amsterdam was also surrounded by large towns such as Leiden (about 67,000), Rotterdam (45,000), Haarlem (38,000) and Utrecht (30,000).
The city's population declined in the early 19th century, dipping under 200,000 in 1820. By the second half of the 19th century, industrialization spurred renewed growth. Amsterdam's population hit an all-time high of 872,000 in 1959, before declining in the following decades due to government-sponsored suburbanisation to so-called groeikernen (growth centres) such as Purmerend and Almere. Between 1970 and 1980, Amsterdam experienced a sharp population decline, peaking at a net loss of 25,000 people in 1973. By 1985 the city had only 675,570 residents. This was soon followed by reurbanization and gentrification, leading to renewed population growth in the 2010s. Also in the 2010s, much of Amsterdam's population growth was due to immigration to the city.
Immigration
In the 16th and 17th century, non-Dutch immigrants to Amsterdam were mostly Protestant Huguenots and Flemings, Sephardic Jews, and Westphalians. Huguenots came after the Edict of Fontainebleau in 1685, while the Flemish Protestants came during the Eighty Years' War against Catholic Spain. The Westphalians came to Amsterdam mostly for economic reasons; their influx continued through the 18th and 19th centuries. Before the Second World War, 10% of the city population was Jewish. Just twenty percent of them survived the Holocaust.
The first mass immigration in the 20th century was by people from Indonesia, who came to Amsterdam after the independence of the Dutch East Indies in the 1940s and 1950s. In the 1960s guest workers from Turkey, Morocco, Italy, and Spain emigrated to Amsterdam. After the independence of Suriname in 1975, a large wave of Surinamese settled in Amsterdam, mostly in the Bijlmer area. Other immigrants, including refugees asylum seekers and undocumented immigrants, came from Europe, the Americas, Asia and Africa. In the 1970s and 1980s, many 'old' Amsterdammers moved to 'new' cities like Almere and Purmerend, prompted by the third Land-use planning bill of the Dutch Government. This bill promoted suburbanization and arranged for new developments in so-called "groeikernen", literally cores of growth. Young professionals and artists moved into neighborhoods De Pijp and the Jordaan abandoned by these Amsterdammers. The non-Western immigrants settled mostly in the social housing projects in Amsterdam-West and the Bijlmer. Today, people of non-Western origin make up approximately one-fifth of the population of Amsterdam, and more than 30% of the city's children. A slight majority of the residents of Amsterdam have at least one parent who was born outside the country. However, a much larger majority has at least one parent who was born inside the country (intercultural marriages are common in the city). Thus, while the demographics are changing, the city still has an ethnic Dutch majority. Only one in three inhabitants under 15 is an autochthon, or a person who has two parents of Dutch origin. Segregation along ethnic lines is clearly visible, with people of non-Western origin, considered a separate group by Statistics Netherlands, concentrating in specific neighborhoods especially in Nieuw-West, Zeeburg, Bijlmer and in certain areas of Amsterdam-Noord.
In 2000, Christians formed the largest religious group in the city (28% of the population). The next largest religion was Islam (8%), most of whose followers were Sunni. In 2015, Christians formed the largest religious group in the city (28% of the population). The next largest religion was Islam (7.1%), most of whose followers were Sunni.
Religion
In 1578, the largely Catholic city of Amsterdam joined the revolt against Spanish rule, late in comparison to other major northern Dutch cities. Catholic priests were driven out of the city. Following the Dutch takeover, all churches were converted to Protestant worship. Calvinism was declared the main religion. It was forbidden to openly profess Roman Catholicism and the Catholic hierarchy was prohibited until the mid-19th century. This led to the establishment of clandestine churches, covert religious buildings hidden in pre-existing buildings. Catholics, some Jews and dissenting Protestants worshipped in such buildings. A large influx of foreigners of many religions came to 17th-century Amsterdam, in particular Sefardic Jews from Spain and Portugal, Huguenots from France, Lutherans, Mennonites, as well as Protestants from across the Netherlands. This led to the establishment of many non-Dutch-speaking churches. In 1603, the Jewish received permission to practice their religion in the city. In 1639, the first synagogue was consecrated. The Jews came to call the town "Jerusalem of the West".
As they became established in the city, other Christian denominations used converted Catholic chapels to conduct their own services. The oldest English-language church congregation in the world outside the United Kingdom is found at the Begijnhof. Regular services there are still offered in English under the auspices of the Church of Scotland. Being Calvinists, the Huguenots soon integrated into the Dutch Reformed Church, though often retaining their own congregations. Some, commonly referred to by the moniker 'Walloon', are recognizable today as they offer occasional services in French.
In the second half of the 17th century, Amsterdam experienced an influx of Ashkenazim, Jews from Central and Eastern Europe. Jews often fled the pogroms in those areas. The first Ashkenazis who arrived in Amsterdam were refugees from the Khmelnytsky Uprising occurring in Ukraine and the Thirty Years' War, which devastated much of Central Europe. They not only founded their own synagogues, but had a strong influence on the 'Amsterdam dialect' adding a large Yiddish local vocabulary. Despite an absence of an official Jewish ghetto, most Jews preferred to live in the eastern part, which used to be the centre of medieval Amsterdam. The main street of this Jewish neighbourhood was Jodenbreestraat. The neighbourhood comprised the Waterlooplein and the Nieuwmarkt. Buildings in this neighbourhood fell into disrepair after the Second World War a large section of the neighbourhood was demolished during the construction of the metro system. This led to riots, and as a result the original plans for large-scale reconstruction were abandoned by the government. The neighbourhood was rebuilt with smaller-scale residence buildings on the basis of its original layout.
Catholic churches in Amsterdam have been constructed since the restoration of the episcopal hierarchy in 1853. One of the principal architects behind the city's Catholic churches, Cuypers, was also responsible for the Amsterdam Centraal station and the .
In 1924, the Catholic Church hosted the International Eucharistic Congress in Amsterdam; numerous Catholic prelates visited the city, where festivities were held in churches and stadiums. Catholic processions on the public streets, however, were still forbidden under law at the time. Only in the 20th century was Amsterdam's relation to Catholicism normalised, but despite its far larger population size, the episcopal see of the city was placed in the provincial town of Haarlem.
Historically, Amsterdam has been predominantly Christian. In 1900 Christians formed the largest religious group in the city (70% of the population), Dutch Reformed Church formed 45% of the city population, and the Catholic Church formed 25% of the city population. In recent times, religious demographics in Amsterdam have been changed by immigration from former colonies. Hinduism has been introduced from the Hindu diaspora from Suriname and several distinct branches of Islam have been brought from various parts of the world. Islam is now the largest non-Christian religion in Amsterdam. The large community of Ghanaian immigrants have established African churches, often in parking garages in the Bijlmer area.
Diversity and immigration
Amsterdam experienced an influx of religions and cultures after the Second World War. With 180 different nationalities, Amsterdam is home to one of the widest varieties of nationalities of any city in the world. The proportion of the population of immigrant origin in the city proper is about 50% and 88% of the population are Dutch citizens.
Amsterdam has been one of the municipalities in the Netherlands which provided immigrants with extensive and free Dutch-language courses, which have benefited many immigrants.
Inhabitants by origin
Cityscape and architecture
Amsterdam fans out south from the Amsterdam Centraal station and Damrak, the main street off the station. The oldest area of the town is known as De Wallen (English: "The Quays"). It lies to the east of Damrak and contains the city's famous red-light district. To the south of De Wallen is the old Jewish quarter of Waterlooplein.
The medieval and colonial age canals of Amsterdam, known as grachten, embraces the heart of the city where homes have interesting gables. Beyond the Grachtengordel are the former working-class areas of Jordaan and de Pijp. The Museumplein with the city's major museums, the Vondelpark, a 19th-century park named after the Dutch writer Joost van den Vondel, as well as the Plantage neighbourhood, with the zoo, are also located outside the Grachtengordel.
Several parts of the city and the surrounding urban area are polders. This can be recognised by the suffix -meer which means lake, as in Aalsmeer, Bijlmermeer, Haarlemmermeer and Watergraafsmeer.
Canals
The Amsterdam canal system is the result of conscious city planning. In the early 17th century, when immigration was at a peak, a comprehensive plan was developed that was based on four concentric half-circles of canals with their ends emerging at the IJ bay. Known as the Grachtengordel, three of the canals were mostly for residential development: the Herengracht (where "Heren" refers to Heren Regeerders van de stad Amsterdam, ruling lords of Amsterdam, whilst gracht means canal, so that the name can be roughly translated as "Canal of the Lords"), Keizersgracht (Emperor's Canal) and Prinsengracht (Prince's Canal). The fourth and outermost canal is the Singelgracht, which is often not mentioned on maps because it is a collective name for all canals in the outer ring. The Singelgracht should not be confused with the oldest and innermost canal, the Singel.
The canals served for defense, water management and transport. The defenses took the form of a moat and earthen dikes, with gates at transit points, but otherwise no masonry superstructures. The original plans have been lost, so historians, such as Ed Taverne, need to speculate on the original intentions: it is thought that the considerations of the layout were purely practical and defensive rather than ornamental.
Construction started in 1613 and proceeded from west to east, across the breadth of the layout, like a gigantic windshield wiper as the historian Geert Mak calls it – and not from the centre outwards, as a popular myth has it. The canal construction in the southern sector was completed by 1656. Subsequently, the construction of residential buildings proceeded slowly. The eastern part of the concentric canal plan, covering the area between the Amstel river and the IJ bay, has never been implemented. In the following centuries, the land was used for parks, senior citizens' homes, theatres, other public facilities, and waterways without much planning. Over the years, several canals have been filled in, becoming streets or squares, such as the Nieuwezijds Voorburgwal and the Spui.
Expansion
After the development of Amsterdam's canals in the 17th century, the city did not grow beyond its borders for two centuries. During the 19th century, Samuel Sarphati devised a plan based on the grandeur of Paris and London at that time. The plan envisaged the construction of new houses, public buildings and streets just outside the Grachtengordel. The main aim of the plan, however, was to improve public health. Although the plan did not expand the city, it did produce some of the largest public buildings to date, like the Paleis voor Volksvlijt.
Following Sarphati, civil engineers Jacobus van Niftrik and Jan Kalff designed an entire ring of 19th-century neighbourhoods surrounding the city's centre, with the city preserving the ownership of all land outside the 17th-century limit, thus firmly controlling development. Most of these neighbourhoods became home to the working class.
In response to overcrowding, two plans were designed at the beginning of the 20th century which were very different from anything Amsterdam had ever seen before: Plan Zuid (designed by the architect Berlage) and West. These plans involved the development of new neighbourhoods consisting of housing blocks for all social classes.
After the Second World War, large new neighbourhoods were built in the western, southeastern, and northern parts of the city. These new neighbourhoods were built to relieve the city's shortage of living space and give people affordable houses with modern conveniences. The neighbourhoods consisted mainly of large housing blocks located among green spaces, connected to wide roads, making the neighbourhoods easily accessible by motor car. The western suburbs which were built in that period are collectively called the Westelijke Tuinsteden. The area to the southeast of the city built during the same period is known as the Bijlmer.
Architecture
Amsterdam has a rich architectural history. The oldest building in Amsterdam is the Oude Kerk (English: Old Church), at the heart of the Wallen, consecrated in 1306. The oldest wooden building is Het Houten Huys at the Begijnhof. It was constructed around 1425 and is one of only two existing wooden buildings. It is also one of the few examples of Gothic architecture in Amsterdam. The oldest stone building of the Netherlands, The Moriaan is built in 's-Hertogenbosch.
In the 16th century, wooden buildings were razed and replaced with brick ones. During this period, many buildings were constructed in the architectural style of the Renaissance. Buildings of this period are very recognisable with their stepped gable façades, which is the common Dutch Renaissance style. Amsterdam quickly developed its own Renaissance architecture. These buildings were built according to the principles of the architect Hendrick de Keyser. One of the most striking buildings designed by Hendrick de Keyser is the Westerkerk. In the 17th century baroque architecture became very popular, as it was elsewhere in Europe. This roughly coincided with Amsterdam's Golden Age. The leading architects of this style in Amsterdam were Jacob van Campen, Philips Vingboons and Daniel Stalpaert.
Philip Vingboons designed splendid merchants' houses throughout the city. A famous building in baroque style in Amsterdam is the Royal Palace on Dam Square. Throughout the 18th century, Amsterdam was heavily influenced by French culture. This is reflected in the architecture of that period. Around 1815, architects broke with the baroque style and started building in different neo-styles. Most Gothic style buildings date from that era and are therefore said to be built in a neo-gothic style. At the end of the 19th century, the Jugendstil or Art Nouveau style became popular and many new buildings were constructed in this architectural style. Since Amsterdam expanded rapidly during this period, new buildings adjacent to the city centre were also built in this style. The houses in the vicinity of the Museum Square in Amsterdam Oud-Zuid are an example of Jugendstil. The last style that was popular in Amsterdam before the modern era was Art Deco. Amsterdam had its own version of the style, which was called the Amsterdamse School. Whole districts were built in this style, such as the Rivierenbuurt. A notable feature of the façades of buildings designed in Amsterdamse School is that they are highly decorated and ornate, with oddly shaped windows and doors.
The old city centre is the focal point of all the architectural styles before the end of the 19th century. Jugendstil and Georgian are mostly found outside the city centre in the neighbourhoods built in the early 20th century, although there are also some striking examples of these styles in the city centre. Most historic buildings in the city centre and nearby are houses, such as the famous merchants' houses lining the canals.
Parks and recreational areas
Amsterdam has many parks, open spaces, and squares throughout the city. The Vondelpark, the largest park in the city, is located in the Oud-Zuid neighbourhood and is named after the 17th-century Amsterdam author Joost van den Vondel. Yearly, the park has around 10 million visitors. In the park is an open-air theatre, a playground and several horeca facilities. In the Zuid borough, is the Beatrixpark, named after Queen Beatrix. Between Amsterdam and Amstelveen is the Amsterdamse Bos ("Amsterdam Forest"), the largest recreational area in Amsterdam. Annually, almost 4.5 million people visit the park, which has a size of and is approximately three times the size of Central Park. The Amstelpark in the Zuid borough houses the Rieker windmill, which dates to 1636. Other parks include the Sarphatipark in the De Pijp neighbourhood, the Oosterpark in the Oost borough and the Westerpark in the Westerpark neighbourhood. The city has three beaches: Nemo Beach, Citybeach "Het stenen hoofd" (Silodam) and Blijburg, all located in the Centrum borough.
The city has many open squares (plein in Dutch). The namesake of the city as the site of the original dam, Dam Square, is the main city square and has the Royal Palace and National Monument. Museumplein hosts various museums, including the , Van Gogh Museum, and Stedelijk Museum. Other squares include Rembrandtplein, Muntplein, Nieuwmarkt, Leidseplein, Spui and Waterlooplein. Also, near to Amsterdam is the Nekkeveld estate conservation project.
Economy
Amsterdam is the financial and business capital of the Netherlands.
According to the 2007 European Cities Monitor (ECM) – an annual location survey of Europe's leading companies carried out by global real estate consultant Cushman & Wakefield – Amsterdam is one of the top European cities in which to locate an international business, ranking fifth in the survey. with the survey determining London, Paris, Frankfurt and Barcelona as the four European cities surpassing Amsterdam in this regard.
A substantial number of large corporations and banks' headquarters are located in the Amsterdam area, including: AkzoNobel, Heineken International, ING Group, ABN AMRO, TomTom, Delta Lloyd Group, Booking.com and Philips. Although many small offices remain along the historic canals, centrally based companies have increasingly relocated outside Amsterdam's city centre. Consequently, the Zuidas (English: South Axis) has become the new financial and legal hub of Amsterdam, with the country's five largest law firms and several subsidiaries of large consulting firms, such as Boston Consulting Group and Accenture, as well as the World Trade Centre (Amsterdam) located in the Zuidas district. In addition to the Zuidas, there are three smaller financial districts in Amsterdam:
around Amsterdam Sloterdijk railway station. Where one can find the offices of several newspapers, such as De Telegraaf. as well as those of Deloitte, the Gemeentelijk Vervoerbedrijf (municipal public transport company), and the Dutch tax offices (Belastingdienst);
around the Johan Cruyff Arena in Amsterdam Zuidoost, with the headquarters of ING Group;
around the Amstel railway station in the Amsterdam-Oost district to the east of the historical city. Amsterdam's tallest building, the Rembrandt Tower, is located here. As are the headquarters of Philips, the Dutch multinational conglomerate. Amsterdam has been a leading city to reduce the use of raw materials and has created a plan to become a circular city by 2050.
The adjoining municipality of Amstelveen is the location of KPMG International's global headquarters. Other non-Dutch companies have chosen to settle in communities surrounding Amsterdam since they allow freehold property ownership, whereas Amsterdam retains ground rent.
The Amsterdam Stock Exchange (AEX), now part of Euronext, is the world's oldest stock exchange and, due to Brexit, has overtaken LSE as the largest bourse in Europe. It is near Dam Square in the city centre.
Port of Amsterdam
The Port of Amsterdam is the fourth-largest port in Europe, the 38th largest port in the world and the second-largest port in the Netherlands by metric tons of cargo. In 2014, the Port of Amsterdam had a cargo throughput of 97,4 million tons of cargo, which was mostly bulk cargo. Amsterdam has the biggest cruise port in the Netherlands with more than 150 cruise ships every year. In 2019, the new lock in IJmuiden opened; since then, the port has been able to grow to 125 million tonnes in capacity.
Tourism
Amsterdam is one of the most popular tourist destinations in Europe, receiving more than 5.34 million international visitors annually; this is excluding the 16 million day-trippers visiting the city every year. The number of visitors has been growing steadily over the past decade. This can be attributed to an increasing number of European visitors. Two-thirds of the hotels are located in the city's centre. Hotels with four or five stars contribute 42% of the total beds available and 41% of the overnight stays in Amsterdam. The room occupation rate was 85% in 2017, up from 78% in 2006. The majority of tourists (74%) originate from Europe. The largest group of non-European visitors come from the United States, accounting for 14% of the total. Certain years have a theme in Amsterdam to attract extra tourists. For example, the year 2006 was designated "Rembrandt 400", to celebrate the 400th birthday of Rembrandt van Rijn. Some hotels offer special arrangements or activities during these years. The average number of guests per year staying at the four campsites around the city range from 12,000 to 65,000.
In 2023, the city began running a campaign to dissuade British men between the ages of 18 and 35 from coming to the city as tourists. The ad shows young men being handcuffed by police and is part of a new campaign to clean up the city's reputation. On 25 May 2023, in a bid to crackdown on wild tourist behaviour, the city banned weed smoking in public areas in and around the red light district.
De Wallen (red-light district)
De Wallen, also known as Walletjes or Rosse Buurt, is a designated area for legalised prostitution and is Amsterdam's largest and best-known red-light district. This neighbourhood has become a famous attraction for tourists. It consists of a network of canals, streets, and alleys containing several hundred small, one-room apartments rented by sex workers who offer their services from behind a window or glass door, typically illuminated with red lights. In recent years, the city government has been closing and repurposing the famous red-light district windows in an effort to clean up the area and reduce the amount of party and sex tourism.
Retail
Shops in Amsterdam range from large high-end department stores such as founded in 1870 to small speciality shops. Amsterdam's high-end shops are found in the streets P.C. Hooftstraat and Cornelis Schuytstraat, which are located in the vicinity of the Vondelpark. One of Amsterdam's busiest high streets is the narrow, medieval Kalverstraat in the heart of the city. Other shopping areas include the Negen Straatjes and Haarlemmerdijk and Haarlemmerstraat. Negen Straatjes are nine narrow streets within the Grachtengordel, the concentric canal system of Amsterdam. The Negen Straatjes differ from other shopping districts with the presence of a large diversity of privately owned shops. The Haarlemmerstraat and Haarlemmerdijk were voted best shopping street in the Netherlands in 2011. These streets have as the Negen Straatjes a large diversity of privately owned shops. However, as the Negen Straatjes are dominated by fashion stores, the Haarlemmerstraat and Haarlemmerdijk offer a wide variety of stores, just to name some specialities: candy and other food-related stores, lingerie, sneakers, wedding clothing, interior shops, books, Italian deli's, racing and mountain bikes, skatewear, etc.
The city also features a large number of open-air markets such as the Albert Cuyp Market, Westerstraat-markt, Ten Katemarkt, and Dappermarkt. Some of these markets are held daily, like the Albert Cuypmarkt and the Dappermarkt. Others, like the Westerstraatmarkt, are held every week.
Fashion
Several fashion brands and designers are based in Amsterdam. Fashion designers include Iris van Herpen, Mart Visser, Viktor & Rolf, Marlies Dekkers and Frans Molenaar. Fashion models like Yfke Sturm, Doutzen Kroes and Kim Noorda started their careers in Amsterdam. Amsterdam has its garment centre in the World Fashion Center. Fashion photographers Inez van Lamsweerde and Vinoodh Matadin were born in Amsterdam.
Culture
During the later part of the 16th century, Amsterdam's Rederijkerskamer (Chamber of rhetoric) organised contests between different Chambers in the reading of poetry and drama. In 1637, Schouwburg, the first theatre in Amsterdam was built, opening on 3 January 1638. The first ballet performances in the Netherlands were given in Schouwburg in 1642 with the Ballet of the Five Senses. In the 18th century, French theatre became popular. While Amsterdam was under the influence of German music in the 19th century there were few national opera productions; the Hollandse Opera of Amsterdam was built in 1888 for the specific purpose of promoting Dutch opera. In the 19th century, popular culture was centred on the Nes area in Amsterdam (mainly vaudeville and music-hall). An improved metronome was invented in 1812 by Dietrich Nikolaus Winkel. The (1885) and Stedelijk Museum (1895) were built and opened. In 1888, the Concertgebouworkest orchestra was established. With the 20th century came cinema, radio and television. Though most studios are located in Hilversum and Aalsmeer, Amsterdam's influence on programming is very strong. Many people who work in the television industry live in Amsterdam. Also, the headquarters of the Dutch SBS Broadcasting Group is located in Amsterdam.
Museums
The most important museums of Amsterdam are located on the Museumplein (Museum Square), located at the southwestern side of the Rijksmuseum. It was created in the last quarter of the 19th century on the grounds of the former World's fair. The northeastern part of the square is bordered by the large Rijksmuseum. In front of the Rijksmuseum on the square itself is a long, rectangular pond. This is transformed into an ice rink in winter. The northwestern part of the square is bordered by the Van Gogh Museum, House of Bols Cocktail & Genever Experience and Coster Diamonds. The southwestern border of the Museum Square is the Van Baerlestraat, which is a major thoroughfare in this part of Amsterdam. The Concertgebouw is located across this street from the square. To the southeast of the square are several large houses, one of which contains the American consulate. A parking garage can be found underneath the square, as well as a supermarket. The Museumplein is covered almost entirely with a lawn, except for the northeastern part of the square which is covered with gravel. The current appearance of the square was realised in 1999, when the square was remodelled. The square itself is the most prominent site in Amsterdam for festivals and outdoor concerts, especially in the summer. Plans were made in 2008 to remodel the square again because many inhabitants of Amsterdam are not happy with its current appearance.
The possesses the largest and most important collection of classical Dutch art.
It opened in 1885. Its collection consists of nearly one million objects. The artist most associated with Amsterdam is Rembrandt, whose work, and the work of his pupils, is displayed in the Rijksmuseum. Rembrandt's masterpiece The Night Watch is one of the top pieces of art of the museum. It also houses paintings from artists like Bartholomeus van der Helst, Johannes Vermeer, Frans Hals, Ferdinand Bol, Albert Cuyp, Jacob van Ruisdael and Paulus Potter. Aside from paintings, the collection consists of a large variety of decorative art. This ranges from Delftware to giant doll-houses from the 17th century. The architect of the gothic revival building was P.J.H. Cuypers. The museum underwent a 10-year, 375 million euro renovation starting in 2003. The full collection was reopened to the public on 13 April 2013 and the Rijksmuseum has remained the most visited museum in Amsterdam with 2.2 million visitors in 2016 and 2.16 million in 2017.
Van Gogh lived in Amsterdam for a short while and there is a museum dedicated to his work. The museum is housed in one of the few modern buildings in this area of Amsterdam. The building was designed by Gerrit Rietveld. This building is where the permanent collection is displayed. A new building was added to the museum in 1999. This building, known as the performance wing, was designed by Japanese architect Kisho Kurokawa. Its purpose is to house temporary exhibitions of the museum. Some of Van Gogh's most famous paintings, like The Potato Eaters and Sunflowers, are in the collection. The Van Gogh museum is the second most visited museum in Amsterdam, not far behind the Rijksmuseum in terms of the number of visits, being approximately 2.1 million in 2016, for example.
Next to the Van Gogh museum stands the Stedelijk Museum. This is Amsterdam's most important museum of modern art. The museum is as old as the square it borders and was opened in 1895. The permanent collection consists of works of art from artists like Piet Mondrian, Karel Appel, and Kazimir Malevich. After renovations lasting several years, the museum opened in September 2012 with a new composite extension that has been called 'The Bathtub' due to its resemblance to one.
Amsterdam contains many other museums throughout the city. They range from small museums such as the Verzetsmuseum (Resistance Museum), the Anne Frank House, and the Rembrandt House Museum, to the very large, like the Tropenmuseum (Museum of the Tropics), Amsterdam Museum (formerly known as Amsterdam Historical Museum), H'ART Museum and the Joods Historisch Museum (Jewish Historical Museum). The modern-styled Nemo is dedicated to child-friendly science exhibitions.
Music
Amsterdam's musical culture includes a large collection of songs that treat the city nostalgically and lovingly. The 1949 song "Aan de Amsterdamse grachten" ("On the canals of Amsterdam") was performed and recorded by many artists, including John Kraaijkamp Sr.; the best-known version is probably that by Wim Sonneveld (1962). In the 1950s Johnny Jordaan rose to fame with "Geef mij maar Amsterdam" ("I prefer Amsterdam"), which praises the city above all others (explicitly Paris); Jordaan sang especially about his own neighbourhood, the Jordaan ("Bij ons in de Jordaan"). Colleagues and contemporaries of Johnny include Tante Leen and Manke Nelis. Another notable Amsterdam song is "Amsterdam" by Jacques Brel (1964). A 2011 poll by Amsterdam newspaper Het Parool that Trio Bier's "Oude Wolf" was voted "Amsterdams lijflied". Notable Amsterdam bands from the modern era include the Osdorp Posse and The Ex.
AFAS Live (formerly known as the Heineken Music Hall) is a concert hall located near the Johan Cruyff Arena (known as the Amsterdam Arena until 2018). Its main purpose is to serve as a podium for pop concerts for big audiences. Many famous international artists have performed there. Two other notable venues, Paradiso and the are located near the Leidseplein. Both focus on broad programming, ranging from indie rock to hip hop, R&B, and other popular genres. Other more subcultural music venues are OCCII, OT301, De Nieuwe Anita, Winston Kingdom, and Zaal 100. Jazz has a strong following in Amsterdam, with the Bimhuis being the premier venue. In 2012, Ziggo Dome was opened, also near Amsterdam Arena, a state-of-the-art indoor music arena.
AFAS Live is also host to many electronic dance music festivals, alongside many other venues. Armin van Buuren and Tiesto, some of the world's leading Trance DJ's hail from the Netherlands and frequently perform in Amsterdam. Each year in October, the city hosts the Amsterdam Dance Event (ADE) which is one of the leading electronic music conferences and one of the biggest club festivals for electronic music in the world, attracting over 350,000 visitors each year. Another popular dance festival is 5daysoff, which takes place in the venues Paradiso and . In the summertime, there are several big outdoor dance parties in or nearby Amsterdam, such as Awakenings, Dance Valley, Mystery Land, Loveland, A Day at the Park, Welcome to the Future, and Valtifest.
Amsterdam has a world-class symphony orchestra, the Royal Concertgebouw Orchestra. Their home is the , which is across the Van Baerlestraat from the Museum Square. It is considered by critics to be a concert hall with some of the best acoustics in the world. The building contains three halls, Grote Zaal, Kleine Zaal, and Spiegelzaal. Some nine hundred concerts and other events per year take place in the Concertgebouw, for a public of over 700,000, making it one of the most-visited concert halls in the world. The opera house of Amsterdam is located adjacent to the city hall. Therefore, the two buildings combined are often called the Stopera, (a word originally coined by protesters against it very construction: Stop the Opera[-house]). This huge modern complex, opened in 1986, lies in the former Jewish neighbourhood at Waterlooplein next to the river Amstel. The Stopera is the home base of Dutch National Opera, Dutch National Ballet and the Holland Symfonia. Muziekgebouw aan 't IJ is a concert hall, which is located in the IJ near the central station. Its concerts perform mostly modern classical music. Located adjacent to it, is the Bimhuis, a concert hall for improvised and Jazz music.
Performing arts
Amsterdam has three main theatre buildings.
The Stadsschouwburg at the Leidseplein is the home base of Toneelgroep Amsterdam. The current building dates from 1894. Most plays are performed in the Grote Zaal (Great Hall). The normal program of events encompasses all sorts of theatrical forms. In 2009, the new hall of the Stadsschouwburg Amsterdam, Toneelgroep Amsterdam and Melkweg opened, and the renovation of the front end of the theatre was ready.
The Dutch National Opera and Ballet (formerly known as Het Muziektheater), dating from 1986, is the principal opera house and home to Dutch National Opera and Dutch National Ballet. Royal Theatre Carré was built as a permanent circus theatre in 1887 and is currently mainly used for musicals, cabaret performances, and pop concerts.
The recently re-opened DeLaMar Theater houses more commercial plays and musicals. A new theatre has also moved into the Amsterdam scene in 2014, joining other established venues: Theater Amsterdam is located in the west part of Amsterdam, on the Danzigerkade. It is housed in a modern building with a panoramic view over the harbour. The theatre is the first-ever purpose-built venue to showcase a single play entitled ANNE, the play based on Anne Frank's life.
On the east side of town, there is a small theatre in a converted bathhouse, the Badhuistheater. The theatre often has English programming.
The Netherlands has a tradition of cabaret or kleinkunst, which combines music, storytelling, commentary, theatre and comedy. Cabaret dates back to the 1930s and artists like Wim Kan, Wim Sonneveld and Toon Hermans were pioneers of this form of art in the Netherlands. In Amsterdam is the Kleinkunstacademie (English: Cabaret Academy) and Nederlied Kleinkunstkoor (English: Cabaret Choir). Contemporary popular artists are Youp van 't Hek, Freek de Jonge, Herman Finkers, Hans Teeuwen, Theo Maassen, Herman van Veen, Najib Amhali, Raoul Heertje, Jörgen Raymann, Brigitte Kaandorp and Comedytrain. The English spoken comedy scene was established with the founding of Boom Chicago in 1993. They have their own theatre at Leidseplein.
Nightlife
Amsterdam is famous for its vibrant and diverse nightlife. Amsterdam has many cafés (bars). They range from large and modern to small and cosy. The typical Bruine Kroeg (brown café) breathe a more old fashioned atmosphere with dimmed lights, candles, and somewhat older clientele. These brown cafés mostly offer a wide range of local and international artisanal beers. Most cafés have terraces in summertime. A common sight on the Leidseplein during summer is a square full of terraces packed with people drinking beer or wine. Many restaurants can be found in Amsterdam as well. Since Amsterdam is a multicultural city, a lot of different ethnic restaurants can be found. Restaurants range from being rather luxurious and expensive to being ordinary and affordable. Amsterdam also possesses many discothèques. The two main nightlife areas for tourists are the Leidseplein and the Rembrandtplein. The Paradiso, and Sugar Factory are cultural centres, which turn into discothèques on some nights. Examples of discothèques near the Rembrandtplein are the Escape, Air, John Doe and Club Abe. Also noteworthy are Panama, Hotel Arena (East), TrouwAmsterdam and Studio 80. In recent years '24-hour' clubs opened their doors, most notably Radion De School, Shelter and Marktkantine. Bimhuis located near the Central Station, with its rich programming hosting the best in the field is considered one of the best jazz clubs in the world. The Reguliersdwarsstraat is the main street for the LGBT community and nightlife.
Festivals
In 2008, there were 140 festivals and events in Amsterdam. During the same year, Amsterdam was designated as the World Book Capital for one year by UNESCO.
Famous festivals and events in Amsterdam include: Koningsdag (which was named Koninginnedag until the crowning of King Willem-Alexander in 2013) (King's Day – Queen's Day); the Holland Festival for the performing arts; the yearly Prinsengrachtconcert (classical concerto on the Prinsen canal) in August; the 'Stille Omgang' (a silent Roman Catholic evening procession held every March); Amsterdam Gay Pride; The Cannabis Cup; and the Uitmarkt. On Koningsdag—that is held each year on 27 April—hundreds of thousands of people travel to Amsterdam to celebrate with the city's residents. The entire city becomes overcrowded with people buying products from the freemarket, or visiting one of the many music concerts.
The yearly Holland Festival attracts international artists and visitors from all over Europe. Amsterdam Gay Pride is a yearly local LGBT parade of boats in Amsterdam's canals, held on the first Saturday in August. The annual Uitmarkt is a three-day cultural event at the start of the cultural season in late August. It offers previews of many different artists, such as musicians and poets, who perform on podia.
Sports
Amsterdam is home of the Eredivisie football club AFC Ajax. The stadium Johan Cruyff Arena is the home of Ajax. It is located in the south-east of the city next to the new Amsterdam Bijlmer ArenA railway station. Before moving to their current location in 1996, Ajax played their regular matches in the now demolished De Meer Stadion in the eastern part of the city or in the Olympic Stadium.
In 1928, Amsterdam hosted the Summer Olympics. The Olympic Stadium built for the occasion has been completely restored and is now used for cultural and sporting events, such as the Amsterdam Marathon. In 1920, Amsterdam assisted in hosting some of the sailing events for the Summer Olympics held in neighbouring Antwerp, Belgium by hosting events at Buiten IJ.
The city holds the Dam to Dam Run, a race from Amsterdam to Zaandam, as well as the Amsterdam Marathon. The ice hockey team Amstel Tijgers play in the Jaap Eden ice rink. The team competes in the Dutch ice hockey premier league. Speed skating championships have been held on the 400-meter lane of this ice rink.
Amsterdam holds two American football franchises: the Amsterdam Crusaders and the Amsterdam Panthers. The Amsterdam Pirates baseball team competes in the Dutch Major League. There are three field hockey teams: Amsterdam, Pinoké and Hurley, who play their matches around the Wagener Stadium in the nearby city of Amstelveen. The basketball team MyGuide Amsterdam competes in the Dutch premier division and play their games in the Sporthallen Zuid.
There is one rugby club in Amsterdam, which also hosts sports training classes such as RTC (Rugby Talenten Centrum or Rugby Talent Centre) and the National Rugby stadium.
Since 1999, the city of Amsterdam honours the best sportsmen and women at the Amsterdam Sports Awards. Boxer Raymond Joval and field hockey midfielder Carole Thate were the first to receive the awards, in 1999.
Amsterdam hosted the World Gymnaestrada in 1991 and will do so again in 2023.
Politics
The city of Amsterdam is a municipality under the Dutch Municipalities Act. It is governed by a directly elected municipal council, a municipal executive board and a mayor. Since 1981, the municipality of Amsterdam has gradually been divided into semi-autonomous boroughs, called stadsdelen or 'districts'. Over time, a total of 15 boroughs were created. In May 2010, under a major reform, the number of Amsterdam boroughs was reduced to eight: Amsterdam-Centrum covering the city centre including the canal belt, Amsterdam-Noord consisting of the neighbourhoods north of the IJ lake, Amsterdam-Oost in the east, Amsterdam-Zuid in the south, Amsterdam-West in the west, Amsterdam Nieuw-West in the far west, Amsterdam Zuidoost in the southeast, and Westpoort covering the Port of Amsterdam area.
City government
As with all Dutch municipalities, Amsterdam is governed by a directly elected municipal council, a municipal executive board and a government appointed mayor (burgemeester). The mayor is a member of the municipal executive board, but also has individual responsibilities in maintaining public order. On 27 June 2018, Femke Halsema (former member of House of Representatives for GroenLinks from 1998 to 2011) was appointed as the first woman to be Mayor of Amsterdam by the King's Commissioner of North Holland for a six-year term after being nominated by the Amsterdam municipal council and began serving a six-year term on 12 July 2018. She replaces Eberhard van der Laan (Labour Party) who was the Mayor of Amsterdam from 2010 until his death in October 2017. After the 2014 municipal council elections, a governing majority of D66, VVD and SP was formed – the first coalition without the Labour Party since World War II. Next to the Mayor, the municipal executive board consists of eight wethouders ('alderpersons') appointed by the municipal council: four D66 alderpersons, two VVD alderpersons and two SP alderpersons.
On 18 September 2017, it was announced by Eberhard van der Laan in an open letter to Amsterdam citizens that Kajsa Ollongren would take up his office as acting Mayor of Amsterdam with immediate effect due to ill health. Ollongren was succeeded as acting Mayor by Eric van der Burg on 26 October 2017 and by Jozias van Aartsen on 4 December 2017.
Unlike most other Dutch municipalities, Amsterdam is subdivided into eight boroughs, called stadsdelen or 'districts', and the urban area of Weesp, a system that was implemented gradually in the 1980s to improve local governance. The boroughs are responsible for many activities that had previously been run by the central city. In 2010, the number of Amsterdam boroughs reached fifteen. Fourteen of those had their own district council (deelraad), elected by a popular vote. The fifteenth, Westpoort, covers the harbour of Amsterdam and had very few residents. Therefore, it was governed by the central municipal council.
Under the borough system, municipal decisions are made at borough level, except for those affairs pertaining to the whole city such as major infrastructure projects, which are the jurisdiction of the central municipal authorities. In 2010, the borough system was restructured, in which many smaller boroughs merged into larger boroughs. In 2014, under a reform of the Dutch Municipalities Act, the Amsterdam boroughs lost much of their autonomous status, as their district councils were abolished.
The municipal council of Amsterdam voted to maintain the borough system by replacing the district councils with smaller, but still directly elected district committees (bestuurscommissies). Under a municipal ordinance, the new district committees were granted responsibilities through delegation of regulatory and executive powers by the central municipal council.
Metropolitan area
"Amsterdam" is usually understood to refer to the municipality of Amsterdam. Colloquially, some areas within the municipality, such as the town of Durgerdam, may not be considered part of Amsterdam.
Statistics Netherlands uses three other definitions of Amsterdam: metropolitan agglomeration Amsterdam (Grootstedelijke Agglomeratie Amsterdam, not to be confused with Grootstedelijk Gebied Amsterdam, a synonym of Groot Amsterdam), Greater Amsterdam (Groot Amsterdam, a COROP region) and the urban region Amsterdam (Stadsgewest Amsterdam). The Amsterdam Department for Research and Statistics uses a fourth conurbation, namely the Stadsregio Amsterdam ('City Region of Amsterdam'). The city region is similar to Greater Amsterdam but includes the municipalities of Zaanstad and Wormerland. It excludes Graft-De Rijp.
The smallest of these areas is the municipality of Amsterdam with a population of about 870,000 in 2021. The larger conurbation had a population of over one million. It includes the municipalities of Zaanstad, Wormerland, Oostzaan, Diemen and Amstelveen only, as well as the municipality of Amsterdam. Greater Amsterdam includes 15 municipalities, and had a population of 1,400,000 in 2021. Though much larger in area, the population of this area is only slightly larger, because the definition excludes the relatively populous municipality of Zaanstad. The largest area by population, the Amsterdam Metropolitan Area (Dutch: Metropoolregio Amsterdam), has a population of 2,33 million. It includes for instance Zaanstad, Wormerland, Muiden, Abcoude, Haarlem, Almere and Lelystad but excludes Graft-De Rijp. Amsterdam is part of the conglomerate metropolitan area Randstad, with a total population of 6,659,300 inhabitants.
Of these various metropolitan area configurations, only the Stadsregio Amsterdam (City Region of Amsterdam) has a formal governmental status. Its responsibilities include regional spatial planning and the metropolitan public transport concessions.
National capital
Under the Dutch Constitution, Amsterdam is the capital of the Netherlands. Since the 1983 constitutional revision, the constitution mentions "Amsterdam" and "capital" in chapter 2, article 32: The king's confirmation by oath and his coronation take place in "the capital Amsterdam" ("de hoofdstad Amsterdam"). Previous versions of the constitution only mentioned "the city of Amsterdam" ("de stad Amsterdam"). For a royal investiture, therefore, the States General of the Netherlands (the Dutch Parliament) meets for a ceremonial joint session in Amsterdam. The ceremony traditionally takes place at the Nieuwe Kerk on Dam Square, immediately after the former monarch has signed the act of abdication at the nearby Royal Palace of Amsterdam. Normally, however, the Parliament sits in The Hague, the city which has historically been the seat of the Dutch government, the Dutch monarchy, and the Dutch supreme court. Foreign embassies are also located in The Hague.
Symbols
The coat of arms of Amsterdam is composed of several historical elements. First and centre are three St Andrew's crosses, aligned in a vertical band on the city's shield (although Amsterdam's patron saint was Saint Nicholas). These St Andrew's crosses can also be found on the city shields of neighbours Amstelveen and Ouder-Amstel. This part of the coat of arms is the basis of the flag of Amsterdam, flown by the city government, but also as civil ensign for ships registered in Amsterdam. Second is the Imperial Crown of Austria. In 1489, out of gratitude for services and loans, Maximilian I awarded Amsterdam the right to adorn its coat of arms with the king's crown. Then, in 1508, this was replaced with Maximilian's imperial crown when he was crowned Holy Roman Emperor. In the early years of the 17th century, Maximilian's crown in Amsterdam's coat of arms was again replaced, this time with the crown of Emperor Rudolph II, a crown that became the Imperial Crown of Austria. The lions date from the late 16th century, when city and province became part of the Republic of the Seven United Netherlands. Last came the city's official motto: Heldhaftig, Vastberaden, Barmhartig ("Heroic, Determined, Merciful"), bestowed on the city in 1947 by Queen Wilhelmina, in recognition of the city's bravery during the Second World War.
Transport
Metro, tram and bus
Currently, there are sixteen tram routes and five metro routes. All are operated by municipal public transport operator Gemeentelijk Vervoerbedrijf (GVB), which also runs the city bus network.
Four fare-free GVB ferries carry pedestrians and cyclists across the IJ lake to the borough of Amsterdam-Noord, and two fare-charging ferries run east and west along the harbour. There are also privately operated water taxis, a water bus, a boat sharing operation, electric rental boats and canal cruises, that transport people along Amsterdam's waterways.
Regional buses, and some suburban buses, are operated by Connexxion and EBS. International coach services are provided by Eurolines from Amsterdam Amstel railway station, IDBUS from Amsterdam Sloterdijk railway station, and Megabus from the Zuiderzeeweg in the east of the city.
In order to facilitate easier transport to the centre of Amsterdam, the city has various P+R Locations where people can park their car at an affordable price and transfer to one of the numerous public transport lines.
Car
Amsterdam was intended in 1932 to be the hub, a kind of Kilometre Zero, of the highway system of the Netherlands, with freeways numbered One to Eight planned to originate from the city. The outbreak of the Second World War and shifting priorities led to the current situation, where only roads A1, A2, and A4 originate from Amsterdam according to the original plan. The A3 to Rotterdam was cancelled in 1970 in order to conserve the Groene Hart. Road A8, leading north to Zaandam and the A10 Ringroad were opened between 1968 and 1974. Besides the A1, A2, A4 and A8, several freeways, such as the A7 and A6, carry traffic mainly bound for Amsterdam.
The A10 ringroad surrounding the city connects Amsterdam with the Dutch national network of freeways. Interchanges on the A10 allow cars to enter the city by transferring to one of the 18 city roads, numbered S101 through to S118. These city roads are regional roads without grade separation, and sometimes without a central reservation. Most are accessible by cyclists. The S100 Centrumring is a smaller ringroad circumnavigating the city's centre.
In the city centre, driving a car is discouraged. Parking fees are expensive, and many streets are closed to cars or are one-way. The local government sponsors carsharing and carpooling initiatives such as Autodelen and Meerijden.nu. The local government has also started removing parking spaces in the city, with the goal of removing 10,000 spaces (roughly 1,500 per year) by 2025.
National rail
Amsterdam is served by ten stations of the Nederlandse Spoorwegen (Dutch Railways). Five are intercity stops: Sloterdijk, Zuid, Amstel, Bijlmer ArenA and Amsterdam Centraal. The stations for local services are: Lelylaan, RAI, Holendrecht, Muiderpoort and Science Park. Amsterdam Centraal is also an international railway station. From the station there are regular services to destinations such as Austria, Belarus, Belgium, Czech Republic, Denmark, France, Germany, Hungary, Poland, Russia, Switzerland and the United Kingdom. Among these trains are international trains of the Nederlandse Spoorwegen (Amsterdam-Berlin), the Eurostar (Amsterdam-Brussels-London), Thalys (Amsterdam-Brussels-Paris/Lille), and Intercity-Express (Amsterdam–Cologne–Frankfurt).
Airport
Amsterdam Airport Schiphol is less than 20 minutes by train from Amsterdam Centraal station and is served by domestic and international intercity trains, such as Thalys, Eurostar and Intercity Brussel. Schiphol is the largest airport in the Netherlands, the third-largest in Europe, and the 14th-largest in the world in terms of passengers. It handles over 68 million passengers per year and is the home base of four airlines, KLM, Transavia, Martinair and Arkefly. , Schiphol was the fifth busiest airport in the world measured by international passenger numbers. This airport is 4 meters below sea level. Although Schiphol is internationally known as Amsterdam Schiphol Airport it actually lies in the neighbouring municipality of Haarlemmermeer, southwest of the city.
Cycling
Amsterdam is one of the most bicycle-friendly large cities in the world and is a centre of bicycle culture with good facilities for cyclists such as bike paths and bike racks, and several guarded bike storage garages (fietsenstalling) which can be used.
According to the most recent figures published by the Central Bureau of Statistics (CBS), in 2015 the 442,693 households (850,000 residents) in Amsterdam together owned 847,000 bicycles – 1.91 bicycles per household. Theft is widespreadin 2011, about 83,000 bicycles were stolen in Amsterdam. Bicycles are used by all socio-economic groups because of their convenience, Amsterdam's small size, the of bike paths, the flat terrain, and the inconvenience of driving an automobile.
Education
Amsterdam has two universities: the University of Amsterdam (Universiteit van Amsterdam, UvA), and the Vrije Universiteit Amsterdam (VU). Other institutions for higher education include an art school – Gerrit Rietveld Academie, a university of applied sciences – the Hogeschool van Amsterdam, and the Amsterdamse Hogeschool voor de Kunsten. Amsterdam's International Institute of Social History is one of the world's largest documentary and research institutions concerning social history, and especially the history of the labour movement. Amsterdam's Hortus Botanicus, founded in the early 17th century, is one of the oldest botanical gardens in the world, with many old and rare specimens, among them the coffee plant that served as the parent for the entire coffee culture in Central and South America.
There are over 200 primary schools in Amsterdam. Some of these primary schools base their teachings on particular pedagogic theories like the various Montessori schools. The biggest Montessori high school in Amsterdam is the Montessori Lyceum Amsterdam. Many schools, however, are based on religion. This used to be primarily Roman Catholicism and various Protestant denominations, but with the influx of Muslim immigrants, there has been a rise in the number of Islamic schools. Jewish schools can be found in the southern suburbs of Amsterdam.
Amsterdam is noted for having five independent grammar schools (Dutch: gymnasia), the Vossius Gymnasium, Barlaeus Gymnasium, St. Ignatius Gymnasium, Het 4e Gymnasium and the Cygnus Gymnasium where a classical curriculum including Latin and classical Greek is taught. Though believed until recently by many to be an anachronistic and elitist concept that would soon die out, the gymnasia have recently experienced a revival, leading to the formation of a fourth and fifth grammar school in which the three aforementioned schools participate. Most secondary schools in Amsterdam offer a variety of different levels of education in the same school. The city also has various colleges ranging from art and design to politics and economics which are mostly also available for students coming from other countries.
Schools for foreign nationals in Amsterdam include the Amsterdam International Community School, British School of Amsterdam, Albert Einstein International School Amsterdam, Lycée Vincent van Gogh La Haye-Amsterdam primary campus (French school), International School of Amsterdam, and the Japanese School of Amsterdam.
Notable people
Media
Amsterdam is a prominent centre for national and international media. Some locally based newspapers include Het Parool, a national daily paper; De Telegraaf, the largest Dutch daily newspaper; the daily newspapers Trouw, de Volkskrant and NRC; De Groene Amsterdammer, a weekly newspaper; the free newspapers Metro and The Holland Times (printed in English).
Amsterdam is home to the second-largest Dutch commercial TV group SBS Broadcasting Group, consisting of TV-stations SBS 6, Net 5 and Veronica. However, Amsterdam is not considered 'the media city of the Netherlands'. The town of Hilversum, south-east of Amsterdam, has been crowned with this unofficial title. Hilversum is the principal centre for radio and television broadcasting in the Netherlands. Radio Netherlands, heard worldwide via shortwave radio since the 1920s, is also based there. Hilversum is home to an extensive complex of audio and television studios belonging to the national broadcast production company NOS, as well as to the studios and offices of all the Dutch public broadcasting organisations and many commercial TV production companies.
In 2012, the music video of Far East Movement, 'Live My Life', was filmed in various parts of Amsterdam.
Also, several movies were filmed in Amsterdam, such as James Bond's Diamonds Are Forever, Ocean's Twelve, Girl with a Pearl Earring and The Hitman's Bodyguard. Amsterdam is also featured in John Green's book The Fault in Our Stars, which has been made into a film as well that partly takes place in Amsterdam.
Housing
From the late 1960s onwards many buildings in Amsterdam have been squatted both for housing and for using as social centres. A number of these squats have legalised and become well known, such as OCCII, OT301, Paradiso and Vrankrijk.
Sister cities
Manchester, Greater Manchester, United Kingdom, 2007
Zapopan, Jalisco, Mexico, 2011
See also
List of populated places in the Netherlands
List of cities, towns and villages in North Holland
List of cities in the Netherlands by province
List of national capitals
List of national capitals by latitude
List of capital cities by elevation
List of national capitals by population
van Dam
Notes
References
Sources
Charles Caspers & Peter Jan Margry (2017), Het Mirakel van Amsterdam. Biografie van een betwiste devotie (Amsterdam, Prometheus).
Further reading
de Waard, M., ed. Imagining Global Amsterdam: History, Culture, and Geography in a World City. Amsterdam: Amsterdam University Press 2013.
Feddes, Fred. A Millennium of Amsterdam: Spatial History of a Marvelous City. Bussum: Thoth 2012.
Jonker, Joost. Merchants, Bankers, Middlemen: The Amsterdam Money Market during the First Half of the Nineteenth Century. Amsterdam: Amsterdam University Press 1996
Shorto, Russell. Amsterdam: A History of the World's Most Liberal City. New York: Vintage Books 2014.
External links
Amsterdam.nl – Official government site
I amsterdam – Portal for international visitors
Tourist information about Amsterdam () – website of the Netherlands
Capitals in Europe
Cities in the Netherlands
Municipalities of North Holland
Olympic cycling venues
Populated places established in the 13th century
Populated places in North Holland
Port cities and towns in the Netherlands
Port cities and towns of the North Sea
Venues of the 1928 Summer Olympics
Populated lakeshore places in the Netherlands |
846 | https://en.wikipedia.org/wiki/Museum%20of%20Work | Museum of Work | The Museum of Work (Arbetets museum) is a museum located in Norrköping, Sweden. The museum is located in the Strykjärn (Clothes iron), a former weaving mill in the old industrial area on the Motala ström river in the city centre of Norrköping. The former textile factory Holmens Bruk (sv) operated in the building from 1917 to 1962.
The museum documents work and everyday life by collecting personal stories about people's professional lives from both the past and the present. The museum's archive contain material from memory collections and documentation projects.
Since 2009, the museum also houses the EWK – Center for Political Illustration Art, which is based on work of the satirist Ewert Karlsson (1918–2004). For decades he was frequently published in the Swedish tabloid, Aftonbladet.
Overview
The museum is a national central museum with the task of preserving and telling about work and everyday life. It has, among other things, exhibitions on the terms and conditions of the work and the history of the industrial society. The museum is also known to highlight gender perspective in their exhibitions.
The work museum documents work and everyday life by collecting personal stories, including people's professional life from both the past and present. In the museum's archive, there is a rich material of memory collections and documentation projects – over 2600 interviews, stories and photodocumentations have been collected since the museum opened.
The museum is also a support for the country's approximately 1,500 working life museums that are old workplaces preserved to convey their history.
Exhibitions
The Museum of Work shows exhibitions going on over several years, but also shorter exhibitions – including several photo exhibitions on themes that can be linked to work and everyday life.
The history of Alva
The history of Alva Karlsson is the only exhibition in the museum that is permanent. The exhibition connects to the museum's building and its history as part of the textile industry in Norrköping. Alva worked as a rollers between the years 1927 – 1962.
Industriland
One of the museum long-term exhibitions is Industriland – when Sweden became modern, the exhibition was in 2007–2013 and consisted of an ongoing bond with various objects that were somehow significant both for working life and everyday during the period 1930–1980. The exhibition also consisted of presentations of the working life museums in Sweden and a number of rooms with themes such as: leisure, world, living and consumption.
Framtidsland (Future country)
In 2014, the exhibition was inaugurated that takes by where Industriland ends: Future country. It is an exhibition that investigates what a sustainable society is will be part of the museum's exhibitions until 2019. The exhibition consists of materials that are designed based on conversations between young people and researchers around Sweden. The exhibition addresses themes such as work, environment and everyday life. A tour version of the exhibition is given in the locations Falun, Kristianstad and Örebro.
EWK – The Center for Political Illustration Art
Since 2009, the Museum also houses EWK – center for political illustration art. The museum preserves, develops and conveys the political illustrator Ewert Karlsson's production. The museum also holds theme exhibitions with national and international political illustrators with the aim of highlighting and strengthening the political art.
See also
List of museums in Sweden
Culture of Sweden
References
External links
Arbetetsmuseum Official site
Museums in Östergötland County
Buildings and structures in Norrköping
Industry museums in Sweden
Cultural heritage of Sweden |
848 | https://en.wikipedia.org/wiki/Audi | Audi | Audi AG () is a German automotive manufacturer of luxury vehicles headquartered in Ingolstadt, Bavaria, Germany. A subsidiary of the Volkswagen Group, Audi produces vehicles in nine production facilities worldwide.
The origins of the company are complex, dating back to the early 20th century and the initial enterprises (Horch and the Audiwerke) founded by engineer August Horch (1868–1951). Two other manufacturers (DKW and Wanderer) also contributed to the foundation of Auto Union in 1932. The modern Audi era began in the 1960s, when Auto Union was acquired by Volkswagen from Daimler-Benz. After relaunching the Audi brand with the 1965 introduction of the Audi F103 series, Volkswagen merged Auto Union with NSU Motorenwerke in 1969, thus creating the present-day form of the company.
The company name is based on the Latin translation of the surname of the founder, August Horch. , meaning "listen", becomes in Latin. The four rings of the Audi logo each represent one of four car companies that banded together to create Audi's predecessor company, Auto Union. Audi's slogan is , which is translated as "Progress through Technology". Audi, along with German brands BMW and Mercedes-Benz, is among the best-selling luxury automobile brands in the world.
History
Birth of the company and its name
Automobile company Wanderer was originally established in 1885, later becoming a branch of Audi AG. Another company, NSU, which also later merged into Audi, was founded during this time, and later supplied the chassis for Gottlieb Daimler's four-wheeler.
On 14 November 1899, August Horch (1868–1951) established the company A. Horch & Cie. in the Ehrenfeld district of Cologne. In 1902, he moved with his company to Reichenbach im Vogtland. On 10 May 1904, he founded the August Horch & Cie. Motorwagenwerke AG, a joint-stock company in Zwickau (State of Saxony).
After troubles with Horch chief financial officer, August Horch left Motorwagenwerke and founded in Zwickau on 16 July 1909, his second company, the August Horch Automobilwerke GmbH. His former partners sued him for trademark infringement. The German Reichsgericht (Supreme Court) in Leipzig, eventually determined that the Horch brand belonged to his former company.
Since August Horch was prohibited from using "Horch" as a trade name in his new car business, he called a meeting with close business friends, Paul and Franz Fikentscher from Zwickau. At the apartment of Franz Fikentscher, they discussed how to come up with a new name for the company. During this meeting, Franz's son was quietly studying Latin in a corner of the room. Several times he looked like he was on the verge of saying something but would just swallow his words and continue working, until he finally blurted out, "Father – audiatur et altera pars... wouldn't it be a good idea to call it audi instead of horch?" "Horch!" in German means "Hark!" or "hear", which is "Audi" in the singular imperative form of "audire" – "to listen" – in Latin. The idea was enthusiastically accepted by everyone attending the meeting. On 25 April 1910 the Audi Automobilwerke GmbH Zwickau (from 1915 on Audiwerke AG Zwickau) was entered in the company's register of Zwickau registration court.
The first Audi automobile, the Audi Type A 10/ Sport-Phaeton, was produced in the same year, followed by the successor Type B 10/28PS in the same year.
Audi started with a 2,612 cc inline-four engine model Type A, followed by a 3,564 cc model, as well as 4,680 cc and 5,720 cc models. These cars were successful even in sporting events. The first six-cylinder model Type M, 4,655 cc appeared in 1924.
August Horch left the Audiwerke in 1920 for a high position at the ministry of transport, but he was still involved with Audi as a member of the board of trustees. In September 1921, Audi became the first German car manufacturer to present a production car, the Audi Type K, with left-handed drive. Left-hand drive spread and established dominance during the 1920s because it provided a better view of oncoming traffic, making overtaking safer when driving on the right.
The merger of the four companies under the logo of four rings
In August 1928, Jørgen Rasmussen, the owner of Dampf-Kraft-Wagen (DKW), acquired the majority of shares in Audiwerke AG. In the same year, Rasmussen bought the remains of the U.S. automobile manufacturer Rickenbacker, including the manufacturing equipment for 8-cylinder engines. These engines were used in Audi Zwickau and Audi Dresden models that were launched in 1929. At the same time, 6-cylinder and 4-cylinder (the "four" with a Peugeot engine) models were manufactured. Audi cars of that era were luxurious cars equipped with special bodywork.
In 1932, Audi merged with Horch, DKW, and Wanderer, to form Auto Union AG, Chemnitz. It was during this period that the company offered the Audi Front that became the first European car to combine a six-cylinder engine with front-wheel drive. It used a power train shared with the Wanderer, but turned 180 degrees, so that the drive shaft faced the front.
Before World War II, Auto Union used the four interlinked rings that make up the Audi badge today, representing these four brands. However, this badge was used only on Auto Union racing cars in that period while the member companies used their own names and emblems. The technological development became more and more concentrated and some Audi models were propelled by Horch- or Wanderer-built engines.
Reflecting the economic pressures of the time, Auto Union concentrated increasingly on smaller cars through the 1930s, so that by 1938 the company's DKW brand accounted for 17.9% of the German car market, while Audi held only 0.1%. After the final few Audis were delivered in 1939 the "Audi" name disappeared completely from the new car market for more than two decades.
World War II
Richard Bruhn, a Nazi party member, was Auto Union’s Chairman of the Board from 1932 to 1945 and then again after the war when the company was reestablished. In 2014 Audi became the last major German car company, after Volkswagen, BMW and Daimler, to commission a study of their wartime activities. The investigation found that the company worked with the SS to build seven labor camps where more than 3,700 prisoners were put to work for Auto Union. In addition, 16,500 more people were forced to work at the company's factories in Zwickau and Chemnitz, and another 18,000 at an underground plant in Bavaria where 4,500 people died.
Some of the company's factories were bombed by the Allies.
Post-World War II
With no prospect of continuing production in Soviet-controlled East Germany, Auto Union executives began the process of relocating what was left of the company to West Germany. A site was chosen in Ingolstadt, Bavaria, to start a spare parts operation in late 1945, which would eventually serve as the headquarters of the reformed Auto Union in 1949.
On 17 August 1948, Auto Union AG of Chemnitz was deleted from the commercial register. These actions had the effect of liquidating Germany's Auto Union AG. The remains of the Audi plant of Zwickau became the VEB (for "People Owned Enterprise") or AWZ (in English: Automobile Works Zwickau).
The former Audi factory in Zwickau restarted assembly of the pre-war models in 1949. These DKW models were renamed to IFA F8 and IFA F9 and were similar to the West German versions. West and East German models were equipped with the traditional and renowned DKW two-stroke engines. The Zwickau plant later manufactured the infamous Trabant until 1991, after it was acquired by the Volkswagen Group following the reunification of Germany, and has since been substantially rebuilt. In 2021, production of the Audi Q4 e-tron began at the plant, marking the return of Audis being manufactured at Zwickau in over 80 years.
New Auto Union unit
A new West German headquartered Auto Union was launched in Ingolstadt with loans from the Bavarian state government and Marshall Plan aid. The reformed company was launched 3 September 1949 and continued DKW's tradition of producing front-wheel drive vehicles with two-stroke engines. This included production of a small but sturdy 125 cc motorcycle and a DKW delivery van, the DKW F89 L at Ingolstadt. The Ingolstadt site was large, consisting of an extensive complex of formerly military buildings which was suitable for administration as well as vehicle warehousing and distribution, but at this stage there was at Ingolstadt no dedicated plant suitable for mass production of automobiles: for manufacturing the company's first post-war mass-market passenger car plant capacity in Düsseldorf was rented from Rheinmetall-Borsig. It was only ten years later, after the company had attracted an investor, when funds became available for construction of major car plant at the Ingolstadt head office site.
In 1958, in response to pressure from Friedrich Flick, then the company's largest single shareholder, Daimler-Benz took an 87% holding in the Auto Union company, and this was increased to a 100% holding in 1959. However, small two-stroke cars were not the focus of Daimler-Benz's interests, and while the early 1960s saw major investment in new Mercedes models and in a state of the art factory for Auto Union's, the company's aging model range at this time did not benefit from the economic boom of the early 1960s to the same extent as competitor manufacturers such as Volkswagen and Opel. The decision to dispose of the Auto Union business was based on its lack of profitability. Ironically, by the time they sold the business, it also included a large new factory and near production-ready modern four-stroke engine, which would enable the Auto Union business, under a new owner, to embark on a period of profitable growth, now producing not Auto Unions or DKWs, but using the "Audi" name, resurrected in 1965 after a 25-year gap.
In 1964, Volkswagen acquired a 50% holding in the business, which included the new factory in Ingolstadt, the DKW and Audi brands along with the rights to the new engine design which had been funded by Daimler-Benz, who in return retained the dormant Horch trademark and the Düsseldorf factory which became a Mercedes-Benz van assembly plant. Eighteen months later, Volkswagen bought complete control of Ingolstadt, and by 1966 were using the spare capacity of the Ingolstadt plant to assemble an additional 60,000 Volkswagen Beetles per year. Two-stroke engines became less popular during the 1960s as customers were more attracted to the smoother four-stroke engines. In September 1965, the DKW F102 was fitted with a four-stroke engine and a facelift for the car's front and rear. Volkswagen dumped the DKW brand because of its associations with two-stroke technology, and having classified the model internally as the F103, sold it simply as the "Audi". Later developments of the model were named after their horsepower ratings and sold as the Audi 60, 75, 80, and Super 90, selling until 1972. Initially, Volkswagen was hostile to the idea of Auto Union as a standalone entity producing its own models having acquired the company merely to boost its own production capacity through the Ingolstadt assembly plant – to the point where Volkswagen executives ordered that the Auto Union name and flags bearing the four rings were removed from the factory buildings. Then VW chief Heinz Nordhoff explicitly forbade Auto Union from any further product development. Fearing that Volkswagen had no long-term ambition for the Audi brand, Auto Union engineers under the leadership of Ludwig Kraus developed the first Audi 100 in secret, without Nordhoff's knowledge. When presented with a finished prototype, Nordhoff was so impressed he authorised the car for production, which when launched in 1968, went on to be a huge success. With this, the resurrection of the Audi brand was now complete, this being followed by the first generation Audi 80 in 1972, which would in turn provide a template for VW's new front-wheel-drive water-cooled range which debuted from the mid-1970s onward.
In 1969, Auto Union merged with NSU, based in Neckarsulm, near Stuttgart. In the 1950s, NSU had been the world's largest manufacturer of motorcycles, but had moved on to produce small cars like the NSU Prinz, the TT and TTS versions of which are still popular as vintage race cars. NSU then focused on new rotary engines based on the ideas of Felix Wankel. In 1967, the new NSU Ro 80 was a car well ahead of its time in technical details such as aerodynamics, light weight, and safety. However, teething problems with the rotary engines put an end to the independence of NSU. The Neckarsulm plant is now used to produce the larger Audi models A6 and A8. The Neckarsulm factory is also home of the "quattro GmbH" (from November 2016 "Audi Sport GmbH"), a subsidiary responsible for development and production of Audi high-performance models: the R8 and the RS model range.
Modern era
The new merged company was incorporated on 1 January 1969 and was known as Audi NSU Auto Union AG, with its headquarters at NSU's Neckarsulm plant, and saw the emergence of Audi as a separate brand for the first time since the pre-war era. Volkswagen introduced the Audi brand to the United States for the 1970 model year. That same year, the mid-sized car that NSU had been working on, the K70, originally intended to slot between the rear-engined Prinz models and the futuristic NSU Ro 80, was instead launched as a Volkswagen.
After the launch of the Audi 100 of 1968, the Audi 80/Fox (which formed the basis for the 1973 Volkswagen Passat) followed in 1972 and the Audi 50 (later rebadged as the Volkswagen Polo) in 1974. The Audi 50 was a seminal design because it was the first incarnation of the Golf/Polo concept, one that led to a hugely successful world car. Ultimately, the Audi 80 and 100 (progenitors of the A4 and A6, respectively) became the company's biggest sellers, whilst little investment was made in the fading NSU range; the Prinz models were dropped in 1973 whilst the fatally flawed NSU Ro80 went out of production in 1977, spelling the effective end of the NSU brand. Production of the Audi 100 had been steadily moved from Ingolstadt to Neckarsulm as the 1970s had progressed, and by the appearance of the second generation C2 version in 1976, all production was now at the former NSU plant. Neckarsulm from that point onward would produce Audi's higher-end models.
The Audi image at this time was a conservative one, and so, a proposal from chassis engineer Jörg Bensinger was accepted to develop the four-wheel drive technology in Volkswagen's Iltis military vehicle for an Audi performance car and rally racing car. The performance car, introduced in 1980, was named the "Audi Quattro", a turbocharged coupé which was also the first German large-scale production vehicle to feature permanent all-wheel drive through a centre differential. Commonly referred to as the "Ur-Quattro" (the "Ur-" prefix is a German augmentative used, in this case, to mean "original" and is also applied to the first generation of Audi's S4 and S6 Sport Saloons, as in "UrS4" and "UrS6"), few of these vehicles were produced (all hand-built by a single team), but the model was a great success in rallying. Prominent wins proved the viability of all-wheel-drive racecars, and the Audi name became associated with advances in automotive technology.
In 1985, with the Auto Union and NSU brands effectively dead, the company's official name was now shortened to simply Audi AG. At the same time the company's headquarters moved back to Ingolstadt and two new wholly owned subsidiaries; Auto Union GmbH and NSU GmbH, were formed to own and manage the historical trademarks and intellectual property of the original constituent companies (the exception being Horch, which had been retained by Daimler-Benz after the VW takeover), and to operate Audi's heritage operations.
In 1986, as the Passat-based Audi 80 was beginning to develop a kind of "grandfather's car" image, the type 89 was introduced. This completely new development sold extremely well. However, its modern and dynamic exterior belied the low performance of its base engine, and its base package was quite spartan (even the passenger-side mirror was an option.) In 1987, Audi put forward a new and very elegant Audi 90, which had a much superior set of standard features. In the early 1990s, sales began to slump for the Audi 80 series, and some basic construction problems started to surface.
In the early part of the 21st century, Audi set forth on a German racetrack to claim and maintain several world records, such as top speed endurance. This effort was in-line with the company's heritage from the 1930s racing era Silver Arrows.
Through the early 1990s, Audi began to shift its target market upscale to compete against German automakers Mercedes-Benz and BMW. This began with the release of the Audi V8 in 1990. It was essentially a new engine fitted to the Audi 100/200, but with noticeable bodywork differences. Most obvious was the new grille that was now incorporated in the bonnet.
By 1991, Audi had the four-cylinder Audi 80, the 5-cylinder Audi 90 and Audi 100, the turbocharged Audi 200 and the Audi V8. There was also a coupé version of the 80/90 with both four- and five-cylinder engines.
Although the five-cylinder engine was a successful and robust powerplant, it was still a little too different for the target market. With the introduction of an all-new Audi 100 in 1992, Audi introduced a 2.8L V6 engine. This engine was also fitted to a face-lifted Audi 80 (all 80 and 90 models were now badged 80 except for the USA), giving this model a choice of four-, five-, and six-cylinder engines, in saloon, coupé and convertible body styles.
The five-cylinder was soon dropped as a major engine choice; however, a turbocharged version remained. The engine, initially fitted to the 200 quattro 20V of 1991, was a derivative of the engine fitted to the Sport Quattro. It was fitted to the Audi Coupé, named the S2, and also to the Audi 100 body, and named the S4. These two models were the beginning of the mass-produced S series of performance cars.
Audi 5000 unintended acceleration allegations
Sales in the United States fell after a series of recalls from 1982 to 1987 of Audi 5000 models associated with reported incidents of sudden unintended acceleration linked to six deaths and 700 accidents. At the time, NHTSA was investigating 50 car models from 20 manufacturers for sudden surges of power.
A 60 Minutes report aired 23 November 1986, featuring interviews with six people who had sued Audi after reporting unintended acceleration, showing an Audi 5000 ostensibly suffering a problem when the brake pedal was pushed. Subsequent investigation revealed that 60 Minutes had engineered the failure – fitting a canister of compressed air on the passenger-side floor, linked via a hose to a hole drilled into the transmission.
Audi contended, prior to findings by outside investigators, that the problems were caused by driver error, specifically pedal misapplication. Subsequently, the National Highway Traffic Safety Administration (NHTSA) concluded that the majority of unintended acceleration cases, including all the ones that prompted the 60 Minutes report, were caused by driver error such as confusion of pedals. CBS did not acknowledge the test results of involved government agencies, but did acknowledge the similar results of another study.
In a review study published in 2012, NHTSA summarized its past findings about the Audi unintended acceleration problems: "Once an unintended acceleration had begun, in the Audi 5000, due to a failure in the idle-stabilizer system (producing an initial acceleration of 0.3g), pedal misapplication resulting from panic, confusion, or unfamiliarity with the Audi 5000 contributed to the severity of the incident."
This summary is consistent with the conclusions of NHTSA's most technical analysis at the time: "Audi idle-stabilization systems were prone to defects which resulted in excessive idle speeds and brief unanticipated accelerations of up to 0.3g [which is similar in magnitude to an emergency stop in a subway car]. These accelerations could not be the sole cause of [(long-duration) sudden acceleration incidents (SAI)], but might have triggered some SAIs by startling the driver. The defective idle-stabilization system performed a type of electronic throttle control. Significantly: multiple "intermittent malfunctions of the electronic control unit were observed and recorded ... and [were also observed and] reported by Transport Canada."
With a series of recall campaigns, Audi made several modifications; the first adjusted the distance between the brake and accelerator pedal on automatic-transmission models. Later repairs, of 250,000 cars dating back to 1978, added a device requiring the driver to press the brake pedal before shifting out of park. A legacy of the Audi 5000 and other reported cases of sudden unintended acceleration are intricate gear stick patterns and brake interlock mechanisms to prevent inadvertent shifting into forward or reverse. It is unclear how the defects in the idle-stabilization system were addressed.
Audi's U.S. sales, which had reached 74,061 in 1985, dropped to 12,283 in 1991 and remained level for three years, – with resale values falling dramatically. Audi subsequently offered increased warranty protection and renamed the affected models – with the 5000 becoming the 100 and 200 in 1989 – and reached the same sales levels again only by model year 2000.
A 2010 BusinessWeek article – outlining possible parallels between Audi's experience and 2009–2010 Toyota vehicle recalls – noted a class-action lawsuit filed in 1987 by about 7,500 Audi 5000-model owners remains unsettled and remains contested in Chicago's Cook County after appeals at the Illinois state and U.S. federal levels.
Model introductions
In the mid-to-late 1990s, Audi introduced new technologies including the use of aluminium construction. Produced from 1999 to 2005, the Audi A2 was a futuristic super mini, born from the Al2 concept, with many features that helped regain consumer confidence, like the aluminium space frame, which was a first in production car design. In the A2 Audi further expanded their TDI technology through the use of frugal three-cylinder engines. The A2 was extremely aerodynamic and was designed around a wind tunnel. The Audi A2 was criticised for its high price and was never really a sales success but it planted Audi as a cutting-edge manufacturer. The model, a Mercedes-Benz A-Class competitor, sold relatively well in Europe. However, the A2 was discontinued in 2005 and Audi decided not to develop an immediate replacement.
The next major model change came in 1995 when the Audi A4 replaced the Audi 80. The new nomenclature scheme was applied to the Audi 100 to become the Audi A6 (with a minor facelift). This also meant the S4 became the S6 and a new S4 was introduced in the A4 body. The S2 was discontinued. The Audi Cabriolet continued on (based on the Audi 80 platform) until 1999, gaining the engine upgrades along the way. A new A3 hatchback model (sharing the Volkswagen Golf Mk4's platform) was introduced to the range in 1996, and the radical Audi TT coupé and roadster were debuted in 1998 based on the same underpinnings.
The engines available throughout the range were now a 1.4 L, 1.6 L and 1.8 L four-cylinder, 1.8 L four-cylinder turbo, 2.6 L and 2.8 L V6, 2.2 L turbo-charged five-cylinder and the 4.2 L V8 engine. The V6s were replaced by new 2.4 L and 2.8 L 30V V6s in 1998, with marked improvement in power, torque and smoothness. Further engines were added along the way, including a 3.7 L V8 and 6.0 L W12 engine for the A8.
Audi AG today
Audi's sales grew strongly in the 2000s, with deliveries to customers increasing from 653,000 in 2000 to 1,003,000 in 2008. The largest sales increases came from Eastern Europe (+19.3%), Africa (+17.2%) and the Middle East (+58.5%). China in particular has become a key market, representing 108,000 out of 705,000 cars delivered in the first three quarters of 2009. One factor for its popularity in China is that Audis have become the car of choice for purchase by the Chinese government for officials, and purchases by the government are responsible for 20% of its sales in China. As of late 2009, Audi's operating profit of €1.17 billion ($1.85 billion) made it the biggest contributor to parent Volkswagen Group's nine-month operating profit of €1.5 billion, while the other marques in Group such as Bentley and SEAT had suffered considerable losses. May 2011 saw record sales for Audi of America with the new Audi A7 and Audi A3 TDI Clean Diesel. In May 2012, Audi reported a 10% increase in its sales—from 408 units to 480 in the last year alone.
Audi manufactures vehicles in seven plants around the world, some of which are shared with other VW Group marques although many sub-assemblies such as engines and transmissions are manufactured within other Volkswagen Group plants.
Audi's two principal assembly plants in Germany are:
Ingolstadt, the former Auto Union site originally opened in 1945 and substantially rebuilt by Daimler-Benz in 1962, and acquired by Volkswagen in 1964 (Q2, A3, A4, A5)
Neckarsulm, the former NSU plant, acquired by Volkswagen in 1969: (A4, A5 (cabrio), A6, A7, A8, R8, and all RS variants) - a satellite plant at nearby Böllinger Höfe produces the e-tron GT
Outside of Germany, Audi produces vehicles at:
Aurangabad, India, since 2006
Bratislava, Slovakia, shared with Volkswagen, SEAT, Škoda and Porsche (Q7 and Q8)
Brussels, Belgium, acquired from Volkswagen in 2007 (e-tron)
Changchun, China, since 1995
Győr, Hungary (TT, A3, Q3)
Jakarta, Indonesia, since 2011
Martorell, Spain, shared with SEAT and Volkswagen (A1, Q3)
San José Chiapa, Mexico (2nd gen Q5)
In September 2012, Audi announced the construction of its first North American manufacturing plant in Puebla, Mexico. This plant became operative in 2016 and produces the second generation Q5.
From 2002 up to 2003, Audi headed the Audi Brand Group, a subdivision of the Volkswagen Group's Automotive Division consisting of Audi, Lamborghini and SEAT, which was focused on sporty values, with the marques' product vehicles and performance being under the higher responsibility of the Audi brand.
In January 2014, Audi, along with the Wireless Power Consortium, operated a booth which demonstrated a phone compartment using the Qi open interface standard at the Consumer Electronics Show (CES). In May, most of the Audi dealers in the UK falsely claimed that the Audi A7, A8, and R8 were Euro NCAP safety tested, all achieving five out of five stars. In fact none were tested.
In 2015, Audi admitted that at least 2.1 million Audi cars had been involved in the Volkswagen emissions testing scandal in which software installed in the cars manipulated emissions data to fool regulators and allow the cars to pollute at higher than government-mandated levels. The A1, A3, A4, A5, A6, TT, Q3 and Q5 models were implicated in the scandal. Audi promised to quickly find a technical solution and upgrade the cars so they can function within emissions regulations. Ulrich Hackenberg, the head of research and development at Audi, was suspended in relation to the scandal. Despite widespread media coverage about the scandal through the month of September, Audi reported that U.S. sales for the month had increased by 16.2%. Audi's parent company Volkswagen announced on 18 June 2018 that Audi chief executive Rupert Stadler had been arrested.
In November 2015, the U.S. Environmental Protection Agency implicated the 3-liter diesel engine versions of the 2016 Audi A6 Quattro, A7 Quattro, A8, A8L and the Q5 as further models that had emissions regulation defeat-device software installed. Thus, these models emitted nitrogen oxide at up to nine times the legal limit when the car detected that it was not hooked up to emissions testing equipment.
In November 2016, Audi expressed an intention to establish an assembly factory in Pakistan, with the company's local partner acquiring land for a plant in Korangi Creek Industrial Park in Karachi. Approval of the plan would lead to an investment of $30 million in the new plant. Audi planned to cut 9,500 jobs in Germany starting from 2020 till 2025 to fund electric vehicles and digital working.
In February 2020, Volkswagen AG announced that it plans to take over all Audi shares it does not own (totalling 0.36%) via a squeeze-out according to German stock corporation law, thus making Audi a fully owned subsidiary of the Volkswagen Group. This change took effect from 16 November 2020, when Audi became a wholly owned subsidiary of the Volkswagen Group.
In January 2021, Audi announced that it is planning to sell 1 million vehicles in China in 2023, comparing to 726,000 vehicles in 2020.
Technology
Audi AI
Audi AI is a driver assist feature offered by Audi. The company's stated intent is to offer fully autonomous driving at a future time, acknowledging that legal, regulatory and technical hurdles must be overcome to achieve this goal. On 4 June 2017, Audi stated that its new A8 will be fully self-driving for speeds up to 60 km/h using its Audi AI. Contrary to other cars, the driver will not have to do safety checks such as touching the steering wheel every 15 seconds to use this feature. The Audi A8 will therefore be the first production car to reach level 3 autonomous driving, meaning that the driver can safely turn their attention away from driving tasks, e.g. the driver can text or watch a movie. Audi will also be the first manufacturer to use a 3D Lidar system in addition to cameras and ultrasonic sensors for their AI.
Bodyshells
Audi produces 100% galvanised cars to prevent corrosion, and was the first mass-market vehicle to do so, following introduction of the process by Porsche, c. 1975. Along with other precautionary measures, the full-body zinc coating has proved to be very effective in preventing rust. The body's resulting durability even surpassed Audi's own expectations, causing the manufacturer to extend its original 10-year warranty against corrosion perforation to currently 12 years (except for aluminium bodies which do not rust).
Space Frame
Audi introduced a new series of vehicles in the mid-1990s and continues to pursue new technology and high performance. An all-aluminium car was brought forward by Audi, and in 1994 the Audi A8 was launched, which introduced aluminium space frame technology (called Audi Space Frame or ASF) which saves weight and improves torsion rigidity compared to a conventional steel frame. Prior to that effort, Audi used examples of the Type 44 chassis fabricated out of aluminium as test-beds for the technique. The disadvantage of the aluminium frame is that it is very expensive to repair and requires a specialized aluminium bodyshop. The weight reduction is somewhat offset by the quattro four-wheel drive system which is standard in most markets. Nonetheless, the A8 is usually the lightest all-wheel drive car in the full-size luxury segment, also having best-in-class fuel economy. The Audi A2, Audi TT and Audi R8 also use Audi Space Frame designs.
Drivetrains
Layout
For most of its lineup (excluding the A3, A1, and TT models), Audi has not adopted the transverse engine layout which is typically found in economy cars (such as Peugeot and Citroën), since that would limit the type and power of engines that can be installed. To be able to mount powerful engines (such as a V8 engine in the Audi S4 and Audi RS4, as well as the W12 engine in the Audi A8L W12), Audi has usually engineered its more expensive cars with a longitudinally front-mounted engine, in an "overhung" position, over the front wheels in front of the axle line - this layout dates back to the DKW and Auto Union saloons from the 1950s. But while this allows for the easy adoption of all-wheel drive, it goes against the ideal 50:50 weight distribution.
In all its post Volkswagen-era models, Audi has firmly refused to adopt the traditional rear-wheel drive layout favored by its two archrivals Mercedes-Benz and BMW, favoring either front-wheel drive or all-wheel drive. The majority of Audi's lineup in the United States features all-wheel drive standard on most of its expensive vehicles (only the entry-level trims of the A4 and A6 are available with front-wheel drive), in contrast to Mercedes-Benz and BMW whose lineup treats all-wheel drive as an option. BMW did not offer all-wheel drive on its V8-powered cars (as opposed to crossover SUVs) until the 2010 BMW 7 Series and 2011 BMW 5 Series, while the Audi A8 has had all-wheel drive available/standard since the 1990s. Regarding high-performance variants, Audi S and RS models have always had all-wheel drive, unlike their direct rivals from BMW M and Mercedes-AMG whose cars are rear-wheel drive only (although their performance crossover SUVs are all-wheel drive).
Audi has recently applied the quattro badge to models such as the A3 and TT which do not use the Torsen-based system as in prior years with a mechanical center differential, but with the Haldex Traction electro-mechanical clutch AWD system.
Engines
Prior to the introduction of the Audi 80 and Audi 50 in 1972 and 1974, respectively, Audi had led the development of the EA111 and EA827 inline-four engine families. These new power units underpinned the water-cooled revival of parent company Volkswagen (in the Polo, Golf, Passat and Scirocco), whilst the many derivatives and descendants of these two basic engine designs have appeared in every generation of VW Group vehicles right up to the present day.
In the 1980s, Audi, along with Volvo, was the champion of the inline-five cylinder, 2.1/2.2 L engine as a longer-lasting alternative to more traditional six-cylinder engines. This engine was used not only in production cars but also in their race cars. The 2.1 L inline five-cylinder engine was used as a base for the rally cars in the 1980s, providing well over after modification. Before 1990, there were engines produced with a displacement between 2.0 L and 2.3 L. This range of engine capacity allowed for both fuel economy and power.
For the ultra-luxury version of its Audi A8 fullsize luxury flagship sedan, the Audi A8L W12, Audi uses the Volkswagen Group W12 engine instead of the conventional V12 engine favored by rivals Mercedes-Benz and BMW. The W12 engine configuration (also known as a "WR12") is created by forming two imaginary narrow-angle 15° VR6 engines at an angle of 72°, and the narrow angle of each set of cylinders allows just two overhead camshafts to drive each pair of banks, so just four are needed in total. The advantage of the W12 engine is its compact packaging, allowing Audi to build a 12-cylinder sedan with all-wheel drive, whereas a conventional V12 engine could have only a rear-wheel drive configuration as it would have no space in the engine bay for a differential and other components required to power the front wheels. In fact, the 6.0 L W12 in the Audi A8L W12 is smaller in overall dimensions than the 4.2 L V8 that powers the Audi A8 4.2 variants. The 2011 Audi A8 debuted a revised 6.3-litre version of the W12 (WR12) engine with .
Fuel Stratified Injection
New models of the A3, A4, A6 and A8 have been introduced, with the ageing 1.8-litre engine now having been replaced by new Fuel Stratified Injection (FSI) engines. Nearly every petroleum burning model in the range now incorporates this fuel-saving technology.
Direct-Shift Gearbox
In 2003, Volkswagen introduced the Direct-Shift Gearbox (DSG), a type of dual-clutch transmission. It is a type of automatic transmission, drivable like a conventional torque converter automatic transmission. Based on the gearbox found in the Group B S1, the system includes dual electro-hydraulically controlled clutches instead of a torque converter. This is implemented in some VW Golfs, Audi A3, Audi A4 and TT models where DSG is called S-Tronic.
LED daytime running lights
Beginning in 2005, Audi has implemented white LED technology as daytime running lights (DRL) in their products. The distinctive shape of the DRLs has become a trademark of sorts. LEDs were first introduced on the Audi A8 W12, the world's first production car to have LED DRLs, and have since spread throughout the entire model range. The LEDs are present on some Audi billboards.
Since 2010, Audi has also offered the LED technology in low- and high-beam headlights.
Multi Media Interface
Starting with the 2003 Audi A8, Audi has used a centralised control interface for its on-board infotainment systems, called Multi Media Interface (MMI). It is essentially a rotating control knob and 'segment' buttons – designed to control all in-car entertainment devices (radio, CD changer, iPod, TV tuner), satellite navigation, heating and ventilation, and other car controls with a screen.
The availability of MMI has gradually filtered down the Audi lineup, and following its introduction on the third generation A3 in 2011, MMI is now available across the entire range. It has been generally well received, as it requires less menu-surfing with its segment buttons around a central knob, along with 'main function' direct access buttons – with shortcuts to the radio or phone functions. The colour screen is mounted on the upright dashboard, and on the A4 (new), A5, A6, A8, and Q7, the controls are mounted horizontally.
Synthetic fuels
Audi has assisted with technology to produce synthetic diesel from water and carbon dioxide. Audi calls the synthetic diesel E-diesel. It is also working on synthetic gasoline (which it calls E-gasoline).
Logistics
Audi uses scanning gloves for parts registration during assembly, and automatic robots to transfer cars from factory to rail cars.
Models
Current model range
The following tables list Audi production vehicles that are sold as of 2018:
S and RS models
Electric vehicles
Audi is planning an alliance with the Japanese electronics giant Sanyo to develop a pilot hybrid electric project for the Volkswagen Group. The alliance could result in Sanyo batteries and other electronic components being used in future models of the Volkswagen Group. Concept electric vehicles unveiled to date include the Audi A1 Sportback Concept, Audi A4 TDI Concept E, and the fully electric Audi e-tron Concept Supercar.
Self-driving cars
In December 2018, Audi announced to invest 14 billion Euro ($15.9 billion) in e-mobility, self-driving cars.
Production figures
Data from 1998 to 2010. Figures for different body types/versions of models have been merged to create overall figures for each model.
Motorsport
Audi has competed in various forms of motorsports. Audi's tradition in motorsport began with their former company Auto Union in the 1930s. In the 1990s, Audi found success in the Touring and Super Touring categories of motor racing after success in circuit racing in North America.
Rallying
In 1980, Audi released the Quattro, a four-wheel drive (4WD) turbocharged car that went on to win rallies and races worldwide. It is considered one of the most significant rally cars of all time, because it was one of the first to take advantage of the then-recently changed rules which allowed the use of four-wheel drive in competition racing. Many critics doubted the viability of four-wheel drive racers, thinking them to be too heavy and complex, yet the Quattro was to become a successful car. It led its first rally before going off the road, however, the rally world had been served notice 4WD was the future. The Quattro went on to achieve much success in the World Rally Championship. It won the 1983 (Hannu Mikkola) and the 1984 (Stig Blomqvist) drivers' titles, and brought Audi the manufacturers' title in 1982 and 1984.
In 1984, Audi launched the short-wheelbase Sport Quattro which dominated rally races in Monte Carlo and Sweden, with Audi taking all podium places, but succumbed to problems further into WRC contention. In 1985, after another season mired in mediocre finishes, Walter Röhrl finished the season in his Sport Quattro S1, and helped place Audi second in the manufacturers' points. Audi also received rally honours in the Hong Kong to Beijing rally in that same year. Michèle Mouton, the only female driver to win a round of the World Rally Championship and a driver for Audi, took the Sport Quattro S1, now simply called the "S1", and raced in the Pikes Peak International Hill Climb. The climb race pits a driver and car to drive to the summit of the Pikes Peak mountain in Colorado, and in 1985, Michèle Mouton set a new record of 11:25.39, and being the first woman to set a Pikes Peak record. In 1986, Audi formally left international rallying following an accident in Portugal involving driver Joaquim Santos in his Ford RS200. Santos swerved to avoid hitting spectators in the road, and left the track into the crowd of spectators on the side, killing three and injuring 30. Bobby Unser used an Audi in that same year to claim a new record for the Pikes Peak Hill Climb at 11:09.22.
In 1987, Walter Röhrl claimed the title for Audi setting a new Pikes Peak International Hill Climb record of 10:47.85 in his Audi S1, which he had retired from the WRC two years earlier. The Audi S1 employed Audi's time-tested inline-five-cylinder turbocharged engine, with the final version generating . The engine was mated to a six-speed gearbox and ran on Audi's famous four-wheel drive system. All of Audi's top drivers drove this car; Hannu Mikkola, Stig Blomqvist, Walter Röhrl and Michèle Mouton. This Audi S1 started the range of Audi 'S' cars, which now represents an increased level of sports-performance equipment within the mainstream Audi model range.
In the United States
As Audi moved away from rallying and into circuit racing, they chose to move first into America with the Trans-Am in 1988.
In 1989, Audi moved to International Motor Sports Association (IMSA) GTO with the Audi 90, however as they avoided the two major endurance events (Daytona and Sebring) despite winning on a regular basis, they would lose out on the title.
Touring cars
In 1990, having completed their objective to market cars in North America, Audi returned to Europe, turning first to the Deutsche Tourenwagen Meisterschaft (DTM) series with the Audi V8, and then in 1993, being unwilling to build cars for the new formula, they turned their attention to the fast-growing Super Touring series, which are a series of national championships. Audi first entered in the French Supertourisme and Italian Superturismo. In the following year, Audi would switch to the German Super Tourenwagen Cup (known as STW), and then to British Touring Car Championship (BTCC) the year after that.
The Fédération Internationale de l'Automobile (FIA), having difficulty regulating the quattro four-wheel drive system, and the impact it had on the competitors, would eventually ban all four-wheel drive cars from competing in the series in 1998, but by then, Audi switched all their works efforts to sports car racing.
By 2000, Audi would still compete in the US with their RS4 for the SCCA Speed World GT Challenge, through dealer/team Champion Racing competing against Corvettes, Vipers, and smaller BMWs (where it is one of the few series to permit 4WD cars). In 2003, Champion Racing entered an RS6. Once again, the quattro four-wheel drive was superior, and Champion Audi won the championship. They returned in 2004 to defend their title, but a newcomer, Cadillac with the new Omega Chassis CTS-V, gave them a run for their money. After four victories in a row, the Audis were sanctioned with several negative changes that deeply affected the car's performance. Namely, added ballast weights, and Champion Audi deciding to go with different tyres, and reducing the boost pressure of the turbocharger.
In 2004, after years of competing with the TT-R in the revitalised DTM series, with privateer team Abt Racing/Christian Abt taking the 2002 title with Laurent Aïello, Audi returned as a full factory effort to touring car racing by entering two factory-supported Joest Racing A4 DTM cars.
24 Hours of Le Mans
Audi began racing prototype sportscars in 1999, debuting at the Le Mans 24 hour. Two car concepts were developed and raced in their first season - the Audi R8R (open-cockpit 'roadster' prototype) and the Audi R8C (closed-cockpit 'coupé' GT-prototype). The R8R scored a credible podium on its racing debut at Le Mans and was the concept which Audi continued to develop into the 2000 season due to favourable rules for open-cockpit prototypes.
However, most of the competitors (such as BMW, Toyota, Mercedes and Nissan) retired at the end of 1999.
The factory-supported Joest Racing team won at Le Mans three times in a row with the Audi R8 (2000–2002), as well as winning every race in the American Le Mans Series in its first year. Audi also sold the car to customer teams such as Champion Racing.
In 2003, two Bentley Speed 8s, with engines designed by Audi, and driven by Joest drivers loaned to the fellow Volkswagen Group company, competed in the GTP class, and finished the race in the top two positions, while the Champion Racing R8 finished third overall, and first in the LMP900 class. Audi returned to the winner's podium at the 2004 race, with the top three finishers all driving R8s: Audi Sport Japan Team Goh finished first, Audi Sport UK Veloqx second, and Champion Racing third.
At the 2005 24 Hours of Le Mans, Champion Racing entered two R8s, along with an R8 from the Audi PlayStation Team Oreca. The R8s (which were built to old LMP900 regulations) received a narrower air inlet restrictor, reducing power, and an additional of weight compared to the newer LMP1 chassis. On average, the R8s were about 2–3 seconds off pace compared to the Pescarolo–Judd. But with a team of excellent drivers and experience, both Champion R8s were able to take first and third, while the Oreca team took fourth. The Champion team was also the first American team to win Le Mans since the Gulf Ford GTs in 1967. This also ends the long era of the R8; however, its replacement for 2006, called the Audi R10 TDI, was unveiled on 13 December 2005.
The R10 TDI employed many new and innovative features, the most notable being the twin-turbocharged direct injection diesel engine. It was first raced in the 2006 12 Hours of Sebring as a race-test in preparation for the 2006 24 Hours of Le Mans, which it later went on to win. Audi had a win in the first diesel sports car at 12 Hours of Sebring (the car was developed with a Diesel engine due to ACO regulations that favor diesel engines). As well as winning the 24 Hours of Le Mans in 2006, the R10 TDI beat the Peugeot 908 HDi FAP in , and in , (however Peugeot won the 24h in 2009) with a podium clean-sweep (all four 908 entries retired) while breaking a distance record (set by the Porsche 917K of Martini Racing in ), in with the R15 TDI Plus.
Audi's sports car racing success would continue with the Audi R18's victory at the 2011 24 Hours of Le Mans. Audi Sport Team Joest's Benoît Tréluyer earned Audi their first pole position in five years while the team's sister car locked out the front row. Early accidents eliminated two of Audi's three entries, but the sole remaining Audi R18 TDI of Tréluyer, Marcel Fässler, and André Lotterer held off the trio of Peugeot 908s to claim victory by a margin of 13.8 seconds.
Results
American Le Mans Series
Audi entered a factory racing team run by Joest Racing into the American Le Mans Series under the Audi Sport North America name in 2000. This was a successful operation with the team winning on its debut in the series at the 2000 12 Hours of Sebring. Factory-backed Audi R8s were the dominant car in ALMS taking 25 victories between 2000 and the end of the 2002 season. In 2003, Audi sold customer cars to Champion Racing as well as continuing to race the factory Audi Sport North America team. Champion Racing won many races as a private team running Audi R8s and eventually replaced Team Joest as the Audi Sport North America between 2006 and 2008. Since 2009 Audi has not taken part in full American Le Mans Series Championships, but has competed in the series opening races at Sebring, using the 12-hour race as a test for Le Mans, and also as part of the 2012 FIA World Endurance Championship season calendar.
Results
European Le Mans Series
Audi participated in the 2003 1000km of Le Mans which was a one-off sports car race in preparation for the 2004 European Le Mans Series. The factory team Audi Sport UK won races and the championship in the 2004 season but Audi was unable to match their sweeping success of Audi Sport North America in the American Le Mans Series, partly due to the arrival of a factory competitor in LMP1, Peugeot. The French manufacturer's 908 HDi FAP became the car to beat in the series from 2008 onwards with 20 LMP wins. However, Audi were able to secure the championship in 2008 even though Peugeot scored more race victories in the season.
Results
World Endurance Championship
2012
In 2012, the FIA sanctioned a World Endurance Championship which would be organised by the ACO as a continuation of the ILMC. Audi competed won the first WEC race at Sebring and followed this up with a further three successive wins, including the 2012 24 Hours of Le Mans. Audi scored a final 5th victory in the 2012 WEC in Bahrain and were able to win the inaugural WEC Manufacturers' Championship.
2013
As defending champions, Audi once again entered the Audi R18 e-tron quattro chassis into the 2013 WEC and the team won the first five consecutive races, including the 2013 24 Hours of Le Mans. The victory at Round 5, Circuit of the Americas, was of particular significance as it marked the 100th win for Audi in Le Mans prototypes. Audi secured their second consecutive WEC Manufacturers' Championship at Round 6 after taking second place and half points in the red-flagged Fuji race.
2014
For the 2014 season, Audi entered a redesigned and upgraded R18 e-tron quattro which featured a 2 MJ energy recovery system. As defending champions, Audi would once again face a challenge in LMP1 from Toyota, and additionally from Porsche who returned to endurance racing after a 16-year absence. The season-opening 6hrs of Silverstone was a disaster for Audi who saw both cars retire from the race, marking the first time that an Audi car has failed to score a podium in a World Endurance Championship race.
Results
Formula E
Audi provide factory support to Abt Sportsline in the FIA Formula E Championship, The team competed under the title of Audi Sport Abt Formula E Team in the inaugural 2014-15 Formula E season. On 13 February 2014 the team announced its driver line up as Daniel Abt and World Endurance Championship driver Lucas di Grassi.
Formula One
Audi has been linked to Formula One in recent years but has always resisted due to the company's opinion that it is not relevant to road cars, but hybrid power unit technology has been adopted into the sport, swaying the company's view and encouraging research into the program by former Ferrari team principal Stefano Domenicali.
Audi announced in August 2022 that it would enter the Championship as an engine manufacturer in . In October, Audi confirmed its partnership with Sauber Motorsport for the year 2026, acquiring a stake in the company for the German brand to enter the competition by renaming the team and supplying engines.
On 26 April 2024, it was announced that Nico Hülkenberg will take up the seat at Sauber for 2025, on a multi year contract, meaning that Hülkenberg is the first confirmed Audi driver in Formula One in 2026.
Current factory drivers
Marketing
Branding
The Audi emblem is four overlapping rings that represent the four marques of Auto Union. The Audi emblem symbolises the amalgamation of Audi with DKW, Horch and Wanderer: the first ring from the left represents Audi, the second represents DKW, third is Horch, and the fourth and last ring Wanderer.
The design is popularly believed to have been the idea of Klaus von Oertzen, the director of sales at Wanderer – when Berlin was chosen as the host city for the 1936 Summer Olympics and that a form of the Olympic logo symbolized the newly established Auto Union's desire to succeed. Somewhat ironically, the International Olympic Committee later sued Audi in the International Trademark Court in 1995, where they lost.
The original "Audi" script, with the distinctive slanted tails on the "A" and "d" was created for the historic Audi company in 1920 by the famous graphic designer Lucian Bernhard, and was resurrected when Volkswagen revived the brand in 1965. Following the demise of NSU in 1977, less prominence was given to the four rings, in preference to the "Audi" script encased within a black (later red) ellipse, and was commonly displayed next to the Volkswagen roundel when the two brands shared a dealer network under the V.A.G banner. The ellipse (known as the Audi Oval) was phased out after 1994, when Audi formed its own independent dealer network, and prominence was given back to the four rings – at the same time Audi Sans (a derivative of Univers) was adopted as the font for all marketing materials, corporate communications and was also used in the vehicles themselves.
As part of Audi's centennial celebration in 2009, the company updated the logo, changing the font to left-aligned Audi Type, and altering the shading for the overlapping rings. The revised logo was designed by Rayan Abdullah.
Audi developed a Corporate Sound concept, with Audi Sound Studio designed for producing the Corporate Sound. The Corporate Sound project began with sound agency Klangerfinder GmbH & Co KG and s12 GmbH. Audio samples were created in Klangerfinder's sound studio in Stuttgart, becoming part of Audi Sound Studio collection. Other Audi Sound Studio components include The Brand Music Pool, The Brand Voice. Audi also developed Sound Branding Toolkit including certain instruments, sound themes, rhythm and car sounds which all are supposed to reflect the AUDI sound character.
Audi started using a beating heart sound trademark beginning in 1996. An updated heartbeat sound logo, developed by agencies KLANGERFINDER GmbH & Co KG of Stuttgart and S12 GmbH of Munich, was first used in 2010 in an Audi A8 commercial with the slogan The Art of Progress.
Slogans
Audi's corporate tagline is , meaning "Progress through Technology". The German-language tagline is used in many European countries, including the United Kingdom (but not in Italy, where is used), and in other markets, such as Latin America, Oceania, Africa and parts of Asia including Japan. Originally, the American tagline was Innovation through technology, but in Canada Vorsprung durch Technik was used. Since 2007, Audi has used the slogan Truth in Engineering in the U.S. However, since the Audi emissions testing scandal came to light in September 2015, this slogan was lambasted for being discordant with reality. In fact, just hours after disgraced Volkswagen CEO Martin Winterkorn admitted to cheating on emissions data, an advertisement during the 2015 Primetime Emmy Awards promoted Audi's latest advances in low emissions technology with Kermit the Frog stating, "It's not that easy being green."
Vorsprung durch Technik was first used in English-language advertising after Sir John Hegarty of the Bartle Bogle Hegarty advertising agency visited the Audi factory in 1982. In the original British television commercials, the phrase was voiced by Geoffrey Palmer. After its repeated use in advertising campaigns, the phrase found its way into popular culture, including the British comedy Only Fools and Horses, the U2 song "Zooropa" and the Blur song "Parklife". Similar-sounding phrases have also been used, including as the punchline for a joke in the movie Lock, Stock and Two Smoking Barrels and in the British TV series Peep Show.
Typography
Audi Sans (based on Univers Extended) was originally created in 1997 by Ole Schäfer for MetaDesign. MetaDesign was later commissioned for a new corporate typeface called Audi Type, designed by Paul van der Laan and Pieter van Rosmalen of Bold Monday. The font began to appear in Audi's 2009 products and marketing materials.
Sponsorships
Audi is a strong partner of different kinds of sports. In football, long partnerships exist between Audi and domestic clubs including Bayern Munich, Hamburger SV, 1. FC Nürnberg, Hertha BSC, and Borussia Mönchengladbach and international clubs including Chelsea, Real Madrid, FC Barcelona, A.C. Milan, AFC Ajax and Perspolis. Audi also sponsors winter sports: The Audi FIS Alpine Ski World Cup is named after the company. Additionally, Audi supports the German Ski Association (DSV) as well as the alpine skiing national teams of Switzerland, Sweden, Finland, France, Liechtenstein, Italy, Austria and the U.S. For almost two decades, Audi fosters golf sport: for example with the Audi quattro Cup and the HypoVereinsbank Ladies German Open presented by Audi. In sailing, Audi is engaged in the Medcup regatta and supports the team Luna Rossa during the Louis Vuitton Pacific Series and also is the primary sponsor of the Melges 20 sailboat. Further, Audi sponsors the regional teams ERC Ingolstadt (hockey) and FC Ingolstadt 04 (soccer). In 2009, the year of Audi's 100th anniversary, the company organized the Audi Cup for the first time. Audi also sponsor the New York Yankees as well. In October 2010 they agreed to a three sponsorship year-deal with Everton. Audi also sponsors the England Polo Team and holds the Audi Polo Awards.
Marvel Cinematic Universe
Since the start of the Marvel Cinematic Universe, Audi signed a deal to sponsor, promote and provide vehicles for several films. So far these have been, Iron Man, Iron Man 2, Iron Man 3, Avengers: Age of Ultron, Captain America: Civil War, Spider-Man: Homecoming, Avengers: Endgame and Spider-Man: Far From Home. The R8 supercar became the personal vehicle for Tony Stark (played by Robert Downey Jr.) for six of these films. The e-tron vehicles were promoted in Endgame and Far From Home. Several commercials were co-produced by Marvel and Audi to promote several new concepts and some of the latest vehicles such as the A8, SQ7 and the e-Tron fleet.
Multitronic campaign
In 2001, Audi promoted the new multitronic continuously variable transmission with television commercials throughout Europe, featuring an impersonator of musician and actor Elvis Presley. A prototypical dashboard figure – later named "Wackel-Elvis" ("Wobble Elvis" or "Wobbly Elvis") – appeared in the commercials to demonstrate the smooth ride in an Audi equipped with the multitronic transmission. The dashboard figure was originally intended for use in the commercials only, but after they aired the demand for Wackel-Elvis fans grew among fans and the figure was mass-produced in China and marketed by Audi in their factory outlet store.
Audi TDI
As part of Audi's attempt to promote its Diesel technology in 2009, the company began Audi Mileage Marathon. The driving tour featured a fleet of 23 Audi TDI vehicles from 4 models (Audi Q7 3.0 TDI, Audi Q5 3.0 TDI, Audi A4 3.0 TDI, Audi A3 Sportback 2.0 TDI with S tronic transmission) travelling across the American continent from New York to Los Angeles, passing major cities like Chicago, Dallas and Las Vegas during the 13 daily stages, as well as natural wonders including the Rocky Mountains, Death Valley and the Grand Canyon.
Audi e-tron
The next phase of technology Audi is developing is the e-tron electric drive powertrain system. They have shown several concept cars , each with different levels of size and performance. The original e-tron concept shown at the 2009 Frankfurt motor show is based on the platform of the R8 and has been scheduled for limited production. Power is provided by electric motors at all four wheels. The second concept was shown at the 2010 Detroit Motor Show. Power is provided by two electric motors at the rear axle. This concept is also considered to be the direction for a future mid-engined gas-powered 2-seat performance coupe. The Audi A1 e-tron concept, based on the Audi A1 production model, is a hybrid vehicle with a range extending Wankel rotary engine to provide power after the initial charge of the battery is depleted. It is the only concept of the three to have range-extending capability. The car is powered through the front wheels, always using electric power.
It is all set to be displayed at the Auto Expo 2012 in New Delhi, India, from 5 January. It is powered by a 1.4 litre engine, and can cover a distance up to 54 km on a single charge. The e-tron was also shown in the 2013 blockbuster film Iron Man 3 and was driven by Tony Stark (Iron Man).
Lawsuit on the use of the letter Q
In early 2005, Nissan North America Inc. filed a lawsuit against Audi over the use of the letter "Q" as a model name.
Audi is using the "Q" for the designation of their quattro four-wheel drive system, used in production cars for over twenty-five years (Audi's Quattro trademark is actually an umbrella term for several types of four-wheel-drive systems developed by Torsen, Haldex Traction AB, and Borg-Warner, the latter being used in the Q7). Nissan's Infiniti marque first used Q for their 1989 Infiniti Q45 flagship, but later expanded to its entire lineup, with Q for passenger cars (the Q30, Q40, Q50, and Q60) and QX for SUVs (the QX30, QX50, QX60, and QX70).
A settlement between Audi AG and Nissan was reached in late 2006. The agreement stipulates that Audi will only use the Q-prefix for three models, the Q3, Q5 and the Q7. Audi has since released other Q series cars as well, such as the Q2, Q6, and Q8.
In video games
Audi has supported the European version of PlayStation Home, the PlayStation 3's online community-based service, by releasing a dedicated Home space. Audi is the first carmaker to develop such a space for Home. On 17 December 2009, Audi released two spaces; the Audi Home Terminal and the Audi Vertical Run. The Audi Home Terminal features an Audi TV channel delivering video content, an Internet Browser feature, and a view of a city. The Audi Vertical Run is where users can access the mini-game Vertical Run, a futuristic mini-game featuring Audi's e-tron concept. Players collect energy and race for the highest possible speeds and the fastest players earn a place in the Audi apartments located in a large tower in the centre of the Audi Space. In both the Home Terminal and Vertical Run spaces, there are teleports where users can teleport back and forth between the two spaces. Audi had stated that additional content would be added in 2010. On 31 March 2015 Sony shutdown the PlayStation Home service rendering all content for it inaccessible.
See also
DKW, Horch and Wanderer (company) – predecessors of Audi.
Volkswagen Group – parent company of current Audi.
Notes
References
External links
Car brands
Car manufacturers of Germany
Companies based in Baden-Württemberg
Companies based in Bavaria
Companies based in Ingolstadt
Companies formerly listed on the Frankfurt Stock Exchange
Vehicle manufacturing companies established in 1909
Vehicle manufacturing companies disestablished in 1939
Vehicle manufacturing companies established in 1965
Re-established companies
German brands
Luxury motor vehicle manufacturers
Companies based in Saxony
Sports car manufacturers
Volkswagen Group
German companies established in 1909 |
849 | https://en.wikipedia.org/wiki/Aircraft | Aircraft | An aircraft (: aircraft) is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or the dynamic lift of an airfoil, or, in a few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons.
The human activity that surrounds aircraft is called aviation. The science of aviation, including designing and building aircraft, is called aeronautics. Crewed aircraft are flown by an onboard pilot, whereas unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion (if any), usage and others.
History
Flying model craft and stories of manned flight go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger hot-air balloons developed in the 18th century. Each of the two World Wars led to great technical advances. Consequently, the history of aircraft can be divided into five eras:
Pioneers of flight, from the earliest experiments to 1914.
First World War, 1914 to 1918.
Aviation between the World Wars, 1918 to 1939.
Second World War, 1939 to 1945.
Postwar era, also called the Jet Age, 1945 to the present day.
Methods of lift
Lighter than air – aerostats
Aerostats use buoyancy to float in the air in much the same way that ships float on the water. They are characterized by one or more large cells or canopies, filled with a relatively low-density gas such as helium, hydrogen, or hot air, which is less dense than the surrounding air. When the weight of this is added to the weight of the aircraft structure, it adds up to the same weight as the air that the craft displaces.
Small hot-air balloons, called sky lanterns, were first invented in ancient China prior to the 3rd century BC and used primarily in cultural celebrations, and were only the second type of aircraft to fly, the first being kites, which were first invented in ancient China over two thousand years ago (see Han Dynasty).
A balloon was originally any aerostat, while the term airship was used for large, powered aircraft designs — usually fixed-wing. In 1919, Frederick Handley Page was reported as referring to "ships of the air," with smaller passenger types as "Air yachts." In the 1930s, large intercontinental flying boats were also sometimes referred to as "ships of the air" or "flying-ships". — though none had yet been built. The advent of powered balloons, called dirigible balloons, and later of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by a rigid outer framework and separate aerodynamic skin surrounding the gas bags, were produced, the Zeppelins being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so "airship" came to be synonymous with these aircraft. Then several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a "balloon" is an unpowered aerostat and an "airship" is a powered one.
A powered, steerable aerostat is called a dirigible. Sometimes this term is applied only to non-rigid balloons, and sometimes dirigible balloon is regarded as the definition of an airship (which may then be rigid or non-rigid). Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back. These soon became known as blimps. During World War II, this shape was widely adopted for tethered balloons; in windy weather, this both reduces the strain on the tether and stabilizes the balloon. The nickname blimp was adopted along with the shape. In modern times, any small dirigible or airship is called a blimp, though a blimp may be unpowered as well as powered.
Heavier-than-air – aerodynes
Heavier-than-air aircraft, such as airplanes, must find some way to push air or gas downwards so that a reaction occurs (by Newton's laws of motion) to push the aircraft upwards. This dynamic movement through the air is the origin of the term. There are two ways to produce dynamic upthrust — aerodynamic lift, and powered lift in the form of engine thrust.
Aerodynamic lift involving wings is the most common, with fixed-wing aircraft being kept in the air by the forward movement of wings, and rotorcraft by spinning wing-shaped rotors sometimes called "rotary wings." A wing is a flat, horizontal surface, usually shaped in cross-section as an aerofoil. To fly, air must flow over the wing and generate lift. A flexible wing is a wing made of fabric or thin sheet material, often stretched over a rigid frame. A kite is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed, or rotary.
With powered lift, the aircraft directs its engine thrust vertically downward. V/STOL aircraft, such as the Harrier jump jet and Lockheed Martin F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight.
A pure rocket is not usually regarded as an aerodyne because it does not depend on the air for its lift (and can even fly into space); however, many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles that obtain aerodynamic lift at very high speed due to airflow over their bodies are a marginal case.
Fixed-wing
The forerunner of the fixed-wing aircraft is the kite. Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the wind blowing over its wings to provide lift. Kites were the first kind of aircraft to fly and were invented in China around 500 BC. Much aerodynamic research was done with kites before test aircraft, wind tunnels, and computer modelling programs became available.
The first heavier-than-air craft capable of controlled free-flight were gliders. A glider designed by George Cayley carried out the first true manned, controlled flight in 1853. The first powered and controllable fixed-wing aircraft (the airplane or aeroplane) was invented by Wilbur and Orville Wright.
Besides the method of propulsion (if any), fixed-wing aircraft are in general characterized by their wing configuration. The most important wing characteristics are:
Number of wings — Monoplane, biplane, triplane, or multiplane.
Wing support — Braced or cantilever, rigid or flexible.
Wing planform — including aspect ratio, angle of sweep, and any variations along the span (including the important class of delta wings).
Location of the horizontal stabilizer, if any.
Dihedral angle — positive, zero, or negative (anhedral).
A variable geometry aircraft can change its wing configuration during flight.
A flying wing has no fuselage, though it may have small blisters or pods. The opposite of this is a lifting body, which has no wings, though it may have small stabilizing and control surfaces.
Wing-in-ground-effect vehicles are generally not considered aircraft. They "fly" efficiently close to the surface of the ground or water, like conventional aircraft during takeoff. An example is the Russian ekranoplan nicknamed the "Caspian Sea Monster". Man-powered aircraft also rely on ground effect to remain airborne with minimal pilot power, but this is only because they are so underpowered—in fact, the airframe is capable of flying higher.
Rotorcraft
Rotorcraft, or rotary-wing aircraft, use a spinning rotor with aerofoil cross-section blades (a rotary wing) to provide lift. Types include helicopters, autogyros, and various hybrids such as gyrodynes and compound rotorcraft.
Helicopters have a rotor turned by an engine-driven shaft. The rotor pushes air downward to create lift. By tilting the rotor forward, the downward flow is tilted backward, producing thrust for forward flight. Some helicopters have more than one rotor and a few have rotors turned by gas jets at the tips. Some have a tail rotor to counteract the rotation of the main rotor, and to aid directional control.
Autogyros have unpowered rotors, with a separate power plant to provide thrust. The rotor is tilted backward. As the autogyro moves forward, air blows upward across the rotor, making it spin. This spinning increases the speed of airflow over the rotor, to provide lift. Rotor kites are unpowered autogyros, which are towed to give them forward speed or tethered to a static anchor in high-wind for kited flight.
Compound rotorcraft have wings that provide some or all of the lift in forward flight. They are nowadays classified as powered lift types and not as rotorcraft. Tiltrotor aircraft (such as the Bell Boeing V-22 Osprey), tiltwing, tail-sitter, and coleopter aircraft have their rotors/propellers horizontal for vertical flight and vertical for forward flight.
Other methods of lift
A lifting body is an aircraft body shaped to produce lift. If there are any wings, they are too small to provide significant lift and are used only for stability and control. Lifting bodies are not efficient: they suffer from high drag, and must also travel at high speed to generate enough lift to fly. Many of the research prototypes, such as the Martin Marietta X-24, which led up to the Space Shuttle, were lifting bodies, though the Space Shuttle is not, and some supersonic missiles obtain lift from the airflow over a tubular body.
Powered lift types rely on engine-derived lift for vertical takeoff and landing (VTOL). Most types transition to fixed-wing lift for horizontal flight. Classes of powered lift types include VTOL jet aircraft (such as the Harrier jump jet) and tiltrotors, such as the Bell Boeing V-22 Osprey, among others. A few experimental designs rely entirely on engine thrust to provide lift throughout the whole flight, including personal fan-lift hover platforms and jetpacks. VTOL research designs include the Rolls-Royce Thrust Measuring Rig.
Some rotor wings employ horizontal-axis wings, in which airflow across a spinning rotor generates lift. The Flettner airplane uses a rotating cylinder, obtaining lift from the Magnus effect. The FanWing uses a cross-flow fan, while the mechanically more complex cyclogyro comprises multiple wings which rotate together around a central axis.
The ornithopter obtains thrust by flapping its wings.
Size and speed extremes
Size
The smallest aircraft are toys/recreational items, and nano aircraft.
The largest aircraft by dimensions and volume (as of 2016) is the long British Airlander 10, a hybrid blimp, with helicopter and fixed-wing features, and reportedly capable of speeds up to , and an airborne endurance of two weeks with a payload of up to .
The largest aircraft by weight and largest regular fixed-wing aircraft ever built, , was the Antonov An-225 Mriya. That Soviet-built (Ukrainian SSR) six-engine transport of the 1980s was long, with an wingspan. It holds the world payload record, after transporting of goods, and has flown loads commercially. With a maximum loaded weight of , it was also the heaviest aircraft built to date. It could cruise at . The aircraft was destroyed during the Russo-Ukrainian War.
The largest military airplanes are the Ukrainian Antonov An-124 Ruslan (world's second-largest airplane, also used as a civilian transport), and American Lockheed C-5 Galaxy transport, weighing, loaded, over . The 8-engine, piston/propeller Hughes H-4 Hercules "Spruce Goose" — an American World War II wooden flying boat transport with a greater wingspan (94m/260ft) than any current aircraft and a tail height equal to the tallest (Airbus A380-800 at 24.1m/78ft) — flew only one short hop in the late 1940s and never flew out of ground effect.
The largest civilian airplanes, apart from the above-noted An-225 and An-124, are the Airbus Beluga cargo transport derivative of the Airbus A300 jet airliner, the Boeing Dreamlifter cargo transport derivative of the Boeing 747 jet airliner/transport (the 747-200B was, at its creation in the 1960s, the heaviest aircraft ever built, with a maximum weight of over ), and the double-decker Airbus A380 "super-jumbo" jet airliner (the world's largest passenger airliner).
Speeds
The fastest fixed-wing aircraft and fastest glider, is the Space Shuttle, which re-entered the atmosphere at nearly Mach 25 or
The fastest recorded powered aircraft flight and fastest recorded aircraft flight of an air-breathing powered aircraft was of the NASA X-43A Pegasus, a scramjet-powered, hypersonic, lifting body experimental research aircraft, at Mach 9.68 or on 16 November 2004.
Prior to the X-43A, the fastest recorded powered airplane flight, and still the record for the fastest manned powered airplane, was the North American X-15, rocket-powered airplane at Mach 6.7 or 7,274 km/h (4,520 mph) on 3 October 1967.
The fastest manned, air-breathing powered airplane is the Lockheed SR-71 Blackbird, a U.S. reconnaissance jet fixed-wing aircraft, having reached on 28 July 1976.
Propulsion
Unpowered aircraft
Gliders are heavier-than-air aircraft that do not employ propulsion once airborne. Take-off may be by launching forward and downward from a high location, or by pulling into the air on a tow-line, either by a ground-based winch or vehicle, or by a powered "tug" aircraft. For a glider to maintain its forward air speed and lift, it must descend in relation to the air (but not necessarily in relation to the ground). Many gliders can "soar", i.e., gain height from updrafts such as thermal currents. The first practical, controllable example was designed and built by the British scientist and pioneer George Cayley, whom many recognise as the first aeronautical engineer. Common examples of gliders are sailplanes, hang gliders and paragliders.
Balloons drift with the wind, though normally the pilot can control the altitude, either by heating the air or by releasing ballast, giving some directional control (since the wind direction changes with altitude). A wing-shaped hybrid balloon can glide directionally when rising or falling; but a spherically shaped balloon does not have such directional control.
Kites are aircraft that are tethered to the ground or other object (fixed or mobile) that maintains tension in the tether or kite line; they rely on virtual or real wind blowing over and under them to generate lift and drag. Kytoons are balloon-kite hybrids that are shaped and tethered to obtain kiting deflections, and can be lighter-than-air, neutrally buoyant, or heavier-than-air.
Powered aircraft
Powered aircraft have one or more onboard sources of mechanical power, typically aircraft engines although rubber and manpower have also been used. Most aircraft engines are either lightweight reciprocating engines or gas turbines. Engine fuel is stored in tanks, usually in the wings but larger aircraft also have additional fuel tanks in the fuselage.
Propeller aircraft
Propeller aircraft use one or more propellers (airscrews) to create thrust in a forward direction. The propeller is usually mounted in front of the power source in tractor configuration but can be mounted behind in pusher configuration. Variations of propeller layout include contra-rotating propellers and ducted fans.
Many kinds of power plant have been used to drive propellers. Early airships used man power or steam engines. The more practical internal combustion piston engine was used for virtually all fixed-wing aircraft until World War II and is still used in many smaller aircraft. Some types use turbine engines to drive a propeller in the form of a turboprop or propfan. Human-powered flight has been achieved, but has not become a practical means of transport. Unmanned aircraft and models have also used power sources such as electric motors and rubber bands.
Jet aircraft
Jet aircraft use airbreathing jet engines, which take in air, burn fuel with it in a combustion chamber, and accelerate the exhaust rearwards to provide thrust.
Different jet engine configurations include the turbojet and turbofan, sometimes with the addition of an afterburner. Those with no rotating turbomachinery include the pulsejet and ramjet. These mechanically simple engines produce no thrust when stationary, so the aircraft must be launched to flying speed using a catapult, like the V-1 flying bomb, or a rocket, for example. Other engine types include the motorjet and the dual-cycle Pratt & Whitney J58.
Compared to engines using propellers, jet engines can provide much higher thrust, higher speeds and, above about , greater efficiency. They are also much more fuel-efficient than rockets. As a consequence nearly all large, high-speed or high-altitude aircraft use jet engines.
Rotorcraft
Some rotorcraft, such as helicopters, have a powered rotary wing or rotor, where the rotor disc can be angled slightly forward so that a proportion of its lift is directed forwards. The rotor may, like a propeller, be powered by a variety of methods such as a piston engine or turbine. Experiments have also used jet nozzles at the rotor blade tips.
Other types of powered aircraft
Rocket-powered aircraft have occasionally been experimented with, and the Messerschmitt Me 163 Komet fighter even saw action in the Second World War. Since then, they have been restricted to research aircraft, such as the North American X-15, which traveled up into space where air-breathing engines cannot work (rockets carry their own oxidant). Rockets have more often been used as a supplement to the main power plant, typically for the rocket-assisted take off of heavily loaded aircraft, but also to provide high-speed dash capability in some hybrid designs such as the Saunders-Roe SR.53.
The ornithopter obtains thrust by flapping its wings. It has found practical use in a model hawk used to freeze prey animals into stillness so that they can be captured, and in toy birds.
Design and construction
Aircraft are designed according to many factors such as customer and manufacturer demand, safety protocols and physical and economic constraints. For many types of aircraft the design process is regulated by national airworthiness authorities.
The key parts of an aircraft are generally divided into three categories:
The structure ("airframe") comprises the main load-bearing elements and associated equipment, as well as flight controls.
The propulsion system ("powerplant") (if it is powered) comprises the power source and associated equipment, as described above.
The avionics comprise the electrical and electronic control, navigation and communication systems.
Structure
The approach to structural design varies widely between different types of aircraft. Some, such as paragliders, comprise only flexible materials that act in tension and rely on aerodynamic pressure to hold their shape. A balloon similarly relies on internal gas pressure, but may have a rigid basket or gondola slung below it to carry its payload. Early aircraft, including airships, often employed flexible doped aircraft fabric covering to give a reasonably smooth aeroshell stretched over a rigid frame. Later aircraft employed semi-monocoque techniques, where the skin of the aircraft is stiff enough to share much of the flight loads. In a true monocoque design there is no internal structure left.
The key structural parts of an aircraft depend on what type it is.
Aerostats
Lighter-than-air types are characterised by one or more gasbags, typically with a supporting structure of flexible cables or a rigid framework called its hull. Other elements such as engines or a gondola may also be attached to the supporting structure.
Aerodynes
Heavier-than-air types are characterised by one or more wings and a central fuselage. The fuselage typically also carries a tail or empennage for stability and control, and an undercarriage for takeoff and landing. Engines may be located on the fuselage or wings. On a fixed-wing aircraft the wings are rigidly attached to the fuselage, while on a rotorcraft the wings are attached to a rotating vertical shaft. Smaller designs sometimes use flexible materials for part or all of the structure, held in place either by a rigid frame or by air pressure. The fixed parts of the structure comprise the airframe.
Power
The source of motive power for an aircraft is normally called the powerplant, and includes engine or motor, propeller or rotor, (if any), jet nozzles and thrust reversers (if any), and accessories essential to the functioning of the engine or motor (e.g.: starter, ignition system, intake system, exhaust system, fuel system, lubrication system, engine cooling system, and engine controls).
Powered aircraft are typically powered by internal combustion engines (piston or turbine) burning fossil fuels -- typically gasoline (avgas) or jet fuel. A very few are powered by rocket power, ramjet propulsion, or by electric motors, or by internal combustion engines of other types, or using other fuels. A very few have been powered, for short flights, by human muscle energy (e.g.: Gossamer Condor).
Avionics
The avionics comprise any electronic aircraft flight control systems and related equipment, including electronic cockpit instrumentation, navigation, radar, monitoring, and communications systems.
Flight characteristics
Flight envelope
The flight envelope of an aircraft refers to its approved design capabilities in terms of airspeed, load factor and altitude. The term can also refer to other assessments of aircraft performance such as maneuverability. When an aircraft is abused, for instance by diving it at too-high a speed, it is said to be flown outside the envelope, something considered foolhardy since it has been taken beyond the design limits which have been established by the manufacturer. Going beyond the envelope may have a known outcome such as flutter or entry to a non-recoverable spin (possible reasons for the boundary).
Range
The range is the distance an aircraft can fly between takeoff and landing, as limited by the time it can remain airborne.
For a powered aircraft the time limit is determined by the fuel load and rate of consumption.
For an unpowered aircraft, the maximum flight time is limited by factors such as weather conditions and pilot endurance. Many aircraft types are restricted to daylight hours, while balloons are limited by their supply of lifting gas. The range can be seen as the average ground speed multiplied by the maximum time in the air.
The Airbus A350-900ULR is now the longest range airliner.
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation around three axes which pass through the vehicle's center of gravity, known as pitch, roll, and yaw.
Roll is a rotation about the longitudinal axis (equivalent to the rolling or heeling of a ship) giving an up-down movement of the wing tips measured by the roll or bank angle.
Pitch is a rotation about the sideways horizontal axis giving an up-down movement of the aircraft nose measured by the angle of attack.
Yaw is a rotation about the vertical axis giving a side-to-side movement of the nose known as sideslip.
Flight dynamics is concerned with the stability and control of an aircraft's rotation about each of these axes.
Stability
An aircraft that is unstable tends to diverge from its intended flight path and so is difficult to fly. A very stable aircraft tends to stay on its flight path and is difficult to maneuver. Therefore, it is important for any design to achieve the desired degree of stability. Since the widespread use of digital computers, it is increasingly common for designs to be inherently unstable and rely on computerised control systems to provide artificial stability.
A fixed wing is typically unstable in pitch, roll, and yaw. Pitch and yaw stabilities of conventional fixed wing designs require horizontal and vertical stabilisers, which act similarly to the feathers on an arrow. These stabilizing surfaces allow equilibrium of aerodynamic forces and to stabilise the flight dynamics of pitch and yaw. They are usually mounted on the tail section (empennage), although in the canard layout, the main aft wing replaces the canard foreplane as pitch stabilizer. Tandem wing and tailless aircraft rely on the same general rule to achieve stability, the aft surface being the stabilising one.
A rotary wing is typically unstable in yaw, requiring a vertical stabiliser.
A balloon is typically very stable in pitch and roll due to the way the payload is slung underneath the center of lift.
Control
Flight control surfaces enable the pilot to control an aircraft's flight attitude and are usually part of the wing or mounted on, or integral with, the associated stabilizing surface. Their development was a critical advance in the history of aircraft, which had until that point been uncontrollable in flight.
Aerospace engineers develop control systems for a vehicle's orientation (attitude) about its center of mass. The control systems include actuators, which exert forces in various directions, and generate rotational forces or moments about the aerodynamic center of the aircraft, and thus rotate the aircraft in pitch, roll, or yaw. For example, a pitching moment is a vertical force applied at a distance forward or aft from the aerodynamic center of the aircraft, causing the aircraft to pitch up or down. Control systems are also sometimes used to increase or decrease drag, for example to slow the aircraft to a safe speed for landing.
The two main aerodynamic forces acting on any aircraft are lift supporting it in the air and drag opposing its motion. Control surfaces or other techniques may also be used to affect these forces directly, without inducing any rotation.
Environmental impact
Aircraft permit long distance, high speed travel and may be a more fuel efficient mode of transportation in some circumstances. Aircraft have environmental and climate impacts beyond fuel efficiency considerations, however. They are also relatively noisy compared to other forms of travel and high altitude aircraft generate contrails, which experimental evidence suggests may alter weather patterns.
Uses for aircraft
Aircraft are produced in several different types optimized for various uses; military aircraft, which includes not just combat types but many types of supporting aircraft, and civil aircraft, which include all non-military types, experimental and model.
Military
A military aircraft is any aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat:
Combat aircraft are aircraft designed to destroy enemy equipment using its own armament. Combat aircraft divide broadly into fighters and bombers, with several in-between types, such as fighter-bombers and attack aircraft, including attack helicopters.
Non-combat aircraft are not designed for combat as their primary function, but may carry weapons for self-defense. Non-combat roles include search and rescue, reconnaissance, observation, transport, training, and aerial refueling. These aircraft are often variants of civil aircraft.
Most military aircraft are powered heavier-than-air types. Other types, such as gliders and balloons, have also been used as military aircraft; for example, balloons were used for observation during the American Civil War and World War I, and military gliders were used during World War II to land troops.
Civil
Civil aircraft divide into commercial and general types, however there are some overlaps.
Commercial aircraft include types designed for scheduled and charter airline flights, carrying passengers, mail and other cargo. The larger passenger-carrying types are the airliners, the largest of which are wide-body aircraft. Some of the smaller types are also used in general aviation, and some of the larger types are used as VIP aircraft.
General aviation is a catch-all covering other kinds of private (where the pilot is not paid for time or expenses) and commercial use, and involving a wide range of aircraft types such as business jets (bizjets), trainers, homebuilt, gliders, warbirds and hot air balloons to name a few. The vast majority of aircraft today are general aviation types.
Experimental
An experimental aircraft is one that has not been fully proven in flight, or that carries a Special Airworthiness Certificate, called an Experimental Certificate in United States parlance. This often implies that the aircraft is testing new aerospace technologies, though the term also refers to amateur-built and kit-built aircraft, many of which are based on proven designs.
Model
A model aircraft is a small unmanned type made to fly for fun, for static display, for aerodynamic research or for other purposes. A scale model is a replica of some larger design.
See also
Lists
Early flying machines
Flight altitude record
List of aircraft
List of civil aircraft
List of fighter aircraft
List of individual aircraft
List of large aircraft
List of aviation, aerospace and aeronautical terms
Topics
Aircraft hijacking
Aircraft spotting
Air traffic control
Airport
Flying car
Personal air vehicle
Powered parachute
Spacecraft
Spaceplane
References
External links
History
The Evolution of Modern Aircraft (NASA)
Virtual Museum
Smithsonian Air and Space Museum - online collection with a particular focus on history of aircraft and spacecraft
Amazing Early Flying Machines slideshow by Life magazine
Information
Airliners.net
Aviation Dictionary - free aviation terms, phrases and jargons
New Scientists aviation page |
857 | https://en.wikipedia.org/wiki/Aberdeenshire | Aberdeenshire | Aberdeenshire (; ) is one of the 32 council areas of Scotland.
It takes its name from the County of Aberdeen, which has substantially different boundaries. The Aberdeenshire Council area includes all of the area of the historic counties of Aberdeenshire and Kincardineshire (except the area making up Aberdeen City council area), as well as part of Banffshire. The county boundaries are officially used for a few purposes, namely land registration and lieutenancy.
Aberdeenshire Council is headquartered at Woodhill House, in Aberdeen, making it the only Scottish council whose headquarters are located outside its jurisdiction. Aberdeen itself forms a different council area (Aberdeen City). Aberdeenshire borders onto Angus and Perth and Kinross to the south, Highland and Moray to the west and Aberdeen City to the east.
Traditionally, it has depended economically on the primary sector (agriculture, fishing, and forestry) and related processing industries. Over the last 40 years, the development of the oil and gas industry and associated service sector has broadened Aberdeenshire's economic base, and contributed to a rapid population growth of some 50% since 1975. Its land represents 8% of Scotland's overall territory. It covers an area of .
History
Aberdeenshire has a rich prehistoric and historical heritage. It is the locus of a large number of Neolithic and Bronze Age archaeological sites, including Longman Hill, Kempstone Hill, Catto Long Barrow and Cairn Lee. The area was settled in the Bronze Age by the Beaker culture, who arrived from the south around 2000–1800 BC. Stone circles and cairns were constructed predominantly in this era. In the Iron Age, hill forts were built. Around the 1st century AD, the Taexali people, who have left little history, were believed to have resided along the coast. The Picts were the next documented inhabitants of the area and were no later than 800–900 AD. The Romans also were in the area during this period, as they left signs at Kintore. Christianity influenced the inhabitants early on, and there were Celtic monasteries at Old Deer and Monymusk.
Since medieval times, there have been many traditional paths that crossed the Mounth (a spur of mountainous land that extends from the higher inland range to the North Sea slightly north of Stonehaven) through present-day Aberdeenshire from the Scottish Lowlands to the Highlands. Some of the most well-known and historically important trackways are the Causey Mounth and Elsick Mounth.
Aberdeenshire played an important role in the fighting between the Scottish clans. Clan MacBeth and the Clan Canmore were two of the larger clans. Macbeth fell at Lumphanan in 1057. During the Anglo-Norman penetration, other families arrive, such as House of Balliol, Clan Bruce, and Clan Cumming (Comyn). When the fighting amongst these newcomers resulted in the Scottish Wars of Independence, the English king Edward I travelled across the area twice, in 1296 and 1303. In 1307, Robert the Bruce was victorious near Inverurie. Along with his victory came new families, namely the Forbeses and the Gordons.
These new families set the stage for the upcoming rivalries during the 14th and 15th centuries. This rivalry grew worse during and after the Protestant Reformation when religion was another reason for conflict between the clans. The Gordon family adhered to Catholicism and the Forbeses to Protestantism. Aberdeenshire was the historic seat of the clan Dempster. Three universities were founded in the area prior to the 17th century, King's College in Old Aberdeen (1494), Marischal College in Aberdeen (1593), and the University of Fraserburgh (1597).
After the end of the Revolution of 1688, an extended peaceful period was interrupted only by fleeting events such as the Rising of 1715 and the Rising of 1745. The latter resulted in the end of the ascendancy of Episcopalianism and the feudal power of landowners. An era began of increased agricultural and industrial progress. During the 17th century, Aberdeenshire was the location of more fighting, centred on the Marquess of Montrose and the English Civil Wars. This period also saw increased wealth due to the increase in trade with Germany, Poland, and the Low Countries.
The present council area is named after the historic county of Aberdeenshire, which has different boundaries and was abandoned as an administrative area in 1975 under the Local Government (Scotland) Act 1973. It was replaced by Grampian Regional Council and five district councils: Banff and Buchan, Gordon, Kincardine and Deeside, Moray and the City of Aberdeen. Local government functions were shared between the two levels. In 1996, under the Local Government, etc. (Scotland) Act 1994, the Banff and Buchan District, Gordon District, and Kincardine and Deeside District were merged to form the present Aberdeenshire Council area. Moray and the City of Aberdeen were made their own council areas. The present Aberdeenshire Council area consists of all of the historic counties of Aberdeenshire and Kincardineshire (except the area of those two counties making up the City of Aberdeen), as well as the north-east portions of Banffshire.
Demographics
The population of the council area has risen over 50% since 1971 to approximately , representing 4.7% of Scotland's total. Aberdeenshire's population has increased by 9.1% since 2001, while Scotland's total population grew by 3.8%.
The census lists a relatively high proportion of under 16s and slightly fewer working-age people compared with the Scottish average.
Aberdeenshire is one of the most homogeneous/indigenous regions of the UK. In 2011, 82.2% of residents identified as 'White Scottish', followed by 12.3% who are 'White British', whilst ethnic minorities constitute only 0.9% of the population. The largest ethnic minority group are Asian Scottish/British at 0.8%. In addition to the English language, 48.8% of residents reported being able to speak and understand the Scots language.
Settlements
The largest settlements in Aberdeenshire are:
Economy
Aberdeenshire's Gross Domestic Product (GDP) is estimated at £3,496M (2011), representing 5.2% of the Scottish total. Aberdeenshire's economy is closely linked to Aberdeen City's (GDP £7,906M), and in 2011, the region as a whole was calculated to contribute 16.8% of Scotland's GDP. Between 2012 and 2014, the combined Aberdeenshire and Aberdeen City economic forecast GDP growth rate is 8.6%, the highest growth rate of any local council area in the UK and above the Scottish rate of 4.8%.
A significant proportion of Aberdeenshire's working residents commute to Aberdeen City for work, varying from 11.5% from Fraserburgh to 65% from Westhill.
Average Gross Weekly Earnings (for full-time employees employed in workplaces in Aberdeenshire in 2011) are £572.60. This is lower than the Scottish average by £2.10 and a fall of 2.6% on the 2010 figure. The average gross weekly pay of people resident in Aberdeenshire is much higher, at £741.90, as many people commute out
of Aberdeenshire, principally into Aberdeen City.
Total employment (excluding farm data) in Aberdeenshire is estimated at 93,700 employees (Business Register and
Employment Survey 2009). The majority of employees work within the service sector, predominantly in public administration, education and health. Almost 19% of employment is within the public sector. Aberdeenshire's economy remains closely linked to Aberdeen City's and the North Sea oil industry, with many employees in oil-related jobs.
The average monthly unemployment (claimant count) rate for Aberdeenshire in 2011 was 1.5%. This is lower than the average rate of Aberdeen City (2.3%), Scotland (4.2%) and the UK (3.8%).
Major industries
Energy – There are significant energy-related infrastructure, presence and expertise in Aberdeenshire. Peterhead is an important centre for the energy industry. Peterhead Port includes an extensive new quay with an adjacent laydown area at Smith Quay, is a major support location for North Sea oil and gas exploration and production and the fast-growing global sub-sea sector. The Gas Terminal at St Fergus handles around 15% of the UK's natural gas requirements, and the Peterhead power station is looking to host Britain's first carbon capture and storage power generation project. There are numerous offshore wind turbines near the coast.
Fishing – Aberdeenshire is Scotland's foremost fishing area. In 2010, catches landed at Aberdeenshire's ports accounted for over half the total fish landings in Scotland and almost 45% in the UK. Along with Aberdeen City, Peterhead and Fraserburgh ports provide much employment in these sectors. The River Deeis also rich in salmon.
Agriculture – Aberdeenshire is rich in arable land, with an estimated 9,000 people employed in the sector, and is best known for rearing livestock, mainly cattle. Sheep are important in the higher ground.
Tourism – this sector continues to grow, with a range of sights to be seen in the area. From the lively Cairngorm Mountain range to the bustling fishing ports on the northeast coast, Aberdeenshire samples a bit of everything. Aberdeenshire also has a rugged coastline, many sandy beaches and is a hot spot for tourist activity throughout the year. Almost 1.3 million tourists visited the region in 2011 – up 3% on the previous year.
Whisky distilling is still a practised art in the area.
Governance
Notable features
The following significant structures or places are within Aberdeenshire:
Balmoral Castle, Scottish Highland residence of the British royal family.
Bennachie
Burn O'Vat
Cairness House
Cairngorms National Park
Corgarff Castle
Crathes Castle
Causey Mounth, an ancient road
Drum Castle
Dunnottar Castle
Fetteresso Castle
Fowlsheugh Nature Reserve
Haddo House
Herscha Hill
Huntly Castle
Kildrummy Castle
Loch of Strathbeg
Lochnagar
Monboddo House
Muchalls Castle
Pitfour estate
Portlethen Moss
Raedykes Roman Camp
River Dee
River Don
Sands of Forvie Nature Reserve
Slains Castles, Old and New
Stonehaven Tolbooth
Ythan Estuary Nature Reserve
Hydrology and climate
There are numerous rivers and burns in Aberdeenshire, including Cowie Water, Carron Water, Burn of Muchalls, River Dee, River Don, River Ury, River Ythan, Water of Feugh, Burn of Myrehouse, Laeca Burn and Luther Water. Numerous bays and estuaries are found along the seacoast of Aberdeenshire, including Banff Bay, Ythan Estuary, Stonehaven Bay and Thornyhive Bay. Aberdeenshire has a marine west coast climate on the Köppen climate classification. Aberdeenshire is in the rain shadow of the Grampians, therefore it has a generally dry climate for a maritime region, with portions of the coast receiving of moisture annually. Summers are mild, and winters are typically cold in Aberdeenshire; Coastal temperatures are moderated by the North Sea such that coastal areas are typically cooler in the summer and warmer in winter than inland locations. Coastal areas are also subject to haar, or coastal fog.
Notable residents
John Skinner, (1721–1807) author, poet and ecclesiastic. Penned the famous verse, "Tullochgorum".
Hugh Mercer, (1726–1777), born in the manse of Pitsligo Kirk, near Rosehearty, brigadier general of the Continental Army during the American Revolution.
Alexander Garden, (1730–1791), born in Birse, was a noted naturalist and physician. He moved to North America in 1754 and discovered two species of lizards. He was a Loyalist during the American Revolutionary War, which led to the confiscation of his property and his banishment in 1782. The gardenia flower is named in his honour.
John Kemp, (1763–1812), born in Auchlossan, was a noted educator at Columbia University who is said to have influenced DeWitt Clinton's opinions and policies.
George MacDonald (1824–1905), author, poet, and theologian born and raised in Huntly.
Dame Evelyn Glennie, DBE, born and raised in Ellon on 19 July 1965, is a virtuoso percussionist and the first full-time solo percussionist in 20th-century western society. She is very highly regarded in the Scottish musical community and has proven that her profound deafness does not inhibit her musical talent or day-to-day life.
Evan Duthie, (born 2000), an award-winning DJ and producer.
Peter Nicol, MBE, born in Inverurie on 5 April 1973, is a former professional squash player who represented first Scotland and then England in international squash.
Peter Shepherd, (1841–1879), Surgeon Major, Royal Army Medical Corps
Johanna Basford (born 1983), illustrator and textile designer
Iona Fyfe (born 1998), award-winning Scots singer and musician.
References
External links
Aberdeenshire Council
Aberdeenshire Tourist Guide
Aberdeenshire Libraries Service
Aberdeenshire Museums Service
Peterhead and Buchan Tourism Web Site
Aberdeenshire Arts
Aberdeenshire Sports Council
Council areas of Scotland |
859 | https://en.wikipedia.org/wiki/Aztlan%20Underground | Aztlan Underground | Aztlan Underground is a band from Los Angeles, California that combines Hip-Hop, Punk Rock, Jazz, and electronic music with Chicano and Native American themes, and indigenous instrumentation. They are often cited as progenitors of Chicano rap.
Background
The band traces its roots to the late-1980s hardcore scene in the Eastside of Los Angeles. They have played rapcore, with elements of punk, hip hop, rock, funk, jazz, indigenous music, and spoken word. Indigenous drums, flutes, and rattles are also commonly used in their music. Their lyrics often address the family and economic issues faced by the Chicano community, and they have been noted as activists for that community.
As an example of the politically active and culturally important artists in Los Angeles in the 1990s, Aztlan Underground appeared on Culture Clash on Fox in 1993; and was part of Breaking Out, a concert on pay per view in 1998, The band was featured in the independent films Algun Dia and Frontierland in the 1990s, and on the upcoming Studio 49. The band has been mentioned or featured in various newspapers and magazines: the Vancouver Sun, New Times, BLU Magazine (an underground hip hop magazine), BAM Magazine, La Banda Elastica Magazine, and the Los Angeles Times calendar section. The band is also the subject of a chapter in the book It's Not About a Salary, by Brian Cross.
Aztlan Underground remains active in the community, lending their voice to annual events such as The Farce of July, and the recent movement to recognize Indigenous People's Day in Los Angeles and beyond.
In addition to forming their own label, Xicano Records and Film, Aztlan Underground were signed to the Basque record label Esan Ozenki in 1999 which enabled them to tour Spain extensively and perform in France and Portugal. Aztlan Underground have also performed in Canada, Australia, and Venezuela. The band has been recognized for their music with nominations in the New Times 1998 "Best Latin Influenced" category, the BAM Magazine 1999 "Best Rock en Español" category, and the LA Weekly 1999 "Best Hip Hop" category. The release of their eponymous third album on August 29, 2009, was met with positive reviews and earned the band four Native American Music Award (NAMMY) nominations in 2010.
Discography
Decolonize
Year:1995
"Teteu Innan"
"Killing Season"
"Lost Souls"
"My Blood Is Red"
"Natural Enemy"
"Sacred Circle"
"Blood On Your Hands"
"Interlude"
"Aug 2 the 9"
"Indigena"
"Lyrical Drive By"
Sub-Verses
Year:1998
"Permiso"
"They Move In Silence"
"No Soy Animal"
"Killing Season"
"Blood On Your Hands"
"Reality Check"
"Lemon Pledge"
"Revolution"
"Preachers of the Blind State"
"Lyrical Drive-By"
"Nahui Ollin"
"How to Catch a Bullet"
"Ik Otik"
"Obsolete Man"
"Decolonize"
"War Flowers"
Aztlan Underground
Year: 2009
"Moztlitta"
"Be God"
"Light Shines"
"Prey"
"In the Field"
"9 10 11 12"
"Smell the Dead"
"Sprung"
"Medicine"
"Acabando"
"Crescent Moon"
See also
Chicano rap
Native American hip hop
Rapcore
Chicano rock
References
External links
Myspace link
Facebook page
Native American rappers
American rappers of Mexican descent
Musical groups from Los Angeles
West Coast hip hop musicians |
869 | https://en.wikipedia.org/wiki/American%20Film%20Institute | American Film Institute | The American Film Institute (AFI) is an American nonprofit film organization that educates filmmakers and honors the heritage of the motion picture arts in the United States. AFI is supported by private funding and public membership fees.
Leadership
The institute is composed of leaders from the film, entertainment, business, and academic communities. The board of trustees is chaired by Kathleen Kennedy and the board of directors chaired by Robert A. Daly guide the organization, which is led by President and CEO, film historian Bob Gazzale. Prior leaders were founding director George Stevens Jr. (from the organization's inception in 1967 until 1980) and Jean Picker Firstenberg (from 1980 to 2007).
History
The American Film Institute was founded by a 1965 presidential mandate announced in the Rose Garden of the White House by Lyndon B. Johnson—to establish a national arts organization to preserve the legacy of American film heritage, educate the next generation of filmmakers, and honor the artists and their work. Two years later, in 1967, AFI was established, supported by the National Endowment for the Arts, the Motion Picture Association of America and the Ford Foundation.
The original 22-member Board of Trustees included actor Gregory Peck as chairman and actor Sidney Poitier as vice-chairman, as well as director Francis Ford Coppola, film historian Arthur Schlesinger, Jr., lobbyist Jack Valenti, and other representatives from the arts and academia.
The institute established a training program for filmmakers known then as the Center for Advanced Film Studies. Also created in the early years were a repertory film exhibition program at the Kennedy Center for the Performing Arts and the AFI Catalog of Feature Films — a scholarly source for American film history. The institute moved to its current eight-acre Hollywood campus in 1981. The film training program grew into the AFI Conservatory, an accredited graduate school.
AFI moved its presentation of first-run and auteur films from the Kennedy Center to the historic AFI Silver Theatre and Cultural Center, which hosts the AFI DOCS film festival, making AFI the largest nonprofit film exhibitor in the world. AFI educates audiences and recognizes artistic excellence through its awards programs and 10 Top 10 Lists.
In 2017, then-aspiring filmmaker Ilana Bar-Din Giannini claimed that the AFI expelled her after she accused Dezso Magyar of sexually harassing her in the early 1980s.
List of programs in brief
AFI educational and cultural programs include:
American Film Institute Awards – an honor celebrating the creative ensembles of the most outstanding motion picture and television programs of the year
AFI Catalog of Feature Films and AFI Archive – the written history of all feature films during the first 100 years of the art form – accessible free online
AFI Conservatory – a film school led by master filmmakers in a graduate-level program
AFI Directing Workshop for Women – a production-based training program committed to increasing the number of women working professionally in screen directing
AFI Life Achievement Award – a tradition since 1973, a high honor for a career in film
AFI 100 Years... series – television events and movie reference lists
AFI's two film festivals – AFI Fest in Los Angeles and AFI Docs in Washington, D.C., and Silver Spring, Maryland
AFI Silver Theatre and Cultural Center – a historic theater with year-round art house, first-run and classic film programming in Silver Spring, Maryland
American Film – a magazine launched in October 1975 that explores the art of new and historic film classics, now a blog on AFI.com
AFI Conservatory
In 1969, the institute established the AFI Conservatory for Advanced Film Studies at Greystone, the Doheny Mansion in Beverly Hills, California. The first class included filmmakers Terrence Malick, Caleb Deschanel, and Paul Schrader. That program grew into the AFI Conservatory, an accredited graduate film school located in the hills above Hollywood, California, providing training in six filmmaking disciplines: cinematography, directing, editing, producing, production design, and screenwriting. Mirroring a professional production environment, Fellows collaborate to make more films than any other graduate level program. Admission to AFI Conservatory is highly selective, with a maximum of 140 graduates per year.
In 2013, Emmy and Oscar-winning director, producer, and screenwriter James L. Brooks (As Good as It Gets, Broadcast News, Terms of Endearment) joined as the artistic director of the AFI Conservatory where he provides leadership for the film program. Brooks' artistic role at the AFI Conservatory has a rich legacy that includes Daniel Petrie, Jr., Robert Wise, and Frank Pierson. Award-winning director Bob Mandel served as dean of the AFI Conservatory for nine years. Jan Schuette took over as dean in 2014 and served until 2017. Film producer Richard Gladstein was dean from 2017 until 2019, when Susan Ruskin was appointed.
Notable alumni
AFI Conservatory's alumni have careers in film, television and on the web. They have been recognized with all of the major industry awards—Academy Award, Emmy Award, guild awards, and the Tony Award.
AFI programs
AFI Catalog of Feature Films
The AFI Catalog, started in 1968, is a web-based filmographic database. A research tool for film historians, the catalog consists of entries on more than 60,000 feature films and 17,000 short films produced from 1893 to 2011, as well as AFI Awards Outstanding Movies of the Year from 2000 through 2010. Early print copies of this catalog may also be found at local libraries.
AFI Life Achievement Award
AFI Awards
Created in 2000, the AFI Awards honor the ten outstanding films ("Movies of the Year") and ten outstanding television programs ("TV Programs of the Year"). The awards are a non-competitive acknowledgment of excellence.
The awards are announced in December, and a private luncheon for award honorees takes place the following January.
AFI Maya Deren Award
AFI 100 Years... series
The AFI 100 Years... series, which ran from 1998 to 2008 and created jury-selected lists of America's best movies in categories such as Musicals, Laughs and Thrills, prompted new generations to experience classic American films. The juries consisted of over 1,500 artists, scholars, critics, and historians. Citizen Kane was voted the greatest American film twice.
AFI film festivals
AFI operates two film festivals: AFI Fest in Los Angeles, and AFI Docs (formally known as Silverdocs) in Silver Spring, Maryland, and Washington, D.C.
AFI Fest
AFI Fest is the American Film Institute's annual celebration of artistic excellence. It is a showcase for the best festival films of the year and an opportunity for master filmmakers and emerging artists to come together with audiences in the movie capital of the world. It is the only festival of its stature that is free to the public. The Academy of Motion Picture Arts and Sciences recognizes AFI Fest as a qualifying festival for the Short Films category for the annual Academy Awards.
The festival has paid tribute to numerous influential filmmakers and artists over the years, including Agnès Varda, Pedro Almodóvar and David Lynch as guest artistic directors, and has screened scores of films that have produced Oscar nominations and wins.
AFI Docs
Held annually in June, AFI Docs (formerly Silverdocs) is a documentary festival in Washington, D.C. The festival attracts over 27,000 documentary enthusiasts.
AFI Silver Theatre and Cultural Center
The AFI Silver Theatre and Cultural Center is a moving image exhibition, education and cultural center located in Silver Spring, Maryland. Anchored by the restoration of noted architect John Eberson's historic 1938 Silver Theatre, it features 32,000 square feet of new construction housing two stadium theatres, office and meeting space, and reception and exhibit areas.
The AFI Silver Theatre and Cultural Center presents film and video programming, augmented by filmmaker interviews, panels, discussions, and musical performances.
The AFI Directing Workshop for Women
The Directing Workshop for Women is a training program committed to educating and mentoring participants in an effort to increase the number of women working professionally in screen directing. In this tuition-free program, each participant is required to complete a short film by the end of the year-long program.
Alumnae of the program include Maya Angelou, Anne Bancroft, Dyan Cannon, Ellen Burstyn, Jennifer Getzinger, Lesli Linka Glatter, Lily Tomlin, Susan Oliver and Nancy Malone.
AFI Directors Series
AFI released a set of hour-long programs reviewing the career of acclaimed directors. The Directors Series content was copyrighted in 1997 by Media Entertainment Inc and The American Film Institute, and the VHS and DVDs were released between 1999 and 2001 on Winstar TV and Video.
Directors featured included:
John McTiernan (WHE73067)
Ron Howard (WHE73068)
Sydney Pollack (WHE73071)
Norman Jewison (WHE73076)
Lawrence Kasdan (WHE73088)
Terry Gilliam (WHE73089)
Spike Lee (WHE73090)
Barry Levinson (WHE73093)
Miloš Forman (WHE73094)
Martin Scorsese (WHE73098)
Barbra Streisand (WHE73099)
David Cronenberg (WHE73101)
Robert Zemeckis (WHE73131)
Robert Altman
John Frankenheimer
Adrian Lyne
Garry Marshall
William Friedkin
Clint Eastwood
David Zucker, Jim Abrahams and Jerry Zucker
Roger Corman
Michael Mann
James Cameron
Rob Reiner
Joel Schumacher
Steven Spielberg
Wes Craven
See also
British Film Institute, the British equivalent to AFI
References
External links
American Film Institute on Internet Archive
AFI Los Angeles Film Festival – history and information (archived July 17, 2009)
Arts organizations based in California
Cinema of Southern California
Culture of Hollywood, Los Angeles
Los Feliz, Los Angeles
Organizations based in Los Angeles
1967 establishments in California
Educational organizations established in 1967
FIAF-affiliated institutions
Arts organizations established in 1967 |
872 | https://en.wikipedia.org/wiki/Akira%20Kurosawa | Akira Kurosawa | was a Japanese filmmaker and painter who directed 30 films in a career spanning over five decades. He is widely regarded as one of the greatest and most influential filmmakers in the history of cinema. Kurosawa displayed a bold, dynamic style, strongly influenced by Western cinema yet distinct from it; he was involved with all aspects of film production.
Kurosawa entered the Japanese film industry in 1936, following a brief stint as a painter. After years of working on numerous films as an assistant director and scriptwriter, he made his debut as a director during World War II with the popular action film Sanshiro Sugata (1943). After the war, the critically acclaimed Drunken Angel (1948), in which Kurosawa cast the then little-known actor Toshiro Mifune in a starring role, cemented the director's reputation as one of the most important young filmmakers in Japan. The two men would go on to collaborate on another fifteen films.
Rashomon (1950), which premiered in Tokyo, became the surprise winner of the Golden Lion at the 1951 Venice Film Festival. The commercial and critical success of that film opened up Western film markets for the first time to the products of the Japanese film industry, which in turn led to international recognition for other Japanese filmmakers. Kurosawa directed approximately one film per year throughout the 1950s and early 1960s, including a number of highly regarded (and often adapted) films, such as (1952), Seven Samurai (1954), Throne of Blood (1957), Yojimbo (1961) and High and Low (1963). After the 1960s he became much less prolific; even so, his later work—including two of his final films, (1980) and (1985)—continued to receive great acclaim.
In 1990, he accepted the Academy Award for Lifetime Achievement. Posthumously, he was named "Asian of the Century" in the "Arts, Literature, and Culture" category by AsianWeek magazine and CNN, cited there as being among the five people who most prominently contributed to the improvement of Asia in the 20th century. His career has been honored by many retrospectives, critical studies and biographies in both print and video, and by releases in many consumer media.
Biography
Childhood to war years (1910–1945)
Childhood and youth (1910–1935)
Kurosawa was born on March 23, 1910, in Ōimachi in the Ōmori district of Tokyo. His father Isamu (1864–1948), a member of a samurai family from Akita Prefecture, worked as the director of the Army's Physical Education Institute's lower secondary school, while his mother Shima (1870–1952) came from a merchant's family living in Osaka. Akira was the eighth and youngest child of the moderately wealthy family, with two of his siblings already grown up at the time of his birth and one deceased, leaving Kurosawa to grow up with three sisters and a brother.
In addition to promoting physical exercise, Isamu Kurosawa was open to Western traditions and considered theatre and motion pictures to have educational merit. He encouraged his children to watch films; young Akira viewed his first movies at the age of six. An important formative influence was his elementary school teacher Mr. Tachikawa, whose progressive educational practices ignited in his young pupil first a love of drawing and then an interest in education in general. During this time, Akira also studied calligraphy and Kendo swordsmanship.
Another major childhood influence was Heigo Kurosawa (1906-1933), Akira's older brother by four years. In the aftermath of the Great Kantō earthquake and the subsequent Kantō Massacre of 1923, Heigo took the thirteen-year-old Akira to view the devastation. When Akira wanted to look away from the corpses of humans and animals scattered everywhere, Heigo forbade him to do so, encouraging Akira instead to face his fears by confronting them directly. Some commentators have suggested that this incident would influence Kurosawa's later artistic career, as the director was seldom hesitant to confront unpleasant truths in his work.
Heigo was academically gifted, but soon after failing to secure a place in Tokyo's foremost high school, he began to detach himself from the rest of the family, preferring to concentrate on his interest in foreign literature. In the late 1920s, Heigo became a benshi (silent film narrator) for Tokyo theaters showing foreign films and quickly made a name for himself. Akira, who at this point planned to become a painter, moved in with him, and the two brothers became inseparable. With Heigo's guidance, Akira devoured not only films but also theater and circus performances, while exhibiting his paintings and working for the left-wing Proletarian Artists' League. However, he was never able to make a living with his art, and, as he began to perceive most of the proletarian movement as "putting unfulfilled political ideals directly onto the canvas", he lost his enthusiasm for painting.
With the increasing production of talking pictures in the early 1930s, film narrators like Heigo began to lose work, and Akira moved back in with his parents. In July 1933, Heigo died by suicide. Kurosawa has commented on the lasting sense of loss he felt at his brother's death and the chapter of Something Like an Autobiography that describes it—written nearly half a century after the event—is titled, "A Story I Don't Want to Tell". Only four months later, Kurosawa's eldest brother also died, leaving Akira, at age 23, the only one of the Kurosawa brothers still living, together with his three surviving sisters.
Director in training (1935–1941)
In 1935, the new film studio Photo Chemical Laboratories, known as P.C.L. (which later became the major studio Toho), advertised for assistant directors. Although he had demonstrated no previous interest in film as a profession, Kurosawa submitted the required essay, which asked applicants to discuss the fundamental deficiencies of Japanese films and find ways to overcome them. His half-mocking view was that if the deficiencies were fundamental, there was no way to correct them. Kurosawa's essay earned him a call to take the follow-up exams, and director Kajirō Yamamoto, who was among the examiners, took a liking to Kurosawa and insisted that the studio hire him. The 25-year-old Kurosawa joined P.C.L. in February 1936.
During his five years as an assistant director, Kurosawa worked under numerous directors, but by far the most important figure in his development was Yamamoto. Of his 24 films as A.D., he worked on 17 under Yamamoto, many of them comedies featuring the popular actor Ken'ichi Enomoto, known as "Enoken". Yamamoto nurtured Kurosawa's talent, promoting him directly from third assistant director to chief assistant director after a year. Kurosawa's responsibilities increased, and he worked at tasks ranging from stage construction and film development to location scouting, script polishing, rehearsals, lighting, dubbing, editing, and second-unit directing. In the last of Kurosawa's films as an assistant director for Yamamoto, Horse (1941), Kurosawa took over most of the production, as his mentor was occupied with the shooting of another film.
Yamamoto advised Kurosawa that a good director needed to master screenwriting. Kurosawa soon realized that the potential earnings from his scripts were much higher than what he was paid as an assistant director. He later wrote or co-wrote all his films, and frequently penned screenplays for other directors such as Satsuo Yamamoto's film, A Triumph of Wings (Tsubasa no gaika, 1942). This outside scriptwriting would serve Kurosawa as a lucrative sideline lasting well into the 1960s, long after he became famous.
Wartime films and marriage (1942–1945)
In the two years following the release of Horse in 1941, Kurosawa searched for a story he could use to launch his directing career. Towards the end of 1942, about a year after the Japanese attack on Pearl Harbor, novelist Tsuneo Tomita published his Musashi Miyamoto-inspired judo novel, Sanshiro Sugata, the advertisements for which intrigued Kurosawa. He bought the book on its publication day, devoured it in one sitting, and immediately asked Toho to secure the film rights. Kurosawa's initial instinct proved correct as, within a few days, three other major Japanese studios also offered to buy the rights. Toho prevailed, and Kurosawa began pre-production on his debut work as director.
Shooting of Sanshiro Sugata began on location in Yokohama in December 1942. Production proceeded smoothly, but getting the completed film past the censors was an entirely different matter. The censorship office considered the work to be objectionably "British-American" by the standards of wartime Japan, and it was only through the intervention of director Yasujirō Ozu, who championed the film, that Sanshiro Sugata was finally accepted for release on March 25, 1943. (Kurosawa had just turned 33.) The movie became both a critical and commercial success. Nevertheless, the censorship office would later decide to cut out some 18 minutes of footage, much of which is now considered lost.
He next turned to the subject of wartime female factory workers in The Most Beautiful, a propaganda film which he shot in a semi-documentary style in early 1944. To elicit realistic performances from his actresses, the director had them live in a real factory during the shoot, eat the factory food and call each other by their character names. He would use similar methods with his performers throughout his career.
During production, the actress playing the leader of the factory workers, Yōko Yaguchi, was chosen by her colleagues to present their demands to the director. She and Kurosawa were constantly at odds, and it was through these arguments that the two paradoxically became close. They married on May 21, 1945, with Yaguchi two months pregnant (she never resumed her acting career), and the couple would remain together until her death in 1985. They had two children, both surviving Kurosawa : a son, Hisao, born December 20, 1945, who served as producer on some of his father's last projects, and Kazuko, a daughter, born April 29, 1954, who became a costume designer.
Shortly before his marriage, Kurosawa was pressured by the studio against his will to direct a sequel to his debut film. The often blatantly propagandistic Sanshiro Sugata Part II, which premiered in May 1945, is generally considered one of his weakest pictures.
Kurosawa decided to write the script for a film that would be both censor-friendly and less expensive to produce. The Men Who Tread on the Tiger's Tail, based on the Kabuki play Kanjinchō and starring the comedian Enoken, with whom Kurosawa had often worked during his assistant director days, was completed in September 1945. By this time, Japan had surrendered and the occupation of Japan had begun. The new American censors interpreted the values allegedly promoted in the picture as overly "feudal" and banned the work. It was not released until 1952, the year another Kurosawa film, , was also released. Ironically, while in production, the film had already been savaged by Japanese wartime censors as too Western and "democratic" (they particularly disliked the comic porter played by Enoken), so the movie most probably would not have seen the light of day even if the war had continued beyond its completion.
Early postwar years to Red Beard (1946–1965)
First postwar works (1946–1950)
After the war, Kurosawa, influenced by the democratic ideals of the Occupation, sought to make films that would establish a new respect towards the individual and the self. The first such film, No Regrets for Our Youth (1946), inspired by both the 1933 Takigawa incident and the Hotsumi Ozaki wartime spy case, criticized Japan's prewar regime for its political oppression. Atypically for the director, the heroic central character is a woman, Yukie (Setsuko Hara), who, born into upper-middle-class privilege, comes to question her values in a time of political crisis. The original script had to be extensively rewritten and, because of its controversial theme and gender of its protagonist, the completed work divided critics. Nevertheless, it managed to win the approval of audiences, who turned variations on the film's title into a postwar catchphrase.
His next film, One Wonderful Sunday, premiered in July 1947 to mixed reviews. It is a relatively uncomplicated and sentimental love story dealing with an impoverished postwar couple trying to enjoy, within the devastation of postwar Tokyo, their one weekly day off. The movie bears the influence of Frank Capra, D. W. Griffith and F. W. Murnau, each of whom was among Kurosawa's favorite directors. Another film released in 1947 with Kurosawa's involvement was the action-adventure thriller, Snow Trail, directed by Senkichi Taniguchi from Kurosawa's screenplay. It marked the debut of the intense young actor Toshiro Mifune. It was Kurosawa who, with his mentor Yamamoto, had intervened to persuade Toho to sign Mifune, during an audition in which the young man greatly impressed Kurosawa, but managed to alienate most of the other judges.
Drunken Angel is often considered the director's first major work. Although the script, like all of Kurosawa's occupation-era works, had to go through rewrites due to American censorship, Kurosawa felt that this was the first film in which he was able to express himself freely. A gritty story of a doctor who tries to save a gangster (yakuza) with tuberculosis, it was also the first time that Kurosawa directed Mifune, who went on to play major roles in all but one of the director's next 16 films (the exception being ). While Mifune was not cast as the protagonist in Drunken Angel, his explosive performance as the gangster so dominates the drama that he shifted the focus from the title character, the alcoholic doctor played by Takashi Shimura, who had already appeared in several Kurosawa movies. However, Kurosawa did not want to smother the young actor's immense vitality, and Mifune's rebellious character electrified audiences in much the way that Marlon Brando's defiant stance would startle American film audiences a few years later. The film premiered in Tokyo in April 1948 to rave reviews and was chosen by the prestigious Kinema Junpo critics poll as the best film of its year, the first of three Kurosawa movies to be so honored.
After the completion of Drunken Angel, Toho became embroiled in a months-long labor strike, in which the Toho union occupied the grounds of the studio. When Toho management ceased paying workers' salaries, Kurosawa formed a touring acting troupe to raise funds, directing Anton Chekhov's The Proposal, and an adaptation of Drunken Angel starring Mifune and Shimura. Disillusioned by the division and violence between employees at Toho, the underhanded tactics of Toho leadership, and the breaking of the occupation by police and military standoff, Kurosawa left Toho, later recalling "I had come to understand that the studio I had thought was my home actually belonged to strangers".
Kurosawa, with producer Sōjirō Motoki and fellow directors and friends Kajiro Yamamoto, Mikio Naruse and Senkichi Taniguchi, formed a new independent production unit called Film Art Association (Eiga Geijutsu Kyōkai). For this organization's debut work, and first film for Daiei studios, Kurosawa turned to a contemporary play by Kazuo Kikuta and, together with Taniguchi, adapted it for the screen. The Quiet Duel starred Toshiro Mifune as an idealistic young doctor struggling with syphilis, a deliberate attempt by Kurosawa to break the actor away from being typecast as gangsters. Released in March 1949, it was a box office success, but is generally considered one of the director's lesser achievements.
His second film of 1949, also produced by Film Art Association and released by Shintoho, was Stray Dog. It is a detective movie (perhaps the first important Japanese film in that genre) that explores the mood of Japan during its painful postwar recovery through the story of a young detective, played by Mifune, and his fixation on the recovery of his handgun, which was stolen by a penniless war veteran who proceeds to use it to rob and murder. Adapted from an unpublished novel by Kurosawa in the style of a favorite writer of his, Georges Simenon, it was the director's first collaboration with screenwriter Ryuzo Kikushima, who would later help to script eight other Kurosawa films. A famous, virtually wordless sequence, lasting over eight minutes, shows the detective, disguised as an impoverished veteran, wandering the streets in search of the gun thief; it employed actual documentary footage of war-ravaged Tokyo neighborhoods shot by Kurosawa's friend, Ishirō Honda, the future director of Godzilla. The film is considered a precursor to the contemporary police procedural and buddy cop film genres.
Scandal, released by Shochiku in April 1950, was inspired by the director's personal experiences with, and anger towards, Japanese yellow journalism. The work is an ambitious mixture of courtroom drama and social problem film about free speech and personal responsibility, but even Kurosawa regarded the finished product as dramatically unfocused and unsatisfactory, and almost all critics agree. However, it would be Kurosawa's second film of 1950 that would ultimately win him, and Japanese cinema, a whole new international audience.
International recognition (1950–1958)
After finishing Scandal, Kurosawa was approached by Daiei studios to make another film for them. Kurosawa picked a script by an aspiring young screenwriter, Shinobu Hashimoto, who would eventually work on nine of his films. Their first joint effort was based on Ryūnosuke Akutagawa's experimental short story "In a Grove", which recounts the murder of a samurai and the rape of his wife from various different and conflicting points-of-view. Kurosawa saw potential in the script, and with Hashimoto's help, polished and expanded it and then pitched it to Daiei, who were happy to accept the project due to its low budget.
The shooting of Rashomon began on July 7, 1950, and, after extensive location work in the primeval forest of Nara, wrapped on August 17. Just one week was spent in hurried post-production, hampered by a studio fire, and the finished film premiered at Tokyo's Imperial Theatre on August 25, expanding nationwide the following day. The movie was met by lukewarm reviews, with many critics puzzled by its unique theme and treatment, but it was nevertheless a moderate financial success for Daiei.
Kurosawa's next film, for Shochiku, was The Idiot, an adaptation of the novel by the director's favorite writer, Fyodor Dostoevsky. The story is relocated from Russia to Hokkaido, but otherwise adheres closely to the original, a fact seen by many critics as detrimental to the work. A studio-mandated edit shortened it from Kurosawa's original cut of 265 minutes to just 166 minutes, making the resulting narrative exceedingly difficult to follow. The severely edited film version is widely considered to be one of the director's least successful works and the original full-length version no longer exists. Contemporary reviews of the much shortened edited version were very negative, but the film was a moderate success at the box office, largely because of the popularity of one of its stars, Setsuko Hara.
Meanwhile, unbeknownst to Kurosawa, Rashomon had been entered in the Venice Film Festival, due to the efforts of Giuliana Stramigioli, a Japan-based representative of an Italian film company, who had seen and admired the movie and convinced Daiei to submit it. On September 10, 1951, Rashomon was awarded the festival's highest prize, the Golden Lion, shocking not only Daiei but the international film world, which at the time was largely unaware of Japan's decades-old cinematic tradition.
After Daiei briefly exhibited a subtitled print of the film in Los Angeles, RKO purchased distribution rights to Rashomon in the United States. The company was taking a considerable gamble. It had put out only one prior subtitled film in the American market, and the only previous Japanese talkie commercially released in New York had been Mikio Naruse's comedy, Wife! Be Like a Rose!, in 1937: a critical and box-office flop. However, Rashomons commercial run, greatly helped by strong reviews from critics and even the columnist Ed Sullivan, earned $35,000 in its first three weeks at a single New York theatre, an almost unheard-of sum at the time.
This success in turn led to a vogue in America and the West for Japanese movies throughout the 1950s, replacing the enthusiasm for Italian neorealist cinema. By the end of 1952 Rashomon was released in Japan, the United States, and most of Europe. Among the Japanese film-makers whose work, as a result, began to win festival prizes and commercial release in the West were Kenji Mizoguchi (The Life of Oharu, Ugetsu, Sansho the Bailiff) and, somewhat later, Yasujirō Ozu (Tokyo Story, An Autumn Afternoon)—artists highly respected in Japan but, before this period, almost totally unknown in the West. Kurosawa's growing reputation among Western audiences in the 1950s would make Western audiences more sympathetic to the reception of later generations of Japanese film-makers ranging from Kon Ichikawa, Masaki Kobayashi, Nagisa Oshima and Shohei Imamura to Juzo Itami, Takeshi Kitano and Takashi Miike.
His career boosted by his sudden international fame, Kurosawa, now reunited with his original film studio, Toho (which would go on to produce his next 11 films), set to work on his next project, . Based on Leo Tolstoy's The Death of Ivan Ilyich, the movie stars Takashi Shimura as a cancer-ridden Tokyo bureaucrat, Watanabe, on a final quest for meaning before his death. For the screenplay, Kurosawa brought in Hashimoto as well as writer Hideo Oguni, who would go on to co-write twelve Kurosawa films. Despite the work's grim subject matter, the screenwriters took a satirical approach, which some have compared to the work of Brecht, to both the bureaucratic world of its hero and the U.S. cultural colonization of Japan. (American pop songs figure prominently in the film.) Because of this strategy, the filmmakers are usually credited with saving the picture from the kind of sentimentality common to dramas about characters with terminal illnesses. opened in October 1952 to rave reviews—it won Kurosawa his second Kinema Junpo "Best Film" award—and enormous box office success. It remains the most acclaimed of all the artist's films set in the modern era.
In December 1952, Kurosawa took his screenwriters, Shinobu Hashimoto and Hideo Oguni, for a forty-five-day secluded residence at an inn to create the screenplay for his next movie, Seven Samurai. The ensemble work was Kurosawa's first proper samurai film, the genre for which he would become most famous. The simple story, about a poor farming village in Sengoku period Japan that hires a group of samurai to defend it against an impending attack by bandits, was given a full epic treatment, with a huge cast (largely consisting of veterans of previous Kurosawa productions) and meticulously detailed action, stretching out to almost three-and-a-half hours of screen time.
Three months were spent in pre-production and a month in rehearsals. Shooting took up 148 days spread over almost a year, interrupted by production and financing troubles and Kurosawa's health problems. The film finally opened in April 1954, half a year behind its original release date and about three times over budget, making it at the time the most expensive Japanese film ever made. (However, by Hollywood standards, it was a quite modestly budgeted production, even for that time.) The film received positive critical reaction and became a big hit, quickly making back the money invested in it and providing the studio with a product that they could, and did, market internationally—though with extensive edits. Over time—and with the theatrical and home video releases of the uncut version—its reputation has steadily grown. It is now regarded by some commentators as the greatest Japanese film ever made, and in 1999, a poll of Japanese film critics also voted it the best Japanese film ever made. In the most recent (2022) version of the widely respected British Film Institute (BFI) Sight & Sound "Greatest Films of All Time" poll, Seven Samurai placed 20th among all films from all countries in the critics' and tied at 14th in the directors' polls, receiving a place in the Top Ten lists of 48 critics and 22 directors.
In 1954, nuclear tests in the Pacific were causing radioactive rainstorms in Japan and one particular incident in March had exposed a Japanese fishing boat to nuclear fallout, with disastrous results. It is in this anxious atmosphere that Kurosawa's next film, I Live in Fear, was conceived. The story concerned an elderly factory owner (Toshiro Mifune) so terrified of the prospect of a nuclear attack that he becomes determined to move his entire extended family (both legal and extra-marital) to what he imagines is the safety of a farm in Brazil. Production went much more smoothly than the director's previous film, but a few days before shooting ended, Kurosawa's composer, collaborator, and close friend Fumio Hayasaka died (of tuberculosis) at the age of 41. The film's score was finished by Hayasaka's student, Masaru Sato, who would go on to score all of Kurosawa's next eight films. I Live in Fear opened in November 1955 to mixed reviews and muted audience reaction, becoming the first Kurosawa film to lose money during its original theatrical run. Today, it is considered by many to be among the finest films dealing with the psychological effects of the global nuclear stalemate.
Kurosawa's next project, Throne of Blood, an adaptation of William Shakespeare's Macbeth—set, like Seven Samurai, in the Sengoku Era—represented an ambitious transposition of the English work into a Japanese context. Kurosawa instructed his leading actress, Isuzu Yamada, to regard the work as if it were a cinematic version of a Japanese rather than a European literary classic. Given Kurosawa's appreciation of traditional Japanese stage acting, the acting of the players, particularly Yamada, draws heavily on the stylized techniques of the Noh theater. It was filmed in 1956 and released in January 1957 to a slightly less negative domestic response than had been the case with the director's previous film. Abroad, Throne of Blood, regardless of the liberties it takes with its source material, quickly earned a place among the most celebrated Shakespeare adaptations.
Another adaptation of a classic European theatrical work followed almost immediately, with production of The Lower Depths, based on a play by Maxim Gorky, taking place in May and June 1957. In contrast to the Shakespearean sweep of Throne of Blood, The Lower Depths was shot on only two confined sets, in order to emphasize the restricted nature of the characters' lives. Though faithful to the play, this adaptation of Russian material to a completely Japanese setting—in this case, the late Edo period—unlike his earlier The Idiot, was regarded as artistically successful. The film premiered in September 1957, receiving a mixed response similar to that of Throne of Blood. However, some critics rank it among the director's most underrated works.
Kurosawa's three next movies after Seven Samurai had not managed to capture Japanese audiences in the way that that film had. The mood of the director's work had been growing increasingly pessimistic and dark even as Japan entered a boom period of high-speed growth and rising standards of living. Out of step with the prevailing mood of the era, Kurosawa's films questioned the possibility of redemption through personal responsibility, particularly in Throne of Blood and The Lower Depths. He recognized this, and deliberately aimed for a more light-hearted and entertaining film for his next production while switching to the new widescreen format that had been gaining popularity in Japan. The resulting film, The Hidden Fortress, is an action-adventure comedy-drama about a medieval princess, her loyal general, and two peasants who all need to travel through enemy lines in order to reach their home region. Released in December 1958, The Hidden Fortress became an enormous box-office success in Japan and was warmly received by critics both in Japan and abroad. Today, the film is considered one of Kurosawa's most lightweight efforts, though it remains popular, not least because it is one of several major influences on George Lucas's 1977 space opera, Star Wars.
Birth of a company and Red Beard (1959–1965)
Starting with Rashomon, Kurosawa's productions had become increasingly large in scope and so had the director's budgets. Toho, concerned about this development, suggested that he might help finance his own works, therefore making the studio's potential losses smaller, while in turn allowing himself more artistic freedom as co-producer. Kurosawa agreed, and the Kurosawa Production Company was established in April 1959, with Toho as the majority shareholder.
Despite risking his own money, Kurosawa chose a story that was more directly critical of the Japanese business and political elites than any previous work. The Bad Sleep Well, based on a script by Kurosawa's nephew Mike Inoue, is a revenge drama about a young man who is able to infiltrate the hierarchy of a corrupt Japanese company with the intention of exposing the men responsible for his father's death. Its theme proved topical: while the film was in production, the massive Anpo protests were held against the new U.S.–Japan Security treaty, which was seen by many Japanese, particularly the young, as threatening the country's democracy by giving too much power to corporations and politicians. The film opened in September 1960 to positive critical reaction and modest box office success. The 25-minute opening sequence depicting a corporate wedding reception is widely regarded as one of Kurosawa's most skillfully executed set pieces, but the remainder of the film is often perceived as disappointing by comparison. The movie has also been criticized for employing the conventional Kurosawan hero to combat a social evil that cannot be resolved through the actions of individuals, however courageous or cunning.
Yojimbo (The Bodyguard), Kurosawa Production's second film, centers on a masterless samurai, Sanjuro, who strolls into a 19th-century town ruled by two opposing violent factions and provokes them into destroying each other. The director used this work to play with many genre conventions, particularly the Western, while at the same time offering an unprecedentedly (for the Japanese screen) graphic portrayal of violence. Some commentators have seen the Sanjuro character in this film as a fantasy figure who magically reverses the historical triumph of the corrupt merchant class over the samurai class. Featuring Tatsuya Nakadai in his first major role in a Kurosawa movie, and with innovative photography by Kazuo Miyagawa (who shot Rashomon) and Takao Saito, the film premiered in April 1961 and was a critically and commercially successful venture, earning more than any previous Kurosawa film. The movie and its blackly comic tone were also widely imitated abroad. Sergio Leone's A Fistful of Dollars was a virtual (unauthorized) scene-by-scene remake with Toho filing a lawsuit on Kurosawa's behalf and prevailing.
Following the success of Yojimbo, Kurosawa found himself under pressure from Toho to create a sequel. Kurosawa turned to a script he had written before Yojimbo, reworking it to include the hero of his previous film. Sanjuro was the first of three Kurosawa films to be adapted from the work of the writer Shūgorō Yamamoto (the others would be Red Beard and Dodeskaden). It is lighter in tone and closer to a conventional period film than Yojimbo, though its story of a power struggle within a samurai clan is portrayed with strongly comic undertones. The film opened on January 1, 1962, quickly surpassing Yojimbos box office success and garnering positive reviews.
Kurosawa had meanwhile instructed Toho to purchase the film rights to King's Ransom, a novel about a kidnapping written by American author and screenwriter Evan Hunter, under his pseudonym of Ed McBain, as one of his 87th Precinct series of crime books. The director intended to create a work condemning kidnapping, which he considered one of the very worst crimes. The suspense film, titled High and Low, was shot during the latter half of 1962 and released in March 1963. It broke Kurosawa's box office record (the third film in a row to do so), became the highest grossing Japanese film of the year, and won glowing reviews. However, his triumph was somewhat tarnished when, ironically, the film was blamed for a wave of kidnappings which occurred in Japan about this time (he himself received kidnapping threats directed at his young daughter, Kazuko). High and Low is considered by many commentators to be among the director's strongest works.
Kurosawa quickly moved on to his next project, Red Beard. Based on a short story collection by Shūgorō Yamamoto and incorporating elements from Dostoevsky's novel The Insulted and Injured, it is a period film, set in a mid-nineteenth century clinic for the poor, in which Kurosawa's humanist themes receive perhaps their fullest statement. A conceited and materialistic, foreign-trained young doctor, Yasumoto, is forced to become an intern at the clinic under the stern tutelage of Doctor Niide, known as "Akahige" ("Red Beard"), played by Mifune. Although he resists Red Beard initially, Yasumoto comes to admire his wisdom and courage and to perceive the patients at the clinic, whom he at first despised, as worthy of compassion and dignity.
Yūzō Kayama, who plays Yasumoto, was an extremely popular film and music star at the time, particularly for his "Young Guy" (Wakadaishō) series of musical comedies, so signing him to appear in the film virtually guaranteed Kurosawa strong box-office. The shoot, the filmmaker's longest ever, lasted well over a year (after five months of pre-production), and wrapped in spring 1965, leaving the director, his crew and his actors exhausted. Red Beard premiered in April 1965, becoming the year's highest-grossing Japanese production and the third (and last) Kurosawa film to top the prestigious Kinema Jumpo yearly critics poll. It remains one of Kurosawa's best-known and most-loved works in his native country. Outside Japan, critics have been much more divided. Most commentators concede its technical merits and some praise it as among Kurosawa's best, while others insist that it lacks complexity and genuine narrative power, with still others claiming that it represents a retreat from the artist's previous commitment to social and political change.
The film marked something of an end of an era for its creator. The director himself recognized this at the time of its release, telling critic Donald Richie that a cycle of some kind had just come to an end and that his future films and production methods would be different. His prediction proved quite accurate. Beginning in the late 1950s, television began increasingly to dominate the leisure time of the formerly large and loyal Japanese cinema audience. And as film company revenues dropped, so did their appetite for risk—particularly the risk represented by Kurosawa's costly production methods.
Red Beard also marked the midway point, chronologically, in the artist's career. During his previous twenty-nine years in the film industry (which includes his five years as assistant director), he had directed twenty-three films, while during the remaining twenty-eight years, for many complex reasons, he would complete only seven more. Also, for reasons never adequately explained, Red Beard would be his final film starring Toshiro Mifune. Yū Fujiki, an actor who worked on The Lower Depths, observed, regarding the closeness of the two men on the set, "Mr. Kurosawa's heart was in Mr. Mifune's body." Donald Richie has described the rapport between them as a unique "symbiosis".
Hollywood ambitions to last films (1966–1998)
Hollywood detour (1966–1968)
When Kurosawa's exclusive contract with Toho came to an end in 1966, the 56-year-old director was seriously contemplating change. Observing the troubled state of the domestic film industry, and having already received dozens of offers from abroad, the idea of working outside Japan appealed to him as never before.
For his first foreign project, Kurosawa chose a story based on a Life magazine article. The Embassy Pictures action thriller, to be filmed in English and called simply Runaway Train, would have been his first in color. But the language barrier proved a major problem, and the English version of the screenplay was not even finished by the time filming was to begin in autumn 1966. The shoot, which required snow, was moved to autumn 1967, then canceled in 1968. Almost two decades later, another foreign director working in Hollywood, Andrei Konchalovsky, finally made Runaway Train (1985), though from a new script loosely based on Kurosawa's.
The director meanwhile had become involved in a much more ambitious Hollywood project. Tora! Tora! Tora!, produced by 20th Century Fox and Kurosawa Production, would be a portrayal of the Japanese attack on Pearl Harbor from both the American and the Japanese points of view, with Kurosawa helming the Japanese half and an Anglophonic film-maker directing the American half. He spent several months working on the script with Ryuzo Kikushima and Hideo Oguni, but very soon the project began to unravel. The director of the American sequences turned out not to be David Lean, as originally planned, but American Richard Fleischer. The budget was also cut, and the screen time allocated for the Japanese segment would now be no longer than 90 minutes—a major problem, considering that Kurosawa's script ran over four hours. After numerous revisions with the direct involvement of Darryl Zanuck, a more or less finalized cut screenplay was agreed upon in May 1968.
Shooting began in early December, but Kurosawa would last only a little over three weeks as director. He struggled to work with an unfamiliar crew and the requirements of a Hollywood production, while his working methods puzzled his American producers, who ultimately concluded that the director must be mentally ill. Kurosawa was examined at Kyoto University Hospital by a neuropsychologist, Dr. Murakami, whose diagnosis was forwarded to Darryl Zanuck and Richard Zanuck at Fox studios indicating a diagnosis of neurasthenia stating that, "He is suffering from disturbance of sleep, agitated with feelings of anxiety and in manic excitement caused by the above mentioned illness. It is necessary for him to have rest and medical treatment for more than two months." On Christmas Eve 1968, the Americans announced that Kurosawa had left the production due to "fatigue", effectively firing him. He was ultimately replaced, for the film's Japanese sequences, with two directors, Kinji Fukasaku and Toshio Masuda.
Tora! Tora! Tora!, finally released to unenthusiastic reviews in September 1970, was, as Donald Richie put it, an "almost unmitigated tragedy" in Kurosawa's career. He had spent years of his life on a logistically nightmarish project to which he ultimately did not contribute a foot of film shot by himself. (He had his name removed from the credits, though the script used for the Japanese half was still his and his co-writers'.) He became estranged from his longtime collaborator, writer Ryuzo Kikushima, and never worked with him again. The project had inadvertently exposed corruption in his own production company (a situation reminiscent of his own movie, The Bad Sleep Well). His very sanity had been called into question. Worst of all, the Japanese film industry—and perhaps Kurosawa himself—began to suspect that he would never make another film.
A difficult decade (1969–1977)
Knowing that his reputation was at stake following the much publicised Tora! Tora! Tora! debacle, Kurosawa moved quickly to a new project to prove he was still viable. To his aid came friends and famed directors Keisuke Kinoshita, Masaki Kobayashi and Kon Ichikawa, who together with Kurosawa established in July 1969 a production company called the Club of the Four Knights (Yonki no kai). Although the plan was for the four directors to create a film each, it has been suggested that the real motivation for the other three directors was to make it easier for Kurosawa to successfully complete a film, and therefore find his way back into the business.
The first project proposed and worked on was a period film to be called Dora-heita, but when this was deemed too expensive, attention shifted to Dodesukaden, an adaptation of yet another Shūgorō Yamamoto work, again about the poor and destitute. The film was shot quickly (by Kurosawa's standards) in about nine weeks, with Kurosawa determined to show he was still capable of working quickly and efficiently within a limited budget. For his first work in color, the dynamic editing and complex compositions of his earlier pictures were set aside, with the artist focusing on the creation of a bold, almost surreal palette of primary colors, in order to reveal the toxic environment in which the characters live. It was released in Japan in October 1970, but though a minor critical success, it was greeted with audience indifference. The picture lost money and caused the Club of the Four Knights to dissolve. Initial reception abroad was somewhat more favorable, but Dodesukaden has since been typically considered an interesting experiment not comparable to the director's best work.
After struggling through the production of Dodesukaden, Kurosawa turned to television work the following year for the only time in his career with Song of the Horse, a documentary about thoroughbred race horses. It featured a voice-over narrated by a fictional man and a child (voiced by the same actors as the beggar and his son in Dodesukaden). It is the only documentary in Kurosawa's filmography; the small crew included his frequent collaborator Masaru Sato, who composed the music. Song of the Horse is also unique in Kurosawa's oeuvre in that it includes an editor's credit, suggesting that it is the only Kurosawa film that he did not cut himself.
Unable to secure funding for further work and allegedly having health problems, Kurosawa apparently reached the breaking point: on December 22, 1971, he slit his wrists and throat multiple times. The suicide attempt proved unsuccessful and the director's health recovered fairly quickly, with Kurosawa now taking refuge in domestic life, uncertain if he would ever direct another film.
In early 1973, the Soviet studio Mosfilm approached the film-maker to ask if he would be interested in working with them. Kurosawa proposed an adaptation of Russian explorer Vladimir Arsenyev's autobiographical work Dersu Uzala. The book, about a Goldi hunter who lives in harmony with nature until destroyed by encroaching civilization, was one that he had wanted to make since the 1930s. In December 1973, the 63-year-old Kurosawa set off for the Soviet Union with four of his closest aides, beginning a year-and-a-half stay in the country. Shooting began in May 1974 in Siberia, with filming in exceedingly harsh natural conditions proving very difficult and demanding. The picture wrapped in April 1975, with a thoroughly exhausted and homesick Kurosawa returning to Japan and his family in June. Dersu Uzala had its world premiere in Japan on August 2, 1975, and did well at the box office. While critical reception in Japan was muted, the film was better reviewed abroad, winning the Golden Prize at the 9th Moscow International Film Festival, as well as an Academy Award for Best Foreign Language Film. Today, critics remain divided over the film: some see it as an example of Kurosawa's alleged artistic decline, while others count it among his finest works.
Although proposals for television projects were submitted to him, he had no interest in working outside the film world. Nevertheless, the hard-drinking director did agree to appear in a series of television ads for Suntory whiskey, which aired in 1976. While fearing that he might never be able to make another film, the director nevertheless continued working on various projects, writing scripts and creating detailed illustrations, intending to leave behind a visual record of his plans in case he would never be able to film his stories.
Two epics (1978–1986)
In 1977, George Lucas released Star Wars, a wildly successful science fiction film influenced by Kurosawa's The Hidden Fortress. Lucas, like many other New Hollywood directors, revered Kurosawa and considered him a role model, and was shocked to discover that the Japanese film-maker was unable to secure financing for any new work. The two met in San Francisco in July 1978 to discuss the project Kurosawa considered most financially viable: , the epic story of a thief hired as the double of a medieval Japanese lord of a great clan. Lucas, enthralled by the screenplay and Kurosawa's illustrations, leveraged his influence over 20th Century Fox to coerce the studio that had fired Kurosawa just ten years earlier to produce , then recruited fellow fan Francis Ford Coppola as co-producer.
Production began the following April, with Kurosawa in high spirits. Shooting lasted from June 1979 through March 1980 and was plagued with problems, not the least of which was the firing of the original lead actor, Shintaro Katsu—known for portraying the popular character Zatoichi—due to an incident in which the actor insisted, against the director's wishes, on videotaping his own performance. (He was replaced by Tatsuya Nakadai, in his first of two consecutive leading roles in a Kurosawa movie.) The film was completed only a few weeks behind schedule and opened in Tokyo in April 1980. It quickly became a massive hit in Japan. The film was also a critical and box office success abroad, winning the coveted at the 1980 Cannes Film Festival in May, though some critics, then and now, have faulted the film for its alleged coldness. Kurosawa spent much of the rest of the year in Europe and America promoting , collecting awards and accolades, and exhibiting as art the drawings he had made to serve as storyboards for the film.
The international success of allowed Kurosawa to proceed with his next project, , another epic in a similar vein. The script, partly based on Shakespeare's King Lear, depicted a ruthless, bloodthirsty daimyō (warlord), played by Tatsuya Nakadai, who, after foolishly banishing his one loyal son, surrenders his kingdom to his other two sons, who then betray him, thus plunging the entire kingdom into war. As Japanese studios still felt wary about producing another film that would rank among the most expensive ever made in the country, international help was again needed. This time it came from French producer Serge Silberman, who had produced Luis Buñuel's final movies. Filming did not begin until December 1983 and lasted more than a year.
In January 1985, production of was halted as Kurosawa's 64-year-old wife Yōko fell ill. She died on February 1. Kurosawa returned to finish his film and premiered at the Tokyo Film Festival on May 31, with a wide release the next day. The film was a moderate financial success in Japan, but a larger one abroad and, as he had done with , Kurosawa embarked on a trip to Europe and America, where he attended the film's premieres in September and October.
won several awards in Japan, but was not quite as honored there as many of the director's best films of the 1950s and 1960s had been. The film world was surprised, however, when Japan passed over the selection of in favor of another film as its official entry to compete for an Oscar nomination in the Best Foreign Film category, which was ultimately rejected for competition at the 58th Academy Awards. Both the producer and Kurosawa himself attributed the failure to even submit for competition to a misunderstanding: because of the academy's arcane rules, no one was sure whether qualified as a Japanese film, a French film (due to its financing), or both, so it was not submitted at all. In response to what at least appeared to be a blatant snub by his own countrymen, the director Sidney Lumet led a successful campaign to have Kurosawa receive an Oscar nomination for Best Director that year (Sydney Pollack ultimately won the award for directing Out of Africa). s costume designer, Emi Wada, won the movie's only Oscar.
and , particularly the latter, are often considered to be among Kurosawa's finest works. After s release, Kurosawa would point to it as his best film, a major change of attitude for the director who, when asked which of his works was his best, had always previously answered "my next one".
Final works and last years (1987–1998)
For his next movie, Kurosawa chose a subject very different from any that he had ever filmed before. While some of his previous pictures (for example, Drunken Angel and ) had included brief dream sequences, Dreams was to be entirely based upon the director's own dreams. Significantly, for the first time in over forty years, Kurosawa, for this deeply personal project, wrote the screenplay alone. Although its estimated budget was lower than the films immediately preceding it, Japanese studios were still unwilling to back one of his productions, so Kurosawa turned to another famous American fan, Steven Spielberg, who convinced Warner Bros. to buy the international rights to the completed film. This made it easier for Kurosawa's son, Hisao, as co-producer and soon-to-be head of Kurosawa Production, to negotiate a loan in Japan that would cover the film's production costs. Shooting took more than eight months to complete, and Dreams premiered at Cannes in May 1990 to a polite but muted reception, similar to the reaction the picture would generate elsewhere in the world. In 1990, he accepted the Academy Award for Lifetime Achievement. In his acceptance speech, he famously said "I'm a little worried because I don't feel that I understand cinema yet." At the time, Bob Thomas of The Daily Spectrum noted that Kurosawa was "considered by many critics as the greatest living filmmaker."
Kurosawa now turned to a more conventional story with Rhapsody in August—the director's first film fully produced in Japan since Dodeskaden over twenty years before—which explored the scars of the nuclear bombing which destroyed Nagasaki at the very end of World War II. It was adapted from a Kiyoko Murata novel, but the film's references to the Nagasaki bombing came from the director rather than from the book. This was his only movie to include a role for an American movie star: Richard Gere, who plays a small role as the nephew of the elderly heroine. Shooting took place in early 1991, with the film opening on May 25 that year to a largely negative critical reaction, especially in the United States, where the director was accused of promulgating naïvely anti-American sentiments, though Kurosawa rejected these accusations.
Kurosawa wasted no time moving onto his next project: Madadayo, or Not Yet. Based on autobiographical essays by Hyakken Uchida, the film follows the life of a Japanese professor of German through the Second World War and beyond. The narrative centers on yearly birthday celebrations with his former students, during which the protagonist declares his unwillingness to die just yet—a theme that was becoming increasingly relevant for the film's 81-year-old creator. Filming began in February 1992 and wrapped by the end of September. Its release on April 17, 1993, was greeted by an even more disappointed reaction than had been the case with his two preceding works.
Kurosawa nevertheless continued to work. He wrote the original screenplays The Sea is Watching in 1993 and After the Rain in 1995. While putting finishing touches on the latter work in 1995, Kurosawa slipped and broke the base of his spine. Following the accident, he would use a wheelchair for the rest of his life, putting an end to any hopes of him directing another film. His longtime wish—to die on the set while shooting a movie—was never to be fulfilled.
After his accident, Kurosawa's health began to deteriorate. While his mind remained sharp and lively, his body was giving up, and for the last half-year of his life, the director was largely confined to bed, listening to music and watching television at home. On September 6, 1998, Kurosawa died of a stroke in Setagaya, Tokyo, at the age of 88. At the time of his death, Kurosawa had two children, his son Hisao Kurosawa who married Hiroko Hayashi and his daughter Kazuko Kurosawa who married Harayuki Kato, along with several grandchildren. One of his grandchildren, the actor Takayuki Kato and grandson by Kazuko, became a supporting actor in two films posthumously developed from screenplays written by Kurosawa which remained unproduced during his own lifetime, Takashi Koizumi's After the Rain (1999) and Kei Kumai's The Sea is Watching (2002).
Filmography
Although Kurosawa is primarily known as a filmmaker, he also worked in theater and television and wrote books. A detailed list, including his complete filmography, can be found in the list of works by Akira Kurosawa.
Style, themes and techniques
Kurosawa displayed a bold, dynamic style, strongly influenced by Western cinema yet distinct from it; he was involved with all aspects of film production. He was a gifted screenwriter and worked closely with his co-writers from the film's development onward to ensure a high-quality script, which he considered the firm foundation of a good film. He frequently served as editor of his own films. His team, known as the , which included the cinematographer Asakazu Nakai, the production assistant Teruyo Nogami and the actor Takashi Shimura, was notable for its loyalty and dependability.
Kurosawa's style is marked by a number of devices and techniques. In his films of the 1940s and 1950s, he frequently employs the "axial cut", in which the camera moves toward or away from the subject through a series of matched jump cuts rather than tracking shots or dissolves. Another stylistic trait is "cut on motion", which displays the motion on the screen in two or more shots instead of one uninterrupted one. A form of cinematic punctuation strongly identified with Kurosawa is the wipe, an effect created through an optical printer: a line or bar appears to move across the screen, wiping away the end of a scene and revealing the first image of the next. As a transitional device, it is used as a substitute for the straight cut or the dissolve; in his mature work, the wipe became Kurosawa's signature.
In the film's soundtrack, Kurosawa favored the sound-image counterpoint, in which the music or sound effects appeared to comment ironically on the image rather than emphasizing it. Teruyo Nogami's memoir gives several such examples from Drunken Angel and Stray Dog. Kurosawa was also involved with several of Japan's outstanding contemporary composers, including Fumio Hayasaka and Tōru Takemitsu.
Kurosawa employed a number of recurring themes in his films: the master-disciple relationship between a usually older mentor and one or more novices, which often involves spiritual as well as technical mastery and self-mastery; the heroic champion, the exceptional individual who emerges from the mass of people to produce something or right some wrong; the depiction of extremes of weather as both dramatic devices and symbols of human passion; and the recurrence of cycles of savage violence within history. According to Stephen Prince, the last theme, which he calls, "the countertradition to the committed, heroic mode of Kurosawa's cinema," began with Throne of Blood (1957), and recurred in the films of the 1980s.
Legacy and cultural impact
Kurosawa is often cited as one of the greatest filmmakers of all time. In 1999, he was named "Asian of the Century" in the "Arts, Literature, and Culture" category by AsianWeek magazine and CNN, cited as "one of the [five] people who contributed most to the betterment of Asia in the past 100 years". Kurosawa was ranked third in the directors' poll and fifth in the critics' poll in Sight & Sound'''s 2002 list of the greatest directors of all time. In commemoration of the 100th anniversary of Kurosawa's birth in 2010, a project called AK100 was launched in 2008. The AK100 Project aims to "expose young people who are the representatives of the next generation, and all people everywhere, to the light and spirit of Akira Kurosawa and the wonderful world he created".
Reputation among filmmakers
Many filmmakers have been influenced by Kurosawa's work. Ingmar Bergman called his own film The Virgin Spring a "touristic... lousy imitation of Kurosawa", and added, "At that time my admiration for the Japanese cinema was at its height. I was almost a samurai myself!" Federico Fellini considered Kurosawa to be "the greatest living example of all that an author of the cinema should be". Steven Spielberg cited Kurosawa's cinematic vision as shaping his own. Satyajit Ray, who was posthumously awarded the Akira Kurosawa Award for Lifetime Achievement in Directing at the San Francisco International Film Festival in 1992, had said earlier of Rashomon:
Roman Polanski considered Kurosawa to be among the three film-makers he favored most, along with Fellini and Orson Welles, and picked Seven Samurai, Throne of Blood and The Hidden Fortress for praise. Bernardo Bertolucci considered Kurosawa's influence to be seminal: "Kurosawa's movies and La Dolce Vita of Fellini are the things that pushed me, sucked me into being a film director." Andrei Tarkovsky cited Kurosawa as one of his favorites and named Seven Samurai as one of his ten favorite films. Sidney Lumet called Kurosawa the "Beethoven of movie directors". Werner Herzog reflected on film-makers with whom he feels kinship and the movies that he admires:
According to an assistant, Stanley Kubrick considered Kurosawa to be "one of the great film directors" and spoke of him "consistently and admiringly", to the point that a letter from him "meant more than any Oscar" and caused him to agonize for months over drafting a reply. Robert Altman upon first seeing Rashomon was so impressed by the sequence of frames of the sun that he began to shoot the same sequences in his work the very next day, he claimed. George Lucas cited The Hidden Fortress as the main inspiration for Star Wars. He also cited other films of Kurosawa as his favorites including Seven Samurai, Yojimbo, and . He also said, "I had never seen anything that powerful or cinematographic. The emotions were so strong that it didn't matter that I did not understand the culture or the traditions. From that moment on, Kurosawa's films have served as one of my strongest sources of creative inspiration." Wes Anderson's animated film Isle of Dogs is partially inspired by Kurosawa's filming techniques. At the 64th Sydney Film Festival, there was a retrospective of Akira Kurosawa where films of his were screened to remember the great legacy he has created from his work. Zack Snyder cited him as one of his influences for his Netflix film Rebel Moon.
Criticism
Kenji Mizoguchi, the acclaimed director of Ugetsu (1953) and Sansho the Bailiff (1954), was eleven years Kurosawa's senior. After the mid-1950s, some critics of the French New Wave began to favor Mizoguchi over Kurosawa. New Wave critic and film-maker Jacques Rivette, in particular, thought Mizoguchi to be the only Japanese director whose work was at once entirely Japanese and truly universal; Kurosawa, by contrast, was thought to be more influenced by Western cinema and culture, a view that has been disputed.
In Japan, some critics and filmmakers considered Kurosawa to be elitist. They viewed him to center his effort and attention on exceptional or heroic characters. In her DVD commentary on Seven Samurai, Joan Mellen argued that certain shots of the samurai characters Kambei and Kyuzo, which show Kurosawa to have accorded higher status or validity to them, constitutes evidence for this point of view. These Japanese critics argued that Kurosawa was not sufficiently progressive because the peasants were unable to find leaders from within their ranks. In an interview with Mellen, Kurosawa defended himself, saying,
From the early 1950s, Kurosawa was also charged with catering to Western tastes due to his popularity in Europe and America. In the 1970s, the politically engaged, left-wing director Nagisa Ōshima, who was noted for his critical reaction to Kurosawa's work, accused Kurosawa of pandering to Western beliefs and ideologies. Author Audie Block, however, assessed Kurosawa to have never played up to a non-Japanese viewing public and to have denounced those directors who did.
Posthumous screenplays
Following Kurosawa's death, several posthumous works based on his unfilmed screenplays have been produced. After the Rain, directed by Takashi Koizumi, was released in 1999, and The Sea Is Watching, directed by Kei Kumai, premiered in 2002. A script created by the Yonki no Kai ("Club of the Four Knights") (Kurosawa, Keisuke Kinoshita, Masaki Kobayashi, and Kon Ichikawa), around the time that Dodeskaden was made, finally was filmed and released (in 2000) as Dora-heita, by the only surviving founding member of the club, Kon Ichikawa. Huayi Brothers Media and CKF Pictures in China announced in 2017 plans to produce a film of Kurosawa's posthumous screenplay of The Masque of the Red Death by Edgar Allan Poe for 2020, to be entitled The Mask of the Black Death. Patrick Frater writing for Variety magazine in May 2017 stated that another two unfinished films by Kurosawa were planned, with Silvering Spear to start filming in 2018.
Kurosawa Production Company
In September 2011, it was reported that remake rights to most of Kurosawa's movies and unproduced screenplays were assigned by the Akira Kurosawa 100 Project to the L.A.-based company Splendent. Splendent's chief Sakiko Yamada, stated that he aimed to "help contemporary film-makers introduce a new generation of moviegoers to these unforgettable stories".
Kurosawa Production Co., established in 1959, continues to oversee many of the aspects of Kurosawa's legacy. The director's son, Hisao Kurosawa, is the current head of the company. Its American subsidiary, Kurosawa Enterprises, is located in Los Angeles. Rights to Kurosawa's works were then held by Kurosawa Production and the film studios under which he worked, most notably Toho. These rights were then assigned to the Akira Kurosawa 100 Project before being reassigned in 2011 to the L.A. based company Splendent. Kurosawa Production works closely with the Akira Kurosawa Foundation, established in December 2003 and also run by Hisao Kurosawa. The foundation organizes an annual short film competition and spearheads Kurosawa-related projects, including a recently shelved one to build a memorial museum for the director.
Film studios
In 1981, the Kurosawa Film Studio was opened in Yokohama; two additional locations have since been launched in Japan. A large collection of archive material, including scanned screenplays, photos and news articles, has been made available through the Akira Kurosawa Digital Archive, a Japanese proprietary website maintained by Ryukoku University Digital Archives Research Center in collaboration with Kurosawa Production.
Anaheim University Akira Kurosawa School of Film
Anaheim University in collaboration with Kurosawa Production and the Kurosawa family established the Anaheim University Akira Kurosawa School of Film in spring 2009. The Anaheim University Akira Kurosawa School of Film offers an Online Master of Fine Arts (MFA) in Digital Filmmaking supported by many of the world's greatest filmmakers.
Kurosawa Restaurant Group
Kurosawa was known to be a connoisseur of Japanese cuisine and as such, the Kurosawa family foundation established the Kurosawa Restaurant Group after his passing in 1999, opening four restaurants in the Tokyo area bearing the family name. Nagatacho Kurosawa specializing in Shabu-shabu, Teppanyaki Kurosawa in Tsukiji specializing in Teppanyaki, Keyaki Kurosawa in Nishi-Azabu specializing in soba, and Udon Kurosawa specializing in udon in Roppongi. All four locations were designed to evoke the Meiji era machiya of Kurosawa's youth and feature memorabilia of Kurosawa's career. As of 2023, only the Tsukiji location is currently still operating. A number of entrepreneurs around the world have also opened restaurants and businesses in honor of Kurosawa without any connection to Akira or the estate.
Awards and honors
Two film awards have also been named in Kurosawa's honor. The Akira Kurosawa Award for Lifetime Achievement in Film Directing is awarded during the San Francisco International Film Festival, while the Akira Kurosawa Award is given during the Tokyo International Film Festival.
Kurosawa has also been given a number of state honors, including being named as an officer of the French Légion d'honneur in 1984, a Knight Grand Cross of the Order of Merit of the Italian Republic in 1986, and was the first filmmaker to receive the Order of Culture from his native Japan in 1985. Posthumously, he was recognized with the Junior Third Court Rank, which would be the modern equivalent of a noble title under the Kazoku aristocracy.
Documentaries
A significant number of short and full-length documentaries concerning the life and work of Kurosawa were made both during his artistic heyday and after his death. AK, by French video essay director Chris Marker, was filmed while Kurosawa was working on ; however, the documentary is more concerned about Kurosawa's distant yet polite personality than on the making of the film. Other documentaries concerning Kurosawa's life and works produced posthumously include:
Kurosawa: The Last Emperor (Alex Cox, 1999)
A Message from Akira Kurosawa: For Beautiful Movies (Hisao Kurosawa, 2000)
Kurosawa (Adam Low, 2001)
Akira Kurosawa: It Is Wonderful to Create (Toho Masterworks, 2002)
Akira Kurosawa: The Epic and the Intimate (2010)
Kurosawa's Way (Catherine Cadou, 2011)
Notes
References
Sources
Further reading
Buchanan, Judith (2005). Shakespeare on Film. Pearson Longman. .
Burch, Nöel (1979). To the Distant Observer: Form and Meaning in the Japanese Cinema. University of California Press. .
Cowie, Peter (2010). Akira Kurosawa: Master of Cinema. Rizzoli Publications. .
Davies, Anthony (1990). Filming Shakespeare's Plays: The Adaptions of Laurence Olivier, Orson Welles, Peter Brook and Akira Kurosawa. Cambridge University Press. .
Desser, David (1983). The Samurai Films of Akira Kurosawa (Studies in Cinema No. 23). UMI Research Press. .
Leonard, Kendra Preston (2009). Shakespeare, Madness, and Music: Scoring Insanity in Cinematic Adaptations. Plymouth: The Scarecrow Press. .
Sorensen, Lars-Martin (2009). Censorship of Japanese Films During the U.S. Occupation of Japan: The Cases of Yasujiro Ozu and Akira Kurosawa. Edwin Mellen Press. .
Wild, Peter. (2014) Akira Kurosawa'' Reaktion Books
External links
Akira Kurosawa at The Criterion Collection
Akira Kurosawa: News, Information and Discussion
Senses of Cinema: Great Directors Critical Database
Akira Kurosawa at Japanese celebrity's grave guide
Several trailers
Anaheim University Akira Kurosawa School of Film
1910 births
1998 deaths
20th-century Japanese writers
20th-century male writers
Academy Honorary Award recipients
Akira Kurosawa Award winners
Best Director BAFTA Award winners
César Award winners
David di Donatello winners
Directors Guild of America Award winners
Directors of Best Foreign Language Film Academy Award winners
Directors of Palme d'Or winners
Directors of Golden Lion winners
Filmmakers who won the Best Foreign Language Film BAFTA Award
Fellows of the American Academy of Arts and Sciences
Recipients of the Fukuoka Prize
Japanese film directors
Japanese film editors
Japanese film producers
Japanese male writers
Japanese male screenwriters
Japanese screenwriters
Kyoto laureates in Arts and Philosophy
Recipients of the Legion of Honour
People from Shinagawa
People from the Empire of Japan
People's Honour Award winners
Persons of Cultural Merit
Propaganda film directors
Ramon Magsaysay Award winners
Recipients of the Order of Culture
Recipients of the Order of Friendship of Peoples
Recipients of the Praemium Imperiale
Samurai film directors
Silver Bear for Best Director recipients
Writers from Tokyo
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Golden Lion for Lifetime Achievement recipients |
876 | https://en.wikipedia.org/wiki/Motor%20neuron%20diseases | Motor neuron diseases | Motor neuron diseases or motor neurone diseases (MNDs) are a group of rare neurodegenerative disorders that selectively affect motor neurons, the cells which control voluntary muscles of the body. They include amyotrophic lateral sclerosis (ALS), progressive bulbar palsy (PBP), pseudobulbar palsy, progressive muscular atrophy (PMA), primary lateral sclerosis (PLS), spinal muscular atrophy (SMA) and monomelic amyotrophy (MMA), as well as some rarer variants resembling ALS.
Motor neuron diseases affect both children and adults. While each motor neuron disease affects patients differently, they all cause movement-related symptoms, mainly muscle weakness. Most of these diseases seem to occur randomly without known causes, but some forms are inherited. Studies into these inherited forms have led to discoveries of various genes (e.g. SOD1) that are thought to be important in understanding how the disease occurs.
Symptoms of motor neuron diseases can be first seen at birth or can come on slowly later in life. Most of these diseases worsen over time; while some, such as ALS, shorten one's life expectancy, others do not. Currently, there are no approved treatments for the majority of motor neuron disorders, and care is mostly symptomatic.
Signs and symptoms
Signs and symptoms depend on the specific disease, but motor neuron diseases typically manifest as a group of movement-related symptoms. They come on slowly, and worsen over the course of more than three months. Various patterns of muscle weakness are seen, and muscle cramps and spasms may occur. One can have difficulty breathing with climbing stairs (exertion), difficulty breathing when lying down (orthopnea), or even respiratory failure if breathing muscles become involved. Bulbar symptoms, including difficulty speaking (dysarthria), difficulty swallowing (dysphagia), and excessive saliva production (sialorrhea), can also occur. Sensation, or the ability to feel, is typically not affected. Emotional disturbance (e.g. pseudobulbar affect) and cognitive and behavioural changes (e.g. problems in word fluency, decision-making, and memory) are also seen. There can be lower motor neuron findings (e.g. muscle wasting, muscle twitching), upper motor neuron findings (e.g. brisk reflexes, Babinski reflex, Hoffman's reflex, increased muscle tone), or both.
Motor neuron diseases are seen both in children and adults. Those that affect children tend to be inherited or familial, and their symptoms are either present at birth or appear before learning to walk. Those that affect adults tend to appear after age 40. The clinical course depends on the specific disease, but most progress or worsen over the course of months. Some are fatal (e.g. ALS), while others are not (e.g. PLS).
Patterns of weakness
Various patterns of muscle weakness occur in different motor neuron diseases. Weakness can be symmetric or asymmetric, and it can occur in body parts that are distal, proximal, or both. According to Statland et al., there are three main weakness patterns that are seen in motor neuron diseases, which are:
Asymmetric distal weakness without sensory loss (e.g. ALS, PLS, PMA, MMA)
Symmetric weakness without sensory loss (e.g. PMA, PLS)
Symmetric focal midline proximal weakness (neck, trunk, bulbar involvement; e.g. ALS, PBP, PLS)
Lower and upper motor neuron findings
Motor neuron diseases are on a spectrum in terms of upper and lower motor neuron involvement. Some have just lower or upper motor neuron findings, while others have a mix of both. Lower motor neuron (LMN) findings include muscle atrophy and fasciculations, and upper motor neuron (UMN) findings include hyperreflexia, spasticity, muscle spasm, and abnormal reflexes.
Pure upper motor neuron diseases, or those with just UMN findings, include PLS.
Pure lower motor neuron diseases, or those with just LMN findings, include PMA.
Motor neuron diseases with both UMN and LMN findings include both familial and sporadic ALS.
Causes
Most cases are sporadic and their causes are usually not known. It is thought that environmental, toxic, viral, or genetic factors may be involved.
DNA damage
TAR DNA-binding protein 43 (TDP-43), is a critical component of the non-homologous end joining (NHEJ) enzymatic pathway that repairs DNA double-strand breaks in pluripotent stem cell-derived motor neurons. TDP-43 is rapidly recruited to double-strand breaks where it acts as a scaffold for the recruitment of the XRCC4-DNA ligase protein complex that then acts to repair double-strand breaks. About 95% of ALS patients have abnormalities in the nucleus-cytoplasmic localization in spinal motor neurons of TDP43. In TDP-43 depleted human neural stem cell-derived motor neurons, as well as in sporadic ALS patients' spinal cord specimens there is significant double-strand break accumulation and reduced levels of NHEJ.
Associated risk factors
In adults, men are more commonly affected than women.
Diagnosis
Differential diagnosis can be challenging due to the number of overlapping symptoms, shared between several motor neuron diseases. Frequently, the diagnosis is based on clinical findings (i.e. LMN vs. UMN signs and symptoms, patterns of weakness), family history of MND, and a variation of tests, many of which are used to rule out disease mimics, which can manifest with identical symptoms.
Classification
Motor neuron disease describes a collection of clinical disorders, characterized by progressive muscle weakness and the degeneration of the motor neuron on electrophysiological testing. The term "motor neuron disease" has varying meanings in different countries. Similarly, the literature inconsistently classifies which degenerative motor neuron disorders can be included under the umbrella term "motor neuron disease". The four main types of MND are marked (*) in the table below.
All types of MND can be differentiated by two defining characteristics:
Is the disease sporadic or inherited?
Is there involvement of the upper motor neurons (UMN), the lower motor neurons (LMN), or both?
Sporadic or acquired MNDs occur in patients with no family history of degenerative motor neuron disease. Inherited or genetic MNDs adhere to one of the following inheritance patterns: autosomal dominant, autosomal recessive, or X-linked. Some disorders, like ALS, can occur sporadically (85%) or can have a genetic cause (15%) with the same clinical symptoms and progression of disease.
UMNs are motor neurons that project from the cortex down to the brainstem or spinal cord. LMNs originate in the anterior horns of the spinal cord and synapse on peripheral muscles. Both motor neurons are necessary for the strong contraction of a muscle, but damage to an UMN can be distinguished from damage to a LMN by physical exam.
Tests
Cerebrospinal fluid (CSF) tests: Analysis of the fluid from around the brain and spinal cord could reveal signs of an infection or inflammation.
Magnetic resonance imaging (MRI): An MRI of the brain and spinal cord is recommended in patients with UMN signs and symptoms to explore other causes, such as a tumor, inflammation, or lack of blood supply (stroke).
Electromyogram (EMG) & nerve conduction study (NCS): The EMG, which evaluates muscle function, and NCS, which evaluates nerve function, are performed together in patients with LMN signs.
For patients with MND affecting the LMNs, the EMG will show evidence of: (1) acute denervation, which is ongoing as motor neurons degenerate, and (2) chronic denervation and reinnervation of the muscle, as the remaining motor neurons attempt to fill in for lost motor neurons.
By contrast, the NCS in these patients is usually normal. It can show a low compound muscle action potential (CMAP), which results from the loss of motor neurons, but the sensory neurons should remain unaffected.
Tissue biopsy: Taking a small sample of a muscle or nerve may be necessary if the EMG/NCS is not specific enough to rule out other causes of progressive muscle weakness, but it is rarely used.
Treatment
There are no known curative treatments for the majority of motor neuron disorders. Please refer to the articles on individual disorders for more details.
Prognosis
The table below lists life expectancy for patients who are diagnosed with MND.
Terminology
In the United States and Canada, the term motor neuron disease usually refers to the group of disorders while amyotrophic lateral sclerosis is frequently called Lou Gehrig's disease. In the United Kingdom and Australia, the term motor neuron(e) disease is used for amyotrophic lateral sclerosis, although is not uncommon to refer to the entire group.
While MND refers to a specific subset of similar diseases, there are numerous other diseases of motor neurons that are referred to collectively as "motor neuron disorders", for instance the diseases belonging to the spinal muscular atrophies group. However, they are not classified as "motor neuron diseases" by the 11th edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-11), which is the definition followed in this article.
See also
Spinal muscular atrophies
Hereditary motor and sensory neuropathies
References
External links
Motor neuron diseases
Rare diseases
Systemic atrophies primarily affecting the central nervous system |
878 | https://en.wikipedia.org/wiki/Abugida | Abugida | An abugida (; from Ge'ez: )sometimes also called alphasyllabary, neosyllabary, or pseudo-alphabetis a segmental writing system in which consonant–vowel sequences are written as units; each unit is based on a consonant letter, and vowel notation is secondary, similar to a diacritical mark. This contrasts with a full alphabet, in which vowels have status equal to consonants, and with an abjad, in which vowel marking is absent, partial, or optional – in less formal contexts, all three types of the script may be termed "alphabets". The terms also contrast them with a syllabary, in which a single symbol denotes the combination of one consonant and one vowel.
Related concepts were introduced independently in 1948 by James Germain Février (using the term ) and David Diringer (using the term semisyllabary), then in 1959 by Fred Householder (introducing the term pseudo-alphabet). The Ethiopic term "abugida" was chosen as a designation for the concept in 1990 by Peter T. Daniels. In 1992, Faber suggested "segmentally coded syllabically linear phonographic script", and in 1992 Bright used the term alphasyllabary, and Gnanadesikan and Rimzhim, Katz, & Fowler have suggested aksara or āksharik.
Abugidas include the extensive Brahmic family of scripts of Tibet, South and Southeast Asia, Semitic Ethiopic scripts, and Canadian Aboriginal syllabics. As is the case for syllabaries, the units of the writing system may consist of the representations both of syllables and of consonants. For scripts of the Brahmic family, the term akshara is used for the units.
Etymology
In several languages of Ethiopia and Eritrea, abugida traditionally meant letters of the Ethiopic or Ge‘ez script in which many of these languages are written. Ge'ez is one of several segmental writing systems in the world, others include Indic/Brahmic scripts and Canadian Aboriginal Syllabics. The word abugida is derived from the four letters, ä, bu, gi, and da, in much the same way that abecedary is derived from Latin letters a be ce de, abjad is derived from the Arabic a b j d, and alphabet is derived from the names of the two first letters in the Greek alphabet, alpha and beta. Abugida as a term in linguistics was proposed by Peter T. Daniels in his 1990 typology of writing systems.
Terminology
As Daniels used the word, an abugida is in contrast with a syllabary, where letters with shared consonant or vowel sounds show no particular resemblance to one another. Furthermore, an abugida is also in contrast with an alphabet proper, where independent letters are used to denote both consonants and vowels. The term alphasyllabary was suggested for the Indic scripts in 1997 by William Bright, following South Asian linguistic usage, to convey the idea that, "they share features of both alphabet and syllabary."
The formal definitions given by Daniels and Bright for abugida and alphasyllabary differ; some writing systems are abugidas but not alphasyllabaries, and some are alphasyllabaries but not abugidas. An abugida is defined as "a type of writing system whose basic characters denote consonants followed by a particular vowel, and in which diacritics denote other vowels". (This 'particular vowel' is referred to as the inherent or implicit vowel, as opposed to the explicit vowels marked by the 'diacritics'.)
An alphasyllabary is defined as "a type of writing system in which the vowels are denoted by subsidiary symbols, not all of which occur in a linear order (with relation to the consonant symbols) that is congruent with their temporal order in speech". Bright did not require that an alphabet explicitly represent all vowels. ʼPhags-pa is an example of an abugida because it has an inherent vowel, but it is not an alphasyllabary because its vowels are written in linear order. Modern Lao is an example of an alphasyllabary that is not an abugida, for there is no inherent vowel and its vowels are always written explicitly and not in accordance to their temporal order in speech, meaning that a vowel can be written before, below or above a consonant letter, while the syllable is still pronounced in the order of a consonant-vowel combination (CV).
General description
The fundamental principles of an abugida apply to words made up of consonant-vowel (CV) syllables. The syllables are written as letters in a straight line, where each syllable is either a letter that represents the sound of a consonant and its inherent vowel or a letter modified to indicate the vowel. Letters can be modified either by means of diacritics or by changes in the form of the letter itself. If all modifications are by diacritics and all diacritics follow the direction of the writing of the letters, then the abugida is not an alphasyllabary. However, most languages have words that are more complicated than a sequence of CV syllables, even ignoring tone.
The first complication is syllables that consist of just a vowel (V). For some languages, a zero consonant letter is used as though every syllable began with a consonant. For other languages, each vowel has a separate letter that is used for each syllable consisting of just the vowel. These letters are known as independent vowels, and are found in most Indic scripts. These letters may be quite different from the corresponding diacritics, which by contrast are known as dependent vowels. As a result of the spread of writing systems, independent vowels may be used to represent syllables beginning with a glottal stop, even for non-initial syllables.
The next two complications are consonant clusters before a vowel (CCV) and syllables ending in a consonant (CVC). The simplest solution, which is not always available, is to break with the principle of writing words as a sequence of syllables and use a letter representing just a consonant (C). This final consonant may be represented with:
a modification of the final letter that explicitly indicates the lack of a vowel (virama),
a lack of vowel marking on the letter (often with ambiguity between no vowel and a default inherent vowel),
vowel marking on the letter for a short or neutral vowel such as schwa (with ambiguity between no vowel and that short or neutral vowel), or
a visually unrelated letter.
In a true abugida, the lack of distinctive vowel marking of the letter may result from the diachronic loss of the inherent vowel, e.g. by syncope and apocope in Hindi.
When not separating syllables containing consonant clusters (CCV) into C + CV, these syllables are often written by combining the two consonants. In the Indic scripts, the earliest method was simply to arrange them vertically, writing the second consonant of the cluster below the first one. The two consonants may also merge as conjunct consonant letters, where two or more letters are graphically joined in a ligature, or otherwise change their shapes. Rarely, one of the consonants may be replaced by a gemination mark, e.g. the Gurmukhi addak.
When they are arranged vertically, as in Burmese or Khmer, they are said to be 'stacked'. Often there has been a change to writing the two consonants side by side. In the latter case, this combination may be indicated by a diacritic on one of the consonants or a change in the form of one of the consonants, e.g. the half forms of Devanagari. Generally, the reading order of stacked consonants is top to bottom, or the general reading order of the script, but sometimes the reading order can be reversed.
The division of a word into syllables for the purposes of writing does not always accord with the natural phonetics of the language. For example, Brahmic scripts commonly handle a phonetic sequence CVC-CV as CV-CCV or CV-C-CV. However, sometimes phonetic CVC syllables are handled as single units, and the final consonant may be represented:
in much the same way as the second consonant in CCV, e.g. in the Tibetan, Khmer and Tai Tham scripts. The positioning of the components may be slightly different, as in Khmer and Tai Tham.
by a special dependent consonant sign, which may be a smaller or differently placed version of the full consonant letter, or may be a distinct sign altogether.
not at all. For example, repeated consonants need not be represented, homorganic nasals may be ignored, and in Baybayin and Makasar script, the syllable-final consonant was traditionally never represented.
More complicated unit structures (e.g. CC or CCVC) are handled by combining the various techniques above.
Examples using the Devanagari script
K = /ka/ =
Ki = /ki/ =
K* = /k/ = (with a Halant under the character)
K*M = /kma/ =
İK = /ika/ =
İK* = /ik/ =
İKi = /iki/ =
etc.
Family-specific features
There are three principal families of abugidas, depending on whether vowels are indicated by modifying consonants by diacritics, distortion, or orientation.
The oldest and largest is the Brahmic family of India and Southeast Asia, in which vowels are marked with diacritics and syllable-final consonants, when they occur, are indicated with ligatures, diacritics, or with a special vowel-canceling mark.
In the Ethiopic family, vowels are marked by modifying the shapes of the consonants, and one of the vowel-forms serves additionally to indicate final consonants.
In Canadian Aboriginal syllabics, vowels are marked by rotating or flipping the consonants, and final consonants are indicated with either special diacritics or superscript forms of the main initial consonants.
Lao and Tāna have dependent vowels and a zero vowel sign, but no inherent vowel.
Indic (Brahmic)
Indic scripts originated in India and spread to Southeast Asia, Bangladesh, Sri Lanka, Nepal, Bhutan, Tibet, Mongolia, and Russia. All surviving Indic scripts are descendants of the Brahmi alphabet. Today they are used in most languages of South Asia (although replaced by Perso-Arabic in Urdu, Kashmiriand some other languages of Pakistan and India), mainland Southeast Asia (Myanmar, Thailand, Laos, Cambodia, and Vietnam), Tibet (Tibetan), Indonesian archipelago (Javanese, Balinese, Sundanese, Batak, Lontara, Rejang, Rencong, Makasar, etc.), Philippines (Baybayin, Buhid, Hanunuo, Kulitan, and Aborlan Tagbanwa), Malaysia (Rencong).
The primary division is with North Indic scripts, used in Northern India, Nepal, Tibet, Bhutan, Mongolia, and Russia; and Southern Indic scripts, used in South India, Sri Lanka and Southeast Asia. South Indic letter forms are more rounded than North Indic forms, though Odia, Golmol and Litumol of Nepal script are rounded. Most North Indic scripts' full letters incorporate a horizontal line at the top, with Gujarati and Odia as exceptions; South Indic scripts do not.
Indic scripts indicate vowels through dependent vowel signs (diacritics) around the consonants, often including a sign that explicitly indicates the lack of a vowel. If a consonant has no vowel sign, this indicates a default vowel. Vowel diacritics may appear above, below, to the left, to the right, or around the consonant.
The most widely used Indic script is Devanagari, shared by Hindi, Bihari, Marathi, Konkani, Nepali, and often Sanskrit. A basic letter such as क in Hindi represents a syllable with the default vowel, in this case ka (). In some languages, including Hindi, it becomes a final closing consonant at the end of a word, in this case k. The inherent vowel may be changed by adding vowel mark (diacritics), producing syllables such as कि ki, कु ku, के ke, को ko.
In many of the Brahmic scripts, a syllable beginning with a cluster is treated as a single character for purposes of vowel marking, so a vowel marker like ि -i, falling before the character it modifies, may appear several positions before the place where it is pronounced. For example, the game cricket in Hindi is क्रिकेट ; the diacritic for appears before the consonant cluster , not before the . A more unusual example is seen in the Batak alphabet: Here the syllable bim is written ba-ma-i-(virama). That is, the vowel diacritic and virama are both written after the consonants for the whole syllable.
In many abugidas, there is also a diacritic to suppress the inherent vowel, yielding the bare consonant. In Devanagari, क् is k, and ल् is l. This is called the virāma or halantam in Sanskrit. It may be used to form consonant clusters, or to indicate that a consonant occurs at the end of a word. Thus in Sanskrit, a default vowel consonant such as क does not take on a final consonant sound. Instead, it keeps its vowel. For writing two consonants without a vowel in between, instead of using diacritics on the first consonant to remove its vowel, another popular method of special conjunct forms is used in which two or more consonant characters are merged to express a cluster, such as Devanagari: क्ल kla. (Some fonts display this as क् followed by ल, rather than forming a conjunct. This expedient is used by ISCII and South Asian scripts of Unicode.) Thus a closed syllable such as kal requires two aksharas to write.
The Róng script used for the Lepcha language goes further than other Indic abugidas, in that a single akshara can represent a closed syllable: Not only the vowel, but any final consonant is indicated by a diacritic. For example, the syllable [sok] would be written as something like s̥̽, here with an underring representing and an overcross representing the diacritic for final . Most other Indic abugidas can only indicate a very limited set of final consonants with diacritics, such as or , if they can indicate any at all.
Ethiopic
In Ethiopic or Ge'ez script, fidels (individual "letters" of the script) have "diacritics" that are fused with the consonants to the point that they must be considered modifications of the form of the letters. Children learn each modification separately, as in a syllabary; nonetheless, the graphic similarities between syllables with the same consonant are readily apparent, unlike the case in a true syllabary.
Though now an abugida, the Ge'ez script, until the advent of Christianity (ca. AD 350), had originally been what would now be termed an abjad. In the Ge'ez abugida (or fidel), the base form of the letter (also known as fidel) may be altered. For example, ሀ hä (base form), ሁ hu (with a right-side diacritic that does not alter the letter), ሂ hi (with a subdiacritic that compresses the consonant, so it is the same height), ህ hə or (where the letter is modified with a kink in the left arm).
Canadian Aboriginal syllabics
In the family known as Canadian Aboriginal syllabics, which was inspired by the Devanagari script of India, vowels are indicated by changing the orientation of the syllabogram. Each vowel has a consistent orientation; for example, Inuktitut ᐱ pi, ᐳ pu, ᐸ pa; ᑎ ti, ᑐ tu, ᑕ ta. Although there is a vowel inherent in each, all rotations have equal status and none can be identified as basic. Bare consonants are indicated either by separate diacritics, or by superscript versions of the aksharas; there is no vowel-killer mark.
Borderline cases
Vowelled abjads
Abjads are typically written without indication of many vowels. However, in some contexts like teaching materials or scriptures, Arabic and Hebrew are written with full indication of vowels via diacritic marks (harakat, niqqud) making them effectively alphasyllabaries.
The Arabic scripts used for Kurdish in Iraq and for Uyghur in Xinjiang, China, as well as the Hebrew script of Yiddish, are fully vowelled, but because the vowels are written with full letters rather than diacritics (with the exception of distinguishing between /a/ and /o/ in the latter) and there are no inherent vowels, these are considered alphabets, not abugidas.
The Arabic script used for South Azerbaijani generally writes the vowel /æ/ (written as ə in North Azerbaijani) as a diacritic, but writes all other vowels as full letters (similarly to Kurdish and Uyghur). This means that when no vowel diacritics are present (most of the time), it technically has an inherent vowel. However, like the Phagspa and Meroitic scripts whose status as abugidas is controversial (see below), all other vowels are written in-line. Additionally, the practice of explicitly writing all-but-one vowel does not apply to loanwords from Arabic and Persian, so the script does not have an inherent vowel for Arabic and Persian words. The inconsistency of its vowel notation makes it difficult to categorize.
Phagspa
The imperial Mongol script called Phagspa was derived from the Tibetan abugida, but all vowels are written in-line rather than as diacritics. However, it retains the features of having an inherent vowel /a/ and having distinct initial vowel letters.
Pahawh
Pahawh Hmong is a non-segmental script that indicates syllable onsets and rimes, such as consonant clusters and vowels with final consonants. Thus it is not segmental and cannot be considered an abugida. However, it superficially resembles an abugida with the roles of consonant and vowel reversed. Most syllables are written with two letters in the order rime–onset (typically vowel-consonant), even though they are pronounced as onset-rime (consonant-vowel), rather like the position of the vowel in Devanagari, which is written before the consonant. Pahawh is also unusual in that, while an inherent rime (with mid tone) is unwritten, it also has an inherent onset . For the syllable , which requires one or the other of the inherent sounds to be overt, it is that is written. Thus it is the rime (vowel) that is basic to the system.
Meroitic
It is difficult to draw a dividing line between abugidas and other segmental scripts. For example, the Meroitic script of ancient Sudan did not indicate an inherent a (one symbol stood for both m and ma, for example), and is thus similar to Brahmic family of abugidas. However, the other vowels were indicated with full letters, not diacritics or modification, so the system was essentially an alphabet that did not bother to write the most common vowel.
Shorthand
Several systems of shorthand use diacritics for vowels, but they do not have an inherent vowel, and are thus more similar to Thaana and Kurdish script than to the Brahmic scripts. The Gabelsberger shorthand system and its derivatives modify the following consonant to represent vowels. The Pollard script, which was based on shorthand, also uses diacritics for vowels; the placements of the vowel relative to the consonant indicates tone. Pitman shorthand uses straight strokes and quarter-circle marks in different orientations as the principal "alphabet" of consonants; vowels are shown as light and heavy dots, dashes and other marks in one of 3 possible positions to indicate the various vowel-sounds. However, to increase writing speed, Pitman has rules for "vowel indication" using the positioning or choice of consonant signs so that writing vowel-marks can be dispensed with.
Development
As the term alphasyllabary suggests, abugidas have been considered an intermediate step between alphabets and syllabaries. Historically, abugidas appear to have evolved from abjads (vowelless alphabets). They contrast with syllabaries, where there is a distinct symbol for each syllable or consonant-vowel combination, and where these have no systematic similarity to each other, and typically develop directly from logographic scripts. Compare the examples above to sets of syllables in the Japanese hiragana syllabary: か ka, き ki, く ku, け ke, こ ko have nothing in common to indicate k; while ら ra, り ri, る ru, れ re, ろ ro have neither anything in common for r, nor anything to indicate that they have the same vowels as the k set.
Most Indian and Indochinese abugidas appear to have first been developed from abjads with the Kharoṣṭhī and Brāhmī scripts; the abjad in question is usually considered to be the Aramaic one, but while the link between Aramaic and Kharosthi is more or less undisputed, this is not the case with Brahmi. The Kharosthi family does not survive today, but Brahmi's descendants include most of the modern scripts of South and Southeast Asia.
Ge'ez derived from a different abjad, the Sabean script of Yemen; the advent of vowels coincided with the introduction or adoption of Christianity about AD 350. The Ethiopic script is the elaboration of an abjad.
The Cree syllabary was invented with full knowledge of the Devanagari system.
The Meroitic script was developed from Egyptian hieroglyphs, within which various schemes of 'group writing' had been used for showing vowels.
List of abugidas
Brahmic family, descended from Brāhmī ()
Ahom
Assamese
Balinese
BatakToba and other Batak languages
BaybayinIlocano, Pangasinan, Tagalog, Bikol languages, Visayan languages, and possibly other Philippine languages
BengaliBengali
Bhaiksuki
BrahmiSanskrit, Prakrit
Buhid
BurmeseBurmese, Karen languages, Mon, and Shan
Chakma
Cham
DevanagariHindi, Sanskrit, Marathi, Nepali, Konkani and other languages of northern India
Dhives Akuru
GranthaSanskrit
GujaratiGujarāti, Kachchi
Gurmukhi scriptPunjabi
Hanunó’o
Javanese
KagangaLampung, Rencong, Rejang
KaithiBhojpuri and other languages of northern and eastern India
KannadaKannada, Tulu, Konkani, Kodava
Kawi
Khmer
Khojki
Khotanese
Khudawadi
KolezhuthuTamil, Malayalam
Kulitan
Lao
Leke
Lepcha
Limbu
Lontara'Buginese, Makassar, and Mandar
Mahajani
MalayalamMalayalam
MalayanmaMalayalam
MarchenZhang-Zhung
Meetei Mayek
ModiMarathi
MultaniSaraiki
NandinagariSanskrit
NewarNepal Bhasa, Sanskrit
New Tai Lue
Odia
Pallava scriptTamil, Sanskrit, various Prakrits
Phags-paMongolian, Chinese, and other languages of the Yuan dynasty Mongol Empire
RanjanaNepal Bhasa, Sanskrit
SharadaSanskrit
SiddhamSanskrit
Sinhala
Sourashtra
Soyombo
Sundanese
Sylheti NagriSylheti language
TagbanwaPalawan languages
Tai Dam
Tai Le
Tai ThamKhün, and Northern Thai
Takri
Tamil
Telugu
Thai
Tibetan
TigalariSanskrit, Tulu
TirhutaMaithili
Tocharian
VatteluttuTamil, Malayalam
Zanabazar Square
Zhang zhung scripts
Kharoṣṭhī, from the 3rd century BC
Meroitic
Ge'ez, from the 4th century AD
Canadian Aboriginal syllabics
CreeOjibwe syllabics
Blackfoot syllabics
Carrier syllabics
Inuktitut syllabics
Pollard script
Pitman shorthand
Fictional
Tengwar
Ihathvé Sabethired
Abugida-like scripts
Meroitic (an alphabet with an inherent vowel) – Meroitic, Old Nubian (possibly)
Thaana (abugida with no inherent vowel)
References |
881 | https://en.wikipedia.org/wiki/Allegiance | Allegiance | An allegiance is a duty of fidelity said to be owed, or freely committed, by the people, subjects or citizens to their state or sovereign.
Etymology
The word allegiance comes from Middle English (see Medieval Latin , "a liegance"). The al- prefix was probably added through confusion with another legal term, allegiance, an "allegation" (the French comes from the English). Allegiance is formed from "liege," from Old French , "liege, free", of Germanic origin. The connection with Latin , "to bind," is erroneous.
Usage
Traditionally, English legal commentators used the term allegiance in two ways. In one sense, it referred to the deference which anyone, even a foreigner, was expected to pay to the institutions of the country where one lived. In the other sense, it meant national character and the subjection due to that character.
Types
Local allegiance
Natural allegiance
United Kingdom
The English doctrine, which was at one time adopted in the United States, asserted that allegiance was indelible: "Nemo potest exuere patriam". As the law stood prior to 1870, every person who by birth or naturalisation satisfied the conditions set forth, even if removed in infancy to another country where their family resided, owed an allegiance to the British crown which they could never resign or lose, except by act of parliament or by the recognition of the independence or the cession of the portion of British territory in which they resided.
This refusal to accept any renunciation of allegiance to the Crown led to conflict with the United States over impressment, which led to further conflicts during the War of 1812, when thirteen Irish American prisoners of war were executed as traitors after the Battle of Queenston Heights; Winfield Scott urged American reprisal, but none was carried out.
Allegiance was the tie which bound the subject to the sovereign, in return for that protection which the sovereign afforded the subject. It was the mutual bond and obligation between monarch and subjects, whereby subjects were called their liege subjects, because they are bound to obey and serve them; and the monarch was called their liege lord, because they should maintain and defend them (Ex parte Anderson (1861) 3 El & El 487; 121 ER 525; China Navigation Co v Attorney-General (1932) 48 TLR 375; Attorney-General v Nissan [1969] 1 All ER 629; Oppenheimer v Cattermole [1972] 3 All ER 1106). The duty of the crown towards its subjects was to govern and protect them. The reciprocal duty of the subject towards the crown was that of allegiance.
At common law, allegiance was a true and faithful obedience of the subject due to their sovereign. As the subject owed to their sovereign their true and faithful allegiance and obedience, so the sovereign
(Calvin's Case (1608) 7 Co Rep 1a; Jenk 306; 2 State Tr 559; 77 ER 377).
Natural allegiance and obedience is an incident inseparable to every subject, for parte Anderson (1861) 3 El & El 487; 121 ER 525). Natural-born subjects owe allegiance wherever they may be. Where territory is occupied in the course of hostilities by an enemy's force, even if the annexation of the occupied country is proclaimed by the enemy, there can be no change of allegiance during the progress of hostilities on the part of a citizen of the occupied country (R v Vermaak (1900) 21 NLR 204 (South Africa)).
Allegiance is owed both to the sovereign as a natural person and to the sovereign in the political capacity (Re Stepney Election Petition, Isaacson v Durant (1886) 17 QBD 54 (per Lord Coleridge CJ)). Attachment to the person of the reigning sovereign is not sufficient. Loyalty requires affection also to the office of the sovereign, attachment to royalty, attachment to the law and to the constitution of the realm, and he who would, by force or by fraud, endeavour to prostrate that law and constitution, though he may retain his affection for its head, can boast but an imperfect and spurious species of loyalty (R v O'Connell (1844) 7 ILR 261).
There were four kinds of allegiances (Rittson v Stordy (1855) 3 Sm & G 230; De Geer v Stone (1882) 22 Ch D 243; Isaacson v Durant (1886) 54 LT 684; Gibson, Gavin v Gibson [1913] 3 KB 379; Joyce v DPP [1946] AC 347; Collingwood v Pace (1661) O Bridg 410; Lane v Bennett (1836) 1 M & W 70; Lyons Corp v East India Co (1836) 1 Moo PCC 175; Birtwhistle v Vardill (1840) 7 Cl & Fin 895; R v Lopez, R v Sattler (1858) Dears & B 525; Ex p Brown (1864) 5 B & S 280);
(a) Ligeantia naturalis, absoluta, pura et indefinita, and this originally is due by nature and birthright, and is called alta ligeantia, and those that owe this are called subditus natus;
(b) Ligeantia acquisita, not by nature but by acquisition or denization, being called a denizen, or rather denizon, because they are subditus datus;
(c) Ligeantia localis, by operation of law, when a friendly alien enters the country, because so long as they are in the country they are within the sovereign's protection, therefore they owe the sovereign a local obedience or allegiance (R v Cowle (1759) 2 Burr 834; Low v Routledge (1865) 1 Ch App 42; Re Johnson, Roberts v Attorney-General [1903] 1 Ch 821; Tingley v Muller [1917] 2 Ch 144; Rodriguez v Speyer [1919] AC 59; Johnstone v Pedlar [1921] 2 AC 262; R v Tucker (1694) Show Parl Cas 186; R v Keyn (1876) 2 Ex D 63; Re Stepney Election Petn, Isaacson v Durant (1886) 17 QBD 54);
(d) A legal obedience, where a particular law requires the taking of an oath of allegiance by subject or alien alike.
Natural allegiance was acquired by birth within the sovereign's dominions (except for the issue of diplomats or of invading forces or of an alien in an enemy occupied territory). The natural allegiance and obedience are an incident inseparable from every subject, for as soon as they are born they owe by birthright allegiance and obedience to the Sovereign (Ex p. Anderson (1861) 3 E & E 487). A natural-born subject owes allegiance wherever they may be, so that where territory is occupied in the course of hostilities by an enemy's force, even if the annexation of the occupied country is proclaimed by the enemy, there can be no change of allegiance during the progress of hostilities on the part of a citizen of the occupied country (R v Vermaak (1900) 21 NLR 204 (South Africa)).
Acquired allegiance was acquired by naturalisation or denization. Denization, or ligeantia acquisita, appears to be threefold (Thomas v Sorrel (1673) 3 Keb 143);
(a) absolute, as the common denization, without any limitation or restraint;
(b) limited, as when the sovereign grants letters of denization to an alien, and the alien's male heirs, or to an alien for the term of their life;
(c) It may be granted upon condition, cujus est dare, ejus est disponere, and this denization of an alien may come about three ways: by parliament; by letters patent, which was the usual manner; and by conquest.
Local allegiance was due by an alien while in the protection of the crown. All friendly resident aliens incurred all the obligations of subjects (The Angelique (1801) 3 Ch Rob App 7). An alien, coming into a colony, also became, temporarily, a subject of the crown, and acquired rights both within and beyond the colony, and these latter rights could not be affected by the laws of that colony (Routledge v Low (1868) LR 3 HL 100; 37 LJ Ch 454; 18 LT 874; 16 WR 1081, HL; Reid v Maxwell (1886) 2 TLR 790; Falcon v Famous Players Film Co [1926] 2 KB 474).
A resident alien owed allegiance even when the protection of the crown was withdrawn owing to the occupation of an enemy, because the absence of the crown's protection was temporary and involuntary (de Jager v Attorney-General of Natal [1907] AC 326).
Legal allegiance was due when an alien took an oath of allegiance required for a particular office under the crown.
By the Naturalisation Act 1870, it was made possible for British subjects to renounce their nationality and allegiance, and the ways in which that nationality is lost were defined. So British subjects voluntarily naturalized in a foreign state are deemed aliens from the time of such naturalization, unless, in the case of persons naturalized before the passing of the act, they had declared their desire to remain British subjects within two years from the passing of the act. Persons who, from having been born within British territory, are British subjects, but who, at birth, came under the law of any foreign state or of subjects of such state, and, also, persons who, though born abroad, are British subjects by reason of parentage, may, by declarations of alienage, get rid of British nationality. Emigration to an uncivilized country left British nationality unaffected: indeed the right claimed by all states to follow with their authority their subjects so emigrating was one of the usual and recognized means of colonial expansion.
United States
The doctrine that no man can cast off his native allegiance without the consent of his sovereign was early abandoned in the United States, and Chief Justice John Rutledge also declared in Talbot v. Janson, "a man may, at the same time, enjoy the rights of citizenship under two governments." On July 27, 1868, the day before the Fourteenth Amendment was adopted, U.S. Congress declared in the preamble of the Expatriation Act that "the right of expatriation is a natural and inherent right of all people, indispensable to the enjoyment of the rights of life, liberty and the pursuit of happiness," and (Section I) one of "the fundamental principles of this government" (United States Revised Statutes, sec. 1999). Every natural-born citizen of a foreign state who is also an American citizen, and every natural-born American citizen who is also a citizen of a foreign land, owes a double allegiance, one to the United States, and one to their homeland (in the event of an immigrant becoming a citizen of the US) or to their adopted land (in the event of an emigrant natural-born citizen of the US becoming a citizen of another nation). If these allegiances come into conflict, the person may be guilty of treason against one or both. If the demands of these two sovereigns upon their duty of allegiance come into conflict, those of the United States have the paramount authority in American law; likewise, those of the foreign land have paramount authority in their legal system. In such a situation, it may be incumbent on the individual to renounce one of their citizenships, to avoid possibly being forced into situations where countervailing duties are required of them, such as might occur in the event of war.
Oath of allegiance
The oath of allegiance is an oath of fidelity to the sovereign taken by all persons holding important public office and as a condition of naturalization. By ancient common law, it was required of all persons above the age of 12, and it was repeatedly used as a test for the disaffected. In England, it was first imposed by statute in the reign of Elizabeth I (1558), and its form has, more than once, been altered since. Up to the time of the revolution, the promise was "to be true and faithful to the king and his heirs, and truth and faith to bear of life and limb and terrene honour, and not to know or hear of any ill or damage intended him without defending him therefrom." This was thought to favour the doctrine of absolute non-resistance, and, accordingly, the Convention Parliament enacted the form that has been in use since that time – "I do sincerely promise and swear that I will be faithful and bear true allegiance to His Majesty ..."
In the United States and some other republics, the oath is known as the Pledge of Allegiance. Instead of declaring fidelity to a monarch, the pledge is made to the flag, the republic, and to the core values of the country, specifically liberty and justice. The reciting of the pledge in the United States is voluntary because of the rights guaranteed to the people under the First Amendment to the United States Constitution - specifically, the guarantee of freedom of speech, which inherently includes the freedom not to speak.
In Islam
The word used in the Arabic language for allegiance is bay'at (Arabic: بيعة), which means "taking hand". The practice is sanctioned in the Quran by Surah 48:10: "Verily, those who give thee their allegiance, they give it but to Allah Himself". The word is used for the oath of allegiance to an emir. It is also used for the initiation ceremony specific to many Sufi orders.
See also
Impressment
Legitimacy (political)
Mandate of Heaven
Renunciation of citizenship
Treason
Usurpation
War of 1812
Winfield Scott
References
Further reading
Salmond on "Citizenship and Allegiance," in the Law Quarterly Review (July 1901, January 1902).
Nationalism |
885 | https://en.wikipedia.org/wiki/Altenberg | Altenberg | Altenberg (German for "old mountain" or "mountain of the old") may refer to:
Places
Austria
Altenberg, a town in Sankt Andrä-Wördern, Tulln District
Altenberg bei Linz, in Upper Austria
Altenberg an der Rax, in Styria
Germany
Altenberg (Bergisches Land), an area in Odenthal, North Rhine-Westphalia
Altenberg Abbey, Cistercian monastery in Altenberg (Bergisches Land)
Altenberger Dom, sometimes called Altenberg Cathedral, the former church of this Cistercian monastery
Altenberg (Hohenahr), hill in Hesse
Altenberg (Limpurg Hills), highest summit in the Limpurg Hills
Altenberg, Saxony, a town
Altenberga, a municipality in the Saale-Holzfeld district, Thuringia
Altenberg Abbey, Solms, a former Premonstratensian nunnery near Wetzlar in Hesse
Zinkfabrik Altenberg, a former zinc factory, now a branch of the LVR Industrial Museum, Oberhausen, North Rhine-Westphalia
Grube Altenberg, a show mine near Kreuztal, North Rhine-Westphalia
Other places
Altenberg, the German name for Vieille Montagne (old mountain in French), a former zinc mine in Kelmis, Moresnet, Belgium
Altenberg, a district in the city of Bern, Switzerland
Other uses
Altenberg Lieder (Five Orchestral Songs), composed by Alban Berg in 1911/12
Altenberg Publishing (1880–1934), a former Polish publishing house
Altenberg Trio, a Viennese piano trio
People with the surname
Alfred Altenberg (1878–1924), Polish bookseller and publisher
Jakob Altenberg (1875–1944), Austrian businessman
Lee Altenberg, theoretical biologist
Peter Altenberg (1859–1919), nom de plume of Austrian writer and poet Richard Engländer
See also
Altenburg (disambiguation) |
887 | https://en.wikipedia.org/wiki/MessagePad | MessagePad | The MessagePad was a series of personal digital assistant devices developed by Apple Computer for the Newton platform in 1993. Some electronic engineering and the manufacture of Apple's MessagePad devices was undertaken in Japan by Sharp. The devices are based on the ARM 610 RISC processor and all featured handwriting recognition software and were developed and marketed by Apple. The devices run Newton OS.
History
The development of the Newton MessagePad first began with Apple's former senior vice president of research and development, Jean-Louis Gassée; his team included Steve Capps, co-writer of Mac OS Finder, and an employed engineer named Steve Sakoman. The development of the Newton MessagePad operated in secret until it was eventually revealed to the Apple Board of Directors in late 1990.
When Gassée resigned from his position due to a significant disagreement with the board, seeing how his employer was treated, Sakoman also stopped developing the MessagePad on March 2, 1990.
Bill Atkinson, an Apple Executive responsible for the company's Lisa graphical interface, invited Steve Capps, John Sculley, Andy Hertzfeld, Susan Kare, and Marc Porat to a meeting on March 11, 1990. There, they brainstormed a way of saving the MessagePad. Sculley suggested adding new features, including libraries, museums, databases, or institutional archives features, allowing customers to navigate through various window tabs or opened galleries/stacks. The Board later approved his suggestion; he then gave Newton it is official and full backing.
The first MessagePad was unveiled by Sculley on the 29th of May 1992 at the summer Consumer Electronics Show (CES) in Chicago. Sculley caved in to pressure to unveil the product early because the Newton did not officially ship for another 14 months on August 2, 1993, starting at a price of . Over 50,000 units were sold by late November 1993.
Details
Screen and input
With the MessagePad 120 with Newton OS 2.0, the Newton Keyboard by Apple became available, which can also be used via the dongle on Newton devices with a Newton InterConnect port, most notably the Apple MessagePad 2000/2100 series, as well as the Apple eMate 300.
Newton devices featuring Newton OS 2.1 or higher can be used with the screen turned horizontally ("landscape") as well as vertically ("portrait"). A change of a setting rotates the contents of the display by 90, 180 or 270 degrees. Handwriting recognition still works properly with the display rotated, although display calibration is needed when rotation in any direction is used for the first time or when the Newton device is reset.
Handwriting recognition
In initial versions (Newton OS 1.x) the handwriting recognition gave extremely mixed results for users and was sometimes inaccurate. The original handwriting recognition engine was called Calligrapher, and was licensed from a Russian company called Paragraph International. Calligrapher's design was quite sophisticated; it attempted to learn the user's natural handwriting, using a database of known words to make guesses as to what the user was writing, and could interpret writing anywhere on the screen, whether hand-printed, in cursive, or a mix of the two. By contrast, Palm Pilot's Graffiti had a less sophisticated design than Calligrapher, but was sometimes found to be more accurate and precise due to its reliance on a fixed, predefined stroke alphabet. The stroke alphabet used letter shapes which resembled standard handwriting, but which were modified to be both simple and very easy to differentiate. Palm Computing also released two versions of Graffiti for Newton devices. The Newton version sometimes performed better and could also show strokes as they were being written as input was done on the display itself, rather than on a silkscreen area.
For editing text, Newton had a very intuitive system for handwritten editing, such as scratching out words to be deleted, circling text to be selected, or using written carets to mark inserts.
Later releases of the Newton operating system retained the original recognizer for compatibility, but added a hand-printed-text-only (not cursive) recognizer, called "Rosetta", which was developed by Apple, included in version 2.0 of the Newton operating system, and refined in Newton 2.1. Rosetta is generally considered a significant improvement and many reviewers, testers, and most users consider the Newton 2.1 handwriting recognition software better than any of the alternatives even 10 years after it was introduced. Recognition and computation of handwritten horizontal and vertical formulas such as "1 + 2 =" was also under development but never released. However, users wrote similar programs which could evaluate mathematical formulas using the Newton OS Intelligent Assistant, a unique part of every Newton device.
The handwriting recognition and parts of the user interface for the Newton are best understood in the context of the broad history of pen computing, which is quite extensive.
A vital feature of the Newton handwriting recognition system is the modeless error correction. That is, correction done in situ without using a separate window or widget, using a minimum of gestures. If a word is recognized improperly, the user could double-tap the word and a list of alternatives would pop up in a menu under the stylus. Most of the time, the correct word will be in the list. If not, a button at the bottom of the list allows the user to edit individual characters in that word. Other pen gestures could do such things as transpose letters (also in situ). The correction popup also allowed the user to revert to the original, un-recognized letter shapes - this would be useful in note-taking scenarios if there was insufficient time to make corrections immediately. To conserve memory and storage space, alternative recognition hypotheses would not be saved indefinitely. If the user returned to a note a week later, for example, they would only see the best match. Error correction in many current handwriting systems provides such functionality but adds more steps to the process, greatly increasing the interruption to a user's workflow that a given correction requires.
User interface
Text could also be entered by tapping with the stylus on a small on-screen pop-up QWERTY virtual keyboard, although more layouts were developed by users. Newton devices could also accept free-hand "Sketches", "Shapes", and "Ink Text", much like a desktop computer graphics tablet. With "Shapes", Newton could recognize that the user was attempting to draw a circle, a line, a polygon, etc., and it would clean them up into perfect vector representations (with modifiable control points and defined vertices) of what the user was attempting to draw. "Shapes" and "Sketches" could be scaled or deformed once drawn. "Ink text" captured the user's free-hand writing but allowed it to be treated somewhat like recognized text when manipulating for later editing purposes ("ink text" supported word wrap, could be formatted to be bold, italic, etc.). At any time a user could also direct their Newton device to recognize selected "ink text" and turn it into recognized text (deferred recognition). A Newton note (or the notes attached to each contact in Names and each Dates calendar or to-do event) could contain any mix of interleaved text, Ink Text, Shapes, and Sketches.
While the Newton offered handwriting recognition training and would clean up sketches into vector shapes, both were unreliable and required much rewriting and redrawing. The most reliable application of the Newton was collecting and organizing address and phone numbers. While handwritten messages could be stored, they could not be easily filed, sorted or searched. While the technology was a probable cause for the failure of the device (which otherwise met or exceeded expectations), the technology has been instrumental in producing the future generation of handwriting software that realizes the potential and promise that began in the development of Newton-Apple's Ink Handwriting Recognition.
Connectivity
The MessagePad 100 series of devices used Macintosh's proprietary serial ports—round Mini-DIN 8 connectors. The MessagePad 2000/2100 models (as well as the eMate 300) have a small, proprietary Newton InterConnect port. However, the development of the Newton hardware/software platform was canceled by Steve Jobs on February 27, 1998, so the InterConnect port, while itself very advanced, can only be used to connect a serial dongle. A prototype multi-purpose InterConnect device containing serial, audio in, audio out, and other ports was also discovered. In addition, all Newton devices have infrared connectivity, initially only the Sharp ASK protocol, but later also IrDA, though the Sharp ASK protocol was kept in for compatibility reasons. Unlike the Palm Pilot, all Newton devices are equipped with a standard PC Card expansion slot (two on the 2000/2100). This allows native modem and even Ethernet connectivity; Newton users have also written drivers for 802.11b wireless networking cards and ATA-type flash memory cards (including the popular CompactFlash format), as well as for Bluetooth cards. Newton can also dial a phone number through the built-in speaker of the Newton device by simply holding a telephone handset up to the speaker and transmitting the appropriate tones. Fax and printing support is also built in at the operating system level, although it requires peripherals such as parallel adapters, PCMCIA cards, or serial modems, the most notable of which is the lightweight Newton Fax Modem released by Apple in 1993. It is powered by 2 AA batteries, and can also be used with a power adapter. It provides data transfer at 2,400 bit/s, and can also send and receive fax messages at 9,600 and 4,800 bit/s respectively.
Power options
The original Apple MessagePad and MessagePad 100 used four AAA batteries. They were eventually replaced by AA batteries with the release of the Apple MessagePad 110.
The use of 4 AA NiCd (MessagePad 110, 120 and 130) and 4x AA NiMH cells (MP2x00 series, eMate 300) give a runtime of up to 30 hours (MP2100 with two 20 MB Linear Flash memory PC Cards, no backlight usage) and up to 24 hours with backlight on. While adding more weight to the handheld Newton devices than AAA batteries or custom battery packs, the choice of an easily replaceable/rechargeable cell format gives the user a still unsurpassed runtime and flexibility of power supply. This, together with the flash memory used as internal storage starting with the Apple MessagePad 120 (if all cells lost their power, no data was lost due to the non-volatility of this storage), gave birth to the slogan "Newton never dies, it only gets new batteries".
Later efforts and improvements
The Apple MessagePad 2000/2100, with a vastly improved handwriting recognition system, 162 MHz StrongARM SA-110 RISC processor, Newton OS 2.1, and a better, clearer, backlit screen, attracted critical plaudits.
eMate 300
The eMate 300 was a Newton device in a laptop form factor offered to schools in 1997 as an inexpensive ($799 US, originally sold to education markets only) and durable computer for classroom use. However, in order to achieve its low price, the eMate 300 did not have all the speed and features of the contemporary MessagePad equivalent, the MessagePad 2000. The eMate was cancelled along with the rest of the Newton products in 1998. It is the only Newton device to use the ARM710 microprocessor (running at 25 MHz), have an integrated keyboard, use Newton OS 2.2 (officially numbered 2.1), and its batteries are officially irreplaceable, although several users replaced them with longer-lasting ones without any damage to the eMate hardware whatsoever.
Prototypes
Many prototypes of additional Newton devices were spotted. Most notable was a Newton tablet or "slate", a large, flat screen that could be written on. Others included a "Kids Newton" with side handgrips and buttons, "VideoPads" which would have incorporated a video camera and screen on their flip-top covers for two-way communications, the "Mini 2000" which would have been very similar to a Palm Pilot, and the NewtonPhone developed by Siemens, which incorporated a handset and a keyboard.
Market reception
Fourteen months after Sculley demoed it at the May 1992, Chicago CES, the MessagePad was first offered for sale on August 2, 1993, at the Boston Macworld Expo. The hottest item at the show, it cost $900. 50,000 MessagePads were sold in the device's first three months on the market.
The original Apple MessagePad and MessagePad 100 were limited by the very short lifetime of their inadequate AAA batteries.
Later versions of Newton OS offered improved handwriting recognition, quite possibly a leading reason for the continued popularity of the devices among Newton users. Even given the age of the hardware and software, Newtons still demand a sale price on the used market far greater than that of comparatively aged PDAs produced by other companies. In 2006, CNET compared an Apple MessagePad 2000 to a Samsung Q1, and the Newton was declared better. In 2009, CNET compared an Apple MessagePad 2000 to an iPhone 3GS, and the Newton was declared more innovative at its time of release.
A chain of dedicated Newton-only stores called Newton Source, independently run by Stephen Elms, existed from 1994 until 1998. Locations included New York, Los Angeles, San Francisco, Chicago and Boston. The Westwood Village, California, near UCLA featured the trademark red and yellow light bulb Newton logo in neon. The stores provided an informative educational venue to learn about the Newton platform in a hands on relaxed fashion. The stores had no traditional computer retail counters and featured oval desktops where interested users could become intimately involved with the Newton product range. The stores were a model for the later Apple Stores.
Newton device models
{| class="wikitable"
|+
!Brand
| colspan="2" |Apple Computer
|Sharp
|Siemens
| colspan="2" |Apple
|Sharp
|Apple Computer
|Digital Ocean
|Motorola
|Harris
|Digital Ocean
| colspan="4" |Apple
| colspan="3" |Harris
|Siemens
|Schlumberger
|-
!Device
|OMP (Original Newton MessagePad)
|Newton "Dummy"
|ExpertPad PI-7000
|Notephone.[better source needed]
|MessagePad 100
|MessagePad 110
|Sharp ExpertPad PI-7100
|MessagePad 120
|Tarpon
|Marco
|SuperTech 2000
|Seahorse
|MessagePad 130
|eMate 300
|MessagePad 2000
|MessagePad 2100
|Access Device 2000
|Access Device, GPS
|Access Device, Wireline
|Online Terminal, also known as Online Access Device(OAD)
|Watson
|-
!Introduced
|August 3, 1993 (US) December 1993 (Germany)
|?
|August 3, 1993 (US and Japan)
|1993?
| colspan="2" |March 1994
|April 1994
|October 1994 (Germany), January 1995 (US)
| colspan="2" |January 1995 (US)
|August 1995 (US)
|January 1996 (US)
|March 1996
| colspan="2" |March 1997
|November 1997
| colspan="3" |1998
|Announced 1997
|?
|-
!Discontinued
| colspan="3" |March 1994
|?
| colspan="2" |April 1995
|late 1994
|June 1996
|?
|?
|?
|?
|April 1997
| colspan="3" |February 1998
|
|
|
|
|
|-
!Code name
|Junior
|
|?
|?
|Junior
|Lindy
|?
|Gelato
|?
|?
|?
|?
|Dante
|?
|Q
|?
|
|
|
|
|
|-
!Model No.
|H1000
|
|?
|?
|H1000
|H0059
|?
|H0131
|?
|?
|?
|?
|H0196
|H0208
|H0136
|H0149
|
|
|
|
|
|-
!Processor
| colspan="13" |ARM 610 (20 MHz)
|ARM 710a (25 MHz)
| colspan="7" |StrongARM SA-110 (162 MHz)
|-
!ROM
| colspan="7" |4 MB
| colspan="2" |4 MB (OS 1.3) or 8 MB (OS 2.0)
|5 MB
|4 MB
| colspan="5" |8 MB
|
|
|
|
|
|-
!System Memory (RAM)
| colspan="5" |490 KB* SRAM
|544 KB SRAM
|490 KB* SRAM
| colspan="2" |639/687 KB DRAM
|544 KB SRAM
|639 KB DRAM
| colspan="2" |1199 KB DRAM
|1 MB DRAM (Upgradable)
|1 MB DRAM
|4 MB DRAM
| colspan="3" |1 MB DRAM
|?
|1 MB DRAM
|-
!User Storage
| colspan="5" |150 KB* SRAM
|480 KB SRAM
|150 KB* SRAM
| colspan="2" |385/1361 KB Flash RAM
|480 KB SRAM
|385 KB Flash RAM
| colspan="2" |1361 KB Flash RAM
|2 MB Flash RAM(Upgradable)
| colspan="5" |4 MB Flash RAM
|?
|4 MB Flash RAM
|-
!Total RAM
| colspan="5" |640 KB
|1 MB
|640 KB
| colspan="2" |1.0/2.0 MB
| colspan="2" |1 MB
| colspan="2" |2.5 MB
|3 MB (Upgradable via Internal Expansion)
|5 MB
|8 MB
| colspan="3" |5 MB
|?
|5 MB
|-
!Display
| colspan="5" |336 × 240 (B&W)
|320 × 240 (B&W)
|336 × 240 (B&W)
|320 × 240 (B&W)
|320 × 240 (B&W) w/ backlight
|320 × 240 (B&W)
| colspan="3" |320 × 240 (B&W) w/ backlight
| colspan="6" |480 × 320 grayscale (16 shades) w/ backlight
|
|480 × 320 greyscale (16 shades) w/ backlight
|-
!Newton OS version
| colspan="3" |1.0 to 1.05, or 1.10 to 1.11
|1.11
| colspan="2" |1.2 or 1.3
|1.3
| colspan="2" |1.3 or 2.0
| colspan="2" |1.3
| colspan="2" |2.0
|2.1 (2.2)
| colspan="2" |2.1
| colspan="5" |2.1
|-
!Newton OS languages
|English or German
|
|English or Japanese
|German
|English, German or French
|English or French
|English or Japanese
|English, German or French
| colspan="4" |English
|English or German
| colspan="2" |English
|English or German
| colspan="3" |English
|German
|French
|-
!Connectivity
| colspan="3" |RS-422, LocalTalk & SHARP ASK Infrared
|Modem and Telephone dock Attachment
| colspan="4" |RS-422, LocalTalk & SHARP ASK Infrared
|RS-422, LocalTalk & SHARP ASK Infrared
|RS-422, LocalTalk, Infrared, ARDIS Network
|RS-232, LocalTalk WLAN, V.22bis modem, Analog/Digital Cellular, CDPD, RAM, ARDIS, Trunk Radio
|RS-232, LocalTalk, CDPD, WLAN, Optional dGPS, GSM, or IR via modular attachments
|RS-422, LocalTalk & SHARP ASK Infrared
|IrDA, headphone port, Interconnect port, LocalTalk, Audio I/O, Autodock
|Dual-mode IR;IrDA & SHARP ASK, LocalTalk, Audio I/O, Autodock, Phone I/O
|Dual-mode IR; IrDA & SHARP ASK, LocalTalk, Audio I/O, Autodock
| colspan="3" |Dual-mode IR;IrDA & SHARP ASK, LocalTalk, Audio I/O, Autodock, Phone I/O
|?
|Dual-mode IR;IrDA & SHARP ASK, LocalTalk, Audio I/O, Autodock, Phone I/O
|-
!PCMCIA
| colspan="13" |1 PCMCIA-slot II, 5v or 12v
|1 PCMCIA-slot I/II/III, 5v
| colspan="2" |2 PCMCIA-slot II, 5v or 12v
| colspan="2" |1 PCMCIA-slot II, 5v or 12v
|1 PCMCIA-slot II, 5v or 12v, 2nd slot Propriety Rado Card
| colspan="2" |1 PCMCIA-slot II, 5v or 12v, 1 Smart Card Reader
|-
!Power
| colspan="5" |4 AAA or NiCd rechargeable or external power supply
|4 AA or NiCd rechargeable or external power supply
|4 AAA or NiCd rechargeable or external power supply
|4 AA or NiCd rechargeable or external power supply
| colspan="2" |NiCd battery pack or external power supply
|4 AA or NiCd rechargeable or external power supply
|NiCd battery pack or external power supply
|4 AA or NiCd rechargeable or external power supply
|NiMH battery pack (built-in) or external power supply
| colspan="2" |4 AA or NiMH rechargeable or external power supply
| colspan="3" |Custom NiMH rechargeable or external power supply
|? Unknown, but likely external power supply
|4 AA or NiMH rechargeable or external power supply
|-
!Dimensions
(HxWxD)
|
|
|
(lid open)
| colspan="2" |
|
|
(lid open)
|
|
|
|?
|
|
|
| colspan="2" |
|?
|?
|?
|9 x 14.5 x 5.1 inches
(23 x 37 x 13 cm)
|?
|-
!Weight
|
|
|
with batteries installed
|
|
| with batteries installed
|
with batteries installed
|with batteries installed
|
|
|?
|
|
with batteries installed
|
| colspan="2" |
|?
|?
|?
|?
|?
|}
* Varies with installed OS
Notes: The eMate 300 actually has ROM chips silk screened with 2.2 on them. Stephanie Mak on her website discusses this:
If one removes all patches to the eMate 300 (by replacing the ROM chip, and then putting in the original one again, as the eMate and the MessagePad 2000/2100 devices erase their memory completely after replacing the chip), the result will be the Newton OS saying that this is version 2.2.00. Also, the Original MessagePad and the MessagePad 100 share the same model number, as they only differ in the ROM chip version. (The OMP has OS versions 1.0 to 1.05, or 1.10 to 1.11, while the MP100 has 1.3 that can be upgraded with various patches.)
Timeline
Third party licenses
The Newton OS was also licensed to a number of third party developers including Sharp and Motorola who developed additional PDA devices based on the Newton platform. Motorola added wireless connectivity, as well as made a unique two-part design, and shipped additional software with its Newton device, called the Marco. Sharp developed a line of Newton devices called the ExpertPad PI-7000/7100; those were the same as Apple's MessagePad and MessagePad 100, the only difference is the physical design (the ExpertPads feature a screen lid, which Apple added in 1994 with the release of the MessagePad 110) and the naming.
Other uses
There were a number of projects that used the Newton as a portable information device in cultural settings such as museums. For example, Visible Interactive created a walking tour in San Francisco's Chinatown but the most significant effort took place in Malaysia at the Petronas Discovery Center, known as Petrosains.
In 1995, an exhibit design firm, DMCD Inc., was awarded the contract to design a new science museum in the Petronas Towers in Kuala Lumpur. A major factor in the award was the concept that visitors would use a Newton device to access additional information, find out where they were in the museum, listen to audio, see animations, control robots and other media, and to bookmark information for printout at the end of the exhibit.
The device became known as the ARIF, a Malay word for "wise man" or "seer" and it was also an acronym for A Resourceful Informative Friend. Some 400 ARIFS were installed and over 300 are still in use today. The development of the ARIF system was extremely complex and required a team of hardware and software engineers, designers, and writers. ARIF is an ancestor of the PDA systems used in museums today and it boasted features that have not been attempted since.
Anyway & Company firm was involved with the Petronas Discovery Center project back in 1998 and NDAs were signed which prevents getting to know more information about this project. It was confirmed that they purchased of MP2000u or MP2100's by this firm on the behalf of the project under the name of "Petrosains Project Account". By 1998 they had invested heavily into the R&D of this project with the Newton at the center. After Apple officially cancelled the Newton in 1998 they had to acquire as many Newtons as possible for this project. It was estimated initially 1000 Newtons, but later readjusted the figure to possibly 750 Newtons. They placed an “Internet Call” for Newtons. They purchased them in large and small quantities.
The Newton was also used in healthcare applications, for example in collecting data directly from patients. Newtons were used as electronic diaries, with patients entering their symptoms and other information concerning their health status on a daily basis. The compact size of the device and its ease of use made it possible for the electronic diaries to be carried around and used in the patients' everyday life setting. This was an early example of electronic patient-reported outcomes (ePRO).
See also
Newton (platform)
Newton OS
eMate 300
NewtonScript
Orphaned technology
Pen computing
References
Bibliography
Apple's press release on the debut of the MessagePad 2100:
Apple's overview of features & limitations of Newton Connection Utilities:
Newton overview at Newton Source archived from Apple:
Newton FAQ:
Newton Gallery:
Birth of the Newton:
The Newton Hall of Fame: People behind the Newton:
Pen Computing's Why did Apple kill the Newton?:
Pen Computing's Newton Notes column archive:
A.I. Magazine article by Yaeger on Newton HWR design, algorithms, & quality:
Associated slides:
Info on Newton HWR from Apple's HWR Technical Lead:
Notes on the History of Pen-based Computing:
This links to:
External links
Additional resources and information
Defying Gravity: The Making of Newton, by Kounalakis & Menuez (Hardcover)
Hardcover: 192 pages
Publisher: Beyond Words Publishing (October 1993)
Complete Developer's manual for the StrongARM SA-110
Beginner's overview of the StrongARM SA-110 Microprocessor
Reviews
MessagePad 2000 review at "The History and Macintosh Society"
Prof. Wittmann's collection of Newton & MessagePad reviews
Apple Newton
Products introduced in 1993
Apple Inc. personal digital assistants |
888 | https://en.wikipedia.org/wiki/A.%20E.%20van%20Vogt | A. E. van Vogt | Alfred Elton van Vogt ( ; April 26, 1912 – January 26, 2000) was a Canadian-born American science fiction author. His fragmented, bizarre narrative style influenced later science fiction writers, notably Philip K. Dick. He was one of the most popular and influential practitioners of science fiction in the mid-twentieth century, the genre's so-called Golden Age, and one of the most complex. The Science Fiction Writers of America named him their 14th Grand Master in 1995 (presented 1996).
Early life
Alfred Vogt (both "Elton" and "van" were added much later) was born on April 26, 1912, on his grandparents' farm in Edenburg, Manitoba, a tiny (and now defunct) Russian Mennonite community east of Gretna, Manitoba, Canada, in the Mennonite West Reserve. He was the third of six children born to Heinrich "Henry" Vogt and Aganetha "Agnes" Vogt (née Buhr), both of whom were born in Manitoba and grew up in heavily immigrant communities. Until he was four, van Vogt spoke only Plautdietsch at home.
For the first dozen or so years of his life, van Vogt's father, Henry Vogt, a lawyer, moved his family several times within central Canada, moving to Neville, Saskatchewan; Morden, Manitoba; and finally Winnipeg, Manitoba. Alfred Vogt found these moves difficult, later remarking:
By the 1920s, living in Winnipeg, father Henry worked as an agent for a steamship company, but the stock market crash of 1929 proved financially disastrous, and the family could not afford to send Alfred to college. During his teen years, Alfred worked as a farmhand and a truck driver, and by the age of 19, he was working in Ottawa for the Canadian Census Bureau.
In "the dark days of '31 and '32," van Vogt took a correspondence course in writing from the Palmer Institute of Authorship. He sold his first story in fall 1932. His early published works were stories in the true confession style of magazines such as True Story. Most of these stories were published anonymously, with the first-person narratives allegedly being written by people (often women) in extraordinary, emotional, and life-changing circumstances.
After a year in Ottawa, he moved back to Winnipeg, where he sold newspaper advertising space and continued to write. While continuing to pen melodramatic "true confessions" stories through 1937, he also began writing short radio dramas for local radio station CKY, as well as conducting interviews published in trade magazines. He added the middle name "Elton" at some point in the mid-1930s, and at least one confessional story (1937's "To Be His Keeper") was sold to the Toronto Star, who misspelled his name "Alfred Alton Bogt" in the byline. Shortly thereafter, he added the "van" to his surname, and from that point forward he used the name "A. E. van Vogt" both personally and professionally.
Career
By 1938, van Vogt decided to switch to writing science fiction, a genre he enjoyed reading. He was inspired by the August 1938 issue of Astounding Science Fiction, which he picked up at a newsstand. John W. Campbell's novelette "Who Goes There?" (later adapted into The Thing from Another World and The Thing) inspired van Vogt to write "Vault of the Beast", which he submitted to that same magazine. Campbell, who edited Astounding (and had written the story under a pseudonym), sent van Vogt a rejection letter in which Campbell encouraged van Vogt to try again. Van Vogt sent another story, entitled "Black Destroyer", which was accepted. It featured a fierce, carnivorous alien stalking the crew of a spaceship, and served as the inspiration for multiple science fiction movies, including Alien (1979). A revised version of "Vault of the Beast" was published in 1940.
While still living in Winnipeg, in 1939 van Vogt married Edna Mayne Hull, a fellow Manitoban. Hull, who had previously worked as a private secretary, went on to act as van Vogt's typist, and was credited with writing several SF stories of her own throughout the early 1940s.
The outbreak of World War II in September 1939 caused a change in van Vogt's circumstances. Ineligible for military service due to his poor eyesight, he accepted a clerking job with the Canadian Department of National Defence. This necessitated a move back to Ottawa, where he and his wife stayed for the next year and a half.
Meanwhile, his writing career continued. "Discord in Scarlet" was van Vogt's second story to be published, also appearing as the cover story. It was accompanied by interior illustrations created by Frank Kramer and Paul Orban. (Van Vogt and Kramer thus debuted in the issue of Astounding that is sometimes identified as the start of the Golden Age of Science Fiction.) Among his most famous works of this era, "Far Centaurus" appeared in the January 1944 edition of Astounding.
Van Vogt's first completed novel, and one of his most famous, is Slan (Arkham House, 1946), which Campbell serialized in Astounding (September to December 1940). Using what became one of van Vogt's recurring themes, it told the story of a nine-year-old superman living in a world in which his kind are slain by Homo sapiens.
Others saw van Vogt's talent from his first story, and in May 1941 van Vogt decided to become a full-time writer, quitting his job at the Canadian Department of National Defence. Freed from the necessity of living in Ottawa, he and his wife lived for a time in the Gatineau region of Quebec before moving to Toronto in the fall of 1941.
Prolific throughout this period, van Vogt wrote many of his more famous short stories and novels in the years from 1941 through 1944. The novels The Book of Ptath and The Weapon Makers both appeared in magazines in serial form during this period; they were later published in book form after World War II. As well, several (though not all) of the stories that were compiled to make up the novels The Weapon Shops of Isher, The Mixed Men and The War Against the Rull were published during this time.
California and post-war writing (1944–1950)
In November 1944, van Vogt and Hull moved to Hollywood; van Vogt would spend the rest of his life in California. He had been using the name "A. E. van Vogt" in his public life for several years, and as part of the process of obtaining American citizenship in 1945 he finally and formally changed his legal name from Alfred Vogt to Alfred Elton van Vogt. To his friends in the California science fiction community, he was known as "Van".
Method and themes
Van Vogt systematized his writing method, using scenes of 800 words or so where a new complication was added or something resolved. Several of his stories hinge on temporal conundra, a favorite theme. He stated that he acquired many of his writing techniques from three books: Narrative Technique by Thomas Uzzell, The Only Two Ways to Write a Story by John Gallishaw, and Twenty Problems of the Fiction Writer by Gallishaw. He also claimed many of his ideas came from dreams; throughout his writing life he arranged to be awakened every 90 minutes during his sleep period so he could write down his dreams.
Van Vogt was also always interested in the idea of all-encompassing systems of knowledge (akin to modern meta-systems). The characters in his very first story used a system called "Nexialism" to analyze the alien's behavior. Around this time, he became particularly interested in the general semantics of Alfred Korzybski.
He subsequently wrote a novel merging these overarching themes, The World of Ā, originally serialized in Astounding in 1945. Ā (often rendered as Null-A), or non-Aristotelian logic, refers to the capacity for, and practice of, using intuitive, inductive reasoning (compare fuzzy logic), rather than reflexive, or conditioned, deductive reasoning. The novel recounts the adventures of an individual living in an apparent Utopia, where those with superior brainpower make up the ruling class... though all is not as it seems. A sequel, The Players of Ā (later re-titled The Pawns of Null-A) was serialized in 1948–49.
At the same time, in his fiction, van Vogt was consistently sympathetic to absolute monarchy as a form of government. This was the case, for instance, in the Weapon Shop series, the Mixed Men series, and in single stories such as "Heir Apparent" (1945), whose protagonist was described as a "benevolent dictator". These sympathies were the subject of much critical discussion during van Vogt's career, and afterwards.
Van Vogt published "Enchanted Village" in the July 1950 issue of Other Worlds Science Stories. It was reprinted in over 20 collections or anthologies, and appeared many times in translation.
Dianetics and fix-ups (1950–1961)
In 1950, van Vogt was briefly appointed as head of L. Ron Hubbard's Dianetics operation in California. Van Vogt had first met Hubbard in 1945, and became interested in his theories, which were published shortly thereafter. Dianetics was the secular precursor to Hubbard's Church of Scientology; van Vogt would have no association with Scientology, as he did not approve of its mysticism.
The California Dianetics operation went broke nine months later, but never went bankrupt, due to van Vogt's arrangements with creditors. Shortly afterward, van Vogt and his wife opened their own Dianetics center, partly financed by his writings, until he "signed off" around 1961. From 1951 until 1961, van Vogt's focus was on Dianetics, and no new story ideas flowed from his typewriter.
Fix-ups
However, during the 1950s, van Vogt retrospectively patched together many of his previously published stories into novels, sometimes creating new interstitial material to help bridge gaps in the narrative. Van Vogt referred to the resulting books as "fix-ups", a term that entered the vocabulary of science-fiction criticism. When the original stories were closely related this was often successful, although some van Vogt fix-ups featured disparate stories thrown together that bore little relation to each other, generally making for a less coherent plot. One of his best-known (and well-regarded) novels, The Voyage of the Space Beagle (1950) was a fix-up of four short stories including "Discord in Scarlet"; it was published in at least five European languages by 1955.
Although Van Vogt averaged a new book title every ten months from 1951 to 1961, none of them were entirely new content; they were all fix-ups, collections of previously published stories, expansions of previously published short stories to novel length, or republications of previous books under new titles and all based on story material written and originally published between 1939 and 1950. Examples include The Weapon Shops of Isher (1951), The Mixed Men (1952), The War Against the Rull (1959), and the two "Clane" novels, Empire of the Atom (1957) and The Wizard of Linn (1962), which were inspired (like Asimov's Foundation series) by Roman imperial history; specifically, as Damon Knight wrote, the plot of Empire of the Atom was "lifted almost bodily" from that of Robert Graves' I, Claudius. (Also, one non-fiction work, The Hypnotism Handbook, appeared in 1956, though it had apparently been written much earlier.)
After more than a decade of running their Dianetics center, Hull and van Vogt closed it in 1961. Nevertheless, van Vogt maintained his association with the organization and was still president of the Californian Association of Dianetic Auditors into the 1980s.
Return to writing and later career (1962–1986)
Though the constant re-packaging of his older work meant that he had never really been away from the book publishing world, van Vogt had not published any wholly new fiction for almost 12 years when he decided to return to writing in 1962. He did not return immediately to science fiction, but instead wrote the only mainstream, non-sf novel of his career.
Van Vogt was profoundly affected by revelations of totalitarian police states that emerged after World War II. Accordingly, he wrote a mainstream novel that he set in Communist China, The Violent Man (1962). Van Vogt explained that to research this book he had read 100 books about China. Into this book he incorporated his view of "the violent male type", which he described as a "man who had to be right", a man who "instantly attracts women" and who he said were the men who "run the world". Contemporary reviews were lukewarm at best, and van Vogt thereafter returned to science fiction.
From 1963 through the mid-1980s, van Vogt once again published new material on a regular basis, though fix-ups and reworked material also appeared relatively often. His later novels included fix-ups such as The Beast (also known as Moonbeast) (1963), Rogue Ship (1965), Quest for the Future (1970) and Supermind (1977). He also wrote novels by expanding previously published short stories; works of this type include The Darkness on Diamondia (1972) and Future Glitter (also known as Tyranopolis; 1973).
Novels that were written simply as novels, and not serialized magazine pieces or fix-ups, had been very rare in van Vogt's oeuvre, but began to appear regularly beginning in the 1970s. Van Vogt's original novels included Children of Tomorrow (1970), The Battle of Forever (1971) and The Anarchistic Colossus (1977). Over the years, many sequels to his classic works were promised, but only one appeared: Null-A Three (1984; originally published in French). Several later books were initially published in Europe, and at least one novel only ever appeared in foreign language editions and was never published in its original English.
Final years
When the 1979 film Alien appeared, it was noted that the plot closely matched the plots of both Black Destroyer and Discord in Scarlet, both published in Astounding magazine in 1939, and then later published in the 1950 book Voyage of the Space Beagle. Van Vogt sued the production company for plagiarism, and eventually collected an out-of-court settlement of $50,000 from 20th Century Fox.
In increasingly frail health, van Vogt published his final short story in 1986.
Personal life
Van Vogt's first wife, Edna Mayne Hull, died in 1975. Van Vogt married Lydia Bereginsky in 1979; they remained together until his death.
Death
On January 26, 2000, A. E. van Vogt died in Los Angeles from Alzheimer's disease. He was survived by his second wife.
Critical reception
Critical opinion about the quality of van Vogt's work is sharply divided. An early and articulate critic was Damon Knight. In a 1945 chapter-long essay reprinted in In Search of Wonder, entitled "Cosmic Jerrybuilder: A. E. van Vogt", Knight described van Vogt as "no giant; he is a pygmy who has learned to operate an overgrown typewriter". Knight described The World of Null-A as "one of the worst allegedly adult science fiction stories ever published". Concerning van Vogt's writing, Knight said:
About Empire of the Atom Knight wrote:
Knight also expressed misgivings about van Vogt's politics. He noted that van Vogt's stories almost invariably present absolute monarchy in a favorable light. In 1974, Knight retracted some of his criticism after finding out about Vogt's writing down his dreams as a part of his working methods:
Knight's criticism greatly damaged van Vogt's reputation. On the other hand, when science fiction author Philip K. Dick was asked which science fiction writers had influenced his work the most, he replied:
Dick also defended van Vogt against Damon Knight's criticisms:
In a review of Transfinite: The Essential A. E. van Vogt, science fiction writer Paul Di Filippo said:
In The John W. Campbell Letters, Campbell says, "The son-of-a-gun gets hold of you in the first paragraph, ties a knot around you, and keeps it tied in every paragraph thereafter—including the ultimate last one".
Harlan Ellison (who had begun reading van Vogt as a teenager) wrote, "Van was the first writer to shine light on the restricted ways in which I had been taught to view the universe and the human condition".
Writing in 1984, David Hartwell said:
The literary critic Leslie A. Fiedler said something similar:
American literary critic Fredric Jameson says of van Vogt:
Van Vogt still has his critics. For example, Darrell Schweitzer, writing to The New York Review of Science Fiction in 1999, quoted a passage from the original van Vogt novelette "The Mixed Men", which he was then reading, and remarked:
Recognition
In 1946, van Vogt and his first wife, Edna Mayne Hull, were Guests of Honor at the fourth World Science Fiction Convention.
In 1980, van Vogt received a "Casper Award" (precursor to the Canadian Prix Aurora Awards) for Lifetime Achievement.
The Science Fiction Writers of America (SFWA) named him its 14th Grand Master in 1995 (presented 1996). Great controversy within SFWA accompanied its long wait in bestowing its highest honor (limited to living writers, no more than one annually). Writing an obituary of van Vogt, Robert J. Sawyer, a fellow Canadian writer of science fiction, remarked:
It is generally held that a key factor in the delay was "damnable SFWA politics" reflecting the concerns of Damon Knight, the founder of the SFWA, who abhorred van Vogt's style and politics and thoroughly demolished his literary reputation in the 1950s.
Harlan Ellison was more explicit in 1999 introduction to Futures Past: The Best Short Fiction of A. E. van Vogt:
In 1996, van Vogt received a Special Award from the World Science Fiction Convention "for six decades of golden age science fiction". That same year, the Science Fiction and Fantasy Hall of Fame inducted him in its inaugural class of two deceased and two living persons, along with writer Jack Williamson (also living) and editors Hugo Gernsback and John W. Campbell.
The works of van Vogt were translated into French by the surrealist Boris Vian (The World of Null-A as Le Monde des Å in 1958), and van Vogt's works were "viewed as great literature of the surrealist school". In addition, Slan was published in French, translated by Jean Rosenthal, under the title À la poursuite des Slans, as part of the paperback series 'Editions J'ai Lu: Romans-Texte Integral' in 1973. This edition also listing the following works by van Vogt as having been published in French as part of this series: Le Monde des Å, La faune de l'espace, Les joueurs du Å, L'empire de l'atome, Le sorcier de Linn, Les armureries d'Isher, Les fabricants d'armes, and Le livre de Ptath. Van Vogt's last novel, 1985's To Conquer Kiber, has only been released in French (as À la conquête de Kiber.)
Works
Novels and novellas
Special works published as books
Planets for Sale by E. Mayne Hull (1954). A fix-up of five stories by Hull, originally published 1942 to 1946. Certain later editions (from 1965) credit both authors.
The Enchanted Village (1979). A 25-page chapbook of a short story originally published in 1950.
Slan Hunter by Kevin J. Anderson (2007). A sequel to Slan, based an unfinished draft by van Vogt.
Null-A Continuum by John C. Wright (2008). An authorized continuation of the Null-A series which ignored the events of Null-A Three.
Collections
Out of the Unknown (1948), with Edna Mayne Hull
Masters of Time (1950) (a.k.a. Recruiting Station) [also includes The Changeling, both works were later published separately]
Triad (1951) omnibus of The World of Null A, The Voyage of the Space Beagle, Slan.
Away and Beyond (1952) (abridged in paperback in 1959; abridged (differently) in paperback in 1963)
Destination: Universe! (1952)
The Twisted Men (1964)
Monsters (1965) (later as SF Monsters (1967)) abridged as The Blal (1976)
A Van Vogt Omnibus (1967), omnibus of Planets for Sale (with Edna Mayne Hull), The Beast, The Book of Ptath
The Far Out Worlds of Van Vogt (1968)
The Sea Thing and Other Stories (1970) (expanded from Out of the Unknown by adding an original story by Hull; later abridged in paperback as Out of the Unknown by removing 2 of the stories)
M33 in Andromeda (1971)
More Than Superhuman (1971)
The Proxy Intelligence and Other Mind Benders, ), with Edna Mayne Hull (1971), revised as The Gryb (1976)
Van Vogt Omnibus 2 (1971), omnibus of The Mind Cage, The Winged Man (with Edna Mayne Hull), Slan.
The Book of Van Vogt (1972), also published as Lost: Fifty Suns (1979)
The Three Eyes of Evil Including Earth's Last Fortress (1973)
The Best of A. E. van Vogt (1974) later split into 2 volumes
The Worlds of A. E. van Vogt (1974) (expanded from The Far Out Worlds of Van Vogt by adding 3 stories)
The Best of A. E. van Vogt (1976) [differs to 1974 edition]
Away and Beyond (1977)
Pendulum (1978) (almost all original stories and articles)
Tales from the Vulgar Unicorn(1980) (one short story by Van Vogt in a fantasy anthology by various authors)
Futures Past: The Best Short Fiction of A.E. Van Vogt (1999)
Transfinite: The Essential A.E. van Vogt (2002)
Transgalactic (2006)
Nonfiction
The Hypnotism Handbook (1956, Griffin Publishing Company, with Charles Edward Cooke)
The Money Personality (1972, Parker Publishing Company Inc., West Nyack, NY, )
Reflections of A. E. Van Vogt: The Autobiography of a Science Fiction Giant (1979, Fictioneer Books Ltd., Lakemont, GA)
A Report on the Violent Male (1992, Paupers' Press, UK, )
See also
Explanatory notes
Citations
General and cited references
External links
Sevagram, the A.E. van Vogt information site
Obituary at Locus
"Writers: A. E. van Vogt (1912–2000, Canada)" – bibliography at SciFan
A. E. van Vogt Papers (MS 322) at the Kenneth Spencer Research Library, University of Kansas
A. E. van Vogt's fiction at Free Speculative Fiction Online
1912 births
2000 deaths
20th-century American male writers
20th-century American novelists
20th-century American short story writers
20th-century Canadian male writers
20th-century Canadian short story writers
American male novelists
American male short story writers
American science fiction writers
Analog Science Fiction and Fact people
Canadian Mennonites
Canadian emigrants to the United States
Canadian male novelists
Canadian male short story writers
Canadian science fiction writers
Deaths from Alzheimer's disease in California
Deaths from dementia in California
Mennonite writers
Pulp fiction writers
SFWA Grand Masters
Science Fiction Hall of Fame inductees
Weird fiction writers
Writers from Winnipeg |
890 | https://en.wikipedia.org/wiki/Anna%20Kournikova | Anna Kournikova | Anna Sergeyevna Kournikova (; born 7 June 1981) is a Russian model and television personality, and former professional tennis player. Her appearance and celebrity status made her one of the best known tennis stars worldwide. At the peak of her fame, fans looking for images of Kournikova made her name one of the most common search strings on Google Search.
Despite never winning a singles title, she reached No. 8 in the world in 2000. She achieved greater success playing doubles, where she was at times the world No. 1 player. With Martina Hingis as her partner, she won Grand Slam titles in Australia in 1999 and 2002, and the WTA Championships in 1999 and 2000. They referred to themselves as the "Spice Girls of Tennis".
Kournikova retired from professional tennis in 2003 due to serious back and spinal problems, including a herniated disk. She lives in Miami Beach, Florida, and played in occasional exhibitions and in doubles for the St. Louis Aces of World Team Tennis before the team folded in 2011. She was a new trainer for season 12 of the television show The Biggest Loser, replacing Jillian Michaels, but did not return for season 13. In addition to her tennis and television work, Kournikova serves as a Global Ambassador for Population Services International's "Five & Alive" program, which addresses health crises facing children under the age of five and their families.
Early life
Kournikova was born in Moscow, Russia, on 7 June 1981. Her father, Sergei Kournikov (born 1961), a former Greco-Roman wrestling champion, eventually earned a PhD and was a professor at the University of Physical Culture and Sport in Moscow. As of 2001, he was still a part-time martial arts instructor there. Her mother Alla (born 1963) had been a 400-metre runner. Her younger half-brother, Allan, is a youth golf world champion who was featured in the 2013 documentary film The Short Game.
Sergei Kournikov has said, "We were young and we liked the clean, physical life, so Anna was in a good environment for sport from the beginning".
Kournikova received her first tennis racquet as a New Year gift in 1986 at the age of five. Describing her early regimen, she said, "I played two times a week from age six. It was a children's program. And it was just for fun; my parents didn't know I was going to play professionally, they just wanted me to do something because I had lots of energy. It was only when I started playing well at seven that I went to a professional academy. I would go to school, and then my parents would take me to the club, and I'd spend the rest of the day there just having fun with the kids." In 1986, Kournikova became a member of the Spartak Tennis Club, coached by Larissa Preobrazhenskaya. In 1989, at the age of eight, Kournikova began appearing in junior tournaments, and by the following year, was attracting attention from tennis scouts across the world. She signed a management deal at age ten and went to Bradenton, Florida, to train at Nick Bollettieri's celebrated tennis academy.
Tennis career
1989–1997: early years and breakthrough
Following her arrival in the United States, she became prominent on the tennis scene. At the age of 14, she won the European Championships and the Italian Open Junior tournament. In December 1995, she became the youngest player to win the 18-and-under division of the Junior Orange Bowl tennis tournament. By the end of the year, Kournikova was crowned the ITF Junior World Champion U-18 and Junior European Champion U-18.
Earlier, in September 1995, Kournikova, still only 14 years of age, debuted in the WTA Tour, when she received a wildcard into the qualifications at the WTA tournament in Moscow, the Moscow Ladies Open, and qualified before losing in the second round of the main draw to third-seeded Sabine Appelmans. She also reached her first WTA Tour doubles final in that debut appearance — partnering with 1995 Wimbledon girls' champion in both singles and doubles Aleksandra Olsza, she lost the title match to Meredith McGrath and Larisa Savchenko-Neiland.
In February–March 1996, Kournikova won two ITF titles, in Midland, Michigan and Rockford, Illinois. Still only 14 years of age, in April 1996 she debuted at the Fed Cup for Russia, the youngest player ever to participate and win a match.
In 1996, she started playing under a new coach, Ed Nagel. Her six-year association with Nagel was successful. At 15, she made her Grand Slam debut, reaching the fourth round of the 1996 US Open, losing to Steffi Graf, the eventual champion. After this tournament, Kournikova's ranking jumped from No. 144 to debut in the Top 100 at No. 69. Kournikova was a member of the Russian delegation to the 1996 Olympic Games in Atlanta, Georgia. In 1996, she was named WTA Newcomer of the Year, and she was ranked No. 57 in the end of the season.
Kournikova entered the 1997 Australian Open as world No. 67, where she lost in the first round to world No. 12, Amanda Coetzer. At the Italian Open, Kournikova lost to Amanda Coetzer in the second round. She reached the semi-finals in the doubles partnering with Elena Likhovtseva, before losing to the sixth seeds Mary Joe Fernández and Patricia Tarabini.
At the French Open, Kournikova made it to the third round before losing to world No. 1, Martina Hingis. She also reached the third round in doubles with Likhovtseva. At the Wimbledon Championships, Kournikova became only the second woman in the open era to reach the semi-finals in her Wimbledon debut, the first being Chris Evert in 1972. There she lost to eventual champion Martina Hingis.
At the US Open, she lost in the second round to the eleventh seed Irina Spîrlea. Partnering with Likhovtseva, she reached the third round of the women's doubles event. Kournikova played her last WTA Tour event of 1997 at Porsche Tennis Grand Prix in Filderstadt, losing to Amanda Coetzer in the second round of singles, and in the first round of doubles to Lindsay Davenport and Jana Novotná partnering with Likhovtseva. She broke into the top 50 on 19 May, and was ranked No. 32 in singles and No. 41 in doubles at the end of the season.
1998–2000: success and stardom
In 1998, Kournikova broke into the WTA's top 20 rankings for the first time, when she was ranked No. 16. At the Australian Open, Kournikova lost in the third round to world No. 1 player, Martina Hingis. She also partnered with Larisa Savchenko-Neiland in women's doubles, and they lost to eventual champions Hingis and Mirjana Lučić in the second round. Although she lost in the second round of the Paris Open to Anke Huber in singles, Kournikova reached her second doubles WTA Tour final, partnering with Larisa Savchenko-Neiland. They lost to Sabine Appelmans and Miriam Oremans. Kournikova and Savchenko-Neiland reached their second consecutive final at the Linz Open, losing to Alexandra Fusai and Nathalie Tauziat. At the Miami Open, Kournikova reached her first WTA Tour singles final, before losing to Venus Williams in the final.
Kournikova then reached two consecutive quarterfinals, at Amelia Island and the Italian Open, losing respectively to Lindsay Davenport and Martina Hingis. At the German Open, she reached the semi-finals in both singles and doubles, partnering with Larisa Savchenko-Neiland. At the French Open Kournikova had her best result at this tournament, making it to the fourth round before losing to Jana Novotná. She also reached her first Grand Slam doubles semi-finals, losing with Savchenko-Neiland to Lindsay Davenport and Natasha Zvereva. During her quarterfinals match at the grass-court Eastbourne Open versus Steffi Graf, Kournikova injured her thumb, which would eventually force her to withdraw from the 1998 Wimbledon Championships. However, she won that match, but then withdrew from her semi-finals match against Arantxa Sánchez Vicario. Kournikova returned for the Du Maurier Open and made it to the third round, before losing to Conchita Martínez. At the US Open Kournikova reached the fourth round before losing to Arantxa Sánchez Vicario. Her strong year qualified her for the year-end 1998 WTA Tour Championships, but she lost to Monica Seles in the first round. However, with Seles, she won her first WTA doubles title, in Tokyo, beating Mary Joe Fernández and Arantxa Sánchez Vicario in the final. At the end of the season, she was ranked No. 10 in doubles.
At the start of the 1999 season, Kournikova advanced to the fourth round in singles at the Australian Open before losing to Mary Pierce. In the doubles Kournikova won her first Grand Slam title, partnering with Martina Hingis to defeat Lindsay Davenport and Natasha Zvereva in the final. At the Tier I Family Circle Cup, Kournikova reached her second WTA Tour final, but lost to Martina Hingis. She then defeated Jennifer Capriati, Lindsay Davenport and Patty Schnyder on her route to the Bausch & Lomb Championships semi-finals, losing to Ruxandra Dragomir. At The French Open, Kournikova reached the fourth round before losing to eventual champion Steffi Graf. Once the grass-court season commenced in England, Kournikova lost to Nathalie Tauziat in the semi-finals in Eastbourne. At Wimbledon, Kournikova lost to Venus Williams in the fourth round. She also reached the final in mixed doubles, partnering with Jonas Björkman, but they lost to Leander Paes and Lisa Raymond. Kournikova again qualified for year-end WTA Tour Championships, but lost to Mary Pierce in the first round, and ended the season as World No. 12.
While Kournikova had a successful singles season, she was even more successful in doubles. After their victory at the Australian Open, she and Martina Hingis won tournaments in Indian Wells, Rome, Eastbourne and the WTA Tour Championships, and reached the final of The French Open where they lost to Serena and Venus Williams. Partnering with Elena Likhovtseva, Kournikova also reached the final in Stanford. On 22 November 1999 she reached the world No. 1 ranking in doubles, and ended the season at this ranking. Kournikova and Hingis were presented with the WTA Award for Doubles Team of the Year.
Kournikova opened her 2000 season winning the Gold Coast Open doubles tournament partnering with Julie Halard. She then reached the singles semi-finals at the Medibank International Sydney, losing to Lindsay Davenport. At the Australian Open, she reached the fourth round in singles and the semi-finals in doubles. That season, Kournikova reached eight semi-finals (Sydney, Scottsdale, Stanford, San Diego, Luxembourg, Leipzig and Tour Championships), seven quarterfinals (Gold Coast, Tokyo, Amelia Island, Hamburg, Eastbourne, Zürich and Philadelphia) and one final. On 20 November 2000 she broke into top 10 for the first time, reaching No. 8. She was also ranked No. 4 in doubles at the end of the season. Kournikova was once again, more successful in doubles. She reached the final of the US Open in mixed doubles, partnering with Max Mirnyi, but they lost to Jared Palmer and Arantxa Sánchez Vicario. She also won six doubles titles – Gold Coast (with Julie Halard), Hamburg (with Natasha Zvereva), Filderstadt, Zürich, Philadelphia and the Tour Championships (with Martina Hingis).
2001–2003: injuries and final years
Her 2001 season was plagued by injuries, including a left foot stress fracture which made her withdraw from 12 tournaments, including the French Open and Wimbledon. She underwent surgery in April. She reached her second career grand slam quarterfinals, at the Australian Open. Kournikova then withdrew from several events due to continuing problems with her left foot and did not return until Leipzig. With Barbara Schett, she won the doubles title in Sydney. She then lost in the finals in Tokyo, partnering with Iroda Tulyaganova, and at San Diego, partnering with Martina Hingis. Hingis and Kournikova also won the Kremlin Cup. At the end of the 2001 season, she was ranked No. 74 in singles and No. 26 in doubles.
Kournikova regained some success in 2002. She reached the semi-finals of Auckland, Tokyo, Acapulco and San Diego, and the final of the China Open, losing to Anna Smashnova. This was Kournikova's last singles final. With Martina Hingis, she lost in the final at Sydney, but they won their second Grand Slam title together, the Australian Open. They also lost in the quarterfinals of the US Open. With Chanda Rubin, Kournikova played the semi-finals of Wimbledon, but they lost to Serena and Venus Williams. Partnering with Janet Lee, she won the Shanghai title. At the end of 2002 season, she was ranked No. 35 in singles and No. 11 in doubles.
In 2003, Anna Kournikova achieved her first Grand Slam match victory in two years at the Australian Open. She defeated Henrieta Nagyová in the first round, and then lost to Justine Henin-Hardenne in the 2nd round. She withdrew from Tokyo due to a sprained back suffered at the Australian Open and did not return to Tour until Miami. On 9 April, in what would be the final WTA match of her career, Kournikova dropped out in the first round of the Family Circle Cup in Charleston, due to a left adductor strain. Her singles world ranking was 67. She reached the semi-finals at the ITF tournament in Sea Island, before withdrawing from a match versus Maria Sharapova due to the adductor injury. She lost in the first round of the ITF tournament in Charlottesville. She did not compete for the rest of the season due to a continuing back injury. At the end of the 2003 season and her professional career, she was ranked No. 305 in singles and No. 176 in doubles.
Kournikova's two Grand Slam doubles titles came in 1999 and 2002, both at the Australian Open in the Women's Doubles event with partner Martina Hingis. Kournikova proved a successful doubles player on the professional circuit, winning 16 tournament doubles titles, including two Australian Opens and being a finalist in mixed doubles at the US Open and at Wimbledon, and reaching the No. 1 ranking in doubles in the WTA Tour rankings. Her pro career doubles record was 200–71. However, her singles career plateaued after 1999. For the most part, she managed to retain her ranking between 10 and 15 (her career high singles ranking was No.8), but her expected finals breakthrough failed to occur; she only reached four finals out of 130 singles tournaments, never in a Grand Slam event, and never won one.
Her singles record is 209–129. Her final playing years were marred by a string of injuries, especially back injuries, which caused her ranking to erode gradually. As a personality Kournikova was among the most common search strings for both articles and images in her prime.
2004–present: exhibitions and World Team Tennis
Kournikova has not played on the WTA Tour since 2003, but still plays exhibition matches for charitable causes. In late 2004, she participated in three events organized by Elton John and by fellow tennis players Serena Williams and Andy Roddick. In January 2005, she played in a doubles charity event for the Indian Ocean tsunami with John McEnroe, Andy Roddick, and Chris Evert. In November 2005, she teamed up with Martina Hingis, playing against Lisa Raymond and Samantha Stosur in the WTT finals for charity. Kournikova is also a member of the St. Louis Aces in the World Team Tennis (WTT), playing doubles only.
In September 2008, Kournikova showed up for the 2008 Nautica Malibu Triathlon held at Zuma Beach in Malibu, California. The Race raised funds for children's Hospital Los Angeles. She won that race for women's K-Swiss team. On 27 September 2008, Kournikova played exhibition mixed doubles matches in Charlotte, North Carolina, partnering with Tim Wilkison and Karel Nováček. Kournikova and Wilkison defeated Jimmy Arias and Chanda Rubin, and then Kournikova and Novacek defeated Rubin and Wilkison.
On 12 October 2008, Anna Kournikova played one exhibition match for the annual charity event, hosted by Billie Jean King and Elton John, and raised more than $400,000 for the Elton John AIDS Foundation and Atlanta AIDS Partnership Fund. She played doubles with Andy Roddick (they were coached by David Chang) versus Martina Navratilova and Jesse Levine (coached by Billie Jean King); Kournikova and Roddick won.
Kournikova was one of "four former world No. 1 players" who participated in "Legendary Night", held on 2 May 2009, at the Turning Stone Event Center in Verona, New York, the others being John McEnroe (who had been No. 1 in both singles and doubles), Tracy Austin and Jim Courier (both of whom who had been No. 1 in singles but not doubles). The exhibition included a mixed doubles match in which McEnroe and Kournikova defeated Courier and Austin.
In 2008, she was named a spokesperson for K-Swiss. In 2005, Kournikova stated that if she were 100% fit, she would like to come back and compete again.
In June 2010, Kournikova reunited with her doubles partner Martina Hingis to participate in competitive tennis for the first time in seven years in the Invitational Ladies Doubles event at Wimbledon. On 29 June 2010 they defeated the British pair Samantha Smith and Anne Hobbs.
Playing style
Kournikova plays right-handed with a two-handed backhand. She is a great player at the net. She can hit forceful groundstrokes and also drop shots.
Her playing style fits the profile for a doubles player, and is complemented by her height. She has been compared to such doubles specialists as Pam Shriver and Peter Fleming.
Personal life
Kournikova was in a relationship with fellow Russian, Pavel Bure, an NHL ice hockey player. The two met in 1999, when Kournikova was still linked to Bure's former Russian teammate Sergei Fedorov. Bure and Kournikova were reported to have been engaged in 2000 after a reporter took a photo of them together in a Florida restaurant where Bure supposedly asked Kournikova to marry him. As the story made headlines in Russia, where they were both heavily followed in the media as celebrities, Bure and Kournikova both denied any engagement. Kournikova, 10 years younger than Bure, was 18 years old at the time.
Fedorov claimed that he and Kournikova were married in 2001, and divorced in 2003. Kournikova's representatives deny any marriage to Fedorov; however, Fedorov's agent Pat Brisson claims that although he does not know when they got married, he knew "Fedorov was married".
Kournikova started dating singer Enrique Iglesias in late 2001 after she had appeared in his music video for "Escape". The couple have three children together, fraternal twins, a son and daughter, born on 16 December 2017, and another daughter born on 30 January 2020.
It was reported in 2010 that Kournikova had become an American citizen.
Media publicity
In 2000, Kournikova became the new face for Berlei's shock absorber sports bras, and appeared in the "only the ball should bounce" billboard campaign. Following that, she was cast by the Farrelly brothers for a minor role in the 2000 film Me, Myself & Irene starring Jim Carrey and Renée Zellweger. Photographs of her have appeared on covers of various publications, including men's magazines, such as one in the much-publicized 2004 Sports Illustrated Swimsuit Issue, where she posed in bikinis and swimsuits, as well as in FHM and Maxim.
Kournikova was named one of Peoples 50 Most Beautiful People in 1998 and was voted "hottest female athlete" on ESPN.com. In 2002, she also placed first in FHM's 100 Sexiest Women in the World in US and UK editions. By contrast, ESPN – citing the degree of hype as compared to actual accomplishments as a singles player – ranked Kournikova 18th in its "25 Biggest Sports Flops of the Past 25 Years". Kournikova was also ranked No. 1 in the ESPN Classic series "Who's number 1?" when the series featured sport's most overrated athletes.
She continued to be the most searched athlete on the Internet through 2008 even though she had retired from the professional tennis circuit years earlier. After slipping from first to sixth among athletes in 2009, she moved back up to third place among athletes in terms of search popularity in 2010.
In October 2010, Kournikova headed to NBC's The Biggest Loser where she led the contestants in a tennis-workout challenge. In May 2011, it was announced that Kournikova would join The Biggest Loser as a regular celebrity trainer in season 12. She did not return for season 13.
Legacy and influence on popular culture
A variation of a White Russian made with skim milk is known as an Anna Kournikova.
A video game featuring Kournikova's licensed appearance, titled Anna Kournikova's Smash Court Tennis, was developed by Namco and released for the PlayStation in Japan and Europe in November 1998.
A computer virus named after her spread worldwide beginning on 12 February 2001 infecting computers through email in a matter of hours.
Career statistics and awards
Doubles performance timeline
Grand Slam tournament finals
Doubles: 3 (2–1)
Mixed doubles: 2 (0–2)
Awards
1996: WTA Newcomer of the Year
1999: WTA Doubles Team of the Year (with Martina Hingis)
Books
Anna Kournikova by Susan Holden (2001) ( / )
Anna Kournikova by Connie Berman (2001) (Women Who Win) ( / )
References
External links
1981 births
Australian Open (tennis) champions
Grand Slam (tennis) champions in women's doubles
Iglesias family
ITF World Champions
Living people
Olympic tennis players for Russia
Participants in American reality television series
People with acquired American citizenship
Russian emigrants to the United States
Russian female models
Russian models
Russian female tennis players
Russian socialites
Sportspeople from Miami-Dade County, Florida
Tennis players at the 1996 Summer Olympics
Tennis players from Moscow
WTA number 1 ranked doubles tennis players |
892 | https://en.wikipedia.org/wiki/Alfons%20Maria%20Jakob | Alfons Maria Jakob | Alfons Maria Jakob (2 July 1884 – 17 October 1931) was a German neurologist who worked in the field of neuropathology.
He was born in Aschaffenburg, Bavaria and educated in medicine at the universities of Munich, Berlin, and Strasbourg, where he received his doctorate in 1908. During the following year, he began clinical work under the psychiatrist Emil Kraepelin and did laboratory work with Franz Nissl and Alois Alzheimer in Munich.
In 1911, by way of an invitation from Wilhelm Weygandt, he relocated to Hamburg, where he worked with Theodor Kaes and eventually became head of the laboratory of anatomical pathology at the psychiatric State Hospital Hamburg-Friedrichsberg. Following the death of Kaes in 1913, Jakob succeeded him as prosector. During World War I he served as an army physician in Belgium, and afterwards returned to Hamburg. In 1919, he obtained his habilitation for neurology and in 1924 became a professor of neurology. Under Jakob's guidance the department grew rapidly. He made significant contributions to knowledge on concussion and secondary nerve degeneration and became a doyen of neuropathology.
Jakob was the author of five monographs and nearly 80 scientific papers. His neuropathological research contributed greatly to the delineation of several diseases, including multiple sclerosis and Friedreich's ataxia. He first recognised and described Alper's disease and Creutzfeldt–Jakob disease (named along with Munich neuropathologist Hans Gerhard Creutzfeldt). He gained experience in neurosyphilis, having a 200-bed ward devoted entirely to that disorder. Jakob made a lecture tour of the United States (1924) and South America (1928), of which, he wrote a paper on the neuropathology of yellow fever.
He suffered from chronic osteomyelitis for the last seven years of his life. This eventually caused a retroperitoneal abscess and paralytic ileus from which he died following operation.
Associated eponym
Creutzfeldt–Jakob disease: A very rare and incurable degenerative neurological disease. It is the most common form of transmissible spongiform encephalopathies caused by prions. Eponym introduced by Walther Spielmeyer in 1922.
Bibliography
Die extrapyramidalen Erkrankungen. In: Monographien aus dem Gesamtgebiete der Neurologie und Psychiatry, Berlin, 1923
Normale und pathologische Anatomie und Histologie des Grosshirns. Separate printing of Handbuch der Psychiatry. Leipzig, 1927–1928
Das Kleinhirn. In: Handbuch der mikroskopischen Anatomie, Berlin, 1928
Die Syphilis des Gehirns und seiner Häute. In: Oswald Bumke (edit.): Handbuch der Geisteskrankheiten, Berlin, 1930.
References
People from Aschaffenburg
Academic staff of the University of Hamburg
German neurologists
German neuroscientists
1884 births
1931 deaths |
896 | https://en.wikipedia.org/wiki/Argon | Argon | Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the most abundant noble gas in Earth's crust, comprising 0.00015% of the crust.
Nearly all argon in Earth's atmosphere is radiogenic argon-40, derived from the decay of potassium-40 in Earth's crust. In the universe, argon-36 is by far the most common argon isotope, as it is the most easily produced by stellar nucleosynthesis in supernovas.
The name "argon" is derived from the Greek word , neuter singular form of meaning 'lazy' or 'inactive', as a reference to the fact that the element undergoes almost no chemical reactions. The complete octet (eight electrons) in the outer atomic shell makes argon stable and resistant to bonding with other elements. Its triple point temperature of 83.8058 K is a defining fixed point in the International Temperature Scale of 1990.
Argon is extracted industrially by the fractional distillation of liquid air. It is mostly used as an inert shielding gas in welding and other high-temperature industrial processes where ordinarily unreactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. It is also used in incandescent, fluorescent lighting, and other gas-discharge tubes. It makes a distinctive blue-green gas laser. It is also used in fluorescent glow starters.
Characteristics
Argon has approximately the same solubility in water as oxygen and is 2.5 times more soluble in water than nitrogen. Argon is colorless, odorless, nonflammable and nontoxic as a solid, liquid or gas. Argon is chemically inert under most conditions and forms no confirmed stable compounds at room temperature.
Although argon is a noble gas, it can form some compounds under various extreme conditions. Argon fluorohydride (HArF), a compound of argon with fluorine and hydrogen that is stable below , has been demonstrated. Although the neutral ground-state chemical compounds of argon are presently limited to HArF, argon can form clathrates with water when atoms of argon are trapped in a lattice of water molecules. Ions, such as , and excited-state complexes, such as ArF, have been demonstrated. Theoretical calculation predicts several more argon compounds that should be stable but have not yet been synthesized.
History
Argon (Greek , neuter singular form of meaning "lazy" or "inactive") is named in reference to its chemical inactivity. This chemical property of this first noble gas to be discovered impressed the namers. An unreactive gas was suspected to be a component of air by Henry Cavendish in 1785.
Argon was first isolated from air in 1894 by Lord Rayleigh and Sir William Ramsay at University College London by removing oxygen, carbon dioxide, water, and nitrogen from a sample of clean air. They first accomplished this by replicating an experiment of Henry Cavendish's. They trapped a mixture of atmospheric air with additional oxygen in a test-tube (A) upside-down over a large quantity of dilute alkali solution (B), which in Cavendish's original experiment was potassium hydroxide, and conveyed a current through wires insulated by U-shaped glass tubes (CC) which sealed around the platinum wire electrodes, leaving the ends of the wires (DD) exposed to the gas and insulated from the alkali solution. The arc was powered by a battery of five Grove cells and a Ruhmkorff coil of medium size. The alkali absorbed the oxides of nitrogen produced by the arc and also carbon dioxide. They operated the arc until no more reduction of volume of the gas could be seen for at least an hour or two and the spectral lines of nitrogen disappeared when the gas was examined. The remaining oxygen was reacted with alkaline pyrogallate to leave behind an apparently non-reactive gas which they called argon.
Before isolating the gas, they had determined that nitrogen produced from chemical compounds was 0.5% lighter than nitrogen from the atmosphere. The difference was slight, but it was important enough to attract their attention for many months. They concluded that there was another gas in the air mixed in with the nitrogen. Argon was also encountered in 1882 through independent research of H. F. Newall and W. N. Hartley. Each observed new lines in the emission spectrum of air that did not match known elements.
Until 1957, the symbol for argon was "A", but now it is "Ar".
Occurrence
Argon constitutes 0.934% by volume and 1.288% by mass of Earth's atmosphere. Air is the primary industrial source of purified argon products. Argon is isolated from air by fractionation, most commonly by cryogenic fractional distillation, a process that also produces purified nitrogen, oxygen, neon, krypton and xenon. Earth's crust and seawater contain 1.2 ppm and 0.45 ppm of argon, respectively.
Isotopes
The main isotopes of argon found on Earth are (99.6%), (0.34%), and (0.06%). Naturally occurring , with a half-life of 1.25 years, decays to stable (11.2%) by electron capture or positron emission, and also to stable (88.8%) by beta decay. These properties and ratios are used to determine the age of rocks by K–Ar dating.
In Earth's atmosphere, is made by cosmic ray activity, primarily by neutron capture of followed by two-neutron emission. In the subsurface environment, it is also produced through neutron capture by , followed by proton emission. is created from the neutron capture by followed by an alpha particle emission as a result of subsurface nuclear explosions. It has a half-life of 35 days.
Between locations in the Solar System, the isotopic composition of argon varies greatly. Where the major source of argon is the decay of in rocks, will be the dominant isotope, as it is on Earth. Argon produced directly by stellar nucleosynthesis is dominated by the alpha-process nuclide . Correspondingly, solar argon contains 84.6% (according to solar wind measurements), and the ratio of the three isotopes 36Ar : 38Ar : 40Ar in the atmospheres of the outer planets is 8400 : 1600 : 1. This contrasts with the low abundance of primordial in Earth's atmosphere, which is only 31.5 ppmv (= 9340 ppmv × 0.337%), comparable with that of neon (18.18 ppmv) on Earth and with interplanetary gasses, measured by probes.
The atmospheres of Mars, Mercury and Titan (the largest moon of Saturn) contain argon, predominantly as , and its content may be as high as 1.93% (Mars).
The predominance of radiogenic is the reason the standard atomic weight of terrestrial argon is greater than that of the next element, potassium, a fact that was puzzling when argon was discovered. Mendeleev positioned the elements on his periodic table in order of atomic weight, but the inertness of argon suggested a placement before the reactive alkali metal. Henry Moseley later solved this problem by showing that the periodic table is actually arranged in order of atomic number (see History of the periodic table).
Compounds
Argon's complete octet of electrons indicates full s and p subshells. This full valence shell makes argon very stable and extremely resistant to bonding with other elements. Before 1962, argon and the other noble gases were considered to be chemically inert and unable to form compounds; however, compounds of the heavier noble gases have since been synthesized. The first argon compound with tungsten pentacarbonyl, W(CO)5Ar, was isolated in 1975. However, it was not widely recognised at that time. In August 2000, another argon compound, argon fluorohydride (HArF), was formed by researchers at the University of Helsinki, by shining ultraviolet light onto frozen argon containing a small amount of hydrogen fluoride with caesium iodide. This discovery caused the recognition that argon could form weakly bound compounds, even though it was not the first. It is stable up to 17 kelvins (−256 °C). The metastable dication, which is valence-isoelectronic with carbonyl fluoride and phosgene, was observed in 2010. Argon-36, in the form of argon hydride (argonium) ions, has been detected in interstellar medium associated with the Crab Nebula supernova; this was the first noble-gas molecule detected in outer space.
Solid argon hydride (Ar(H2)2) has the same crystal structure as the MgZn2 Laves phase. It forms at pressures between 4.3 and 220 GPa, though Raman measurements suggest that the H2 molecules in Ar(H2)2 dissociate above 175 GPa.
Production
Argon is extracted industrially by the fractional distillation of liquid air in a cryogenic air separation unit; a process that separates liquid nitrogen, which boils at 77.3 K, from argon, which boils at 87.3 K, and liquid oxygen, which boils at 90.2 K. About 700,000 tonnes of argon are produced worldwide every year.
Applications
Argon has several desirable properties:
Argon is a chemically inert gas.
Argon is the cheapest alternative when nitrogen is not sufficiently inert.
Argon has low thermal conductivity.
Argon has electronic properties (ionization and/or the emission spectrum) desirable for some applications.
Other noble gases would be equally suitable for most of these applications, but argon is by far the cheapest. It is inexpensive, since it occurs naturally in air and is readily obtained as a byproduct of cryogenic air separation in the production of liquid oxygen and liquid nitrogen: the primary constituents of air are used on a large industrial scale. The other noble gases (except helium) are produced this way as well, but argon is the most plentiful by far. The bulk of its applications arise simply because it is inert and relatively cheap.
Industrial processes
Argon is used in some high-temperature industrial processes where ordinarily non-reactive substances become reactive. For example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning.
For some of these processes, the presence of nitrogen or oxygen gases might cause defects within the material. Argon is used in some types of arc welding such as gas metal arc welding and gas tungsten arc welding, as well as in the processing of titanium and other reactive elements. An argon atmosphere is also used for growing crystals of silicon and germanium.
Argon is used in the poultry industry to asphyxiate birds, either for mass culling following disease outbreaks, or as a means of slaughter more humane than electric stunning. Argon is denser than air and displaces oxygen close to the ground during inert gas asphyxiation. Its non-reactive nature makes it suitable in a food product, and since it replaces oxygen within the dead bird, argon also enhances shelf life.
Argon is sometimes used for extinguishing fires where valuable equipment may be damaged by water or foam.
Scientific research
Liquid argon is used as the target for neutrino experiments and direct dark matter searches. The interaction between the hypothetical WIMPs and an argon nucleus produces scintillation light that is detected by photomultiplier tubes. Two-phase detectors containing argon gas are used to detect the ionized electrons produced during the WIMP–nucleus scattering. As with most other liquefied noble gases, argon has a high scintillation light yield (about 51 photons/keV), is transparent to its own scintillation light, and is relatively easy to purify. Compared to xenon, argon is cheaper and has a distinct scintillation time profile, which allows the separation of electronic recoils from nuclear recoils. On the other hand, its intrinsic beta-ray background is larger due to contamination, unless one uses argon from underground sources, which has much less contamination. Most of the argon in Earth's atmosphere was produced by electron capture of long-lived ( + e− → + ν) present in natural potassium within Earth. The activity in the atmosphere is maintained by cosmogenic production through the knockout reaction (n,2n) and similar reactions. The half-life of is only 269 years. As a result, the underground Ar, shielded by rock and water, has much less contamination. Dark-matter detectors currently operating with liquid argon include DarkSide, WArP, ArDM, microCLEAN and DEAP. Neutrino experiments include ICARUS and MicroBooNE, both of which use high-purity liquid argon in a time projection chamber for fine grained three-dimensional imaging of neutrino interactions.
At Linköping University, Sweden, the inert gas is being utilized in a vacuum chamber in which plasma is introduced to ionize metallic films. This process results in a film usable for manufacturing computer processors. The new process would eliminate the need for chemical baths and use of expensive, dangerous and rare materials.
Preservative
Argon is used to displace oxygen- and moisture-containing air in packaging material to extend the shelf-lives of the contents (argon has the European food additive code E938). Aerial oxidation, hydrolysis, and other chemical reactions that degrade the products are retarded or prevented entirely. High-purity chemicals and pharmaceuticals are sometimes packed and sealed in argon.
In winemaking, argon is used in a variety of activities to provide a barrier against oxygen at the liquid surface, which can spoil wine by fueling both microbial metabolism (as with acetic acid bacteria) and standard redox chemistry.
Argon is sometimes used as the propellant in aerosol cans.
Argon is also used as a preservative for such products as varnish, polyurethane, and paint, by displacing air to prepare a container for storage.
Since 2002, the American National Archives stores important national documents such as the Declaration of Independence and the Constitution within argon-filled cases to inhibit their degradation. Argon is preferable to the helium that had been used in the preceding five decades, because helium gas escapes through the intermolecular pores in most containers and must be regularly replaced.
Laboratory equipment
Argon may be used as the inert gas within Schlenk lines and gloveboxes. Argon is preferred to less expensive nitrogen in cases where nitrogen may react with the reagents or apparatus.
Argon may be used as the carrier gas in gas chromatography and in electrospray ionization mass spectrometry; it is the gas of choice for the plasma used in ICP spectroscopy. Argon is preferred for the sputter coating of specimens for scanning electron microscopy. Argon gas is also commonly used for sputter deposition of thin films as in microelectronics and for wafer cleaning in microfabrication.
Medical use
Cryosurgery procedures such as cryoablation use liquid argon to destroy tissue such as cancer cells. It is used in a procedure called "argon-enhanced coagulation", a form of argon plasma beam electrosurgery. The procedure carries a risk of producing gas embolism and has resulted in the death of at least one patient.
Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects.
Argon has also been used experimentally to replace nitrogen in the breathing or decompression mix known as Argox, to speed the elimination of dissolved nitrogen from the blood.
Lighting
Incandescent lights are filled with argon, to preserve the filaments at high temperature from oxidation. It is used for the specific way it ionizes and emits light, such as in plasma globes and calorimetry in experimental particle physics. Gas-discharge lamps filled with pure argon provide lilac/violet light; with argon and some mercury, blue light. Argon is also used for blue and green argon-ion lasers.
Miscellaneous uses
Argon is used for thermal insulation in energy-efficient windows. Argon is also used in technical scuba diving to inflate a dry suit because it is inert and has low thermal conductivity.
Argon is used as a propellant in the development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). Compressed argon gas is allowed to expand, to cool the seeker heads of some versions of the AIM-9 Sidewinder missile and other missiles that use cooled thermal seeker heads. The gas is stored at high pressure.
Argon-39, with a half-life of 269 years, has been used for a number of applications, primarily ice core and ground water dating. Also, potassium–argon dating and related argon-argon dating are used to date sedimentary, metamorphic, and igneous rocks.
Argon has been used by athletes as a doping agent to simulate hypoxic conditions. In 2014, the World Anti-Doping Agency (WADA) added argon and xenon to the list of prohibited substances and methods, although at this time there is no reliable test for abuse.
Safety
Although argon is non-toxic, it is 38% more dense than air and therefore considered a dangerous asphyxiant in closed areas. It is difficult to detect because it is colorless, odorless, and tasteless. A 1994 incident, in which a man was asphyxiated after entering an argon-filled section of oil pipe under construction in Alaska, highlights the dangers of argon tank leakage in confined spaces and emphasizes the need for proper use, storage and handling.
See also
Industrial gas
Oxygen–argon ratio, a ratio of two physically similar gases, which has importance in various sectors.
References
Further reading
On triple point pressure at 69 kPa.
On triple point pressure at 83.8058 K.
External links
Argon at The Periodic Table of Videos (University of Nottingham)
USGS Periodic Table – Argon
Diving applications: Why Argon?
Chemical elements
E-number additives
Noble gases
Industrial gases |
903 | https://en.wikipedia.org/wiki/Arable%20land | Arable land | Arable land (from the , "able to be ploughed") is any land capable of being ploughed and used to grow crops. Alternatively, for the purposes of agricultural statistics, the term often has a more precise definition:
A more concise definition appearing in the Eurostat glossary similarly refers to actual rather than potential uses: "land worked (ploughed or tilled) regularly, generally under a system of crop rotation". In Britain, arable land has traditionally been contrasted with pasturable land such as heaths, which could be used for sheep-rearing but not as farmland.
Arable land is vulnerable to land degradation and some types of un-arable land can be enriched to create useful land. Climate change and biodiversity loss, are driving pressure on arable land.
By country
According to the Food and Agriculture Organization of the United Nations, in 2013, the world's arable land amounted to 1.407 billion hectares, out of a total of 4.924 billion hectares of land used for agriculture.
Arable land (hectares per person)
Non-arable land
Agricultural land that is not arable according to the FAO definition above includes:
Meadows and pasturesland used as pasture and grazed range, and those natural grasslands and sedge meadows that are used for hay production in some regions.
Permanent cropland that produces crops from woody vegetation, e.g. orchard land, vineyards, coffee plantations, rubber plantations, and land producing nut trees;
Other non-arable land includes land that is not suitable for any agricultural use. Land that is not arable, in the sense of lacking capability or suitability for cultivation for crop production, has one or more limitationsa lack of sufficient freshwater for irrigation, stoniness, steepness, adverse climate, excessive wetness with the impracticality of drainage, excessive salts, or a combination of these, among others. Although such limitations may preclude cultivation, and some will in some cases preclude any agricultural use, large areas unsuitable for cultivation may still be agriculturally productive. For example, United States NRCS statistics indicate that about 59 percent of US non-federal pasture and unforested rangeland is unsuitable for cultivation, yet such land has value for grazing of livestock. In British Columbia, Canada, 41 percent of the provincial Agricultural Land Reserve area is unsuitable for the production of cultivated crops, but is suitable for uncultivated production of forage usable by grazing livestock. Similar examples can be found in many rangeland areas elsewhere.
Changes in arability
Land conversion
Land incapable of being cultivated for the production of crops can sometimes be converted to arable land. New arable land makes more food and can reduce starvation. This outcome also makes a country more self-sufficient and politically independent, because food importation is reduced. Making non-arable land arable often involves digging new irrigation canals and new wells, aqueducts, desalination plants, planting trees for shade in the desert, hydroponics, fertilizer, nitrogen fertilizer, pesticides, reverse osmosis water processors, PET film insulation or other insulation against heat and cold, digging ditches and hills for protection against the wind, and installing greenhouses with internal light and heat for protection against the cold outside and to provide light in cloudy areas. Such modifications are often prohibitively expensive. An alternative is the seawater greenhouse, which desalinates water through evaporation and condensation using solar energy as the only energy input. This technology is optimized to grow crops on desert land close to the sea.
The use of artifices does not make the land arable. Rock still remains rock, and shallowless than turnable soil is still not considered toilable. The use of artifice is an open-air none recycled water hydroponics relationship. The below described circumstances are not in perspective, have limited duration, and have a tendency to accumulate trace materials in soil that either there or elsewhere cause deoxygenation. The use of vast amounts of fertilizer may have unintended consequences for the environment by devastating rivers, waterways, and river endings through the accumulation of non-degradable toxins and nitrogen-bearing molecules that remove oxygen and cause non-aerobic processes to form.
Examples of infertile non-arable land being turned into fertile arable land include:
Aran Islands: These islands off the west coast of Ireland (not to be confused with the Isle of Arran in Scotland's Firth of Clyde) were unsuitable for arable farming because they were too rocky. The people covered the islands with a shallow layer of seaweed and sand from the ocean. Today, crops are grown there, even though the islands are still considered non-arable.
Israel: The construction of desalination plants along Israel's coast allowed agriculture in some areas that were formerly desert. The desalination plants, which remove the salt from ocean water, have produced a new source of water for farming, drinking, and washing.
Slash and burn agriculture uses nutrients in wood ash, but these expire within a few years.
Terra preta, fertile tropical soils produced by adding charcoal.
Land degradation
Examples
Examples of fertile arable land being turned into infertile land include:
Droughts such as the "Dust Bowl" of the Great Depression in the US turned farmland into desert.
Each year, arable land is lost due to desertification and human-induced erosion. Improper irrigation of farmland can wick the sodium, calcium, and magnesium from the soil and water to the surface. This process steadily concentrates salt in the root zone, decreasing productivity for crops that are not salt-tolerant.
Rainforest deforestation: The fertile tropical forests are converted into infertile desert land. For example, Madagascar's central highland plateau has become virtually totally barren (about ten percent of the country) as a result of slash-and-burn deforestation, an element of shifting cultivation practiced by many natives.
See also
Development easement
Land use statistics by country
List of environment topics
Soil fertility
References
External links
Article from Technorati on Shrinking Arable Farmland in the world
Surface area of the Earth
Agricultural land |
904 | https://en.wikipedia.org/wiki/Aluminium | Aluminium | Aluminium (Aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, nonmagnetic, and ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of 26Al, a more unstable isotope, leads to it being used in radiometric dating.
Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it has more polarizing power, and bonds formed by aluminium have a more covalent character. The strong affinity of aluminium for oxygen leads to the common occurrence of its oxides in nature. Aluminium is found on Earth primarily in rocks in the crust, where it is the third-most abundant element, after oxygen and silicon, rather than in the mantle, and virtually never as the free metal. It is obtained industrially by mining bauxite, a sedimentary rock rich in aluminium minerals.
The discovery of aluminium was announced in 1825 by Danish physicist Hans Christian Ørsted. The first industrial production of aluminium was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and the mass production of aluminium led to its extensive use in industry and everyday life. In the First and Second World Wars, aluminium was a crucial strategic resource for aviation. In 1954, aluminium became the most produced non-ferrous metal, surpassing copper. In the 21st century, most aluminium was consumed in transportation, engineering, construction, and packaging in the United States, Western Europe, and Japan.
Despite its prevalence in the environment, no living organism is known to metabolize aluminium salts, but this aluminium is well tolerated by plants and animals. Because of the abundance of these salts, the potential for a biological role for them is of interest, and studies are ongoing.
Physical characteristics
Isotopes
Of aluminium isotopes, only is stable. This situation is common for elements with an odd atomic number. It is the only primordial aluminium isotope, i.e. the only one that has existed on Earth in its current form since the formation of the planet. It is therefore a mononuclidic element and its standard atomic weight is virtually the same as that of the isotope. This makes aluminium very useful in nuclear magnetic resonance (NMR), as its single stable isotope has a high NMR sensitivity. The standard atomic weight of aluminium is low in comparison with many other metals.
All other isotopes of aluminium are radioactive. The most stable of these is 26Al: while it was present along with stable 27Al in the interstellar medium from which the Solar System formed, having been produced by stellar nucleosynthesis as well, its half-life is only 717,000 years and therefore a detectable amount has not survived since the formation of the planet. However, minute traces of 26Al are produced from argon in the atmosphere by spallation caused by cosmic ray protons. The ratio of 26Al to 10Be has been used for radiodating of geological processes over 105 to 106 year time scales, in particular transport, deposition, sediment storage, burial times, and erosion. Most meteorite scientists believe that the energy released by the decay of 26Al was responsible for the melting and differentiation of some asteroids after their formation 4.55 billion years ago.
The remaining isotopes of aluminium, with mass numbers ranging from 22 to 43, all have half-lives well under an hour. Three metastable states are known, all with half-lives under a minute.
Electron shell
An aluminium atom has 13 electrons, arranged in an electron configuration of , with three electrons beyond a stable noble gas configuration. Accordingly, the combined first three ionization energies of aluminium are far lower than the fourth ionization energy alone. Such an electron configuration is shared with the other well-characterized members of its group, boron, gallium, indium, and thallium; it is also expected for nihonium. Aluminium can surrender its three outermost electrons in many chemical reactions (see below). The electronegativity of aluminium is 1.61 (Pauling scale).
A free aluminium atom has a radius of 143 pm. With the three outermost electrons removed, the radius shrinks to 39 pm for a 4-coordinated atom or 53.5 pm for a 6-coordinated atom. At standard temperature and pressure, aluminium atoms (when not affected by atoms of other elements) form a face-centered cubic crystal system bound by metallic bonding provided by atoms' outermost electrons; hence aluminium (at these conditions) is a metal. This crystal system is shared by many other metals, such as lead and copper; the size of a unit cell of aluminium is comparable to that of those other metals. The system, however, is not shared by the other members of its group: boron has ionization energies too high to allow metallization, thallium has a hexagonal close-packed structure, and gallium and indium have unusual structures that are not close-packed like those of aluminium and thallium. The few electrons that are available for metallic bonding in aluminium are a probable cause for it being soft with a low melting point and low electrical resistivity.
Bulk
Aluminium metal has an appearance ranging from silvery white to dull gray depending on its surface roughness. Aluminium mirrors are the most reflective of all metal mirrors for near ultraviolet and far infrared light. It is also one of the most reflective for light in the visible spectrum, nearly on par with silver in this respect, and the two therefore look similar. Aluminium is also good at reflecting solar radiation, although prolonged exposure to sunlight in air adds wear to the surface of the metal; this may be prevented if aluminium is anodized, which adds a protective layer of oxide on the surface.
The density of aluminium is 2.70 g/cm3, about 1/3 that of steel, much lower than other commonly encountered metals, making aluminium parts easily identifiable through their lightness. Aluminium's low density compared to most other metals arises from the fact that its nuclei are much lighter, while difference in the unit cell size does not compensate for this difference. The only lighter metals are the metals of groups 1 and 2, which apart from beryllium and magnesium are too reactive for structural use (and beryllium is very toxic). Aluminium is not as strong or stiff as steel, but the low density makes up for this in the aerospace industry and for many other applications where light weight and relatively high strength are crucial.
Pure aluminium is quite soft and lacking in strength. In most applications various aluminium alloys are used instead because of their higher strength and hardness. The yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium is ductile, with a percent elongation of 50-70%, and malleable allowing it to be easily drawn and extruded. It is also easily machined and cast.
Aluminium is an excellent thermal and electrical conductor, having around 60% the conductivity of copper, both thermal and electrical, while having only 30% of copper's density. Aluminium is capable of superconductivity, with a superconducting critical temperature of 1.2 kelvin and a critical magnetic field of about 100 gauss (10 milliteslas). It is paramagnetic and thus essentially unaffected by static magnetic fields. The high electrical conductivity, however, means that it is strongly affected by alternating magnetic fields through the induction of eddy currents.
Chemistry
Aluminium combines characteristics of pre- and post-transition metals. Since it has few available electrons for metallic bonding, like its heavier group 13 congeners, it has the characteristic physical properties of a post-transition metal, with longer-than-expected interatomic distances. Furthermore, as Al3+ is a small and highly charged cation, it is strongly polarizing and bonding in aluminium compounds tends towards covalency; this behavior is similar to that of beryllium (Be2+), and the two display an example of a diagonal relationship.
The underlying core under aluminium's valence shell is that of the preceding noble gas, whereas those of its heavier congeners gallium, indium, thallium, and nihonium also include a filled d-subshell and in some cases a filled f-subshell. Hence, the inner electrons of aluminium shield the valence electrons almost completely, unlike those of aluminium's heavier congeners. As such, aluminium is the most electropositive metal in its group, and its hydroxide is in fact more basic than that of gallium. Aluminium also bears minor similarities to the metalloid boron in the same group: AlX3 compounds are valence isoelectronic to BX3 compounds (they have the same valence electronic structure), and both behave as Lewis acids and readily form adducts. Additionally, one of the main motifs of boron chemistry is regular icosahedral structures, and aluminium forms an important part of many icosahedral quasicrystal alloys, including the Al–Zn–Mg class.
Aluminium has a high chemical affinity to oxygen, which renders it suitable for use as a reducing agent in the thermite reaction. A fine powder of aluminium reacts explosively on contact with liquid oxygen; under normal conditions, however, aluminium forms a thin oxide layer (~5 nm at room temperature) that protects the metal from further corrosion by oxygen, water, or dilute acid, a process termed passivation. Because of its general resistance to corrosion, aluminium is one of the few metals that retains silvery reflectance in finely powdered form, making it an important component of silver-colored paints. Aluminium is not attacked by oxidizing acids because of its passivation. This allows aluminium to be used to store reagents such as nitric acid, concentrated sulfuric acid, and some organic acids.
In hot concentrated hydrochloric acid, aluminium reacts with water with evolution of hydrogen, and in aqueous sodium hydroxide or potassium hydroxide at room temperature to form aluminates—protective passivation under these conditions is negligible. Aqua regia also dissolves aluminium. Aluminium is corroded by dissolved chlorides, such as common sodium chloride, which is why household plumbing is never made from aluminium. The oxide layer on aluminium is also destroyed by contact with mercury due to amalgamation or with salts of some electropositive metals. As such, the strongest aluminium alloys are less corrosion-resistant due to galvanic reactions with alloyed copper, and aluminium's corrosion resistance is greatly reduced by aqueous salts, particularly in the presence of dissimilar metals.
Aluminium reacts with most nonmetals upon heating, forming compounds such as aluminium nitride (AlN), aluminium sulfide (Al2S3), and the aluminium halides (AlX3). It also forms a wide range of intermetallic compounds involving metals from every group on the periodic table.
Inorganic compounds
The vast majority of compounds, including all aluminium-containing minerals and all commercially significant aluminium compounds, feature aluminium in the oxidation state 3+. The coordination number of such compounds varies, but generally Al3+ is either six- or four-coordinate. Almost all compounds of aluminium(III) are colorless.
In aqueous solution, Al3+ exists as the hexaaqua cation [Al(H2O)6]3+, which has an approximate Ka of 10−5. Such solutions are acidic as this cation can act as a proton donor and progressively hydrolyze until a precipitate of aluminium hydroxide, Al(OH)3, forms. This is useful for clarification of water, as the precipitate nucleates on suspended particles in the water, hence removing them. Increasing the pH even further leads to the hydroxide dissolving again as aluminate, [Al(H2O)2(OH)4]−, is formed.
Aluminium hydroxide forms both salts and aluminates and dissolves in acid and alkali, as well as on fusion with acidic and basic oxides. This behavior of Al(OH)3 is termed amphoterism and is characteristic of weakly basic cations that form insoluble hydroxides and whose hydrated species can also donate their protons. One effect of this is that aluminium salts with weak acids are hydrolyzed in water to the aquated hydroxide and the corresponding nonmetal hydride: for example, aluminium sulfide yields hydrogen sulfide. However, some salts like aluminium carbonate exist in aqueous solution but are unstable as such; and only incomplete hydrolysis takes place for salts with strong acids, such as the halides, nitrate, and sulfate. For similar reasons, anhydrous aluminium salts cannot be made by heating their "hydrates": hydrated aluminium chloride is in fact not AlCl3·6H2O but [Al(H2O)6]Cl3, and the Al–O bonds are so strong that heating is not sufficient to break them and form Al–Cl bonds instead:
2[Al(H2O)6]Cl3 Al2O3 + 6 HCl + 9 H2O
All four trihalides are well known. Unlike the structures of the three heavier trihalides, aluminium fluoride (AlF3) features six-coordinate aluminium, which explains its involatility and insolubility as well as high heat of formation. Each aluminium atom is surrounded by six fluorine atoms in a distorted octahedral arrangement, with each fluorine atom being shared between the corners of two octahedra. Such {AlF6} units also exist in complex fluorides such as cryolite, Na3AlF6. AlF3 melts at and is made by reaction of aluminium oxide with hydrogen fluoride gas at .
With heavier halides, the coordination numbers are lower. The other trihalides are dimeric or polymeric with tetrahedral four-coordinate aluminium centers. Aluminium trichloride (AlCl3) has a layered polymeric structure below its melting point of but transforms on melting to Al2Cl6 dimers. At higher temperatures those increasingly dissociate into trigonal planar AlCl3 monomers similar to the structure of BCl3. Aluminium tribromide and aluminium triiodide form Al2X6 dimers in all three phases and hence do not show such significant changes of properties upon phase change. These materials are prepared by treating aluminium with the halogen. The aluminium trihalides form many addition compounds or complexes; their Lewis acidic nature makes them useful as catalysts for the Friedel–Crafts reactions. Aluminium trichloride has major industrial uses involving this reaction, such as in the manufacture of anthraquinones and styrene; it is also often used as the precursor for many other aluminium compounds and as a reagent for converting nonmetal fluorides into the corresponding chlorides (a transhalogenation reaction).
Aluminium forms one stable oxide with the chemical formula Al2O3, commonly called alumina. It can be found in nature in the mineral corundum, α-alumina; there is also a γ-alumina phase. Its crystalline form, corundum, is very hard (Mohs hardness 9), has a high melting point of , has very low volatility, is chemically inert, and a good electrical insulator, it is often used in abrasives (such as toothpaste), as a refractory material, and in ceramics, as well as being the starting material for the electrolytic production of aluminium. Sapphire and ruby are impure corundum contaminated with trace amounts of other metals. The two main oxide-hydroxides, AlO(OH), are boehmite and diaspore. There are three main trihydroxides: bayerite, gibbsite, and nordstrandite, which differ in their crystalline structure (polymorphs). Many other intermediate and related structures are also known. Most are produced from ores by a variety of wet processes using acid and base. Heating the hydroxides leads to formation of corundum. These materials are of central importance to the production of aluminium and are themselves extremely useful. Some mixed oxide phases are also very useful, such as spinel (MgAl2O4), Na-β-alumina (NaAl11O17), and tricalcium aluminate (Ca3Al2O6, an important mineral phase in Portland cement).
The only stable chalcogenides under normal conditions are aluminium sulfide (Al2S3), selenide (Al2Se3), and telluride (Al2Te3). All three are prepared by direct reaction of their elements at about and quickly hydrolyze completely in water to yield aluminium hydroxide and the respective hydrogen chalcogenide. As aluminium is a small atom relative to these chalcogens, these have four-coordinate tetrahedral aluminium with various polymorphs having structures related to wurtzite, with two-thirds of the possible metal sites occupied either in an orderly (α) or random (β) fashion; the sulfide also has a γ form related to γ-alumina, and an unusual high-temperature hexagonal form where half the aluminium atoms have tetrahedral four-coordination and the other half have trigonal bipyramidal five-coordination.
Four pnictides – aluminium nitride (AlN), aluminium phosphide (AlP), aluminium arsenide (AlAs), and aluminium antimonide (AlSb) – are known. They are all III-V semiconductors isoelectronic to silicon and germanium, all of which but AlN have the zinc blende structure. All four can be made by high-temperature (and possibly high-pressure) direct reaction of their component elements.
Aluminium alloys well with most other metals (with the exception of most alkali metals and group 13 metals) and over 150 intermetallics with other metals are known. Preparation involves heating fixed metals together in certain proportion, followed by gradual cooling and annealing. Bonding in them is predominantly metallic and the crystal structure primarily depends on efficiency of packing.
There are few compounds with lower oxidation states. A few aluminium(I) compounds exist: AlF, AlCl, AlBr, and AlI exist in the gaseous phase when the respective trihalide is heated with aluminium, and at cryogenic temperatures. A stable derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine, Al4I4(NEt3)4. Al2O and Al2S also exist but are very unstable. Very simple aluminium(II) compounds are invoked or observed in the reactions of Al metal with oxidants. For example, aluminium monoxide, AlO, has been detected in the gas phase after explosion and in stellar absorption spectra. More thoroughly investigated are compounds of the formula R4Al2 which contain an Al–Al bond and where R is a large organic ligand.
Organoaluminium compounds and related hydrides
A variety of compounds of empirical formula AlR3 and AlR1.5Cl1.5 exist. The aluminium trialkyls and triaryls are reactive, volatile, and colorless liquids or low-melting solids. They catch fire spontaneously in air and react with water, thus necessitating precautions when handling them. They often form dimers, unlike their boron analogues, but this tendency diminishes for branched-chain alkyls (e.g. Pri, Bui, Me3CCH2); for example, triisobutylaluminium exists as an equilibrium mixture of the monomer and dimer. These dimers, such as trimethylaluminium (Al2Me6), usually feature tetrahedral Al centers formed by dimerization with some alkyl group bridging between both aluminium atoms. They are hard acids and react readily with ligands, forming adducts. In industry, they are mostly used in alkene insertion reactions, as discovered by Karl Ziegler, most importantly in "growth reactions" that form long-chain unbranched primary alkenes and alcohols, and in the low-pressure polymerization of ethene and propene. There are also some heterocyclic and cluster organoaluminium compounds involving Al–N bonds.
The industrially most important aluminium hydride is lithium aluminium hydride (LiAlH4), which is used in as a reducing agent in organic chemistry. It can be produced from lithium hydride and aluminium trichloride. The simplest hydride, aluminium hydride or alane, is not as important. It is a polymer with the formula (AlH3)n, in contrast to the corresponding boron hydride that is a dimer with the formula (BH3)2.
Natural occurrence
Space
Aluminium's per-particle abundance in the Solar System is 3.15 ppm (parts per million). It is the twelfth most abundant of all elements and third most abundant among the elements that have odd atomic numbers, after hydrogen and nitrogen. The only stable isotope of aluminium, 27Al, is the eighteenth most abundant nucleus in the universe. It is created almost entirely after fusion of carbon in massive stars that will later become Type II supernovas: this fusion creates 26Mg, which upon capturing free protons and neutrons, becomes aluminium. Some smaller quantities of 27Al are created in hydrogen burning shells of evolved stars, where 26Mg can capture free protons. Essentially all aluminium now in existence is 27Al. 26Al was present in the early Solar System with abundance of 0.005% relative to 27Al but its half-life of 728,000 years is too short for any original nuclei to survive; 26Al is therefore extinct. Unlike for 27Al, hydrogen burning is the primary source of 26Al, with the nuclide emerging after a nucleus of 25Mg catches a free proton. However, the trace quantities of 26Al that do exist are the most common gamma ray emitter in the interstellar gas; if the original 26Al were still present, gamma ray maps of the Milky Way would be brighter.
Earth
Overall, the Earth is about 1.59% aluminium by mass (seventh in abundance by mass). Aluminium occurs in greater proportion in the Earth's crust than in the universe at large. This is because aluminium easily forms the oxide and becomes bound into rocks and stays in the Earth's crust, while less reactive metals sink to the core. In the Earth's crust, aluminium is the most abundant metallic element (8.23% by mass) and the third most abundant of all elements (after oxygen and silicon). A large number of silicates in the Earth's crust contain aluminium. In contrast, the Earth's mantle is only 2.38% aluminium by mass. Aluminium also occurs in seawater at a concentration of 2 μg/kg.
Because of its strong affinity for oxygen, aluminium is almost never found in the elemental state; instead it is found in oxides or silicates. Feldspars, the most common group of minerals in the Earth's crust, are aluminosilicates. Aluminium also occurs in the minerals beryl, cryolite, garnet, spinel, and turquoise. Impurities in Al2O3, such as chromium and iron, yield the gemstones ruby and sapphire, respectively. Native aluminium metal is extremely rare and can only be found as a minor phase in low oxygen fugacity environments, such as the interiors of certain volcanoes. Native aluminium has been reported in cold seeps in the northeastern continental slope of the South China Sea. It is possible that these deposits resulted from bacterial reduction of tetrahydroxoaluminate Al(OH)4−.
Although aluminium is a common and widespread element, not all aluminium minerals are economically viable sources of the metal. Almost all metallic aluminium is produced from the ore bauxite (AlOx(OH)3–2x). Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions. In 2017, most bauxite was mined in Australia, China, Guinea, and India.
History
The history of aluminium has been shaped by usage of alum. The first written record of alum, made by Greek historian Herodotus, dates back to the 5th century BCE. The ancients are known to have used alum as a dyeing mordant and for city defense. After the Crusades, alum, an indispensable good in the European fabric industry, was a subject of international commerce; it was imported to Europe from the eastern Mediterranean until the mid-15th century.
The nature of alum remained unknown. Around 1530, Swiss physician Paracelsus suggested alum was a salt of an earth of alum. In 1595, German doctor and chemist Andreas Libavius experimentally confirmed this. In 1722, German chemist Friedrich Hoffmann announced his belief that the base of alum was a distinct earth. In 1754, German chemist Andreas Sigismund Marggraf synthesized alumina by boiling clay in sulfuric acid and subsequently adding potash.
Attempts to produce aluminium date back to 1760. The first successful attempt, however, was completed in 1824 by Danish physicist and chemist Hans Christian Ørsted. He reacted anhydrous aluminium chloride with potassium amalgam, yielding a lump of metal looking similar to tin. He presented his results and demonstrated a sample of the new metal in 1825. In 1827, German chemist Friedrich Wöhler repeated Ørsted's experiments but did not identify any aluminium. (The reason for this inconsistency was only discovered in 1921.) He conducted a similar experiment in the same year by mixing anhydrous aluminium chloride with potassium and produced a powder of aluminium. In 1845, he was able to produce small pieces of the metal and described some physical properties of this metal. For many years thereafter, Wöhler was credited as the discoverer of aluminium.
As Wöhler's method could not yield great quantities of aluminium, the metal remained rare; its cost exceeded that of gold. The first industrial production of aluminium was established in 1856 by French chemist Henri Etienne Sainte-Claire Deville and companions. Deville had discovered that aluminium trichloride could be reduced by sodium, which was more convenient and less expensive than potassium, which Wöhler had used. Even then, aluminium was still not of great purity and produced aluminium differed in properties by sample. Because of its electricity-conducting capacity, aluminium was used as the cap of the Washington Monument, completed in 1885. The tallest building in the world at the time, the non-corroding metal cap was intended to serve as a lightning rod peak.
The first industrial large-scale production method was independently developed in 1886 by French engineer Paul Héroult and American engineer Charles Martin Hall; it is now known as the Hall–Héroult process. The Hall–Héroult process converts alumina into metal. Austrian chemist Carl Joseph Bayer discovered a way of purifying bauxite to yield alumina, now known as the Bayer process, in 1889. Modern production of the aluminium is based on the Bayer and Hall–Héroult processes.
As large-scale production caused aluminium prices to drop, the metal became widely used in jewelry, eyeglass frames, optical instruments, tableware, and foil, and other everyday items in the 1890s and early 20th century. Aluminium's ability to form hard yet light alloys with other metals provided the metal with many uses at the time. During World War I, major governments demanded large shipments of aluminium for light strong airframes; during World War II, demand by major governments for aviation was even higher.
By the mid-20th century, aluminium had become a part of everyday life and an essential component of housewares. In 1954, production of aluminium surpassed that of copper, historically second in production only to iron, making it the most produced non-ferrous metal. During the mid-20th century, aluminium emerged as a civil engineering material, with building applications in both basic construction and interior finish work, and increasingly being used in military engineering, for both airplanes and land armor vehicle engines. Earth's first artificial satellite, launched in 1957, consisted of two separate aluminium semi-spheres joined and all subsequent space vehicles have used aluminium to some extent. The aluminium can was invented in 1956 and employed as a storage for drinks in 1958.
Throughout the 20th century, the production of aluminium rose rapidly: while the world production of aluminium in 1900 was 6,800 metric tons, the annual production first exceeded 100,000 metric tons in 1916; 1,000,000 tons in 1941; 10,000,000 tons in 1971. In the 1970s, the increased demand for aluminium made it an exchange commodity; it entered the London Metal Exchange, the oldest industrial metal exchange in the world, in 1978. The output continued to grow: the annual production of aluminium exceeded 50,000,000 metric tons in 2013.
The real price for aluminium declined from $14,000 per metric ton in 1900 to $2,340 in 1948 (in 1998 United States dollars). Extraction and processing costs were lowered over technological progress and the scale of the economies. However, the need to exploit lower-grade poorer quality deposits and the use of fast increasing input costs (above all, energy) increased the net cost of aluminium; the real price began to grow in the 1970s with the rise of energy cost. Production moved from the industrialized countries to countries where production was cheaper. Production costs in the late 20th century changed because of advances in technology, lower energy prices, exchange rates of the United States dollar, and alumina prices. The BRIC countries' combined share in primary production and primary consumption grew substantially in the first decade of the 21st century. China is accumulating an especially large share of the world's production thanks to an abundance of resources, cheap energy, and governmental stimuli; it also increased its consumption share from 2% in 1972 to 40% in 2010. In the United States, Western Europe, and Japan, most aluminium was consumed in transportation, engineering, construction, and packaging. In 2021, prices for industrial metals such as aluminium have soared to near-record levels as energy shortages in China drive up costs for electricity.
Etymology
The names aluminium and aluminum are derived from the word alumine, an obsolete term for alumina, a naturally occurring oxide of aluminium. Alumine was borrowed from French, which in turn derived it from alumen, the classical Latin name for alum, the mineral from which it was collected. The Latin word alumen stems from the Proto-Indo-European root *alu- meaning "bitter" or "beer".
Origins
British chemist Humphry Davy, who performed a number of experiments aimed to isolate the metal, is credited as the person who named the element. The first name proposed for the metal to be isolated from alum was alumium, which Davy suggested in an 1808 article on his electrochemical research, published in Philosophical Transactions of the Royal Society. It appeared that the name was created from the English word alum and the Latin suffix -ium; but it was customary then to give elements names originating in Latin, so this name was not adopted universally. This name was criticized by contemporary chemists from France, Germany, and Sweden, who insisted the metal should be named for the oxide, alumina, from which it would be isolated. The English name alum does not come directly from Latin, whereas alumine/alumina obviously comes from the Latin word alumen (upon declension, alumen changes to alumin-).
One example was Essai sur la Nomenclature chimique (July 1811), written in French by a Swedish chemist, Jöns Jacob Berzelius, in which the name aluminium is given to the element that would be synthesized from alum. (Another article in the same journal issue also refers to the metal whose oxide is the basis of sapphire, i.e. the same metal, as to aluminium.) A January 1811 summary of one of Davy's lectures at the Royal Society mentioned the name aluminium as a possibility. The next year, Davy published a chemistry textbook in which he used the spelling aluminum. Both spellings have coexisted since. Their usage is currently regional: aluminum dominates in the United States and Canada; aluminium is prevalent in the rest of the English-speaking world.
Spelling
In 1812, British scientist Thomas Young wrote an anonymous review of Davy's book, in which he proposed the name aluminium instead of aluminum, which he thought had a "less classical sound". This name persisted: although the spelling was occasionally used in Britain, the American scientific language used from the start. Most scientists throughout the world used in the 19th century; and it was entrenched in several other European languages, such as French, German, and Dutch. In 1828, an American lexicographer, Noah Webster, entered only the aluminum spelling in his American Dictionary of the English Language. In the 1830s, the spelling gained usage in the United States; by the 1860s, it had become the more common spelling there outside science. In 1892, Hall used the spelling in his advertising handbill for his new electrolytic method of producing the metal, despite his constant use of the spelling in all the patents he filed between 1886 and 1903: it is unknown whether this spelling was introduced by mistake or intentionally; but Hall preferred aluminum since its introduction because it resembled platinum, the name of a prestigious metal. By 1890, both spellings had been common in the United States, the spelling being slightly more common; by 1895, the situation had reversed; by 1900, aluminum had become twice as common as aluminium; in the next decade, the spelling dominated American usage. In 1925, the American Chemical Society adopted this spelling.
The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990. In 1993, they recognized aluminum as an acceptable variant; the most recent 2005 edition of the IUPAC nomenclature of inorganic chemistry also acknowledges this spelling. IUPAC official publications use the spelling as primary, and they list both where it is appropriate.
Production and refinement
The production of aluminium starts with the extraction of bauxite rock from the ground. The bauxite is processed and transformed using the Bayer process into alumina, which is then processed using the Hall–Héroult process, resulting in the final aluminium.
Aluminium production is highly energy-consuming, and so the producers tend to locate smelters in places where electric power is both plentiful and inexpensive. Production of one kilogram of aluminium requires 7 kilograms of oil energy equivalent, as compared to 1.5 kilograms for steel and 2 kilograms for plastic. As of 2019, the world's largest smelters of aluminium are located in China, India, Russia, Canada, and the United Arab Emirates, while China is by far the top producer of aluminium with a world share of fifty-five percent.
According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of aluminium in use in society (i.e. in cars, buildings, electronics, etc.) is . Much of this is in more-developed countries ( per capita) rather than less-developed countries ( per capita).
Bayer process
Bauxite is converted to alumina by the Bayer process. Bauxite is blended for uniform composition and then is ground. The resulting slurry is mixed with a hot solution of sodium hydroxide; the mixture is then treated in a digester vessel at a pressure well above atmospheric, dissolving the aluminium hydroxide in bauxite while converting impurities into relatively insoluble compounds:
After this reaction, the slurry is at a temperature above its atmospheric boiling point. It is cooled by removing steam as pressure is reduced. The bauxite residue is separated from the solution and discarded. The solution, free of solids, is seeded with small crystals of aluminium hydroxide; this causes decomposition of the [Al(OH)4]− ions to aluminium hydroxide. After about half of aluminium has precipitated, the mixture is sent to classifiers. Small crystals of aluminium hydroxide are collected to serve as seeding agents; coarse particles are converted to alumina by heating; the excess solution is removed by evaporation, (if needed) purified, and recycled.
Hall–Héroult process
The conversion of alumina to aluminium is achieved by the Hall–Héroult process. In this energy-intensive process, a solution of alumina in a molten () mixture of cryolite (Na3AlF6) with calcium fluoride is electrolyzed to produce metallic aluminium. The liquid aluminium sinks to the bottom of the solution and is tapped off, and usually cast into large blocks called aluminium billets for further processing.
Anodes of the electrolysis cell are made of carbon—the most resistant material against fluoride corrosion—and either bake at the process or are prebaked. The former, also called Söderberg anodes, are less power-efficient and fumes released during baking are costly to collect, which is why they are being replaced by prebaked anodes even though they save the power, energy, and labor to prebake the cathodes. Carbon for anodes should be preferably pure so that neither aluminium nor the electrolyte is contaminated with ash. Despite carbon's resistivity against corrosion, it is still consumed at a rate of 0.4–0.5 kg per each kilogram of produced aluminium. Cathodes are made of anthracite; high purity for them is not required because impurities leach only very slowly. The cathode is consumed at a rate of 0.02–0.04 kg per each kilogram of produced aluminium. A cell is usually terminated after 2–6 years following a failure of the cathode.
The Hall–Heroult process produces aluminium with a purity of above 99%. Further purification can be done by the Hoopes process. This process involves the electrolysis of molten aluminium with a sodium, barium, and aluminium fluoride electrolyte. The resulting aluminium has a purity of 99.99%.
Electric power represents about 20 to 40% of the cost of producing aluminium, depending on the location of the smelter. Aluminium production consumes roughly 5% of electricity generated in the United States. Because of this, alternatives to the Hall–Héroult process have been researched, but none has turned out to be economically feasible.
Recycling
Recovery of the metal through recycling has become an important task of the aluminium industry. Recycling was a low-profile activity until the late 1960s, when the growing use of aluminium beverage cans brought it to public awareness. Recycling involves melting the scrap, a process that requires only 5% of the energy used to produce aluminium from ore, though a significant part (up to 15% of the input material) is lost as dross (ash-like oxide). An aluminium stack melter produces significantly less dross, with values reported below 1%.
White dross from primary aluminium production and from secondary recycling operations still contains useful quantities of aluminium that can be extracted industrially. The process produces aluminium billets, together with a highly complex waste material. This waste is difficult to manage. It reacts with water, releasing a mixture of gases (including, among others, hydrogen, acetylene, and ammonia), which spontaneously ignites on contact with air; contact with damp air results in the release of copious quantities of ammonia gas. Despite these difficulties, the waste is used as a filler in asphalt and concrete.
Applications
Metal
The global production of aluminium in 2016 was 58.8 million metric tons. It exceeded that of any other metal except iron (1,231 million metric tons).
Aluminium is almost always alloyed, which markedly improves its mechanical properties, especially when tempered. For example, the common aluminium foils and beverage cans are alloys of 92% to 99% aluminium. The main alloying agents are copper, zinc, magnesium, manganese, and silicon (e.g., duralumin) with the levels of other metals in a few percent by weight. Aluminium, both wrought and cast, has been alloyed with: manganese, silicon, magnesium, copper and zinc among others. For example, the Kynal family of alloys was developed by the British chemical manufacturer Imperial Chemical Industries.
The major uses for aluminium are in:
Transportation (automobiles, aircraft, trucks, railway cars, marine vessels, bicycles, spacecraft, etc.). Aluminium is used because of its low density;
Packaging (cans, foil, frame, etc.). Aluminium is used because it is non-toxic (see below), non-adsorptive, and splinter-proof;
Building and construction (windows, doors, siding, building wire, sheathing, roofing, etc.). Since steel is cheaper, aluminium is used when lightness, corrosion resistance, or engineering features are important;
Electricity-related uses (conductor alloys, motors, and generators, transformers, capacitors, etc.). Aluminium is used because it is relatively cheap, highly conductive, has adequate mechanical strength and low density, and resists corrosion;
A wide range of household items, from cooking utensils to furniture. Low density, good appearance, ease of fabrication, and durability are the key factors of aluminium usage;
Machinery and equipment (processing equipment, pipes, tools). Aluminium is used because of its corrosion resistance, non-pyrophoricity, and mechanical strength.
Compounds
The great majority (about 90%) of aluminium oxide is converted to metallic aluminium. Being a very hard material (Mohs hardness 9), alumina is widely used as an abrasive; being extraordinarily chemically inert, it is useful in highly reactive environments such as high pressure sodium lamps. Aluminium oxide is commonly used as a catalyst for industrial processes; e.g. the Claus process to convert hydrogen sulfide to sulfur in refineries and to alkylate amines. Many industrial catalysts are supported by alumina, meaning that the expensive catalyst material is dispersed over a surface of the inert alumina. Another principal use is as a drying agent or absorbent.
Several sulfates of aluminium have industrial and commercial application. Aluminium sulfate (in its hydrate form) is produced on the annual scale of several millions of metric tons. About two-thirds is consumed in water treatment. The next major application is in the manufacture of paper. It is also used as a mordant in dyeing, in pickling seeds, deodorizing of mineral oils, in leather tanning, and in production of other aluminium compounds. Two kinds of alum, ammonium alum and potassium alum, were formerly used as mordants and in leather tanning, but their use has significantly declined following availability of high-purity aluminium sulfate. Anhydrous aluminium chloride is used as a catalyst in chemical and petrochemical industries, the dyeing industry, and in synthesis of various inorganic and organic compounds. Aluminium hydroxychlorides are used in purifying water, in the paper industry, and as antiperspirants. Sodium aluminate is used in treating water and as an accelerator of solidification of cement.
Many aluminium compounds have niche applications, for example:
Aluminium acetate in solution is used as an astringent.
Aluminium phosphate is used in the manufacture of glass, ceramic, pulp and paper products, cosmetics, paints, varnishes, and in dental cement.
Aluminium hydroxide is used as an antacid, and mordant; it is used also in water purification, the manufacture of glass and ceramics, and in the waterproofing of fabrics.
Lithium aluminium hydride is a powerful reducing agent used in organic chemistry.
Organoaluminiums are used as Lewis acids and co-catalysts.
Methylaluminoxane is a co-catalyst for Ziegler–Natta olefin polymerization to produce vinyl polymers such as polyethene.
Aqueous aluminium ions (such as aqueous aluminium sulfate) are used to treat against fish parasites such as Gyrodactylus salaris.
In many vaccines, certain aluminium salts serve as an immune adjuvant (immune response booster) to allow the protein in the vaccine to achieve sufficient potency as an immune stimulant. Until 2004, most of the adjuvants used in vaccines were aluminium-adjuvanted.
Biology
Despite its widespread occurrence in the Earth's crust, aluminium has no known function in biology. At pH 6–9 (relevant for most natural waters), aluminium precipitates out of water as the hydroxide and is hence not available; most elements behaving this way have no biological role or are toxic. Aluminium sulfate has an LD50 of 6207 mg/kg (oral, mouse), which corresponds to 435 grams (about one pound) for a person.
Toxicity
Aluminium is classified as a non-carcinogen by the United States Department of Health and Human Services. A review published in 1988 said that there was little evidence that normal exposure to aluminium presents a risk to healthy adult, and a 2014 multi-element toxicology review was unable to find deleterious effects of aluminium consumed in amounts not greater than 40 mg/day per kg of body mass. Most aluminium consumed will leave the body in feces; most of the small part of it that enters the bloodstream, will be excreted via urine; nevertheless some aluminium does pass the blood-brain barrier and is lodged preferentially in the brains of Alzheimer's patients. Evidence published in 1989 indicates that, for Alzheimer's patients, aluminium may act by electrostatically crosslinking proteins, thus down-regulating genes in the superior temporal gyrus.
Effects
Aluminium, although rarely, can cause vitamin D-resistant osteomalacia, erythropoietin-resistant microcytic anemia, and central nervous system alterations. People with kidney insufficiency are especially at a risk. Chronic ingestion of hydrated aluminium silicates (for excess gastric acidity control) may result in aluminium binding to intestinal contents and increased elimination of other metals, such as iron or zinc; sufficiently high doses (>50 g/day) can cause anemia.
During the 1988 Camelford water pollution incident people in Camelford had their drinking water contaminated with aluminium sulfate for several weeks. A final report into the incident in 2013 concluded it was unlikely that this had caused long-term health problems.
Aluminium has been suspected of being a possible cause of Alzheimer's disease, but research into this for over 40 years has found, , no good evidence of causal effect.
Aluminium increases estrogen-related gene expression in human breast cancer cells cultured in the laboratory. In very high doses, aluminium is associated with altered function of the blood–brain barrier. A small percentage of people have contact allergies to aluminium and experience itchy red rashes, headache, muscle pain, joint pain, poor memory, insomnia, depression, asthma, irritable bowel syndrome, or other symptoms upon contact with products containing aluminium.
Exposure to powdered aluminium or aluminium welding fumes can cause pulmonary fibrosis. Fine aluminium powder can ignite or explode, posing another workplace hazard.
Exposure routes
Food is the main source of aluminium. Drinking water contains more aluminium than solid food; however, aluminium in food may be absorbed more than aluminium from water. Major sources of human oral exposure to aluminium include food (due to its use in food additives, food and beverage packaging, and cooking utensils), drinking water (due to its use in municipal water treatment), and aluminium-containing medications (particularly antacid/antiulcer and buffered aspirin formulations). Dietary exposure in Europeans averages to 0.2–1.5 mg/kg/week but can be as high as 2.3 mg/kg/week. Higher exposure levels of aluminium are mostly limited to miners, aluminium production workers, and dialysis patients.
Consumption of antacids, antiperspirants, vaccines, and cosmetics provide possible routes of exposure. Consumption of acidic foods or liquids with aluminium enhances aluminium absorption, and maltol has been shown to increase the accumulation of aluminium in nerve and bone tissues.
Treatment
In case of suspected sudden intake of a large amount of aluminium, the only treatment is deferoxamine mesylate which may be given to help eliminate aluminium from the body by chelation. However, this should be applied with caution as this reduces not only aluminium body levels, but also those of other metals such as copper or iron.
Environmental effects
High levels of aluminium occur near mining sites; small amounts of aluminium are released to the environment at the coal-fired power plants or incinerators. Aluminium in the air is washed out by the rain or normally settles down but small particles of aluminium remain in the air for a long time.
Acidic precipitation is the main natural factor to mobilize aluminium from natural sources and the main reason for the environmental effects of aluminium; however, the main factor of presence of aluminium in salt and freshwater are the industrial processes that also release aluminium into air.
In water, aluminium acts as a toxiс agent on gill-breathing animals such as fish when the water is acidic, in which aluminium may precipitate on gills, which causes loss of plasma- and hemolymph ions leading to osmoregulatory failure. Organic complexes of aluminium may be easily absorbed and interfere with metabolism in mammals and birds, even though this rarely happens in practice.
Aluminium is primary among the factors that reduce plant growth on acidic soils. Although it is generally harmless to plant growth in pH-neutral soils, in acid soils the concentration of toxic Al3+ cations increases and disturbs root growth and function. Wheat has developed a tolerance to aluminium, releasing organic compounds that bind to harmful aluminium cations. Sorghum is believed to have the same tolerance mechanism.
Aluminium production possesses its own challenges to the environment on each step of the production process. The major challenge is the greenhouse gas emissions. These gases result from electrical consumption of the smelters and the byproducts of processing. The most potent of these gases are perfluorocarbons from the smelting process. Released sulfur dioxide is one of the primary precursors of acid rain.
Biodegradation of metallic aluminium is extremely rare; most aluminium-corroding organisms do not directly attack or consume the aluminium, but instead produce corrosive wastes. The fungus Geotrichum candidum can consume the aluminium in compact discs. The bacterium Pseudomonas aeruginosa and the fungus Cladosporium resinae are commonly detected in aircraft fuel tanks that use kerosene-based fuels (not avgas), and laboratory cultures can degrade aluminium.
See also
Aluminium granules
Aluminium joining
Aluminium–air battery
Aluminized steel, for corrosion resistance and other properties
Aluminized screen, for display devices
Aluminized cloth, to reflect heat
Aluminized mylar, to reflect heat
Panel edge staining
Quantum clock
Notes
References
Bibliography
Further reading
Mimi Sheller, Aluminum Dream: The Making of Light Modernity. Cambridge, Mass.: Massachusetts Institute of Technology Press, 2014.
External links
Aluminium at The Periodic Table of Videos (University of Nottingham)
Toxicological Profile for Aluminum (PDF) (September 2008) – 357-page report from the United States Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry
Aluminum entry (last reviewed October 30, 2019) in the NIOSH Pocket Guide to Chemical Hazards published by the CDC's National Institute for Occupational Safety and Health
Current and historical prices (1998–present) for aluminum futures on the global commodities market
Chemical elements
Post-transition metals
Aluminium
Electrical conductors
Pyrotechnic fuels
Airship technology
Reducing agents
E-number additives
Native element minerals
Chemical elements with face-centered cubic structure |
905 | https://en.wikipedia.org/wiki/Advanced%20Chemistry | Advanced Chemistry | Advanced Chemistry is a German hip hop group from Heidelberg, a scenic city in Baden-Württemberg, South Germany. Advanced Chemistry was founded in 1987 by Toni L, Linguist, Gee-One, DJ Mike MD (Mike Dippon) and MC Torch. Each member of the group holds German citizenship, and Toni L, Linguist, and Torch are of Italian, Ghanaian, and Haitian backgrounds, respectively.
Influenced by North American socially conscious rap and the Native tongues movement, Advanced Chemistry is regarded as one of the main pioneers in German hip hop. They were one of the first groups to rap in German (although their name is in English). Furthermore, their songs tackled controversial social and political issues, distinguishing them from early German hip hop group "Die Fantastischen Vier" (The Fantastic Four), which had a more light-hearted, playful, party image.
Career
Advanced Chemistry frequently rapped about their lives and experiences as children of immigrants, exposing the marginalization experienced by most ethnic minorities in Germany, and the feelings of frustration and resentment that being denied a German identity can cause. The song "Fremd im eigenen Land" (Foreign in your own nation) was released by Advanced Chemistry in November 1992. The single became a staple in the German hip hop scene. It made a strong statement about the status of immigrants throughout Germany, as the group was composed of multi-national and multi-racial members. The video shows several members brandishing their German passports as a demonstration of their German citizenship to skeptical and unaccepting 'ethnic' Germans.
This idea of national identity is important, as many rap artists in Germany have been of foreign origin. These so-called Gastarbeiter (guest workers) children saw breakdance, graffiti, rap music, and hip hop culture as a means of expressing themselves. Since the release of "Fremd im eigenen Land", many other German-language rappers have also tried to confront anti-immigrant ideas and develop themes of citizenship. However, though many ethnic minority youth in Germany find these German identity themes appealing, others view the desire of immigrants to be seen as German negatively, and they have actively sought to revive and recreate concepts of identity in connection to traditional ethnic origins.
Advanced Chemistry helped to found the German chapter of the Zulu nation.
The rivalry between Advanced Chemistry and Die Fantastischen Vier has served to highlight a dichotomy in the routes that hip hop has taken in becoming a part of the German soundscape. While Die Fantastischen Vier may be said to view hip hop primarily as an aesthetic art form, Advanced Chemistry understand hip hop as being inextricably linked to the social and political circumstances under which it is created. For Advanced Chemistry, hip hop is a “vehicle of general human emancipation,”. In their undertaking of social and political issues, the band introduced the term "Afro-German" into the context of German hip hop, and the theme of race is highlighted in much of their music.
With the release of the single “Fremd im eigenen Land”, Advanced Chemistry separated itself from the rest of the rap being produced in Germany. This single was the first of its kind to go beyond simply imitating US rap and addressed the current issues of the time. Fremd im eigenen Land which translates to “foreign in my own country” dealt with the widespread racism that non-white German citizens faced. This change from simple imitation to political commentary was the start of German identification with rap. The sound of “Fremd im eigenen Land” was influenced by the 'wall of noise' created by Public Enemy's producers, The Bomb Squad.
After the reunification of Germany, an abundance of anti-immigrant sentiment emerged, as well as attacks on the homes of refugees in the early 1990s. Advanced Chemistry came to prominence in the wake of these actions because of their pro-multicultural society stance in their music. Advanced Chemistry's attitudes revolve around their attempts to create a distinct "Germanness" in hip hop, as opposed to imitating American hip hop as other groups had done. Torch has said, "What the Americans do is exotic for us because we don't live like they do. What they do seems to be more interesting and newer. But not for me. For me it's more exciting to experience my fellow Germans in new contexts...For me, it's interesting to see what the kids try to do that's different from what I know." Advanced Chemistry were the first to use the term "Afro-German" in a hip hop context. This was part of the pro-immigrant political message they sent via their music.
While Advanced Chemistry's use of the German language in their rap allows them to make claims to authenticity and true German heritage, bolstering pro-immigration sentiment, their style can also be problematic for immigrant notions of any real ethnic roots. Indeed, part of the Turkish ethnic minority of Frankfurt views Advanced Chemistry's appeal to the German image as a "symbolic betrayal of the right of ethnic minorities to 'roots' or to any expression of cultural heritage." In this sense, their rap represents a complex social discourse internal to the German soundscape in which they attempt to negotiate immigrant assimilation into a xenophobic German culture with the maintenance of their own separate cultural traditions. It is quite possibly the feelings of alienation from the pure-blooded German demographic that drive Advanced Chemistry to attack nationalistic ideologies by asserting their "Germanness" as a group composed primarily of ethnic others. The response to this pseudo-German authenticity can be seen in what Andy Bennett refers to as "alternative forms of local hip hop culture which actively seek to rediscover and, in many cases, reconstruct notions of identity tied to cultural roots." These alternative local hip hop cultures include oriental hip hop, the members of which cling to their Turkish heritage and are confused by Advanced Chemistry's elicitation of a German identity politics to which they technically do not belong. This cultural binary illustrates that rap has taken different routes in Germany and that, even among an already isolated immigrant population, there is still disunity and, especially, disagreement on the relative importance of assimilation versus cultural defiance. According to German hip hop enthusiast 9@home, Advanced Chemistry is part of a "hip-hop movement [which] took a clear stance for the minorities and against the [marginalization] of immigrants who...might be German on paper, but not in real life," which speaks to the group's hope of actually being recognized as German citizens and not foreigners, despite their various other ethnic and cultural ties.
Influences
Advanced Chemistry's work was rooted in German history and the country's specific political realities. However, they also drew inspiration from African-American hip-hop acts like A Tribe Called Quest and Public Enemy, who had helped bring a soulful sound and political consciousness to American hip-hop. One member, Torch, later explicitly listed his references on his solo song "Als (When I Was in School):" "My favorite subject, which was quickly discovered poetry in load Poets, awakens the intellect or policy at Chuck D I'll never forget the lyrics by Public Enemy." Torch goes on to list other American rappers like Biz Markie, Big Daddy Kane and Dr. Dre as influences.
Discography
1992 - "Fremd im eigenen Land" (12"/MCD, MZEE)
1993 - "Welcher Pfad führt zur Geschichte" (12"/MCD, MZEE)
1994 - "Operation § 3" (12"/MCD)
1994 - "Dir fehlt der Funk!" (12"/MCD)
1995 - Advanced Chemistry (2xLP/CD)
External links
Official Website of MC Torch
Website of Toni L
Official Website of Linguist
Official Website DJ Mike MD (Mike Dippon)
Website of 360° Records
Bibliography
El-Tayeb, Fatima “‘If You Cannot Pronounce My Name, You Can Just Call Me
Pride.’ Afro-German Activism, Gender, and Hip Hop,” Gender & History15/3(2003):459-485.
Felbert, Oliver von. “Die Unbestechlichen.” Spex (March 1993): 50–53.
Weheliye, Alexander G. Phonographies:Grooves in Sonic Afro-Modernity, Duke University Press, 2005.
References
German hip hop groups |
910 | https://en.wikipedia.org/wiki/Arne%20Kaijser | Arne Kaijser | Arne Kaijser (born 1950) is a professor emeritus of history of technology at the KTH Royal Institute of Technology in Stockholm, and a former president of the Society for the History of Technology.
Kaijser has published two books in Swedish: Stadens ljus. Etableringen av de första svenska gasverken and I fädrens spår. Den svenska infrastrukturens historiska utveckling och framtida utmaningar, and has co-edited several anthologies. Kaijser is a member of the Royal Swedish Academy of Engineering Sciences since 2007 and also a member of the editorial board of two scientific journals: Journal of Urban Technology and Centaurus. Lately, he has been occupied with the history of Large Technical Systems.
References
External links
Homepage
Extended homepage
1950 births
Living people
20th-century Swedish historians
Academic staff of the KTH Royal Institute of Technology
Members of the Royal Swedish Academy of Engineering Sciences
Historians of science
Historians of technology
Linköping University alumni
21st-century Swedish historians |
911 | https://en.wikipedia.org/wiki/Archipelago | Archipelago | An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or sometimes a sea containing a small number of scattered islands.
Examples of archipelagos include: the Indonesian Archipelago, the Andaman and Nicobar Islands, the Lakshadweep Islands, the Galápagos Islands, the Japanese archipelago, the Philippine Archipelago, the Maldives, the Balearic Islands, the Åland Islands, The Bahamas, the Aegean Islands, the Hawaiian Islands, the Canary Islands, Malta, the Azores, the Canadian Arctic Archipelago, the British Isles, the islands of the Archipelago Sea, and Shetland. Archipelagos are sometimes defined by political boundaries. For example, while they are geopolitically divided, the San Juan Islands and Gulf Islands geologically form part of a larger Gulf Archipelago.
Etymology
The word archipelago is derived from the Ancient Greek ἄρχι-(arkhi-, "chief") and πέλαγος (pélagos, "sea") through the Italian arcipelago. In antiquity, "Archipelago" (from Medieval Greek *ἀρχιπέλαγος and Latin ) was the proper name for the Aegean Sea. Later, usage shifted to refer to the Aegean Islands (since the sea has a large number of islands).
Geographic types
Archipelagos may be found isolated in large amounts of water or neighbouring a large land mass. For example, Scotland has more than 700 islands surrounding its mainland, which form an archipelago.
Archipelagos are often volcanic, forming along island arcs generated by subduction zones or hotspots, but may also be the result of erosion, deposition, and land elevation. Depending on their geological origin, islands forming archipelagos can be referred to as oceanic islands, continental fragments, or continental islands.
Oceanic islands
Oceanic islands are mainly of volcanic origin, and widely separated from any adjacent continent. The Hawaiian Islands and Galapagos Islands in the Pacific, and Mascarene Islands in the south Indian Ocean are examples.
Continental fragments
Continental fragments correspond to land masses that have separated from a continental mass due to tectonic displacement. The Farallon Islands off the coast of California are an example.
Continental archipelagos
Sets of islands formed close to the coast of a continent are considered continental archipelagos when they form part of the same continental shelf, when those islands are above-water extensions of the shelf. The islands of the Inside Passage off the coast of British Columbia and the Canadian Arctic Archipelago are examples.
Artificial archipelagos
Artificial archipelagos have been created in various countries for different purposes. Palm Islands and The World Islands off Dubai were or are being created for leisure and tourism purposes. Marker Wadden in the Netherlands is being built as a conservation area for birds and other wildlife.
Superlatives
The largest archipelago in the world by number of islands is the Archipelago Sea, which is part of Finland. There are approximately 40,000, mostly uninhabited, islands
The largest archipelagic state in the world by area, and by population, is Indonesia.
See also
Island arc
List of landforms
List of archipelagos by number of islands
List of archipelagos
Archipelagic state
List of islands
Aquapelago
References
External links
30 Most Incredible Island Archipelagos
Coastal and oceanic landforms
Oceanographical terminology |
915 | https://en.wikipedia.org/wiki/Andrey%20Markov | Andrey Markov | Andrey Andreyevich Markov (14 June 1856 – 20 July 1922) was a Russian mathematician best known for his work on stochastic processes. A primary subject of his research later became known as the Markov chain. He was also a strong, close to master-level chess player.
Markov and his younger brother Vladimir Andreevich Markov (1871–1897) proved the Markov brothers' inequality.
His son, another Andrey Andreyevich Markov (1903–1979), was also a notable mathematician, making contributions to constructive mathematics and recursive function theory.
Biography
Andrey Markov was born on 14 June 1856 in Russia. He attended the St. Petersburg Grammar School, where some teachers saw him as a rebellious student. In his academics he performed poorly in most subjects other than mathematics. Later in life he attended Saint Petersburg Imperial University (now Saint Petersburg State University). Among his teachers were Yulian Sokhotski (differential calculus, higher algebra), Konstantin Posse (analytic geometry), Yegor Zolotarev (integral calculus), Pafnuty Chebyshev (number theory and probability theory), Aleksandr Korkin (ordinary and partial differential equations), Mikhail Okatov (mechanism theory), Osip Somov (mechanics), and Nikolai Budajev (descriptive and higher geometry). He completed his studies at the university and was later asked if he would like to stay and have a career as a mathematician. He later taught at high schools and continued his own mathematical studies. In this time he found a practical use for his mathematical skills. He figured out that he could use chains to model the alliteration of vowels and consonants in Russian literature. He also contributed to many other mathematical aspects in his time. He died at age 66 on 20 July 1922.
Timeline
In 1877, Markov was awarded a gold medal for his outstanding solution of the problem
About Integration of Differential Equations by Continued Fractions with an Application to the Equation .
During the following year, he passed the candidate's examinations, and he remained at the university to prepare for a lecturer's position.
In April 1880, Markov defended his master's thesis "On the Binary Square Forms with Positive Determinant", which was directed by Aleksandr Korkin and Yegor Zolotarev. Four years later in 1884, he defended his doctoral thesis titled "On Certain Applications of the Algebraic Continuous Fractions".
His pedagogical work began after the defense of his master's thesis in autumn 1880. As a privatdozent he lectured on differential and integral calculus. Later he lectured alternately on "introduction to analysis", probability theory (succeeding Chebyshev, who had left the university in 1882) and the calculus of differences. From 1895 through 1905 he also lectured in differential calculus.
One year after the defense of his doctoral thesis, Markov was appointed extraordinary professor (1886) and in the same year he was elected adjunct to the Academy of Sciences. In 1890, after the death of Viktor Bunyakovsky, Markov became an extraordinary member of the academy. His promotion to an ordinary professor of St. Petersburg University followed in the fall of 1894.
In 1896, Markov was elected an ordinary member of the academy as the successor of Chebyshev. In 1905, he was appointed merited professor and was granted the right to retire, which he did immediately. Until 1910, however, he continued to lecture in the calculus of differences.
In connection with student riots in 1908, professors and lecturers of St. Petersburg University were ordered to monitor their students. Markov refused to accept this decree, and he wrote an explanation in which he declined to be an "agent of the governance". Markov was removed from further teaching duties at St. Petersburg University, and hence he decided to retire from the university.
Markov was an atheist. In 1912, he responded to Leo Tolstoy's excommunication from the Russian Orthodox Church by requesting his own excommunication. The Church complied with his request.
In 1913, the council of St. Petersburg elected nine scientists honorary members of the university. Markov was among them, but his election was not affirmed by the minister of education. The affirmation only occurred four years later, after the February Revolution in 1917. Markov then resumed his teaching activities and lectured on probability theory and the calculus of differences until his death in 1922.
See also
List of things named after Andrey Markov
Chebyshev–Markov–Stieltjes inequalities
Gauss–Markov theorem
Gauss–Markov process
Hidden Markov model
Markov blanket
Markov chain
Markov decision process
Markov's inequality
Markov brothers' inequality
Markov information source
Markov network
Markov number
Markov property
Markov process
Stochastic matrix (also known as Markov matrix)
Subjunctive possibility
Notes
References
Further reading
А. А. Марков. "Распространение закона больших чисел на величины, зависящие друг от друга". "Известия Физико-математического общества при Казанском университете", 2-я серия, том 15, с. 135–156, 1906.
A. A. Markov. "Extension of the limit theorems of probability theory to a sum of variables connected in a chain". reprinted in Appendix B of: R. Howard. Dynamic Probabilistic Systems, volume 1: Markov Chains. John Wiley and Sons, 1971.
External links
Markov, Andrei Andreyevich
Markov, Andrei Andreyevich
19th-century mathematicians from the Russian Empire
20th-century Russian mathematicians
Russian atheists
Former Russian Orthodox Christians
Probability theorists
Saint Petersburg State University alumni
Full members of the Saint Petersburg Academy of Sciences
Full Members of the Russian Academy of Sciences (1917–1925)
People from Ryazan
Russian statisticians
Russian scientists |
921 | https://en.wikipedia.org/wiki/Angst | Angst | Angst is fear or anxiety (anguish is its Latinate equivalent, and the words anxious and anxiety are of similar origin). The dictionary definition for angst is a feeling of anxiety, apprehension, or insecurity.
Etymology
The word angst was introduced into English from the Danish, Norwegian, and Dutch word and the German word . It is attested since the 19th century in English translations of the works of Søren Kierkegaard and Sigmund Freud. It is used in English to describe an intense feeling of apprehension, anxiety, or inner turmoil.
In other languages (with words from the Latin for "fear" or "panic"), the derived words differ in meaning; for example, as in the French and . The word angst has existed in German since the 8th century, from the Proto-Indo-European root , "restraint" from which Old High German developed. It is pre-cognate with the Latin , "tensity, tightness" and , "choking, clogging"; compare to the Ancient Greek () "strangle". It entered English in the 19th century as a technical term used in Psychiatry, though earlier cognates existed, such as ange.
Existentialism
In existentialist philosophy, the term angst carries a specific conceptual meaning. The use of the term was first attributed to Danish philosopher Søren Kierkegaard (1813–1855). In The Concept of Anxiety (also known as The Concept of Dread), Kierkegaard used the word Angest (in common Danish, angst, meaning "dread" or "anxiety") to describe a profound and deep-seated condition. Where non-human animals are guided solely by instinct, said Kierkegaard, human beings enjoy a freedom of choice that we find both appealing and terrifying. It is the anxiety of understanding of being free when considering undefined possibilities of one's life and the immense responsibility of having the power of choice over them. Kierkegaard's concept of angst reappeared in the works of existentialist philosophers who followed, such as Friedrich Nietzsche, Jean-Paul Sartre, and Martin Heidegger, each of whom developed the idea further in individual ways. While Kierkegaard's angst referred mainly to ambiguous feelings about moral freedom within a religious personal belief system, later existentialists discussed conflicts of personal principles, cultural norms, and existential despair.
Music
Existential angst makes its appearance in classical musical composition in the early twentieth century as a result of both philosophical developments and as a reflection of the war-torn times. Notable composers whose works are often linked with the concept include Gustav Mahler, Richard Strauss (operas and ), Claude Debussy (opera , ballet Jeux), Jean Sibelius (especially the Fourth Symphony), Arnold Schoenberg (A Survivor from Warsaw), Alban Berg, Francis Poulenc (opera Dialogues of the Carmelites), Dmitri Shostakovich (opera Lady Macbeth of Mtsensk, symphonies and chamber music), Béla Bartók (opera Bluebeard's Castle), and Krzysztof Penderecki (especially Threnody to the Victims of Hiroshima).
Angst began to be discussed in reference to popular music in the mid- to late 1950s, amid widespread concerns over international tensions and nuclear proliferation. Jeff Nuttall's book Bomb Culture (1968) traced angst in popular culture to Hiroshima. Dread was expressed in works of folk rock such as Bob Dylan's "Masters of War" (1963) and "A Hard Rain's a-Gonna Fall". The term often makes an appearance in reference to punk rock, grunge, nu metal, and works of emo where expressions of melancholy, existential despair, or nihilism predominate.
See also
References
External links
Anxiety
Emotions
Existentialist concepts |
924 | https://en.wikipedia.org/wiki/A.%20A.%20Milne | A. A. Milne | Alan Alexander Milne (; 18 January 1882 – 31 January 1956) was an English writer best known for his books about the teddy bear Winnie-the-Pooh, as well as for children's poetry. Milne was primarily a playwright before the huge success of Winnie-the-Pooh overshadowed all his previous work. Milne served in both world wars, as a lieutenant in the Royal Warwickshire Regiment in the First World War and as a captain in the Home Guard in the Second World War.
Milne was the father of bookseller Christopher Robin Milne, upon whom the character Christopher Robin is based. It was during a visit to London Zoo, where Christopher became enamoured with the tame and amiable bear Winnipeg, that Milne was inspired to write the story of Winnie-the-Pooh for his son. Milne bequeathed the original manuscripts of the Winnie-the-Pooh stories to the Wren Library at Trinity College, Cambridge, his alma mater.
Early life and military career
Alan Alexander Milne was born in Kilburn, London, to John Vine Milne, who was born in Jamaica, and Sarah Marie Milne (née Heginbotham), on 18 January 1882. He grew up at Henley House School, 6/7 Mortimer Road (now Crescent), Kilburn, a small independent school run by his father. One of his teachers was H. G. Wells, who taught there in 1889–90. Milne attended Westminster School and Trinity College, Cambridge, where he studied on a mathematics scholarship, graduating with a B.A. in Mathematics in 1903. He edited and wrote for Granta, a student magazine. He collaborated with his brother Kenneth and their articles appeared over the initials AKM. Milne's work came to the attention of the leading British humour magazine Punch, where Milne was to become a contributor and later an assistant editor. Considered a talented cricket fielder, Milne played for two amateur teams that were largely composed of British writers: the Allahakbarries and the Authors XI. His teammates included fellow writers J. M. Barrie, Arthur Conan Doyle and P. G. Wodehouse.
Milne joined the British Army during World War I and served as an officer in the Royal Warwickshire Regiment. He was commissioned into the 4th Battalion, Royal Warwickshire Regiment, on 1 February 1915 as a second lieutenant (on probation). His commission was confirmed on 20 December 1915. He served on the Somme as a signals officer from July-November 1916, but caught trench fever and was invalided back to England. Having recuperated, he worked as a signals instructor, before being recruited into military intelligence to write propaganda articles for MI7 (b) between 1917 and 1918. He was discharged on 14 February 1919, and settled in Mallord Street, Chelsea. He relinquished his commission on 19 February 1920, retaining the rank of lieutenant.
After the war, he wrote a denunciation of war titled Peace with Honour (1934), which he retracted somewhat with 1940's War with Honour. During World War II, Milne was one of the most prominent critics of fellow English writer (and Authors XI cricket teammate) P. G. Wodehouse, who was captured at his country home in France by the Nazis and imprisoned for a year. Wodehouse made radio broadcasts about his internment, which were broadcast from Berlin. Although the light-hearted broadcasts made fun of the Germans, Milne accused Wodehouse of committing an act of near treason by cooperating with his country's enemy. Wodehouse got some revenge on his former friend (e.g. in The Mating Season) by creating fatuous parodies of the Christopher Robin poems in some of his later stories, and claiming that Milne "was probably jealous of all other writers.... But I loved his stuff."
Milne married Dorothy "Daphne" de Sélincourt (1890–1971) in 1913 and their son Christopher Robin Milne was born in 1920. In 1925, Milne bought a country home, Cotchford Farm, in Hartfield, East Sussex.
During World War II, Milne was a captain in the British Home Guard in Hartfield & Forest Row, insisting on being plain "Mr. Milne" to the members of his platoon. He retired to the farm after a stroke and brain surgery in 1952 left him an invalid; and by August 1953, "he seemed very old and disenchanted." Milne died in January 1956, aged 74.
Literary career
1903 to 1925
After graduating from Cambridge University in 1903, A. A. Milne contributed humorous verse and whimsical essays to Punch, joining the staff in 1906 and becoming an assistant editor.
During this period he published 18 plays and three novels, including the murder mystery The Red House Mystery (1922). His son was born in August 1920 and in 1924 Milne produced a collection of children's poems, When We Were Very Young, which were illustrated by Punch staff cartoonist E. H. Shepard. A collection of short stories for children A Gallery of Children, and other stories that became part of the Winnie-the-Pooh books, were first published in 1925.
Milne was an early screenwriter for the nascent British film industry, writing four stories filmed in 1920 for the company Minerva Films (founded in 1920 by the actor Leslie Howard and his friend and story editor Adrian Brunel). These were The Bump, starring Aubrey Smith; Twice Two; Five Pound Reward; and Bookworms. Some of these films survive in the archives of the British Film Institute. Milne had met Howard when the actor starred in Milne's play Mr Pim Passes By in London.
Looking back on this period (in 1926), Milne observed that when he told his agent that he was going to write a detective story, he was told that what the country wanted from a "Punch humorist" was a humorous story; when two years later he said he was writing nursery rhymes, his agent and publisher were convinced he should write another detective story; and after another two years, he was being told that writing a detective story would be in the worst of taste given the demand for children's books. He concluded that "the only excuse which I have yet discovered for writing anything is that I want to write it; and I should be as proud to be delivered of a Telephone Directory con amore as I should be ashamed to create a Blank Verse Tragedy at the bidding of others."
1926 to 1928
Milne is most famous for his two Pooh books about a boy named Christopher Robin after his son, Christopher Robin Milne (1920–1996), and various characters inspired by his son's stuffed animals, most notably the bear named Winnie-the-Pooh. Christopher Robin Milne's stuffed bear, originally named Edward, was renamed Winnie after a Canadian black bear named Winnie (after Winnipeg), which was used as a military mascot in World War I, and left to London Zoo during the war. "The Pooh" comes from a swan the young Milne named "Pooh". E. H. Shepard illustrated the original Pooh books, using his own son's teddy Growler ("a magnificent bear") as the model. The rest of Christopher Robin Milne's toys, Piglet, Eeyore, Kanga, Roo and Tigger, were incorporated into A. A. Milne's stories, and two more characters – Rabbit and Owl – were created by Milne's imagination. Christopher Robin Milne's own toys are now on display in New York where 750,000 people visit them every year.
The fictional Hundred Acre Wood of the Pooh stories derives from Five Hundred Acre Wood in Ashdown Forest in East Sussex, South East England, where the Pooh stories were set. Milne lived on the northern edge of the forest at Cotchford Farm, , and took his son walking there. E. H. Shepard drew on the landscapes of Ashdown Forest as inspiration for many of the illustrations he provided for the Pooh books. The adult Christopher Robin commented: "Pooh's Forest and Ashdown Forest are identical." Popular tourist locations at Ashdown Forest include: Galleon's Lap, The Enchanted Place, the Heffalump Trap and Lone Pine, Eeyore's Sad and Gloomy Place, and the wooden Pooh Bridge where Pooh and Piglet invented Poohsticks.
Not yet known as Pooh, he made his first appearance in a poem, "Teddy Bear", published in Punch magazine in February 1924 and republished that year in When We Were Very Young. Pooh first appeared in the London Evening News on Christmas Eve, 1925, in a story called "The Wrong Sort of Bees". Winnie-the-Pooh was published in 1926, followed by The House at Pooh Corner in 1928. A second collection of nursery rhymes, Now We Are Six, was published in 1927. All four books were illustrated by E. H. Shepard. Milne also published four plays in this period. He also "gallantly stepped forward" to contribute a quarter of the costs of dramatising P. G. Wodehouse's A Damsel in Distress. The World of Pooh won the Lewis Carroll Shelf Award in 1958.
1929 onward
The success of his children's books was to become a source of considerable annoyance to Milne, whose self-avowed aim was to write whatever he pleased and who had, until then, found a ready audience for each change of direction: he had freed pre-war Punch from its ponderous facetiousness; he had made a considerable reputation as a playwright (like his idol J. M. Barrie) on both sides of the Atlantic; he had produced a witty piece of detective writing in The Red House Mystery (although this was severely criticised by Raymond Chandler for the implausibility of its plot in his essay The Simple Art of Murder in the eponymous collection that appeared in 1950). But once Milne had, in his own words, "said goodbye to all that in 70,000 words" (the approximate length of his four principal children's books), he had no intention of producing any reworkings lacking in originality, given that one of the sources of inspiration, his son, was growing older.
Another reason Milne stopped writing children's books, and especially about Winnie-the-Pooh, was that he felt "amazement and disgust" over the immense fame his son was exposed to, and said that "I feel that the legal Christopher Robin has already had more publicity than I want for him. I do not want CR Milne to ever wish that his name were Charles Robert."
In his literary home, Punch, where the When We Were Very Young verses had first appeared, Methuen continued to publish whatever Milne wrote, including the long poem "The Norman Church" and an assembly of articles entitled Year In, Year Out (which Milne likened to a benefit night for the author).
In 1929, Milne adapted Kenneth Grahame's novel The Wind in the Willows for the stage as Toad of Toad Hall. The title was an implicit admission that such chapters as Chapter 7, "The Piper at the Gates of Dawn," could not survive translation to the theatre. A special introduction written by Milne is included in some editions of Grahame's novel. It was first performed at the Playhouse Theatre, Liverpool, on 21 December 1929 before it made its West End debut the following year at the Lyric Theatre on 17 December 1930. The play was revived in the West End from 1931 to 1935, and since the 1960s there have been West End revivals during the Christmas season; actors who have performed in the play include Judi Dench and Ian McKellen.
Milne and his wife became estranged from their son, who came to resent what he saw as his father's exploitation of his childhood and came to hate the books that had thrust him into the public eye. Christopher's marriage to his first cousin, Lesley de Sélincourt, distanced him still further from his parents – Lesley's father and Christopher's mother had not spoken to each other for 30 years.
Death and legacy
Commemoration
A. A. Milne died at his home in Hartfield, Sussex, on 31 January 1956, nearly two weeks after his 74th birthday. A memorial service took place on 10 February at All Hallows-by-the-Tower church in London.
The rights to A. A. Milne's Pooh books were left to four beneficiaries: his family, the Royal Literary Fund, Westminster School and the Garrick Club. After Milne's death in 1956, thirteen days after his 74th birthday, his widow sold her rights to the Pooh characters to Stephen Slesinger, whose widow sold the rights after Slesinger's death to the Walt Disney Company, which has made many Pooh cartoon movies, a Disney Channel television show, as well as Pooh-related merchandise. In 2001, the other beneficiaries sold their interest in the estate to the Disney Corporation for $350m. Previously Disney had been paying twice-yearly royalties to these beneficiaries. The estate of E. H. Shepard also received a sum in the deal. The UK copyright on the text of the original Winnie the Pooh books expires on 1 January 2027; at the beginning of the year after the 70th anniversary of the author's death (PMA-70), and has already expired in those countries with a PMA-50 rule. This applies to all of Milne's works except those first published posthumously. The illustrations in the Pooh books will remain under copyright until the same amount of time has passed, after the illustrator's death; in the UK, this will be on 1 January 2047. In the US, copyright will not expire until 95 years after publication for each of Milne's books first published before 1978, but this includes the illustrations.
In 2008, a collection of original illustrations featuring Winnie-the-Pooh and his animal friends sold for more than £1.2 million at auction in Sotheby's, London. Forbes magazine ranked Winnie the Pooh the most valuable fictional character in 2002; Winnie the Pooh merchandising products alone had annual sales of more than $5.9 billion. In 2005, Winnie the Pooh generated $6 billion, a figure surpassed only by Mickey Mouse.
A memorial plaque in Ashdown Forest, unveiled by Christopher Robin in 1979, commemorates the work of A. A. Milne and Shepard in creating the world of Pooh. The inscription states they "captured the magic of Ashdown Forest, and gave it to the world". Milne once wrote of Ashdown Forest: "In that enchanted place on the top of the forest a little boy and his bear will always be playing."
In 2003, Winnie-the-Pooh was ranked number 7 on the BBC's The Big Read poll which determined the UK's "best-loved novels". In 2006, Winnie-the-Pooh received a star on the Hollywood Walk of Fame, marking the 80th birthday of Milne's creation.
Marking the 90th anniversary of Milne's creation of the character, and the 90th birthday of Queen Elizabeth II, Winnie-the-Pooh Meets the Queen (2016) sees Pooh meet the Queen at Buckingham Palace. The illustrated and audio adventure is narrated by the actor Jim Broadbent. Also in 2016, a new character, a Penguin, was unveiled in The Best Bear in All the World, which was inspired by a long-lost photograph of Milne and his son Christopher with a toy penguin.
An exhibition entitled Winnie-the-Pooh: Exploring a Classic appeared at the Victoria and Albert Museum in London from 9 December 2017 to 8 April 2018.
The composer Harold Fraser-Simson, a near neighbour, produced six books of Milne songs between 1924 and 1932. The poems have been parodied many times, including with the books When We Were Rather Older and Now We Are Sixty. The 1963 film The King's Breakfast was based on Milne's poem of the same name.
Milne has been portrayed in television and film. Domhnall Gleeson plays him in Goodbye Christopher Robin, a 2017 biographical drama film. In the 2018 fantasy film Christopher Robin, an extension of the Disney Winnie the Pooh franchise, Tristan Sturrock plays Milne, and filming took place at Ashdown Forest.
An elementary school in Houston, Texas, operated by the Houston Independent School District (HISD), is named after Milne. The school, A. A. Milne Elementary School in Brays Oaks, opened in 1991.
Archive
The original manuscripts for Winnie-the-Pooh and The House at Pooh Corner are archived at Trinity College Library, Cambridge.
The bulk of A. A. Milne's papers are housed at the Harry Ransom Center at the University of Texas at Austin. The collection, established at the centre in 1964, consists of manuscript drafts and fragments for over 150 of Milne's works, as well as correspondence, legal documents, genealogical records, and some personal effects. The library division holds several books formerly belonging to Milne and his wife Dorothy. The center also has small collections of correspondence from Christopher Robin Milne and Milne's frequent illustrator E. H. Shepard.
Religious views
Milne did not speak out much on the subject of religion, although he used religious terms to explain his decision, while remaining a pacifist, to join the British Home Guard. He wrote: "In fighting Hitler we are truly fighting the Devil, the Anti-Christ ... Hitler was a crusader against God."
His best known comment on the subject was recalled on his death:
He wrote in the poem "Explained":
He also wrote in the poem "Vespers":
Works
Novels
Lovers in London (1905. Some consider this more of a short story collection; Milne did not like it and considered The Day's Play as his first book.)
Once on a Time (1917)
Mr. Pim (1921) (A novelisation of his 1919 play Mr. Pim Passes By)
The Red House Mystery (1922). Serialised: London (Daily News), serialised daily from 3 to 28 August 1921
Two People (1931) (Inside jacket claims this is Milne's first attempt at a novel.)
Four Days' Wonder (1933)
Chloe Marr (1946)
Non-fiction
Peace With Honour (1934)
It's Too Late Now: The Autobiography of a Writer (1939)
War With Honour (1940)
War Aims Unlimited (1941)
Year In, Year Out (1952) (illustrated by E. H. Shepard)
Punch articles
The Day's Play (1910)
The Holiday Round (1912)
Once a Week (1914)
The Sunny Side (1921)
Those Were the Days (1929) [The four volumes above, compiled]
Newspaper articles and book introductions
The Chronicles of Clovis by "Saki" (1911) [Introduction to]
Not That It Matters (1919)
If I May (1920)
By Way of Introduction (1929)
Women and Children First!. John Bull, 10 November 1934
It Depends on the Book (1943, in September issue of Red Cross Newspaper The Prisoner of War)
Story collections for children
A Gallery of Children (1925)
Winnie-the-Pooh (1926) (illustrated by Ernest H. Shepard)
The House at Pooh Corner (1928) (illustrated by E. H. Shepard)
Short Stories
Poetry collections for children
When We Were Very Young (1924) (illustrated by E. H. Shepard)
Now We Are Six (1927) (illustrated by E. H. Shepard)
Story collections
The Secret and other stories (1929)
The Birthday Party (1948)
A Table Near the Band (1950)
Poetry
When We Were Very Young (1924) (illustrated by E. H. Shepard)
For the Luncheon Interval (1925) [poems from Punch]
Now We Are Six (1927) (illustrated by E. H. Shepard)
Behind the Lines (1940)
The Norman Church (1948)
Screenplays and plays
Wurzel-Flummery (1917)
Belinda (1918)
The Boy Comes Home (1918)
Make-Believe (1918) (children's play)
The Camberley Triangle (1919)
Mr. Pim Passes By (1919)
The Red Feathers (1920)
The Romantic Age (1920)
The Stepmother (1920)
The Truth About Blayds (1920)
The Bump (1920, Minerva Films), starring C. Aubrey Smith and Faith Celli
Twice Two (1920, Minerva Films)
Five Pound Reward (1920, Minerva Films)
Bookworms (1920, Minerva Films)
The Great Broxopp (1921)
The Dover Road (1921)
The Lucky One (1922)
The Truth About Blayds (1922)
The Artist: A Duologue (1923)
Give Me Yesterday (1923) (a.k.a. Success in the UK)
Ariadne (1924)
The Man in the Bowler Hat: A Terribly Exciting Affair (1924)
To Have the Honour (1924)
Portrait of a Gentleman in Slippers (1926)
Success (1926)
Miss Marlow at Play (1927)
Winnie the Pooh. Written specially by Milne for a 'Winnie the Pooh Party' in aid of the National Mother-Saving Campaign, and performed once at Seaford House on 17 March 1928
The Fourth Wall or The Perfect Alibi (1928) (later adapted for the film Birds of Prey (1930), directed by Basil Dean)
The Ivory Door (1929)
Toad of Toad Hall (1929) (adaptation of The Wind in the Willows)
Michael and Mary (1930)
Other People's Lives (1933) (a.k.a. They Don't Mean Any Harm)
Miss Elizabeth Bennet (1936) [based on Pride and Prejudice]
Sarah Simple (1937)
Gentleman Unknown (1938)
The General Takes Off His Helmet (1939) in The Queen's Book of the Red Cross
The Ugly Duckling (1941)
Before the Flood (1951).
References
Further reading
Last, Kevin J. Remembering Christopher Robin: Escaping Winnie-the-Pooh. Lewes (UK), Unicorn. 2023.
Thwaite, Ann. A.A. Milne: His Life. London: Faber and Faber, 1990.
Toby, Marlene. A.A. Milne, Author of Winnie-the-Pooh. Chicago: Children's Press, 1995.
External links
A. A. Milne Collection at the Harry Ransom Center
Ann Thwaite Collection of A. A. Milne at the Harry Ransom Center
Works by A. A. Milne at BiblioWiki (Canada) includes the complete text of the four Pooh books
Portraits of A. A. Milne in the National Portrait Gallery
Essays by Milne at Quotidiana.org
Milne extract in The Guardian
Profile at Just-Pooh.com
A. A. Milne at poeticous.com
AA Milne | Books | The Guardian
Finding aid to the A.A. Milne letters at Columbia University Rare Book & Manuscript Library
1882 births
1956 deaths
English people of Scottish descent
People from Hampstead
Writers from London
People from Kilburn, London
20th-century British dramatists and playwrights
20th-century British short story writers
20th-century English novelists
20th-century English poets
Alumni of Trinity College, Cambridge
British Army personnel of World War I
British Home Guard officers
Royal Warwickshire Fusiliers officers
English children's writers
Members of the Detection Club
People educated at Westminster School, London
Punch (magazine) people
English male poets
Winnie-the-Pooh
English male novelists
Children's poets
Military personnel from London
English autobiographers |
925 | https://en.wikipedia.org/wiki/Asociaci%C3%B3n%20Alumni | Asociación Alumni | Asociación Alumni, usually just Alumni, is an Argentine rugby union club located in Tortuguitas, Greater Buenos Aires. The senior squad currently competes at Top 12, the first division of the Unión de Rugby de Buenos Aires league system.
The club has ties with former football club Alumni because both were established by Buenos Aires English High School students.
History
Background
The first club with the name "Alumni" played association football, having been found in 1898 by students of Buenos Aires English High School (BAEHS) along with director Alexander Watson Hutton. Originally under the name "English High School A.C.", the team would be later obliged by the Association to change its name, therefore "Alumni" was chosen, following a proposal by Carlos Bowers, a former student of the school.
Alumni was the most successful team during the first years of Argentine football, winning 10 of 14 league championships contested. Alumni is still considered the first great football team in the country. Alumni was reorganised in 1908, "in order to encourage people to practise all kinds of sports, specially football". This was the last try to develop itself as a sports club rather than just as a football team, as Lomas, Belgrano and Quilmes had successfully done in the past, but the efforts were not enough. Alumni played its last game in 1911 and was definitely dissolved on April 24, 1913.
Rebirth through rugby
In 1951, two guards of the BAEHS, Daniel Ginhson (also a former player of Buenos Aires F.C.) and Guillermo Cubelli, supported by the school's alumni and fathers of the students, decided to establish a club focused on rugby union exclusively. Former players of Alumni football club and descendants of other players already dead gave their permission to use the name "Alumni".
On December 13, in a meeting presided by Carlos Bowers himself (who had proposed the name "Alumni" to the original football team 50 years before), the club was officially established under the name "Asociación Juvenil Alumni", also adopting the same colors as its predecessor.
The team achieved good results and in 1960 the club presented a team that won the third division of the Buenos Aires league, reaching the second division. Since then, Alumni has played at the highest level of Argentine rugby and its rivalry with Belgrano Athletic Club is one of the fiercest local derbies in Buenos Aires. Alumni would later climb up to the first division winning 5 titles: 4 consecutive between 1989 and 1992, and the other in 2001.
In 2002, Alumni won its first Nacional de Clubes title, defeating Jockey Club de Rosario 23–21 in the final.
Players
Current roster
As of January 2018:
Federico Lucca
Gaspar Baldunciel
Guido Cambareri
Iñaki Etchegaray
Bernardo Quaranta
Tobias Moyano
Mariano Romanini
Santiago Montagner
Tomas Passerotti
Lucas Frana
Luca Sabato
Franco Batezzatti
Franco Sabato
Rafael Desanto
Nito Provenzano
Tomas Bivort
Juan.P Ceraso
Santiago Alduncin
Juan.P Anderson
Lucas Magnasco
Joaquin Diaz Luzzi
Felipe Martignone
Tomas Corneille
Honours
Nacional de Clubes (1): 2002
Torneo de la URBA (6): 1989, 1990, 1991, 1992, 2001, 2018
References
External links
Rugby clubs established in 1951
A
1951 establishments in Argentina |
928 | https://en.wikipedia.org/wiki/Axiom | Axiom | An axiom, postulate, or assumption is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments. The word comes from the Ancient Greek word (), meaning 'that which is thought worthy or fit' or 'that which commends itself as evident'.
The precise definition varies across fields of study. In classic philosophy, an axiom is a statement that is so evident or well-established, that it is accepted without controversy or question. In modern logic, an axiom is a premise or starting point for reasoning.
In mathematics, an axiom may be a "logical axiom" or a "non-logical axiom". Logical axioms are taken to be true within the system of logic they define and are often shown in symbolic form (e.g., (A and B) implies A), while non-logical axioms are substantive assertions about the elements of the domain of a specific mathematical theory, for example a + 0 = a in integer arithmetic.
Non-logical axioms may also be called "postulates" or "assumptions". In most cases, a non-logical axiom is simply a formal logical expression used in deduction to build a mathematical theory, and might or might not be self-evident in nature (e.g., the parallel postulate in Euclidean geometry). To axiomatize a system of knowledge is to show that its claims can be derived from a small, well-understood set of sentences (the axioms), and there are typically many ways to axiomatize a given mathematical domain.
Any axiom is a statement that serves as a starting point from which other statements are logically derived. Whether it is meaningful (and, if so, what it means) for an axiom to be "true" is a subject of debate in the philosophy of mathematics.
Etymology
The word axiom comes from the Greek word (axíōma), a verbal noun from the verb (axioein), meaning "to deem worthy", but also "to require", which in turn comes from (áxios), meaning "being in balance", and hence "having (the same) value (as)", "worthy", "proper". Among the ancient Greek philosophers and mathematicians, axioms were taken to be immediately evident propositions, foundational and common to many fields of investigation, and self-evidently true without any further argument or proof.
The root meaning of the word postulate is to "demand"; for instance, Euclid demands that one agree that some things can be done (e.g., any two points can be joined by a straight line).
Ancient geometers maintained some distinction between axioms and postulates. While commenting on Euclid's books, Proclus remarks that "Geminus held that this [4th] Postulate should not be classed as a postulate but as an axiom, since it does not, like the first three Postulates, assert the possibility of some construction but expresses an essential property." Boethius translated 'postulate' as petitio and called the axioms notiones communes but in later manuscripts this usage was not always strictly kept.
Historical development
Early Greeks
The logico-deductive method whereby conclusions (new knowledge) follow from premises (old knowledge) through the application of sound arguments (syllogisms, rules of inference) was developed by the ancient Greeks, and has become the core principle of modern mathematics. Tautologies excluded, nothing can be deduced if nothing is assumed. Axioms and postulates are thus the basic assumptions underlying a given body of deductive knowledge. They are accepted without demonstration. All other assertions (theorems, in the case of mathematics) must be proven with the aid of these basic assumptions. However, the interpretation of mathematical knowledge has changed from ancient times to the modern, and consequently the terms axiom and postulate hold a slightly different meaning for the present day mathematician, than they did for Aristotle and Euclid.
The ancient Greeks considered geometry as just one of several sciences, and held the theorems of geometry on par with scientific facts. As such, they developed and used the logico-deductive method as a means of avoiding error, and for structuring and communicating knowledge. Aristotle's posterior analytics is a definitive exposition of the classical view.
An "axiom", in classical terminology, referred to a self-evident assumption common to many branches of science. A good example would be the assertion that:
When an equal amount is taken from equals, an equal amount results.
At the foundation of the various sciences lay certain additional hypotheses that were accepted without proof. Such a hypothesis was termed a postulate. While the axioms were common to many sciences, the postulates of each particular science were different. Their validity had to be established by means of real-world experience. Aristotle warns that the content of a science cannot be successfully communicated if the learner is in doubt about the truth of the postulates.
The classical approach is well-illustrated by Euclid's Elements, where a list of postulates is given (common-sensical geometric facts drawn from our experience), followed by a list of "common notions" (very basic, self-evident assertions).
Postulates
It is possible to draw a straight line from any point to any other point.
It is possible to extend a line segment continuously in both directions.
It is possible to describe a circle with any center and any radius.
It is true that all right angles are equal to one another.
("Parallel postulate") It is true that, if a straight line falling on two straight lines make the interior angles on the same side less than two right angles, the two straight lines, if produced indefinitely, intersect on that side on which are the angles less than the two right angles.
Common notions
Things which are equal to the same thing are also equal to one another.
If equals are added to equals, the wholes are equal.
If equals are subtracted from equals, the remainders are equal.
Things which coincide with one another are equal to one another.
The whole is greater than the part.
Modern development
A lesson learned by mathematics in the last 150 years is that it is useful to strip the meaning away from the mathematical assertions (axioms, postulates, propositions, theorems) and definitions. One must concede the need for primitive notions, or undefined terms or concepts, in any study. Such abstraction or formalization makes mathematical knowledge more general, capable of multiple different meanings, and therefore useful in multiple contexts. Alessandro Padoa, Mario Pieri, and Giuseppe Peano were pioneers in this movement.
Structuralist mathematics goes further, and develops theories and axioms (e.g. field theory, group theory, topology, vector spaces) without any particular application in mind. The distinction between an "axiom" and a "postulate" disappears. The postulates of Euclid are profitably motivated by saying that they lead to a great wealth of geometric facts. The truth of these complicated facts rests on the acceptance of the basic hypotheses. However, by throwing out Euclid's fifth postulate, one can get theories that have meaning in wider contexts (e.g., hyperbolic geometry). As such, one must simply be prepared to use labels such as "line" and "parallel" with greater flexibility. The development of hyperbolic geometry taught mathematicians that it is useful to regard postulates as purely formal statements, and not as facts based on experience.
When mathematicians employ the field axioms, the intentions are even more abstract. The propositions of field theory do not concern any one particular application; the mathematician now works in complete abstraction. There are many examples of fields; field theory gives correct knowledge about them all.
It is not correct to say that the axioms of field theory are "propositions that are regarded as true without proof." Rather, the field axioms are a set of constraints. If any given system of addition and multiplication satisfies these constraints, then one is in a position to instantly know a great deal of extra information about this system.
Modern mathematics formalizes its foundations to such an extent that mathematical theories can be regarded as mathematical objects, and mathematics itself can be regarded as a branch of logic. Frege, Russell, Poincaré, Hilbert, and Gödel are some of the key figures in this development.
Another lesson learned in modern mathematics is to examine purported proofs carefully for hidden assumptions.
In the modern understanding, a set of axioms is any collection of formally stated assertions from which other formally stated assertions follow – by the application of certain well-defined rules. In this view, logic becomes just another formal system. A set of axioms should be consistent; it should be impossible to derive a contradiction from the axioms. A set of axioms should also be non-redundant; an assertion that can be deduced from other axioms need not be regarded as an axiom.
It was the early hope of modern logicians that various branches of mathematics, perhaps all of mathematics, could be derived from a consistent collection of basic axioms. An early success of the formalist program was Hilbert's formalization of Euclidean geometry, and the related demonstration of the consistency of those axioms.
In a wider context, there was an attempt to base all of mathematics on Cantor's set theory. Here, the emergence of Russell's paradox and similar antinomies of naïve set theory raised the possibility that any such system could turn out to be inconsistent.
The formalist project suffered a setback a century ago, when Gödel showed that it is possible, for any sufficiently large set of axioms (Peano's axioms, for example) to construct a statement whose truth is independent of that set of axioms. As a corollary, Gödel proved that the consistency of a theory like Peano arithmetic is an unprovable assertion within the scope of that theory.
It is reasonable to believe in the consistency of Peano arithmetic because it is satisfied by the system of natural numbers, an infinite but intuitively accessible formal system. However, at present, there is no known way of demonstrating the consistency of the modern Zermelo–Fraenkel axioms for set theory. Furthermore, using techniques of forcing (Cohen) one can show that the continuum hypothesis (Cantor) is independent of the Zermelo–Fraenkel axioms. Thus, even this very general set of axioms cannot be regarded as the definitive foundation for mathematics.
Other sciences
Experimental sciences - as opposed to mathematics and logic - also have general founding assertions from which a deductive reasoning can be built so as to express propositions that predict properties - either still general or much more specialized to a specific experimental context. For instance, Newton's laws in classical mechanics, Maxwell's equations in classical electromagnetism, Einstein's equation in general relativity, Mendel's laws of genetics, Darwin's Natural selection law, etc. These founding assertions are usually called principles or postulates so as to distinguish from mathematical axioms.
As a matter of facts, the role of axioms in mathematics and postulates in experimental sciences is different. In mathematics one neither "proves" nor "disproves" an axiom. A set of mathematical axioms gives a set of rules that fix a conceptual realm, in which the theorems logically follow. In contrast, in experimental sciences, a set of postulates shall allow deducing results that match or do not match experimental results. If postulates do not allow deducing experimental predictions, they do not set a scientific conceptual framework and have to be completed or made more accurate. If the postulates allow deducing predictions of experimental results, the comparison with experiments allows falsifying (falsified) the theory that the postulates install. A theory is considered valid as long as it has not been falsified.
Now, the transition between the mathematical axioms and scientific postulates is always slightly blurred, especially in physics. This is due to the heavy use of mathematical tools to support the physical theories. For instance, the introduction of Newton's laws rarely establishes as a prerequisite neither Euclidean geometry or differential calculus that they imply. It became more apparent when Albert Einstein first introduced special relativity where the invariant quantity is no more the Euclidean length (defined as ) > but the Minkowski spacetime interval (defined as ), and then general relativity where flat Minkowskian geometry is replaced with pseudo-Riemannian geometry on curved manifolds.
In quantum physics, two sets of postulates have coexisted for some time, which provide a very nice example of falsification. The 'Copenhagen school' (Niels Bohr, Werner Heisenberg, Max Born) developed an operational approach with a complete mathematical formalism that involves the description of quantum system by vectors ('states') in a separable Hilbert space, and physical quantities as linear operators that act in this Hilbert space. This approach is fully falsifiable and has so far produced the most accurate predictions in physics. But it has the unsatisfactory aspect of not allowing answers to questions one would naturally ask. For this reason, another 'hidden variables' approach was developed for some time by Albert Einstein, Erwin Schrödinger, David Bohm. It was created so as to try to give deterministic explanation to phenomena such as entanglement. This approach assumed that the Copenhagen school description was not complete, and postulated that some yet unknown variable was to be added to the theory so as to allow answering some of the questions it does not answer (the founding elements of which were discussed as the EPR paradox in 1935). Taking this ideas seriously, John Bell derived in 1964 a prediction that would lead to different experimental results (Bell's inequalities) in the Copenhagen and the Hidden variable case. The experiment was conducted first by Alain Aspect in the early 1980's, and the result excluded the simple hidden variable approach (sophisticated hidden variables could still exist but their properties would still be more disturbing than the problems they try to solve). This does not mean that the conceptual framework of quantum physics can be considered as complete now, since some open questions still exist (the limit between the quantum and classical realms, what happens during a quantum measurement, what happens in a completely closed quantum system such as the universe itself, etc.).
Mathematical logic
In the field of mathematical logic, a clear distinction is made between two notions of axioms: logical and non-logical (somewhat similar to the ancient distinction between "axioms" and "postulates" respectively).
Logical axioms
These are certain formulas in a formal language that are universally valid, that is, formulas that are satisfied by every assignment of values. Usually one takes as logical axioms at least some minimal set of tautologies that is sufficient for proving all tautologies in the language; in the case of predicate logic more logical axioms than that are required, in order to prove logical truths that are not tautologies in the strict sense.
Examples
Propositional logic
In propositional logic it is common to take as logical axioms all formulae of the following forms, where , , and can be any formulae of the language and where the included primitive connectives are only "" for negation of the immediately following proposition and "" for implication from antecedent to consequent propositions:
Each of these patterns is an axiom schema, a rule for generating an infinite number of axioms. For example, if , , and are propositional variables, then and are both instances of axiom schema 1, and hence are axioms. It can be shown that with only these three axiom schemata and modus ponens, one can prove all tautologies of the propositional calculus. It can also be shown that no pair of these schemata is sufficient for proving all tautologies with modus ponens.
Other axiom schemata involving the same or different sets of primitive connectives can be alternatively constructed.
These axiom schemata are also used in the predicate calculus, but additional logical axioms are needed to include a quantifier in the calculus.
First-order logic
Axiom of Equality.Let be a first-order language. For each variable , the below formula is universally valid.
This means that, for any variable symbol , the formula can be regarded as an axiom. Also, in this example, for this not to fall into vagueness and a never-ending series of "primitive notions", either a precise notion of what we mean by (or, for that matter, "to be equal") has to be well established first, or a purely formal and syntactical usage of the symbol has to be enforced, only regarding it as a string and only a string of symbols, and mathematical logic does indeed do that.
Another, more interesting example axiom scheme, is that which provides us with what is known as Universal Instantiation:
Axiom scheme for Universal Instantiation.Given a formula in a first-order language , a variable and a term that is substitutable for in , the below formula is universally valid.
Where the symbol stands for the formula with the term substituted for . (See Substitution of variables.) In informal terms, this example allows us to state that, if we know that a certain property holds for every and that stands for a particular object in our structure, then we should be able to claim . Again, we are claiming that the formula is valid, that is, we must be able to give a "proof" of this fact, or more properly speaking, a metaproof. These examples are metatheorems of our theory of mathematical logic since we are dealing with the very concept of proof itself. Aside from this, we can also have Existential Generalization:
Axiom scheme for Existential Generalization. Given a formula in a first-order language , a variable and a term that is substitutable for in , the below formula is universally valid.
Non-logical axioms
Non-logical axioms are formulas that play the role of theory-specific assumptions. Reasoning about two different structures, for example, the natural numbers and the integers, may involve the same logical axioms; the non-logical axioms aim to capture what is special about a particular structure (or set of structures, such as groups). Thus non-logical axioms, unlike logical axioms, are not tautologies. Another name for a non-logical axiom is postulate.
Almost every modern mathematical theory starts from a given set of non-logical axioms, and it was thought that, in principle, every theory could be axiomatized in this way and formalized down to the bare language of logical formulas.
Non-logical axioms are often simply referred to as axioms in mathematical discourse. This does not mean that it is claimed that they are true in some absolute sense. For example, in some groups, the group operation is commutative, and this can be asserted with the introduction of an additional axiom, but without this axiom, we can do quite well developing (the more general) group theory, and we can even take its negation as an axiom for the study of non-commutative groups.
Thus, an axiom is an elementary basis for a formal logic system that together with the rules of inference define a deductive system.
Examples
This section gives examples of mathematical theories that are developed entirely from a set of non-logical axioms (axioms, henceforth). A rigorous treatment of any of these topics begins with a specification of these axioms.
Basic theories, such as arithmetic, real analysis and complex analysis are often introduced non-axiomatically, but implicitly or explicitly there is generally an assumption that the axioms being used are the axioms of Zermelo–Fraenkel set theory with choice, abbreviated ZFC, or some very similar system of axiomatic set theory like Von Neumann–Bernays–Gödel set theory, a conservative extension of ZFC. Sometimes slightly stronger theories such as Morse–Kelley set theory or set theory with a strongly inaccessible cardinal allowing the use of a Grothendieck universe is used, but in fact, most mathematicians can actually prove all they need in systems weaker than ZFC, such as second-order arithmetic.
The study of topology in mathematics extends all over through point set topology, algebraic topology, differential topology, and all the related paraphernalia, such as homology theory, homotopy theory. The development of abstract algebra brought with itself group theory, rings, fields, and Galois theory.
This list could be expanded to include most fields of mathematics, including measure theory, ergodic theory, probability, representation theory, and differential geometry.
Arithmetic
The Peano axioms are the most widely used axiomatization of first-order arithmetic. They are a set of axioms strong enough to prove many important facts about number theory and they allowed Gödel to establish his famous second incompleteness theorem.
We have a language where is a constant symbol and is a unary function and the following axioms:
for any formula with one free variable.
The standard structure is where is the set of natural numbers, is the successor function and is naturally interpreted as the number 0.
Euclidean geometry
Probably the oldest, and most famous, list of axioms are the 4 + 1 Euclid's postulates of plane geometry. The axioms are referred to as "4 + 1" because for nearly two millennia the fifth (parallel) postulate ("through a point outside a line there is exactly one parallel") was suspected of being derivable from the first four. Ultimately, the fifth postulate was found to be independent of the first four. One can assume that exactly one parallel through a point outside a line exists, or that infinitely many exist. This choice gives us two alternative forms of geometry in which the interior angles of a triangle add up to exactly 180 degrees or less, respectively, and are known as Euclidean and hyperbolic geometries. If one also removes the second postulate ("a line can be extended indefinitely") then elliptic geometry arises, where there is no parallel through a point outside a line, and in which the interior angles of a triangle add up to more than 180 degrees.
Real analysis
The objectives of the study are within the domain of real numbers. The real numbers are uniquely picked out (up to isomorphism) by the properties of a Dedekind complete ordered field, meaning that any nonempty set of real numbers with an upper bound has a least upper bound. However, expressing these properties as axioms requires the use of second-order logic. The Löwenheim–Skolem theorems tell us that if we restrict ourselves to first-order logic, any axiom system for the reals admits other models, including both models that are smaller than the reals and models that are larger. Some of the latter are studied in non-standard analysis.
Role in mathematical logic
Deductive systems and completeness
A deductive system consists of a set of logical axioms, a set of non-logical axioms, and a set of rules of inference. A desirable property of a deductive system is that it be complete. A system is said to be complete if, for all formulas ,
that is, for any statement that is a logical consequence of there actually exists a deduction of the statement from . This is sometimes expressed as "everything that is true is provable", but it must be understood that "true" here means "made true by the set of axioms", and not, for example, "true in the intended interpretation". Gödel's completeness theorem establishes the completeness of a certain commonly used type of deductive system.
Note that "completeness" has a different meaning here than it does in the context of Gödel's first incompleteness theorem, which states that no recursive, consistent set of non-logical axioms of the Theory of Arithmetic is complete, in the sense that there will always exist an arithmetic statement such that neither nor can be proved from the given set of axioms.
There is thus, on the one hand, the notion of completeness of a deductive system and on the other hand that of completeness of a set of non-logical axioms. The completeness theorem and the incompleteness theorem, despite their names, do not contradict one another.
Further discussion
Early mathematicians regarded axiomatic geometry as a model of physical space, and obviously, there could only be one such model. The idea that alternative mathematical systems might exist was very troubling to mathematicians of the 19th century and the developers of systems such as Boolean algebra made elaborate efforts to derive them from traditional arithmetic. Galois showed just before his untimely death that these efforts were largely wasted. Ultimately, the abstract parallels between algebraic systems were seen to be more important than the details, and modern algebra was born. In the modern view, axioms may be any set of formulas, as long as they are not known to be inconsistent.
See also
Axiomatic system
Dogma
First principle, axiom in science and philosophy
List of axioms
Model theory
Regulæ Juris
Theorem
Presupposition
Principle
Notes
References
Further reading
Mendelson, Elliot (1987). Introduction to mathematical logic. Belmont, California: Wadsworth & Brooks.
External links
Metamath axioms page
Concepts in logic |
929 | https://en.wikipedia.org/wiki/Alpha | Alpha | Alpha (uppercase , lowercase ; , , or ) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , which is the West Semitic word for "ox". Letters that arose from alpha include the Latin letter A and the Cyrillic letter А.
Uses
Greek
In Ancient Greek, alpha was pronounced and could be either phonemically long ([aː]) or short ([a]). Where there is ambiguity, long and short alpha are sometimes written with a macron and breve today: .
= "a time"
= "tongue"
In Modern Greek, vowel length has been lost, and all instances of alpha simply represent the open front unrounded vowel .
In the polytonic orthography of Greek, alpha, like other vowel letters, can occur with several diacritic marks: any of three accent symbols (), and either of two breathing marks (), as well as combinations of these. It can also combine with the iota subscript ().
Greek grammar
In the Attic–Ionic dialect of Ancient Greek, long alpha fronted to (eta). In Ionic, the shift took place in all positions. In Attic, the shift did not take place after epsilon, iota, and rho (; ). In Doric and Aeolic, long alpha is preserved in all positions.
Doric, Aeolic, Attic – Ionic , "country"
Doric, Aeolic – Attic, Ionic , "report"
Privative a is the Ancient Greek prefix or , added to words to negate them. It originates from the Proto-Indo-European * (syllabic nasal) and is cognate with English un-.
Copulative a is the Greek prefix or . It comes from Proto-Indo-European *.
Mathematics and science
The letter alpha represents various concepts in physics and chemistry, including alpha radiation, angular acceleration, alpha particles, alpha carbon and strength of electromagnetic interaction (as fine-structure constant). Alpha also stands for thermal expansion coefficient of a compound in physical chemistry. It is also commonly used in mathematics in algebraic solutions representing quantities such as angles. Furthermore, in mathematics, the letter alpha is used to denote the area underneath a normal curve in statistics to denote significance level when proving null and alternative hypotheses. In ethology, it is used to name the dominant individual in a group of animals. In aerodynamics, the letter is used as a symbol for the angle of attack of an aircraft and the word "alpha" is used as a synonym for this property. In mathematical logic, α is sometimes used as a placeholder for ordinal numbers.
The proportionality operator "∝" (in Unicode: U+221D) is sometimes mistaken for alpha.
The uppercase letter alpha is not generally used as a symbol because it tends to be rendered identically to the uppercase Latin A.
International Phonetic Alphabet
In the International Phonetic Alphabet, the letter ɑ, which looks similar to the lower-case alpha, represents the open back unrounded vowel.
History and symbolism
Origin
The Phoenician alphabet was adopted for Greek in the early 8th century BC, perhaps in Euboea.
The majority of the letters of the Phoenician alphabet were adopted into Greek with much the same sounds as they had had in Phoenician, but ʼāleph, the Phoenician letter representing the glottal stop ,
was adopted as representing the vowel ; similarly, hē and ʽayin are Phoenician consonants that became Greek vowels, epsilon and omicron , respectively.
Plutarch
Plutarch, in Moralia, presents a discussion on why the letter alpha stands first in the alphabet. Ammonius asks Plutarch what he, being a Boeotian, has to say for Cadmus, the Phoenician who reputedly settled in Thebes and introduced the alphabet to Greece, placing alpha first because it is the Phoenician name for ox—which, unlike Hesiod, the Phoenicians considered not the second or third, but the first of all necessities. "Nothing at all," Plutarch replied. He then added that he would rather be assisted by Lamprias, his own grandfather, than by Dionysus' grandfather, i.e. Cadmus. For Lamprias had said that the first articulate sound made is "alpha", because it is very plain and simple—the air coming off the mouth does not require any motion of the tongue—and therefore this is the first sound that children make.
According to Plutarch's natural order of attribution of the vowels to the planets, alpha was connected with the Moon.
Alpha and Omega
As the first letter of the alphabet, Alpha as a Greek numeral came to represent the number 1.
Therefore, Alpha, both as a symbol and term, is used to refer to the "first", or "primary", or "principal" (most significant) occurrence or status of a thing.
The New Testament has God declaring himself to be the "Alpha and Omega, the beginning and the end, the first and the last." (Revelation 22:13, KJV, and see also 1:8).
Consequently, the term "alpha" has also come to be used to denote "primary" position in social hierarchy, examples being the concept of dominant "alpha" members in groups of animals.
Computer encodings
Greek alpha / Coptic alfa
For accented Greek characters, see Greek diacritics: Computer encoding.
Latin / IPA alpha
Mathematical / Technical alpha
References
Greek letters
Vowel letters |
930 | https://en.wikipedia.org/wiki/Alvin%20Toffler | Alvin Toffler | Alvin Eugene Toffler (October 4, 1928 – June 27, 2016) was an American writer, futurist, and businessman known for his works discussing modern technologies, including the digital revolution and the communication revolution, with emphasis on their effects on cultures worldwide. He is regarded as one of the world's outstanding futurists.
Toffler was an associate editor of Fortune magazine. In his early works he focused on technology and its impact, which he termed "information overload". In 1970, his first major book about the future, Future Shock, became a worldwide best-seller and has sold over 6 million copies.
He and his wife Heidi Toffler (1929–2019), who collaborated with him for most of his writings, moved on to examining the reaction to changes in society with another best-selling book, The Third Wave, in 1980. In it, he foresaw such technological advances as cloning, personal computers, the Internet, cable television and mobile communication. His later focus, via their other best-seller, Powershift, (1990), was on the increasing power of 21st-century military hardware and the proliferation of new technologies.
He founded Toffler Associates, a management consulting company, and was a visiting scholar at the Russell Sage Foundation, visiting professor at Cornell University, faculty member of the New School for Social Research, a White House correspondent, and a business consultant. Toffler's ideas and writings were a significant influence on the thinking of business and government leaders worldwide, including China's Zhao Ziyang, and AOL founder Steve Case.
Early life
Alvin Toffler was born on October 4, 1928, in New York City, and raised in Brooklyn. He was the son of Rose (Albaum) and Sam Toffler, a furrier, both Polish Jews who had migrated to America. He had one younger sister. He was inspired to become a writer at the age of 7 by his aunt and uncle, who lived with the Tofflers. "They were Depression-era literary intellectuals," Toffler said, "and they always talked about exciting ideas."
Toffler graduated from New York University in 1950 as an English major, though by his own account he was more focused on political activism than grades. He met his future wife, Adelaide Elizabeth Farrell (nicknamed "Heidi"), when she was starting a graduate course in linguistics. Being radical students, they decided against further graduate work and moved to Cleveland, Ohio, where they married on April 29, 1950.
Career
Seeking experiences to write about, Alvin and Heidi Toffler spent the next five years as blue collar workers on assembly lines while studying industrial mass production in their daily work. He compared his own desire for experience to other writers, such as Jack London, who in his quest for subjects to write about sailed the seas, and John Steinbeck, who went to pick grapes with migrant workers. In their first factory jobs, Heidi became a union shop steward in the aluminum foundry where she worked. Alvin became a millwright and welder. In the evenings Alvin would write poetry and fiction, but discovered he was proficient at neither.
His hands-on practical labor experience helped Alvin Toffler land a position at a union-backed newspaper, a transfer to its Washington bureau in 1957, then three years as a White House correspondent, covering Congress and the White House for a Pennsylvania daily newspaper.
They returned to New York City in 1959 when Fortune magazine invited Alvin to become its labor columnist, later having him write about business and management. After leaving Fortune magazine in 1962, Toffler began a freelance career, writing long form articles for scholarly journals and magazines. His 1964 Playboy interviews with Russian novelist Vladimir Nabokov and Ayn Rand were considered among the magazine's best. His interview with Rand was the first time the magazine had given such a platform to a female intellectual, which as one commentator said, "the real bird of paradise Toffler captured for Playboy in 1964 was Ayn Rand."
Toffler was hired by IBM to conduct research and write a paper on the social and organizational impact of computers, leading to his contact with the earliest computer "gurus" and artificial intelligence researchers and proponents. Xerox invited him to write about its research laboratory and AT&T consulted him for strategic advice. This AT&T work led to a study of telecommunications, which advised the company's top management to break up the company more than a decade before the government forced AT&T to break up.
In the mid-1960s, the Tofflers began five years of research on what would become Future Shock, published in 1970. It has sold over 6 million copies worldwide, according to the New York Times, or over 15 million copies according to the Tofflers' Web site. Toffler coined the term "future shock" to refer to what happens to a society when change happens too fast, which results in social confusion and normal decision-making processes breaking down. The book has never been out of print and has been translated into dozens of languages.
He continued the theme in The Third Wave in 1980. While he describes the first and second waves as the agricultural and industrial revolutions, the "third wave," a phrase he coined, represents the current information, computer-based revolution. He forecast the spread of the Internet and email, interactive media, cable television, cloning, and other digital advancements. He claimed that one of the side effects of the digital age has been "information overload," another term he coined. In 1990, he wrote Powershift, also with the help of his wife, Heidi.
In 1996, with American business consultant Tom Johnson, they co-founded Toffler Associates, an advisory firm designed to implement many of the ideas the Tofflers had written on. The firm worked with businesses, NGOs, and governments in the United States, South Korea, Mexico, Brazil, Singapore, Australia, and other countries. During this period in his career, Toffler lectured worldwide, taught at several schools and met world leaders, such as Mikhail Gorbachev, along with key executives and military officials.
Ideas and opinions
Toffler stated many of his ideas during an interview with the Australian Broadcasting Corporation in 1998. "Society needs people who take care of the elderly and who know how to be compassionate and honest," he said. "Society needs people who work in hospitals. Society needs all kinds of skills that are not just cognitive; they're emotional, they're affectional. You can't run the society on data and computers alone."
His opinions about the future of education, many of which were in Future Shock, have often been quoted. An often misattributed quote, however, is that of psychologist Herbert Gerjuoy: "Tomorrow's illiterate will not be the man who can't read; he will be the man who has not learned how to learn."
Early in his career, after traveling to other countries, he became aware of the new and myriad inputs that visitors received from these other cultures. He explained during an interview that some visitors would become "truly disoriented and upset" by the strange environment, which he described as a reaction to culture shock. From that issue, he foresaw another problem for the future, when a culturally "new environment comes to you ... and comes to you rapidly." That kind of sudden cultural change within one's own country, which he felt many would not understand, would lead to a similar reaction, one of "future shock", which he wrote about in his book by that title. Toffler writes:
In The Third Wave, Toffler describes three types of societies, based on the concept of "waves"—each wave pushes the older societies and cultures aside. He describes the "First Wave" as the society after agrarian revolution and replaced the first hunter-gatherer cultures. The "Second Wave," he labels society during the Industrial Revolution (ca. late 17th century through the mid-20th century). That period saw the increase of urban industrial populations which had undermined the traditional nuclear family, and initiated a factory-like education system, and the growth of the corporation. Toffler said:
The "Third Wave" was a term he coined to describe the post-industrial society, which began in the late 1950s. His description of this period dovetails with other futurist writers, who also wrote about the Information Age, Space Age, Electronic Era, Global Village, terms which highlighted a scientific-technological revolution. The Tofflers claimed to have predicted a number of geopolitical events, such as the collapse of the Soviet Union, the fall of the Berlin Wall and the future economic growth in the Asia-Pacific region.
Influences and popular culture
Toffler often visited with dignitaries in Asia, including China's Zhao Ziyang, Singapore's Lee Kuan Yew and South Korea's Kim Dae Jung, all of whom were influenced by his views as Asia's emerging markets increased in global significance during the 1980s and 1990s. Although they had originally censored some of his books and ideas, China's government cited him along with Franklin Roosevelt and Bill Gates as being among the Westerners who had most influenced their country. The Third Wave along with a video documentary based on it became best-sellers in China and were widely distributed to schools. The video's success inspired the marketing of videos on related themes in the late 1990s by Infowars, whose name is derived from the term coined by Toffler in the book. Toffler's influence on Asian thinkers was summed up in an article in Daedalus, published by the American Academy of Arts & Sciences:
U.S. House Speaker Newt Gingrich publicly lauded his ideas about the future, and urged members of Congress to read Toffler's book, Creating a New Civilization (1995). Others, such as AOL founder Steve Case, cited Toffler's The Third Wave as a formative influence on his thinking, which inspired him to write The Third Wave: An Entrepreneur's Vision of the Future in 2016. Case said that Toffler was a "real pioneer in helping people, companies and even countries lean into the future."
In 1980, Ted Turner founded CNN, which he said was inspired by Toffler's forecasting the end of the dominance of the three main television networks. Turner's company, Turner Broadcasting, published Toffler's Creating a New Civilization in 1995. Shortly after the book was released, the former Soviet president Mikhail Gorbachev hosted the Global Governance Conference in San Francisco with the theme, Toward a New Civilization, which was attended by dozens of world figures, including the Tofflers, George H. W. Bush, Margaret Thatcher, Carl Sagan, Abba Eban and Turner with his then-wife, actress Jane Fonda.
Mexican billionaire Carlos Slim was influenced by his works, and became a friend of the writer. Global marketer J.D. Power also said he was inspired by Toffler's works.
Since the 1960s, people had tried to make sense out of the effect of new technologies and social change, a problem which made Toffler's writings widely influential beyond the confines of scientific, economic, and public policy. His works and ideas have been subject to various criticisms, usually with the same argumentation used against futurology: that foreseeing the future is nigh impossible.
Techno music pioneer Juan Atkins cites Toffler's phrase "techno rebels" in The Third Wave as inspiring him to use the word "techno" to describe the musical style he helped to create
Musician Curtis Mayfield released a disco song called "Future Shock," later covered in an electro version by Herbie Hancock. Science fiction author John Brunner wrote "The Shockwave Rider," from the concept of "future shock."
The nightclub Toffler, in Rotterdam, is named after him.
In the song "Victoria" by The Exponents, the protagonist's daily routine and cultural interests are described: "She's up in time to watch the soap operas, reads Cosmopolitan and Alvin Toffler".
Critical assessment
Accenture, the management consultancy firm, identified Toffler in 2002 as being among the most influential voices in business leaders, along with Bill Gates and Peter Drucker. Toffler has also been described in a Financial Times interview as the "world's most famous futurologist". In 2006, the People's Daily classed him among the 50 foreigners who shaped modern China, which one U.S. newspaper notes made him a "guru of sorts to world statesmen." Chinese Premier and General Secretary Zhao Ziyang was greatly influenced by Toffler. He convened conferences to discuss The Third Wave in the early 1980s, and in 1985 the book was the No. 2 best seller in China.
Author Mark Satin characterizes Toffler as an important early influence on radical centrist political thought.
Newt Gingrich became close to the Tofflers in the 1970s and said The Third Wave had immensely influenced his own thinking and was "one of the great seminal works of our time."
Selected awards
Toffler has received several prestigious prizes and awards, including the McKinsey Foundation Book Award for Contributions to Management Literature, Officier de L'Ordre des Arts et Lettres, and appointments, including Fellow of the American Association for the Advancement of Science and the International Institute for Strategic Studies.
In 2006, Alvin and Heidi Toffler were recipients of Brown University's Independent Award.
Personal life
Toffler was married to Heidi Toffler (born Adelaide Elizabeth Farrell), also a writer and futurist. They lived in the Bel Air section of Los Angeles, California, and previously lived in Redding, Connecticut.
The couple's only child, Karen Toffler (1954–2000), died at age 46 after more than a decade suffering from Guillain–Barré syndrome.
Alvin Toffler died in his sleep on June 27, 2016, at his home in Los Angeles. No cause of death was given. He is buried at Westwood Memorial Park.
Bibliography
Alvin Toffler co-wrote his books with his wife Heidi.
The Culture Consumers (1964) St. Martin's Press,
The Schoolhouse in the City (1968) Praeger (editors),
Future Shock (1970) Bantam Books,
The Futurists (1972) Random House (editors),
Learning for Tomorrow (1974) Random House (editors),
The Eco-Spasm Report (1975) Bantam Books,
The Third Wave (1980) Bantam Books,
Previews & Premises (1983) William Morrow & Co,
The Adaptive Corporation (1985) McGraw-Hill,
Powershift: Knowledge, Wealth and Violence at the Edge of the 21st Century (1990) Bantam Books,
War and Anti-War (1993) Warner Books,
Creating a New Civilization (1995) Turner Pub,
Revolutionary Wealth (2006) Knopf,
See also
Daniel Bell
Norman Swan
Human nature
John Naisbitt
References
External links
– official Alvin Toffler site
Toffler Associates
Interview with Alvin Toffler by the World Affairs Council
Discuss Alvin Toffler's Future Shock with other readers, BookTalk.org
Future Shock Forum 2018
Finding aid to the Alvin and Heidi Toffler papers at Columbia University. Rare Book & Manuscript Library
1928 births
2016 deaths
American people of Polish-Jewish descent
American technology writers
American futurologists
Burials at Westwood Village Memorial Park Cemetery
Jewish American writers
People from Ridgefield, Connecticut
Writers from Connecticut
Writers from Brooklyn
20th-century American non-fiction writers
21st-century American non-fiction writers
American transhumanists
New York University alumni
Singularitarians
People from Redding, Connecticut
20th-century American male writers
American male non-fiction writers
Jewish American journalists
People from Bel Air, Los Angeles
21st-century American male writers
21st-century American Jews |
931 | https://en.wikipedia.org/wiki/The%20Amazing%20Spider-Man | The Amazing Spider-Man | The Amazing Spider-Man is an ongoing American superhero comic book series featuring the Marvel Comics superhero Spider-Man as its title character and main protagonist. Being in the mainstream continuity of the franchise, it was the character's first title, launching seven months after his introduction in the final issue of Amazing Fantasy. The series began publication with a March 1963 cover date and has been published nearly continuously to date over six volumes with only one significant interruption. Issues of the title currently feature an issue number within its sixth volume, as well as a "legacy" number reflecting the issue's overall number across all Amazing Spider-Man volumes. The title reached 900 issues in 2022.
The series began as a bimonthly periodical before being increased to monthly after four issues. It was the character's sole monthly headlining title until Peter Parker, the Spectacular Spider-Man launched in 1978. After 441 issues, The Amazing Spider-Man was restarted in 1999 as issue No. 1 of Volume 2. It ran for 58 issues before reverting to the title's overall issue number with #500 in 2003. The series ran essentially continuously over the first two volumes from 1963 until its landmark 700th issue at the end of 2012 when it was replaced by The Superior Spider-Man as part of the Marvel NOW! relaunch of Marvel's comic lines. The title was occasionally published biweekly during the first two volumes, and was published three times a month from 2008 to 2010. After the relaunch of Action Comics and Detective Comics, The Amazing Spider-Man briefly became the highest-numbered active American comic book.
The Amazing Spider-Man returned with volume 3 in April 2014 following the conclusion of The Superior Spider-Man story arc after 31 issues. In late 2015, the series was relaunched with a fourth volume following the 2015 Secret Wars event. After 45 years , the volume was once again relaunched as part of Marvel Legacy, returning to the overall "legacy" numbering with issue No. 789 in late 2017. Less than a year later, the series was relaunched again with a fifth volume as part of Marvel's Fresh Start. For the first time, although the issue numbers were again restarted from #1, the issues also bore the overall "legacy" issue number. A sixth volume commenced in April 2022 to celebrate Spider-Man's 60th anniversary. Since the second volume, the title has had various release schedules, including monthly and bi-weekly, among others.
Publication history
Writer-editor Stan Lee and artist and co-plotter Steve Ditko created the character of Spider-Man, and the pair produced 38 issues from March 1963 to July 1966. Ditko left after the 38th issue, while Lee remained as writer until issue 100. Since then, many writers and artists have taken over the monthly comic through the years, chronicling the adventures of Marvel's most identifiable hero.
The Amazing Spider-Man has been the character's flagship series for his first fifty years in publication, and was the only monthly series to star Spider-Man until Peter Parker, The Spectacular Spider-Man, in 1976, although 1972 saw the debut of Marvel Team-Up, with the vast majority of issues featuring Spider-Man along with a rotating cast of other Marvel characters. Most of the major characters and villains of the Spider-Man saga have been introduced in Amazing, and with few exceptions, it is where most key events in the character's history have occurred. The title was published continuously until No. 441 (Nov. 1998) when Marvel Comics relaunched it as vol. 2 No. 1 (Jan. 1999), but on Spider-Man's 40th anniversary, this new title reverted to using the numbering of the original series, beginning again with issue No. 500 (Dec. 2003) and lasting until the final issue, No. 700 (Feb. 2013).
1960s
Due to strong sales on the character's first appearance in Amazing Fantasy No. 15, Spider-Man was given his own ongoing series in March 1963. The initial years of the series, under Lee and Ditko, chronicled Spider-Man's nascent career as a masked super-human vigilante with his civilian life as hard-luck yet perpetually good-humored and well-meaning teenager Peter Parker. Peter balanced his career as Spider-Man with his job as a freelance photographer for The Daily Bugle under the bombastic editor-publisher J. Jonah Jameson to support himself and his frail Aunt May. At the same time, Peter dealt with public hostility towards Spider-Man and the antagonism of his classmates Flash Thompson and Liz Allan at Midtown High School, while embarking on a tentative, ill-fated romance with Jameson's secretary, Betty Brant.
By focusing on Parker's everyday problems, Lee and Ditko created a groundbreakingly flawed, self-doubting superhero, and the first major teenaged superhero to be a protagonist and not a sidekick. Ditko's quirky art provided a stark contrast to the more cleanly dynamic stylings of Marvel's most prominent artist, Jack Kirby, and combined with the humor and pathos of Lee's writing to lay the foundation for what became an enduring mythos.
Most of Spider-Man's key villains and supporting characters were introduced during this time. Issue No. 1 (Mar. 1963) featured the first appearances of J. Jonah Jameson and his astronaut son John Jameson, and the supervillain the Chameleon. It included the hero's first encounter with the superhero team the Fantastic Four. Issue No. 2 (May 1963) featured the first appearance of the Vulture and the Tinkerer as well as the beginning of Parker's freelance photography career at the newspaper The Daily Bugle.
The Lee-Ditko era continued to usher in a significant number of villains and supporting characters, including Doctor Octopus in No. 3 (July 1963); the Sandman and Betty Brant in No. 4 (Sept. 1963); the Lizard in No. 6 (Nov. 1963); Living Brain in No. 8 (Jan. 1964); Electro in No. 9 (Mar. 1964); Mysterio in No. 13 (June 1964); the Green Goblin in No. 14 (July 1964); Kraven The Hunter in No. 15 (Aug. 1964); reporter Ned Leeds in No. 18 (Nov. 1964); and the Scorpion in No. 20 (Jan. 1965). The Molten Man was introduced in No. 28 (Sept. 1965) which also featured Parker's graduation from high school. Peter began attending Empire State University in No. 31 (Dec. 1965), which featured the first appearances of friends and classmates Gwen Stacy and Harry Osborn. Harry's father, Norman Osborn first appeared in No. 23 (April 1965) as a member of Jameson's country club but was not named nor revealed as Harry's father until No. 37 (June 1966).
One of the most celebrated issues of the Lee-Ditko run is No. 33 (Feb. 1966), the third part of the story arc "If This Be My Destiny...!", which features the dramatic scene of Spider-Man, through force of will and thoughts of family, escaping from being pinned by heavy machinery. Comics historian Les Daniels noted that "Steve Ditko squeezes every ounce of anguish out of Spider-Man's predicament, complete with visions of the uncle he failed and the aunt he has sworn to save." Peter David observed that "After his origin, this two-page sequence from Amazing Spider-Man No. 33 is perhaps the best-loved sequence from the Stan Lee/Steve Ditko era." Steve Saffel stated the "full page Ditko image from The Amazing Spider-Man No. 33 is one of the most powerful ever to appear in the series and influenced writers and artists for many years to come." and Matthew K. Manning wrote that "Ditko's illustrations for the first few pages of this Lee story included what would become one of the most iconic scenes in Spider-Man's history." The story was chosen as No. 15 in the 100 Greatest Marvels of All Time poll of Marvel's readers in 2001. Editor Robert Greenberger wrote in his introduction to the story that "These first five pages are a modern-day equivalent to Shakespeare as Parker's soliloquy sets the stage for his next action. And with dramatic pacing and storytelling, Ditko delivers one of the great sequences in all comics."
Although credited only as artist for most of his run, Ditko would eventually plot the stories as well as draw them, leaving Lee to script the dialogue. A rift between Ditko and Lee developed, and the two men were not on speaking terms long before Ditko completed his last issue, The Amazing Spider-Man No. 38 (July 1966). The exact reasons for the Ditko-Lee split have never been fully explained. Spider-Man successor artist John Romita Sr., in a 2010 deposition, recalled that Lee and Ditko "ended up not being able to work together because they disagreed on almost everything, cultural, social, historically, everything, they disagreed on characters..."
In successor penciler Romita Sr.'s first issue, No. 39 (Aug. 1966), nemesis the Green Goblin discovers Spider-Man's secret identity and reveals his own to the captive hero. Romita's Spider-Man – more polished and heroic-looking than Ditko's – became the model for two decades. The Lee-Romita era saw the introduction of such characters as Daily Bugle managing editor Robbie Robertson in No. 52 (Sept. 1967) and NYPD Captain George Stacy, father of Parker's girlfriend Gwen Stacy, in No. 56 (Jan. 1968). The most important supporting character to be introduced during the Romita era was Mary Jane Watson, who made her first full appearance in No. 42 (Nov. 1966), although she first appeared in No. 25 (June 1965) with her face obscured and had been mentioned since No. 15 (Aug. 1964). Peter David wrote in 2010 that Romita "made the definitive statement of his arrival by pulling Mary Jane out from behind the oversized potted plant [that blocked the reader's view of her face in issue no. 25] and placing her on panel in what would instantly become an iconic moment." Romita has stated that in designing Mary Jane, he "used Ann-Margret from the movie Bye Bye Birdie as a guide, using her coloring, the shape of her face, her red hair and her form-fitting short skirts."
Lee and Romita toned down the prevalent sense of antagonism in Parker's world by improving Parker's relationship with the supporting characters and having stories focused as much on the social and college lives of the characters as they did on Spider-Man's adventures. The stories became more topical, addressing issues such as civil rights, racism, prisoners' rights, the Vietnam War, and political elections.
Issue No. 50 (June 1967) introduced the highly enduring criminal mastermind the Kingpin, who would become a major force as well in the superhero series Daredevil. Other notable first appearances in the Lee-Romita era include the Rhino in No. 41 (Oct. 1966), the Shocker in No. 46 (Mar. 1967), the Prowler in No. 78 (Nov. 1969), and the Kingpin's son, Richard Fisk, in No. 83 (Apr. 1970).
1970s
Several spin-off series debuted in the 1970s: Marvel Team-Up in 1972, and The Spectacular Spider-Man in 1976. A short-lived series titled Giant-Size Spider-Man began in July 1974 and ran six issues through 1975. Spidey Super Stories, a series aimed at children ages 6–10, ran for 57 issues from October 1974 through 1982.
The flagship title's second decade took a grim turn with a story in #89-90 (Oct.-Nov. 1970) featuring the death of Captain George Stacy. This was the first Spider-Man story to be penciled by Gil Kane, who would alternate drawing duties with Romita for the next year-and-a-half and would draw several landmark issues.
One such story took place in the controversial issues #96–98 (May–July 1971). Writer-editor Lee defied the Comics Code Authority with this story, in which Parker's friend Harry Osborn, was hospitalized after over-dosing on pills. Lee wrote this story upon a request from the U. S. Department of Health, Education, and Welfare for a story about the dangers of drugs. Citing its dictum against depicting drug use, even in an anti-drug context, the CCA refused to put its seal on these issues. With the approval of Marvel publisher Martin Goodman, Lee had the comics published without the seal. The comics sold well and Marvel won praise for its socially conscious efforts. The CCA subsequently loosened the Code to permit negative depictions of drugs, among other new freedoms.
"The Six Arms Saga" of #100–102 (Sept.–Nov. 1971) introduced Morbius, the Living Vampire. The second installment was the first Amazing Spider-Man story not written by co-creator Lee, with Roy Thomas taking over writing the book for several months before Lee returned to write #105–110 (Feb.-July 1972). Lee, who was going on to become Marvel Comics' publisher, with Thomas becoming editor-in-chief, then turned writing duties over to 19-year-old Gerry Conway, who scripted the series through 1975. Romita penciled Conway's first half-dozen issues, which introduced the gangster Hammerhead in No. 113 (Oct. 1972). Kane then succeeded Romita as penciler, although Romita would continue inking Kane for a time.
Issue 121 (June 1973 by Conway-Kane-Romita) featured the death of Gwen Stacy at the hands of the Green Goblin in "The Night Gwen Stacy Died." Her demise and the Goblin's apparent death one issue later formed a story arc widely considered as the most defining in the history of Spider-Man. The aftermath of the story deepened both the characterization of Mary Jane Watson and her relationship with Parker.
In 1973 Gil Kane was succeeded by Ross Andru, whose run lasted from issue #125 (Oct. 1973) to #185 (Oct. 1978). Issue#129 (Feb. 1974) introduced the Punisher, who would become one of Marvel Comics' most popular characters. The Conway-Andru era featured the first appearances of the Man-Wolf in #124–125 (Sept.-Oct. 1973); the near-marriage of Doctor Octopus and Aunt May in #131 (Apr. 1974); Harry Osborn stepping into his father's role as the Green Goblin in #135–137 (Aug.-Oct.1974); and the original "Clone Saga", containing the introduction of Spider-Man's clone, in #147–149 (Aug.-Oct. 1975).
Archie Goodwin and Gil Kane produced the title's 150th issue (Nov. 1975) before Len Wein became writer with issue No. 151. During Wein's tenure, Harry Osborn and Liz Allen dated and became engaged; J. Jonah Jameson was introduced to his eventual second wife, Marla Madison; and Aunt May suffered a heart attack. Wein's last story on Amazing was a five-issue arc in #176–180 (Jan.-May 1978) featuring a third Green Goblin (Harry Osborn's psychiatrist, Bart Hamilton).
Marv Wolfman, Marvel's editor-in-chief from 1975 to 1976, succeeded Wein as writer and, in his first issue, #182 (July 1978), had Parker propose marriage to Watson, who refused in the following issue. Keith Pollard succeeded Andru as artist shortly afterward and, with Wolfman, introduced the likable rogue the Black Cat (Felicia Hardy) in #194 (July 1979). As a love interest for Spider-Man, the Black Cat would go on to be an important supporting character for the better part of the next decade and remain a friend and occasional lover into the 2010s.
1980s
The Amazing Spider-Man #200 (Jan. 1980) featured the return and death of the burglar who killed Spider-Man's Uncle Ben. Writer Marv Wolfman and penciler Keith Pollard both left the title by mid-year, succeeded by Dennis O'Neil, a writer known for groundbreaking 1970s work at rival DC Comics, and penciler John Romita Jr. O'Neil wrote two issues of The Amazing Spider-Man Annual which were both drawn by Frank Miller. The 1980 Annual featured a team-up with Doctor Strange while the 1981 Annual showcased a meeting with the Punisher. Roger Stern, who had written nearly 20 issues of sister title The Spectacular Spider-Man, took over Amazing with #224 (Jan. 1982). During his two years on the title, Stern augmented the backgrounds of long-established Spider-Man villains and, with Romita Jr., created the mysterious supervillain the Hobgoblin in #238–239 (Mar.–Apr. 1983). Fans engaged with the mystery of the Hobgoblin's secret identity, which continued throughout #244–245 and 249–251 (Sept.-Oct. 1983 and Feb.-April 1984). One lasting change was the reintroduction of Mary Jane Watson as a more serious, mature woman who becomes Peter's confidante after she reveals that she knows his secret identity. Stern also wrote "The Kid Who Collects Spider-Man" in The Amazing Spider-Man #248 (Jan. 1984), a story which ranks among his most popular.
By mid-1984, Tom DeFalco and Ron Frenz took over scripting and penciling. DeFalco helped establish Parker and Watson's mature relationship, laying the foundation for the characters' wedding in 1987. Notably, in #257 (Oct. 1984), Watson tells Parker that she knows he is Spider-Man, and in #259 (Dec. 1984), she reveals to Parker the extent of her troubled childhood. Other notable issues of the DeFalco-Frenz era include #252 (May 1984), the first appearance of Spider-Man's black costume, which the hero would wear almost exclusively for the next four years' worth of comics; the debut of criminal mastermind the Rose in #253 (June 1984); the revelation in #258 (Nov. 1984) that the black costume is a living being, a symbiote; and the introduction of the female mercenary Silver Sable in #265 (June 1985).
DeFalco and Frenz were both removed from The Amazing Spider-Man in 1986 by editor Jim Owsley under acrimonious circumstances. A succession of artists including Alan Kupperberg, John Romita Jr., and Alex Saviuk penciled the series from 1987 to 1988, and Owsley wrote the book for the first half of 1987, scripting the five-part "Gang War" story (#284–288) that DeFalco plotted. Former Spectacular Spider-Man writer Peter David scripted #289 (June 1987), which revealed Ned Leeds as being the Hobgoblin although this was retconned in 1996 by Roger Stern into Leeds not being the original Hobgoblin after all.
David Michelinie took over as writer in the next issue, for a story arc in #290–292 (July–Sept. 1987) that led to the marriage of Peter Parker and Mary Jane Watson in Amazing Spider-Man Annual No. 21. The "Kraven's Last Hunt" storyline by writer J.M. DeMatteis and artists Mike Zeck and Bob McLeod crossed over into The Amazing Spider-Man #293 and 294. Issue No.298 (Mar. 1988) was the first Spider-Man comic to be drawn by future industry star Todd McFarlane, the first regular artist on The Amazing Spider-Man since Frenz's departure. McFarlane revolutionized Spider-Man's look. His depiction – "Ditko-esque" poses, large eyes; wiry, contorted limbs; and messy, knotted, convoluted webbing – influenced the way virtually all subsequent artists would draw the character. McFarlane's other significant contribution to the Spider-Man canon was the design for what would become one of Spider-Man's most wildly popular antagonists, the supervillain Venom. Issue No. 299 (Apr. 1988) featured Venom's first appearance (a last-page cameo) before his first full appearance in #300 (May 1988). The latter issue featured Spider-Man reverting to his original red-and-blue costume.
Other notable issues of the Michelinie-McFarlane era include #312 (Feb. 1989), featuring the Green Goblin vs. the Hobgoblin; and #315–317 (May–July 1989), with the return of Venom. In July 2012, Todd McFarlane's original cover art for The Amazing Spider-Man No. 328 sold for a bid of $657,250, making it the most expensive American comic book art ever sold at auction.
1990s
With a civilian life as a married man, the Spider-Man of the 1990s was different from the superhero of the previous three decades. McFarlane left the title in 1990 to write and draw a new series titled simply Spider-Man. His successor, Erik Larsen, penciled the book from early 1990 to mid-1991. After issue No. 350, Larsen was succeeded by Mark Bagley, who had won the 1986 Marvel Tryout Contest and was assigned a number of low-profile penciling jobs followed by a run on New Warriors in 1990. Bagley penciled the flagship Spider-Man title from 1991 to 1996. During that time, Bagley's rendition of Spider-Man was used extensively for licensed material and merchandise.
Issues #361–363 (April–June 1992) introduced Carnage, a second symbiote nemesis for Spider-Man. The series' 30th-anniversary issue, No. 365 (Aug. 1992), was a double-sized, hologram-cover issue with the cliffhanger ending of Peter Parker's parents, long thought dead, reappearing alive. It would be close to two years before they were revealed to be impostors, who are killed in No. 388 (April 1994), scripter Michelinie's last issue. His 1987–1994 stint gave him the second-longest run as writer on the title, behind Stan Lee.
Issue No. 375 was released with a gold foil cover. There was an error affecting some issues and which are missing the majority of the foil.
With No. 389, writer J. M. DeMatteis, whose Spider-Man credits included the 1987 "Kraven's Last Hunt" story arc and a 1991–1993 run on The Spectacular Spider-Man, took over the title. From October 1994 to June 1996, Amazing stopped running stories exclusive to it, and ran installments of multi-part stories that crossed over into all the Spider-Man books. One of the few self-contained stories during this period was in No. 400 (April 1995), which featured the death of Aunt May – later revealed to have been faked (although the death still stands in the MC2 continuity). The "Clone Saga" culminated with the revelation that the Spider-Man who had appeared in the previous 20 years of comics was a clone of the real Spider-Man. This plot twist was massively unpopular with many readers, and was later reversed in the "Revelations" story arc that crossed over the Spider-Man books in late 1996.
The Clone Saga tied into a publishing gap after No. 406 (Oct. 1995), when the title was temporarily replaced by The Amazing Scarlet Spider #1–2 (Nov.-Dec. 1995), featuring Ben Reilly. The series picked up again with No. 407 (Jan. 1996), with Tom DeFalco returning as writer. Bagley completed his 5½-year run by September 1996. A succession of artists, including Ron Garney, Steve Skroce, Joe Bennett, Rafael Kayanan and John Byrne penciled the book until the final issue, No. 441 (Nov. 1998), after which Marvel rebooted the title with vol. 2, No. 1 (Jan. 1999).
Relaunch and the 2000s
Marvel began The Amazing Spider-Man relaunching the 'Amazing' comic book series with (vol. 2) #1 (Jan. 1999). Howard Mackie wrote the first 29 issues. The relaunch included the Sandman being regressed to his criminal ways and the "death" of Mary Jane, which was ultimately reversed. Other elements included the introduction of a new Spider-Woman (who was spun off into her own short-lived series) and references to John Byrne's miniseries Spider-Man: Chapter One, which was launched at the same time as the reboot. Byrne also penciled issues #1–18 (from 1999 to 2000) and wrote #13–14, John Romita Jr. took his place soon after in October 2000. Mackie's run ended with The Amazing Spider-Man Annual 2001, which saw the return of Mary Jane, who then left Parker upon reuniting with him.
With issue No. 30 (June 2001), J. Michael Straczynski took over as writer and oversaw additional storylines – most notably his lengthy "Spider-Totem" arc, which raised the issue of whether Spider-Man's powers were magic-based, rather than as the result of a radioactive spider's bite. Additionally, Straczynski resurrected the plot point of Aunt May discovering her nephew was Spider-Man, and returned Mary Jane, with the couple reuniting in The Amazing Spider-Man (vol. 2) #50. Straczynski gave Spider-Man a new profession, having Parker teach at his former high school.
Issue No. 30 began a dual numbering system, with the original series numbering (#471) returned and placed alongside the volume two number on the cover. Other longtime, rebooted Marvel Comics titles, including Fantastic Four, likewise were given the dual numbering around this time. After (vol. 2) #58 (Nov. 2003), the title reverted completely to its original numbering for issue No. 500 (Dec. 2003). Mike Deodato, Jr. penciled the series from mid-2004 until 2006.
That year Peter Parker revealed his Spider-Man identity on live television in the company-crossover storyline "Civil War", in which the superhero community is split over whether to conform to the federal government's new Superhuman Registration Act. This knowledge was erased from the world with the event of the four-part, crossover story arc, "One More Day", written partially by J. Michael Straczynski and illustrated by Joe Quesada, running through The Amazing Spider-Man #544–545 (Nov.-Dec. 2007), Friendly Neighborhood Spider-Man No. 24 (Nov. 2007) and The Sensational Spider-Man No. 41 (Dec. 2007), the final issues of those two titles. Here, the demon Mephisto makes a Faustian bargain with Parker and Mary Jane, offering to save Parker's dying Aunt May if the couple will allow their marriage to have never existed, rewriting that portion of their pasts. This story arc marked the end of Straczynski's work on the title.
Following this, Marvel made The Amazing Spider-Man the company's sole Spider-Man title, increasing its frequency of publication to three issues monthly, and inaugurating the series with a sequence of "back to basics" story arcs under the banner of "Brand New Day". Parker now exists in a changed world where he and Mary Jane had never married, and Parker has no memory of being married to her, with domino effect differences in their immediate world. The most notable of these revisions to Spider-Man continuity are the return of Harry Osborn, whose death in The Spectacular Spider-Man No. 200 (May 1993) is erased; and the reestablishment of Spider-Man's secret identity, with no one except Mary Jane able to recall that Parker is Spider-Man (although he soon reveals his secret identity to the New Avengers and the Fantastic Four). Under the banner of Brand New Day, Marvel tried to only use newly created villains instead of relying on older ones. Characters like Mister Negative and Overdrive both in Free Comic Book Day 2007 Spider-Man (July 2007), Menace in No. 549 (March 2008), Ana and Sasha Kravinoff in No. 565 (September 2008) and No. 567 (October 2008) respectively, and several more were introduced. The alternating regular writers were initially Dan Slott, Bob Gale, Marc Guggenheim, and Zeb Wells, joined by a rotation of artists that included Steve McNiven, Salvador Larroca, Phil Jimenez, Barry Kitson, Chris Bachalo, Mike McKone, Marcos Martín, and John Romita Jr. Joe Kelly, Mark Waid, Fred Van Lente and Roger Stern later joined the writing team and Paolo Rivera, Lee Weeks and Marco Checchetto the artist roster. Waid's work on the series included a meeting between Spider-Man and Stephen Colbert in The Amazing Spider-Man No. 573 (Dec. 2008).
Issue No. 583 (March 2009) included a back-up story in which Spider-Man meets President Barack Obama.
2010s and temporary end of publication
Mark Waid scripted the opening of "The Gauntlet" storyline in issue No. 612 (Jan. 2010). The Gauntlet story was concluded by Grim Hunt (No. 634–637) which saw the resurrection of long-dead Spider-Man villain, Kraven the Hunter. The series became a twice-monthly title with Dan Slott as sole writer at issue No. 648 (Jan. 2011), launching the Big Time storyline. Eight additional pages were added per issue. Big Time saw major changes in Spider-Man/Peter Parker's life, Peter would start working at Horizon Labs and begin a relationship with Carlie Cooper (his first serious relationship since his marriage to Mary Jane), Mac Gargan returned as Scorpion after spending the past few years as Venom, Phil Urich would take up the mantle of Hobgoblin, and the death of J. Jonah Jameson's wife, Marla Jameson. Issues 654 and 654.1 saw the birth of Agent Venom, Flash Thompson bonded with the Venom symbiote, which would lead to Venom getting his own series Venom (volume 2). Starting in No. 659 and going to No. 665, the series built-up to the Spider-Island event which officially started in No. 666 and ended in No. 673. Ends of the Earth was the next event that ran from No. 682 through No. 687. This publishing format lasted until issue No. 700, which concluded the "Dying Wish" storyline, in which Parker and Doctor Octopus swapped bodies, and the latter taking on the mantle of Spider-Man when Parker apparently died in Doctor Octopus' body. The Amazing Spider-Man ended with this issue, with the story continuing in the new series The Superior Spider-Man. Despite The Superior Spider-Man being considered a different series to The Amazing Spider-Man, the first 33 issue run goes towards the legacy numbering of The Amazing Spider-Man acting as issues 701–733. In December 2013, the series returned for five issues, numbered 700.1 through 700.5, with the first two written by David Morrell and drawn by Klaus Janson.
2014 relaunch
In January 2014, Marvel confirmed that The Amazing Spider-Man would be relaunched on April 30, 2014, starting from issue No. 1, with Peter Parker as Spider-Man once again.
The first issue of this new version of The Amazing Spider-Man was, according to Diamond Comics Distributors, the "best-selling comic book... in over a decade."
Issues #1–6 were a story arc called "Lucky to be Alive", taking place immediately after "Goblin Nation", with issues No. 4 and No. 5 being a crossover with the Original Sin storyline. Issue No. 4 introduced Silk, a new heroine who was bitten by the same spider as Peter Parker. Issues #7–8 featured a team-up between Ms. Marvel and Spider-Man, and had backup stories that tied into "Edge of Spider-Verse". The next major plot arc, titled "Spider-Verse", began in Issue No. 9 and ended in No. 15, features every Spider-Man from across the dimensions being hunted by Morlun, and a team-up to stop him, with Peter Parker of Earth-616 in command of the Spider-Men's Alliance. The Amazing Spider-Man Annual No. 1 of the relaunched series was released in December 2014, featuring stories unrelated to "Spider-Verse".
The Amazing Spider-Man: Renew Your Vows
In 2015, Marvel started the universe wide Secret Wars event where the core and several other Marvel universes were combined into one big planet called Battleworld. Battleworld was divided into sections with most of them being self-contained universes. Marvel announced that several of these self-contained universes would get their own tie in series and one of them was Amazing Spider-Man: Renew Your Vows, an alternate universe where Peter Parker and Mary Jane are still married and give birth to their child Annie May Parker, written by Dan Slott. Despite the series being considered separate from the main Amazing Spider-Man series, the original 5 issue run is counted towards its legacy numbering acting as No. 752-756.
2015 relaunch
Following the 2015 Secret Wars event, a number of Spider-Man-related titles were either relaunched or created as part of the "All-New, All-Different Marvel" event. Among them, The Amazing Spider-Man was relaunched as well and primarily focused on Peter Parker continuing to run Parker Industries and becoming a successful businessman operating worldwide. It also tied with Civil War II (involving an Inhuman named Ulysses Cain who can predict possible futures), Dead No More (where Ben Reilly [the original Scarlet Spider] revealed to be revived and as one of the antagonists instead), and Secret Empire (during Hydra's reign led by a Hydra influenced Captain America/Steve Rogers, and the dismissal of Parker Industries by Peter Parker to stop Otto Octavius). Starting in September 2017, Marvel started the Marvel Legacy event which renumbered several Marvel series to their original numbering. The Amazing Spider-Man was put back to its original numbering for #789. Issues #789 through 791 focused on the aftermath of Peter destroying Parker Industries and his fall from grace. Issues #792 and 793 were part of the Venom Inc. story. Threat Level: Red was the story for the next three issues which saw Norman Osborn obtain and bond with the Carnage symbiote. Go Down Swinging saw the results of the combination of Osborn's goblin serum and Carnage symbiote creating the Red Goblin. Issue No. 801 was Dan Slott's goodbye issue.
2018 relaunch
In March 2018, it was announced that writer Nick Spencer would be writing the main semi-monthly The Amazing Spider-Man series beginning with a new No. 1, replacing long-time writer Dan Slott, as part of the Fresh Start relaunch that July.
The first five-issue story arc was titled 'Back to Basics.' During the Back to Basics story, Kindred, a mysterious villain with some relation to Peter's past, was introduced, and Peter resumed his romantic relationship with Mary Jane once more. The first major story under Spencer was Hunted which ran through issues 16 through 23, the story also included four ".HU" issues for issues 16, 18, 19, and 20. The end of the story saw the death of long-running Spider-Man villain Kraven the Hunter, being replaced by his clone son, The Last Son of Kraven.
2020s
Issue 45 kicked off the Sins Rising story which saw the resurrected Sin-Eater carry out the plans of Kindred to cleanse the world of sin, particularly that of Norman Osborn. The story concluded with issue 49, issue 850 in legacy numbering, seeing Spider-Man and Green Goblin team up to defeat Sin-Eater. Last Remains started in issue 50 and concluded in issue 55, the story saw Kindred's plans come to fruition as he tormented Spider-Man. The story has also seen five ".LR" for issues 50, 51, 52, 53, and 54 which focused on The Order of the Web, a new faction of Spider-People consisting of Julia Carpenter (Madame Web), Miles Morales (Spider-Man), Gwen Stacy (Ghost-Spider), Cindy Moon (Silk), Jessica Drew (Spider-Woman), and Anya Corazon (Spider-Girl) . The story also revealed that Kindred is Harry Osborn. Last Remains also received two fallout issues called Last Remains Post-Mortem.
Nick Spencer concluded his run with the Sinister War story which wrapped up in No. 74 (legacy numbering 875). The story saw several retcons to the Spider-Man mythos including that Kindred was Gabriel and Sarah Stacy all along, the fact that the Stacy twins were actually genetically engineered beings using Norman Osborn and Gwen Stacy's DNA, that the Harry Osborn that returned in Brand New Day was actually a clone, and that Norman had made a deal with Mephisto where he sold Harry's soul to the demon. The story ended with the deaths of the Harry clone, Gabriel, and Sarah and the real Harry's soul being freed from Mephisto's grasp.
After Spencer left the book, Marvel announced the "Beyond" era of Spider-Man would start in #75. The book would be moving back to the format it had during Brand New Day where it would have a rotating cast of writers including Kelly Thompson, Saladin Ahmed, Cody Ziglar, Patrick Gleason, and Zeb Wells. The book would also be released three times a month. "Beyond" would focus on Ben Reilly taking up the mantle of Spider-Man once again but backed by the Beyond corporation. Peter also falls ill and cannot be Spider-Man so he gives Ben his blessing to carry on as the main Spider-Man. However, following the conclusion of the storyline in #93, Peter has resumed active duties as Spider-Man, while Ben suffers a mental breakdown after losing his memories and becomes the villain Chasm.
2022 relaunch
In January 2022, it was announced that writer Zeb Wells and John Romita Jr. would be working on a relaunched The Amazing Spider-Man, bringing the number of volumes for the title to its sixth, with the series beginning in April 2022 as a semi-monthly publication. The relaunch encompasses both a legacy numbering of #900 as well as the 60th anniversary for the character. The relaunch took place months after a mysterious event that left Peter on bad terms with the superhero community and ended his relationship with Mary Jane. He ends up taking a job at Oscorp and begins working closely with Norman Osborn (who becomes the heroic Gold Goblin) and starts dating Black Cat. The volume's first crossover event was entitled Dark Web, with Chasm having teamed up with Madelyne Pryor to bring limbo to Earth.
It's later revealed that Benjamin Rabin, the emissary of the Mayan god of mischief Wayeb', sent Peter and Mary Jane to an alternate dimension to conduct a ceremony that would allow Wayeb to control the Earth. Peter was sent back to his Earth, while due to the alternative passage of time, Mary Jane and Paul, Rabin's son in that dimension, spent four years in the realm together and adopted two children. When Peter eventually rescued them, Mary Jane refused to part with her new family. Rabin then planned to sacrifice Mary Jane to resurrect Wayeb, but is ultimately stopped by Ms. Marvel sacrificing herself, but not before Rabin reveals that Paul and Mary Jane's kids were illusions created by him and ceased their existence. Mary Jane becomes the superheroine Jackpot using the bracelet acquired from the other dimension as Black Cat breaks up with Peter shortly before Janice Lincoln and Randy Robertson's wedding. The second crossover event was entitled Gang War, where Peter led a team of street-level superheroes to stop a massive war between New York's gangs led by Madam Masque, Tombstone, and Beetle. Peter is also infected by Norman Osborn's sins and becomes the villainous Spider-Goblin.
Contributors
Vol. 1 (1963–1998, 2003–2014, 2017–2018)
Writers
Pencilers
Vol. 2 (1999–2003)
Writers
Pencilers
Vol. 3 (2014–2015)
Writers
Pencilers
Vol. 4 (2015–2017)
Writers
Pencilers
Vol. 5 (2018–2022)
Writers
Pencilers
Vol. 6 (2022–present)
Writers
Pencilers
Collected editions
Black-and-white
Essential Spider-Man Vol. 1 [#1–20, Annual #1; Amazing Fantasy #15] ()
Essential Spider-Man Vol. 2 [#21–43, Annual #2–3] ()
Essential Spider-Man Vol. 3 [#44–65, Annual #4] ()
Essential Spider-Man Vol. 4 [#66–89, Annual #5] ()
Essential Spider-Man Vol. 5 [#90–113] ()
Essential Spider-Man Vol. 6 [#114–137; Giant-Size Super Heroes #1; Giant-Size Spider-Man #1–2] ()
Essential Spider-Man Vol. 7 [#138–160, Annual #10; Giant-Size Spider-Man #4–5] ()
Essential Spider-Man Vol. 8 [#161–185, Annual #11; Giant-Size Spider-Man #6; Nova #12] ()
Essential Spider-Man Vol. 9 [#186–210, Annual #13–14; Peter Parker: Spectacular Spider-Man Annual #1] ()
Essential Spider-Man Vol. 10 [#211–230, Annual #15] ()
Essential Spider-Man Vol. 11 [#231–248, Annual #16–17] ()
Major story arcs
Marvel Visionaries: John Romita Sr. [#39–40, 42, 50, 108–109, 365; Daredevil #16–17; Untold Tales of Spider-Man #-1] ()
Spider-Man: The Death of Captain Stacy [#88–90] ()
Spider-Man: The Death of Gwen Stacy [#96–98, 121–122; Webspinners: Tales of Spider-Man #1] ()
Spider-Man: Death of the Stacys [#88–92, 121–122] ()
A New Goblin [#176–180] ()
Spider-Man vs. the Black Cat [#194–195, 204–205, 226–227] ()
Spider-Man: Origin of The Hobgoblin [#238–239, 244–245, 249–251, Spectacular Spider-Man (vol. 1) #85] ()
Spider-Man: Birth of Venom [#252–259, 298–300, 315–317, Annual #25; Fantastic Four #274; Secret Wars #8; Web of Spider-Man #1] ()
The Amazing Spider-Man: The Wedding [#290–292, Annual #2, Not Brand Echh #6] ()
Spider-Man: Kraven's Last Hunt [#293–294; Web of Spider-Man #31–32; The Spectacular Spider-Man #131–132] ()
Visionaries: Todd McFarlane [#298–305] ()
Legends, Vol. 2: Todd McFarlane [#306–314; The Spectacular Spider-Man Annual #10] ()
Legends, Vol. 3: Todd McFarlane [#315–323, 325, 328] ()
Spider-Man: Venom Returns [#330–333, 344–347;Annual #25] ()
Spider-Man: Carnage [#344–345, 359–363] ()
Collections
Vol. 1: Coming Home [#30-35/471-476] ()
Vol. 2: Revelations [#36-39/477-480] ()
Vol. 3: Until the Stars Turn Cold [#40-45/481-486] ()
Vol. 4: The Life and Death of Spiders [#46-50/487-491] ()
Vol. 5: Unintended Consequences [#51-56/492-497] ()
Vol. 6: Happy Birthday [#57–58,500-502/498-502] ()
Vol. 7: The Book of Ezekiel [#503–508] ()
Vol. 8: Sins Past [#509–514] ()
Vol. 9: Skin Deep [#515–518] ()
Vol. 10: New Avengers [#519–524] ()
Spider-Man: The Other [#525–528; Friendly Neighborhood Spider-Man #1–4; Marvel Knights Spider-Man #19–22] ()
Civil War: The Road to Civil War [#529–531; New Avengers: Illuminati (one-shot); Fantastic Four #536–537] ()
Vol. 11: Civil War [#532–538] ()
Vol. 12: Back in Black [#539–543; Friendly Neighborhood Spider-Man #17–23, Annual #1] ()
Spider-Man: One More Day [#544–545; Friendly Neighborhood Spider-Man #24; The Sensational Spider-Man #41; Marvel Spotlight: Spider-Man – One More Day/Brand New Day] ()
Brand New Day Vol. 1 [#546–551; The Amazing Spider-Man: Swing Shift (Director's Cut); Venom Super-Special] ()
Brand New Day Vol. 2 [#552–558] ()
Brand New Day Vol. 3 [#559–563] ()
Kraven's First Hunt [#564–567; The Amazing Spider-Man: Extra! #1 (story #2)] ()
New Ways to Die [#568–573; Marvel Spotlight: Spider-Man – Brand New Day] ()
Crime and Punisher [#574–577; The Amazing Spider-Man: Extra! #1 (story #1)] ()
Death and Dating [#578–583, Annual #35/1] ()
Election Day [#584–588; The Amazing Spider-Man: Extra! #1 (story #3), 3 (story #1); The Amazing Spider-Man Presidents' Day Special] ()
24/7 [#589–594; The Amazing Spider-Man: Extra! #2] ()
American Son [#595–599; material from The Amazing Spider-Man: Extra! #3] ()
Died in Your Arms Tonight [#600–601, Annual #36; material from Amazing Spider-Man Family #7] ()
Red-Headed Stranger [#602–605] ()
Return of the Black Cat [#606–611; material from Web of Spider-Man (vol. 2) #1] ()
The Gauntlet Book 1: Electro and Sandman [#612–616; Dark Reign: The List – The Amazing Spider-Man; Web of Spider-Man (vol. 2) #2 (Electro story)] ()
The Gauntlet Book 2: Rhino and Mysterio [#617–621; Web of Spider-Man (vol. 2) #3–4] ()
The Gauntlet Book 3: Vulture and Morbius [#622–625; Web of Spider-Man (vol. 2) #2, 5 (Vulture story)] ()
The Gauntlet Book 4: Juggernaut [#229–230, 626–629] ()
The Gauntlet Book 5: Lizard [#629–633; Web of Spider-Man (vol. 2) #6] ()
Spider-Man: Grim Hunt [#634–637; The Amazing Spider-Man: Extra! #3; Spider-Man: Grim Hunt – The Kraven Saga; Web of Spider-Man (vol. 2) #7] ()
One Moment in Time [#638–641] ()
Origin of the Species [#642–647; Spider-Man Saga; Web of Spider-Man (vol. 2) #12] ()
Big Time [#648–651] ()
Matters of Life and Death [#652–657, 654.1] ()
Spider-Man: The Fantastic Spider-Man [#658–662] ()
Spider-Man: The Return Of Anti-Venom [#663–665; Free Comic Book Day 2011: Spider-Man] ()
Spider-Man: Spider-Island [#666–673; Venom (2011) #6–8, Spider-Island: Deadly Foes; Infested prologues from #659–660 and 662–665] ()
Spider-Man: Flying Blind [#674–677; Daredevil #8] ()
Spider-Man: Trouble on the Horizon [#678–681, 679.1] ()
Spider-Man: Ends of the Earth [#682–687; Amazing Spider-Man: Ends of the Earth #1; Avenging Spider-Man #8] ()
Spider-Man: Lizard – No Turning Back [#688–691; Untold Tales of Spider-Man #9] ()
Spider-Man: Danger Zone [#692–697; Avenging Spider-Man #11] ()
Spider-Man: Dying Wish [#698–700] ()
The Amazing Spider-Man Omnibus Vol. 1 [#1–38, Annual #1–2; Amazing Fantasy #15; Strange Tales Annual #2; Fantastic Four Annual #1] ()
The Amazing Spider-Man Omnibus Vol. 2 [#39–67, Annual #3–5; Spectacular Spider-Man #1–2] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 1 [#1–10; Amazing Fantasy #15] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 2 [#11–19, Annual #1] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 3 [#20–30, Annual #2] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 4 [#31–40] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 5 [#41–50, Annual #3] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 6 [#51–61, Annual #4] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 7 [#62–67, Annual #5; The Spectacular Spider-Man #1–2 (magazine)] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 8 [#68–77; Marvel Super Heroes #14] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 9 [#78–87] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 10 [#88–99] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 11 [#100–109] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 12 [#110–120] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 13 [#121–131] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 14 [#132–142; Giant-Size Super-Heroes #1] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 15 [#143–155; Marvel Special Edition Treasury #1] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 16 [#156–168; Annual #10] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 17 [#169–180; Annual #11; Nova #12; Marvel Treasury Edition #14] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 18 [#181–192; Mighty Marvel Comics Calendar 1978; material From Annual #12] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 19 [#193–202; Annual #13; Peter Parker, the Spectacular Spider-Man Annual #1] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 20 [#203–212; Annual #14] ()
Marvel Masterworks: The Amazing Spider-Man Vol. 21 [#213–223; Annual #15] ()
Amazing Spider-Man Vol. 1: (The) Parker Luck [Vol. 3 #1–6 (i.e., legacy #732–737)] ()
Amazing Spider-Man Vol. 2: Spider-Verse Prelude [#7–8 (i.e., legacy #738–739); Superior Spider-Man #32–33; Free Comic Book Day 2014 (Guardians of the Galaxy) #1] ()
Amazing Spider-Man Vol. 3: Spider-Verse [#9–15 (i.e., legacy #740–746)] ()
Amazing Spider-Man Vol. 4: Graveyard Shift [#16–18 (i.e., legacy #747–749); Annual 2015] ()
Amazing Spider-Man Vol. 5: Spiral [#16.1–20.1(i.e., legacy #750–751)] ()
Amazing Spider-Man: Renew Your Vows [#1–5 (i.e., legacy #752–756)]
Amazing Spider-Man Worldwide Vol. 1 [Vol. 4 #1–5]
Amazing Spider-Man Worldwide Vol. 2 [#6–11]
Amazing Spider-Man Worldwide Vol. 3 [#12–15]
Amazing Spider-Man Worldwide Vol. 4 [#16–19]
Amazing Spider-Man Worldwide Vol. 5 [#20–24, Annual #1]
Amazing Spider-Man Worldwide Vol. 6 [#25–28]
Amazing Spider-Man Worldwide Vol. 7 [#29–32 (i.e., legacy #785–788), #789–791]
Amazing Spider-Man: Venom Inc. [Venom Inc. Alpha, Venom Inc. Omega, #792–793, Venom #159–160]
Amazing Spider-Man Worldwide Vol. 8 [#794–796, Annual]
Amazing Spider-Man Worldwide Vol. 9 [#797–801]
Amazing Spider-Man: Clone Conspiracy [#19-24; The Clone Conspiracy #1-5; The Clone Conspiracy: Omega; Silk #14-17; Prowler #1-5]
Amazing Spider-Man: Red Goblin [#794–801]
Amazing Spider-Man Vol. 1: Back to Basics [#1–5, FCBD 2018: Amazing Spider-Man]
Amazing Spider-Man Vol. 2: Friends and Foes [#6–10]
Amazing Spider-Man Vol. 3: Lifetime Achievement [#11–15]
Amazing Spider-Man Vol. 4: Hunted [#16–23, #16.1, #18.1–20.1]
Amazing Spider-Man Vol. 5: Behind the Scenes [#24–28]
Amazing Spider-Man Vol. 6: Absolute Carnage [#29–31]
Amazing Spider-Man Vol. 7: 2099 [#32–36]
Amazing Spider-Man Vol. 8: Threats & Menaces [#37–43]
Amazing Spider-Man Vol. 9: Sins Rising [#44–47, Amazing Spider Man: Sins Rising #1]
Amazing Spider-Man Vol. 10: Green Goblin Returns [#48–49, Amazing Spider-Man: The Sins of Norman Osborn #1, FCBD 2020: Spider-Man/Venom]
Amazing Spider-Man Vol. 11: Last Remains [#50–55]
Amazing Spider-Man: Last Remains Companion [#50.1–54.1]
Amazing Spider-Man Vol. 12: Shattered Web [#56–60]
Amazing Spider-Man Vol. 13: King's Ransom [#61–65, Giant Size Amazing Spider-Man: King's Ransom #1]
Amazing Spider-Man Vol. 14: Chameleon Conspiracy [#66–69, Giant Size Amazing Spider-Man: Chameleon Conspiracy #1]
Amazing Spider-Man Vol. 15: What Cost Victory? [#70–74]
Amazing Spider-Man: Beyond Vol. 1 [#75–80, 78.BEY]
Amazing Spider-Man: Beyond Vol. 2 [#81-85, 80.BEY]
Amazing Spider-Man: Beyond Vol. 3 [#86-88, 88.BEY]
Amazing Spider-Man: Beyond Vol. 4 [#89-93, 92.BEY]
Amazing Spider-Man Vol. 1: World Without Love [#1-5]
Amazing Spider-Man Vol. 2: The New Sinister [#6-8]
Amazing Spider-Man Vol. 3: Hobgoblin [#9-14]
Amazing Spider-Man Vol. 4: Dark Web [#15-18, Dark Web #1, Dark Web: Omega #1]
Amazing Spider-Man Vol. 5: Dead Language Part 1 [#19-23]
Amazing Spider-Man Vol. 6: Dead Language Part 2 [#24-26, Annual, Fallen Friend #1]
Amazing Spider-Man Vol. 7: Armed and Dangerous [#27-31, FCBD 2023: Spider-Man/Venom]
See also
References
The Amazing Spider-Man comic book sales figures from 1966–present at The Comics Chronicles
Spider-Man at Marvel Comics wikia
The Amazing Spider-Man cover gallery
Spiderman Videos
1963 comics debuts
Comics by Archie Goodwin (comics)
Comics by Dennis O'Neil
Comics by Gerry Conway
Comics by J. M. DeMatteis
Comics by J. Michael Straczynski
Comics by John Byrne (comics)
Comics by Len Wein
Comics by Mark Waid
Comics by Marv Wolfman
Comics by Roger Stern
Comics by Stan Lee
Comics by Steve Ditko
Spider-Man titles |
933 | https://en.wikipedia.org/wiki/AM | AM | AM or Am may refer to:
Arts and entertainment
Music
A minor, a minor scale in music
A.M. (Chris Young album)
A.M. (Wilco album)
AM (Abraham Mateo album)
AM (Arctic Monkeys album)
AM (musician), American musician
Am, the A minor chord symbol
Armeemarschsammlung (Army March Collection), catalog of German military march music
Andrew Moore (musician), Canadian musician known as A.M.
DJ AM, American DJ and producer
Skengdo & AM, British hip hop duo
Television and radio
AM (radio program), Australian current affairs radio program
American Morning, American morning television news program
Am, Antes del Mediodía, Argentine current affairs television program
Am, a character in the anthology Star Wars: Visions
@fter Midnight (TV series) (logo: @m), U.S. late night comedy celebrity game show
Other media
Allied Mastercomputer, the antagonist of the short story "I Have No Mouth, and I Must Scream"
Education
Active Minds, a mental health awareness charity
Arts et Métiers ParisTech, a French engineering school
Australian Museum, a museum in Australia
Master of Arts, an academic degree
Military
A US Navy hull classification symbol: Minesweeper (AM)
Air marshal, a senior air officer rank used in Commonwealth countries
Anti-materiel rifle, rifle designed for use against military equipment
Aviation structural mechanic, a U.S. Navy occupational rating
Science
AM, a complexity class related to Arthur–Merlin protocol
Adrenomedullin, a protein
Air mass (astronomy), measure of the amount of air along the line of sight in astronomical observations
Am, tropical monsoon climate in the Köppen climate classification
Americium, symbol Am, a chemical element
Attometre, a unit of length
attomolar (aM), a unit of molar concentration
Technology
.am, Internet domain for Armenia
.am, a file extension associated with Automake software
AM broadcasting, radio broadcasting using amplitude modulation
Additive manufacturing, or 3-D printing, a process of making a three-dimensional solid object of virtually any shape from a digital model.
Agile modeling, a software engineering methodology for modeling and documenting software systems
Amplitude modulation, an electronic communication technique
Automated Mathematician, an artificial intelligence program
Timekeeping
anno martyrum, a method of numbering years in the Coptic calendar
Anno Mundi, a calendar era based on the biblical creation of the world
ante meridiem, the time period from midnight to noon; Latin for "before midday", written e.g., 6a.m.
Transportation
A.M. (automobile), a 1906 French car
Aeroméxico (IATA airline code AM), airline in Mexico
All-mountain, a discipline of mountain biking
Arkansas and Missouri Railroad
Other uses
Am (cuneiform), a written syllable
Member of the Order of Australia, postnominal letters which can be used by a Member of the Order
Assembly Member (disambiguation), a political office
formerly a Member of the National Assembly for Wales, now Member of the Senedd
Member of the London Assembly
Amharic language (ISO 639-1 language code am)
Anguilla, LOC MARC code AM
Armenia (ISO country code AM)
Attacking midfielder, a position in association football
The Book of Amos, part of the Tanakh and Old Testament
First-person singular present of the copula verb to be
See also
Pro–am
`am (disambiguation)
A&M (disambiguation)
AM2 (disambiguation)
AMS (disambiguation) |
951 | https://en.wikipedia.org/wiki/Antigua%20and%20Barbuda | Antigua and Barbuda | Antigua and Barbuda (, ) is a sovereign island country in the Caribbean. It lies at the conjuncture of the Caribbean Sea and the Atlantic Ocean in the Leeward Islands part of the Lesser Antilles.
The country consists of two major islands, Antigua and Barbuda, which are approximately apart, and several smaller islands, including Great Bird, Green, Guiana, Long, Maiden, Prickly Pear, York, and Redonda. The permanent population is approximately 97,120 ( estimates), with 97% residing in Antigua. St. John's, Antigua, is the country's capital, major city, and largest port. Codrington is Barbuda's largest town.
In 1493, Christopher Columbus surveyed the island of Antigua, which he named for the Church of Santa María La Antigua. Great Britain colonized Antigua in 1632 and Barbuda in 1678. A part of the Federal Colony of the Leeward Islands from 1871, Antigua and Barbuda joined the West Indies Federation in 1958. With the breakup of the federation in 1962, it became one of the West Indies Associated States in 1967. Following a period of internal self-governance, it gained full independence from the United Kingdom on 1 November 1981. Antigua and Barbuda is a member of the Commonwealth and a Commonwealth realm; it is a constitutional monarchy with Charles III as its head of state.
The economy of Antigua and Barbuda is largely dependent on tourism, which accounts for 80% of its GDP. Like other island nations, Antigua and Barbuda is vulnerable to the effects of climate change, such as sea level rise, and increased intensity of extreme weather like hurricanes. These cause coastal erosion, water scarcity, and other challenges.
Antigua and Barbuda offers a citizenship by investment program. The country levies no personal income tax.
Etymology
is Spanish for 'ancient' and is Spanish for 'bearded'. The island of Antigua was originally called by the Arawaks and is locally known by that name today; the Caribs possibly called Barbuda . Christopher Columbus, while sailing by in 1493, may have named it , after an icon in the Spanish Seville Cathedral. The "bearded" of Barbuda is thought to refer either to the male inhabitants of the island, or the bearded fig trees present there.
History
Pre-colonial period
Antigua was first settled by archaic age hunter-gatherer Native Americans called the Ciboney. Carbon dating has established the earliest settlements started around 3100 BC. They were succeeded by the ceramic age pre-Columbian Arawak-speaking Saladoid people who migrated from the lower Orinoco River. They introduced agriculture, raising, among other crops, the famous Antigua Black Pineapple (Ananas comosus), corn, sweet potatoes, chiles, guava, tobacco, and cotton. Later on the more bellicose Caribs also settled the island, possibly by force.
European arrival and settlement
Christopher Columbus was the first European to sight the islands in 1493. The Spanish did not colonise Antigua until after a combination of European and African diseases, malnutrition, and slavery eventually extirpated most of the native population; smallpox was probably the greatest killer.
The English settled on Antigua in 1632; Christopher Codrington settled on Barbuda in 1685. Tobacco and then sugar was grown, worked by a large population of slaves transported from West Africa, who soon came to vastly outnumber the European settlers.
Colonial era
The English maintained control of the islands, repulsing an attempted French attack in 1666. The brutal conditions endured by the slaves led to revolts in 1701 and 1729 and a planned revolt in 1736, the last led by Prince Klaas, though it was discovered before it began and the ringleaders were executed. Slavery was abolished in the British Empire in 1833, affecting the economy. This was exacerbated by natural disasters such as the 1843 earthquake and the 1847 hurricane. Mining occurred on the isle of Redonda, however, this ceased in 1929 and the island has since remained uninhabited.
Part of the Leeward Islands colony, Antigua and Barbuda became part of the short-lived West Indies Federation from 1958 to 1962. Antigua and Barbuda subsequently became an associated state of the United Kingdom with full internal autonomy on 27 February 1967. The 1970s were dominated by discussions as to the islands' future and the rivalry between Vere Bird of the Antigua and Barbuda Labour Party (ABLP) (Premier from 1967 to 1971 and 1976 to 1981) and the Progressive Labour Movement (PLM) of George Walter (Premier 1971–1976). Eventually, Antigua and Barbuda gained full independence on 1 November 1981; Vere Bird became prime minister of the new country. The country opted to remain within the Commonwealth, retaining Queen Elizabeth as head of state, with the first governor, Sir Wilfred Jacobs, as governor-general. Succeeding Sir Wilfred Jacobs were Sir James Carlisle (June 10, 1993 – June 30, 2007), Dame Louise Lake-Tack (July 17, 2007 – August 14, 2014.), and the present governor, Sir Rodney Williams: (August 14, 2014 – present).
Independence era
The first two decades of Antigua's independence were dominated politically by the Bird family and the ABLP, with Vere Bird ruling from 1981 to 1994, followed by his son Lester Bird from 1994 to 2004. Though providing a degree of political stability, and boosting tourism to the country, the Bird governments were frequently accused of corruption, cronyism and financial malfeasance. Vere Bird Jr., the elder son, was forced to leave the cabinet in 1990 following a scandal in which he was accused of smuggling Israeli weapons to Colombian drug-traffickers. Another son, Ivor Bird, was convicted of selling cocaine in 1995.
In 1995, Hurricane Luis caused severe damage on Barbuda.
The ABLP's dominance of Antiguan politics ended with the 2004 Antiguan general election, which was won by Winston Baldwin Spencer's United Progressive Party (UPP). Winston Baldwin Spencer was Prime Minister of Antigua and Barbuda from 2004 to 2014. However the UPP lost the 2014 Antiguan general election, with the ABLP returning to power under Gaston Browne. ABLP won 15 of the 17 seats in the 2018 snap election under the leadership of incumbent Prime Minister Gaston Browne.
In 2016, Nelson's Dockyard was designated as a UNESCO World Heritage Site.
Most of Barbuda was devastated in early September 2017 by Hurricane Irma, which brought winds with speeds reaching 295 km/h (185 mph). The storm damaged or destroyed 95% of the island's buildings and infrastructure, leaving Barbuda "barely habitable" according to Prime Minister Gaston Browne. Nearly everyone on the island was evacuated to Antigua.
Amidst the following rebuilding efforts on Barbuda that were estimated to cost at least $100 million, the government announced plans to revoke a century-old law of communal land ownership by allowing residents to buy land; a move that has been criticised as promoting "disaster capitalism".
Geography
Limestone formations, rather than volcanic activity, have had the most impact on the topography of both Antigua and Barbuda, which are both relatively low-lying islands. Boggy Peak, also known as Mt. Obama from 2008 to 2016, is the highest point on both Antigua and Barbuda. It is the remnant of a volcanic crater and rises a total of 402 meters. Boggy Peak is located in the southwest of Antigua (1,319 feet).
Both of these islands have very irregularly shaped coastlines that are dotted with beaches, lagoons, and natural harbors. There are reefs and shoals that surround the islands on all sides. Because of the low amount of rainfall, there are not many streams. On neither of these islands can sufficient quantities of fresh groundwater be found.
Redonda is a small, uninhabited island located about 40 kilometers (25 miles) to the south-west of Antigua. Redonda is a rocky island.
Cities and villages
The most populous cities in Antigua and Barbuda are mostly on Antigua, being Saint John's, All Saints, Piggotts, and Liberta. The most populous city on Barbuda is Codrington. It is estimated that 25% of the population lives in an urban area, which is much lower than the international average of 55%.
Islands
Antigua and Barbuda consists mostly of its two namesake islands, Antigua, and Barbuda. Other than that, Antigua and Barbuda's biggest islands are Guiana Island and Long Island off the coast of Antigua, and Redonda island, which is far from both of the main islands.
Climate
Rainfall averages per year, with the amount varying widely from season to season. In general the wettest period is between September and November. The islands generally experience low humidity and recurrent droughts. Temperatures average , with a range from to in the winter to from to in the summer and autumn. The coolest period is between December and February.
Hurricanes strike on an average of once a year, including the powerful Category 5 Hurricane Irma, on 6 September 2017, which damaged 95% of the structures on Barbuda. Some 1,800 people were evacuated to Antigua.
Officials quoted by Time indicated that over $100 million would be required to rebuild homes and infrastructure. Philmore Mullin, Director of Barbuda's National Office of Disaster Services, said that "all critical infrastructure and utilities are non-existent – food supply, medicine, shelter, electricity, water, communications, waste management". He summarised the situation as follows: "Public utilities need to be rebuilt in their entirety... It is optimistic to think anything can be rebuilt in six months ... In my 25 years in disaster management, I have never seen something like this."
Environmental issues
Demographics
Ethnic groups
Antigua has a population of , mostly made up of people of West African, British, and Portuguese descent. The ethnic distribution consists of 91% Black, 4.4% mixed race, 1.7% White, and 2.9% other (primarily East Indian). Most Whites are of British descent. Christian Levantine Arabs and a small number of East Asians and Sephardic Jews make up the remainder of the population.
An increasingly large percentage of the population lives abroad, most notably in the United Kingdom (Antiguan Britons), the United States and Canada. A minority of Antiguan residents are immigrants from other countries, particularly from Dominica, Guyana and Jamaica, and, increasingly, from the Dominican Republic, St. Vincent and the Grenadines and Nigeria. An estimated 4,500 American citizens also make their home in Antigua and Barbuda, making their numbers one of the largest American populations in the English-speaking Eastern Caribbean. 68.47% of the population was born in Antigua and Barbuda.
Languages
The language most commonly used in business is English. There is a noticeable distinction between the Antiguan accent and the Barbudan one.
When compared to Antiguan Creole, Standard English was the language of choice in the years leading up to Antigua and Barbuda's attainment of their independence. The Antiguan Creole language is looked down upon by the upper and middle classes in general. The Antiguan Creole language is discouraged from use in the educational system, and instruction is carried out in Standard (British) English instead.
A significant number of the words that are utilized in the Antiguan dialect are derived from both the British and African languages. This is readily apparent in phrases such as "Innit?" which literally translates to "Isn't it?" Many common island proverbs can be traced back to Africa, such as the pidgin language.
Approximately 10,000 people are able to speak in Spanish.
Religion
A majority (77%) of Antiguans are Christians, with the Anglicans (17.6%) being the largest single denomination. Other Christian denominations present are Seventh-day Adventist Church (12.4%), Pentecostalism (12.2%), Moravian Church (8.3%), Roman Catholics
(8.2%), Methodist Church (5.6%), Wesleyan Holiness Church (4.5%), Church of God (4.1%), Baptists (3.6%), Mormonism (<1.0%), as well as Jehovah's Witnesses.
Governance
Political system
The politics of Antigua and Barbuda take place within a framework of a unitary, parliamentary, representative democratic monarchy, in which the head of state is the monarch who appoints the governor-general as vice-regal representative. Charles III is the present King of Antigua and Barbuda, having served in that position since the death of his mother, Elizabeth II. She had been the queen since the islands' independence from the United Kingdom in 1981. The King is currently represented by Governor-General Sir Rodney Williams. A council of ministers is appointed by the governor-general on the advice of the prime minister, currently Gaston Browne (since 2014). The prime minister is the head of government.
Executive power is exercised by the government while legislative power is vested in both the government and the two chambers of Parliament. The bicameral Parliament consists of the Senate (17 members appointed by members of the government and the opposition party, and approved by the governor-general), and the House of Representatives (17 members elected by first past the post) to serve five-year terms.
The current Leader of His Majesty's Loyal Opposition is Jamale Pringle.
There has been recent development in the republicanism movement in Antigua and Barbuda, following Barbados becoming a republic in 2021 and following the death of Elizabeth II in 2022, with an opinion poll showing majority support for the change.
Elections
The last election was held on 21 March 2018. The Antigua Barbuda Labour Party (ABLP) led by Prime Minister Gaston Browne won 15 of the 17 seats in the House of Representatives. The previous election was on 12 June 2014, during which the Antigua Labour Party won 14 seats, and the United Progressive Party 3 seats.
Since 1951, elections have been won by the populist Antigua Labour Party. However, in the Antigua and Barbuda legislative election of 2004 saw the defeat of the longest-serving elected government in the Caribbean.
Vere Bird was prime minister from 1981 to 1994 and chief minister of Antigua from 1960 to 1981, except for the 1971–1976 period when the Progressive Labour Movement (PLM) defeated his party. Bird, the nation's first prime minister, is credited with having brought Antigua and Barbuda and the Caribbean into a new era of independence. Prime Minister Lester Bryant Bird succeeded the elder Bird in 1994.
Party elections
Gaston Browne defeated his predecessor Lester Bryant Bird at the Antigua Labour Party's biennial convention in November 2012 held to elect a political leader and other officers. The party then altered its name from the Antigua Labour Party (ALP) to the Antigua and Barbuda Labour Party (ABLP). This was done to officially include the party's presence on the sister island of Barbuda in its organisation, the only political party on the mainland to have a physical branch in Barbuda.
Judiciary
The Eastern Caribbean Supreme Court is the highest court in the region's judicial system (based in Saint Lucia; one judge of the Supreme Court is a resident of the islands and presides over the High Court of Justice). The Caribbean Court of Justice counts Antigua as one of its member states. Its highest court of appeal is the Judicial Committee of the Privy Council, which acts in that capacity.
Foreign relations
Antigua and Barbuda is a member of the United Nations, the Bolivarian Alliance for the Americas, the Commonwealth of Nations, the Caribbean Community, the Organization of Eastern Caribbean States, the Organization of American States, the World Trade Organization and the Eastern Caribbean's Regional Security System.
Antigua and Barbuda is also a member of the International Criminal Court (with a Bilateral Immunity Agreement of Protection for the US military as covered under Article 98 of the Rome Statute).
In 2013, Antigua and Barbuda called for reparations for slavery at the United Nations. Prime Minister Baldwin Spencer said "We have recently seen a number of leaders apologising", and that they should now "match their words with concrete and material benefits."
Military
About 260 people are currently serving in the Antigua and Barbuda Defense Force in a variety of capacities. These personnel are distributed across the line infantry regiment, the service and support unit, the air force, and the coast guard. In addition there is the Antigua and Barbuda Cadet Corps, which is made up of two hundred young people between the ages of 12 and 18. The Defence Board is in charge of directing the activities of the armed forces of the nation. The National Security Council and the Financial Intelligence Unit are the two intelligence agencies that Antigua and Barbuda have at their disposal. Camp Blizzard serves as the administrative center for the Defense Force.
In 2018, Antigua and Barbuda signed the UN treaty on the Prohibition of Nuclear Weapons.
Administrative divisions
Antigua and Barbuda is divided into six parishes and two dependencies:
Although they are referred to as dependencies, both Barbuda and Redonda are actually integral parts of the state and can be thought of as administrative divisions. Simply put, "dependency" is just a title. The Redonda is a second-level administrative division that is part of the Saint John Parish's District "A." Barbuda is a local administrative division on the same level as Antigua and Barbuda, and its council is the name of its local governing body. In the year 2023, there have been discussions regarding the possibility of extending governmental authority to Antigua's parishes.
There are currently sixty of what are known as major divisions on the islands of Antigua and Barbuda. This administrative tier is known as the second level.
Local government in the country of Antigua and Barbuda is only present on the island of Barbuda at the present time; however, there is legislation in place for a system of village councils on the island of Antigua; however, village councils have not been active since the 1940s and 1950s.
Human rights
As of July 2022, Same-sex sexual activity is legal in Antigua and Barbuda.
Economy
Tourism dominates the economy, accounting for more than half of the gross domestic product (GDP). As a destination for the most affluent travelers, Antigua is well known for its extensive collection of five-star resorts. However, weaker tourist activity in lower and middle market segments since the beginning of the year 2000 has slowed the economy and put the government into a tight fiscal corner. Antigua and Barbuda has enacted policies to attract high-net-worth citizens and residents, such as enacting a 0% personal income tax rate in 2019.
The provision of investment banking and financial services also constitutes a significant portion of the economy. Major international financial institutions such as the Royal Bank of Canada (RBC) and Scotiabank both maintain offices in Antigua. PriceWaterhouseCoopers, Pannell Kerr Forster, and KPMG are some of the other companies in the financial services industry that have offices in Antigua. The United States Securities and Exchange Commission has leveled allegations against the Antigua-based Stanford International Bank, which is owned by the Texas billionaire Allen Stanford, of orchestrating a massive fraud that may have resulted in the theft of approximately $8 billion from investors.
The nation, which consists of two islands, directs the majority of its agricultural production toward the markets that are found within the nation. This is done despite the fact that the nation has a limited water supply and a shortage of laborers as a result of the higher wages offered in the tourism and construction industries.
Manufacturing comprises 2% of GDP and is made up of enclave-type assembly for export, the major products being bedding, handicrafts, and electronic components. Prospects for economic growth in the medium term will continue to depend on income growth in the industrialised world, especially in the United States, from which about one-third to one-half of all tourists come.
Access to biocapacity is lower than world average. In 2016, Antigua and Barbuda had 0.8 global hectares of biocapacity per person within its territory, much less than the world average of 1.6 global hectares per person. In 2016, Antigua and Barbuda used 4.3 global hectares of biocapacity per person – their ecological footprint of consumption. This means they use more biocapacity than Antigua and Barbuda contains. As a result, Antigua and Barbuda are running a biocapacity deficit.
The Citizenship by Investment Unit (CIU) is the government authority responsible for processing all applications for Agent's Licenses as well as all applications for Citizenship by Investment made by applicants and their family members. This unit was established by the Prime Minister and is known as the Citizenship by Investment Unit.
Transport
The transportation networks of Antigua and Barbuda are made up of both publicly operated and privately managed services. The roads in the countryside are paved, and their paths are winding and gradual in their ascents and descents; they connect parishes to villages and communities. Cars are driven on the left side of the road. Antigua and Barbuda has a speed limit of 40 miles per hour, and there are traffic signs posted along the main roads that make it easier to commute. Additionally, GPS coordinates have been posted throughout the country, which has made the process of navigation more manageable.
On the yellow license plates of public transportation vehicles, the letters "BUS" indicate that the vehicle is a bus, and the letters "TX" indicate that the vehicle is a taxi. Taxi services are subject to government regulation, which results in the establishment of flat rates rather than the use of meters. It is required that taxi drivers keep a copy of the rates posted inside the cab at all times. Taxis are not hard to come by on Antigua, particularly at the airport and major hotels. The role of tour guide is one that is frequently taken on by taxi drivers.
On the island of Antigua, buses run continuously throughout the day from 5:30 a.m. until 6:00 p.m., connecting the capital city of St. John's with a number of the surrounding villages. On the other hand, buses do not make stops at the airport or in the tourist area to the north. Although the timing of the bus' departure is frequently up to the discretion of the driver, most buses operate according to a predetermined schedule. The routes that most buses take are typically displayed in the front windows of the vehicles, which are typically private minivans with seating for approximately 15 passengers each. Both the East Bus Station on Independence Avenue close to the Botanical Gardens and the Market Street Bus Station close to the Central Market are the two bus stations that serve the city of St. John's. There are also a number of bus companies operating on the island of Barbuda.
Education
Culture
The culture is primarily influenced by the traditions of West Africa as well as those of the United Kingdom.
The most popular sport in the country is cricket. Football, boat racing, and surfing are three additional popular forms of athletic competition. (Antigua Sailing Week attracts locals and visitors from all over the world).
Music
Since the majority of Antiguans and Barbudans are descended from West Africans who were brought to the islands as slaves by Europeans, the musical traditions of Antigua and Barbuda are predominately of African origin and have only been marginally influenced by European musical traditions.
The island nation of Antigua and Barbuda can be found in the Caribbean's Lesser Antilles chain of islands. It is a second home for many of the popular music genres that are popular throughout the Caribbean, including calypso, soca, steeldrum, zouk, and reggae, and it has produced stars in these genres. Steeldrum and calypso are two musical styles that were brought to Antigua from Trinidad and Tobago, and they are the two that have had the most significant impact on the development of modern Antiguan popular music.
Other than this, very little to no research has been done on the musical history of Antigua and Barbuda. Consequently, a significant amount of the knowledge on the subject comes from novels, essays, and other types of secondary sources.
Festivals
Although on some islands Carnival may be used to celebrate the beginning of Lent, the national Carnival held every August is held to commemorate the abolition of slavery in the British West Indies. The national Carnival is held in August. The festive pageants, shows, and competitions, along with the other events that take place, are a major draw for tourists.
Cuisine
Antigua and Barbuda cuisine is a term used to describe the culinary traditions of the islands of Antigua and Barbuda in the Caribbean. Fungie, pronounced "foon-jee", and pepperpot are the country's official dish and dish of pride. Cornmeal is the main ingredient in fungie, which is a dish that is very similar to the Italian dish polenta. Other popular dishes from this region include ducana, saltfish, seasoned rice, and lobster (from Barbuda). In addition, there are sweets that are made locally, such as peanut brittle, sugar cake, fudge, raspberry and tamarind stew, and other similar dishes.
Despite the fact that these foods are native to Antigua and Barbuda as well as to a number of other Caribbean nations, the diet of the locals has become increasingly diverse and now also includes traditional dishes from Jamaica and Trinidad, such as jerk meats and roti, as well as specialties from a number of other Caribbean nations.
Saltfish, eggs, eggplant (also referred to as troba), lettuce, and other vegetables are typically served for breakfast. Lunches typically consist of a starch, such as rice, macaroni, or pasta, with vegetables or salad, an entree (such as fish, chicken, pork, or beef), and a side dish, such as macaroni pie, scalloped potatoes, or plantains. Dinners typically consist of a protein, such as fish, chicken, pork, or beef. On Sundays, the majority of people in the country attend religious services, and then they return home to prepare a wide variety of meals for their families. Due to the fact that most people are off work on Sundays, dinner is typically served earlier in the day (around 2:00 pm). Dinners might consist of pork, chicken baked in the oven, stewed lamb, or turkey, served with rice (prepared in a variety of ways), macaroni pie, salads, and a local beverage. Dessert options include ice cream and cake, apple pie (or mango or pineapple pie when those fruits are in season), gelatin, and cake. The soft, buttery loaf of bread known as Antiguan butter bread does not require any additional butter to be added once it has been baked. This dish is another mainstay of Antiguan cuisine. Breakfast and other meals throughout the day often consist of fresh-baked butter bread and cheese for the community's residents. Throughout the city of Antigua, there are a great number of homes that have small bakeries built onto them. These bakeries sell freshly baked loaves, and locals can go to these bakeries to buy them. They are served alongside cheese, sardines or a bright red sausage that residents of the area occasionally refer to as salami, in addition to a great deal of other foods. In addition, the majority of meals feature something known as "provisions", which is typically a root vegetable or starch such as potatoes, yams, sweet potatoes, or eddo. During Carnival, a popular snack is souse, which is a type of soup that is very spicy and is made with pig feet, knuckles, and tails in addition to many onions. This soup is sold by vendors on the side of the road. Black pudding, also referred to as blood sausage, is a well-seasoned sausage that is made with rice, meat, and blood that is also enjoyed by locals in Antigua. On improvised grills, locals in the countryside sell freshly picked corn that has been roasted, typically while still in the husk. The Antiguan pineapple is typically quite succulent and sugary, despite its diminutive size. The entire island is covered with numerous small pineapple plantations.
The following are some examples of local beverages: mauby, seamoss, tamarind juice, raspberry juice, mango juice, lemonade, coconut milk, hibiscus juice, ginger beer, passion fruit juice, guava juice, soursop juice, and ginger beer, which is a soft drink. Beer, malts, and rums are some of the alcoholic beverages that can be found here. Many of these drinks are produced locally, such as the award-winning English Harbour Rum and the Wadadli beer, which takes its name from the island's former name. A significant number of residents in the area consume bottled sodas, which they refer to as sweet drink. Punch is a flavor that is enjoyed by many. In addition to Red Stripe beer, Guinness stout, Heineken beer, and Malta, the locals like to drink Red Malta. Ponche Kuba Cream Liqueur is a special celebratory alcoholic drink that is very popular in Antigua during the Christmas holiday season. This beverage has a brown colour, has a thick and creamy consistency, is extremely sweet, and contains a high percentage of alcohol.
Media
The Antigua Daily Observer, the Antigua News Room, and The Antiguan Times are the names of the country's three newspapers. The Antigua Observer is the only newspaper that is published every day in printed form.
It is possible to watch the local television channel, ABS TV 10. (it is the only station that shows exclusively local programs). There are also a number of radio stations that broadcast regionally and locally. Some of these stations include V2C-AM 620, ZDK-AM 1100, VYBZ-FM 92.9, ZDK-FM 97.1, Observer Radio 91.1 FM, DNECA Radio 90.1 FM, Second Advent Radio 101.5 FM, Abundant Life Radio 103.9 FM, Crusader Radio 107.3 FM, Nice FM 104.3, Pointe FM 99.1, and WTP 93.5FM.
Monuments
Fort James, an 18th-century fort at the eastern entrance to St. John's harbour
Fort Barrington, an 18th-century fort at the western entrance to St. John's harbour
Shirley Heights, grounds of an 18th-century military complex overlooking English Harbour
Fort Berkeley, an 18th-century fort at the western entrance to English Harbour
Fort Charlotte, remains of an 18th-century fort at the eastern entrance to English Harbour
Museums
Museum of Antigua and Barbuda
Dockyard Museum
Betty's Hope
Dow's Hill Interpretation Centre
World heritage
In 2016, Antigua Naval Dockyard and Related Archaeological Sites have been inscribed in the UNESCO World Heritage List.
Sports
Cricket is the most popular sport within the islands. With Sir Isaac Vivian Alexander Richards who represented the West Indies cricket team between 1974 and 1991, Antigua had one of the world's most famous batsmen ever. The Antigua and Barbuda national cricket team represented the country at the 1998 Commonwealth Games, but Antiguan cricketers otherwise play for the Leeward Islands cricket team in domestic matches and the West Indies cricket team internationally. The 2007 Cricket World Cup was hosted in the West Indies from 11 March to 28 April 2007. Antigua hosted eight matches at the Sir Vivian Richards Stadium, which was completed on 11 February 2007 and can hold up to 20,000 people.
Antigua is a Host of Stanford Twenty20 – Twenty20 Cricket, a version started by Allen Stanford in 2006 as a regional cricket game with almost all Caribbean islands taking part. From 15 January to 5 February 2022, the Sir Vivian Richards Stadium was one of the venues for the 2022 ICC Under-19 Cricket World Cup.Rugby and Netball are popular as well.
Association football, or soccer, is also a very popular sport. Antigua has a national football team which entered World Cup qualification for the 1974 tournament for 1986 and beyond. A professional team was formed in 2011, Antigua Barracuda FC, which played in the USL Pro, a lower professional league in the US. The nation's team had a major achievement in 2012, getting out of its preliminary group for the 2014 World Cup, notably due to a victory over powerful Haiti. In its first game in the next CONCACAF group play on 8 June 2012 in Tampa, FL, Antigua and Barbuda, comprising 17 Barracuda players and 7 from the lower English professional leagues, scored a goal against the United States. However, the team lost 3:1 to the US.
Daniel Bailey had become the first Antiguan to reach a world indoor final, where he won a bronze medal at the 2010 IAAF World Indoor Championships. He was also the first Antiguan to make a 100m final at the 2009 World Championships in Athletics, and the first Antiguan to run under 10 seconds over 100m.
Brendan Christian won a gold medal in the 200m and a bronze medal in the 100m at the 2007 Pan American Games. James Grayman won a bronze medal at the same games in the men's High Jump.
Miguel Francis is the first Antiguan to run sub 20 seconds in the 200m.
Heather Samuel won a bronze medal at the 1995 Pan American Games over 100m.
400m Hurdles Olympian Gold Medalist Rai Benjamin previously represented Antigua and Barbuda before representing the United States. His Silver medal run at the 2020 Olympic Games made him the second-fastest person in history over 400m Hurdles with a time of 46.17.
Notable people
Symbols
The frigatebird is the country's official national bird, and the bucida buceras (Whitewood tree) is the official national tree.
Clare Waight Keller designed Meghan Markle's wedding veil, which featured the distinctive flora of each Commonwealth nation. To represent Antigua and Barbuda, Agave karatto was included in the veil.
The European fallow deer, or Dama dama, is the country's official mammal, despite the fact that it is a non-native species.
In 1992, the government held a contest to design a new national dress for the country, and the winner of the competition was the artist Heather Doram.
See also
Geology of Antigua and Barbuda
Outline of Antigua and Barbuda
Index of Antigua and Barbuda–related articles
Transport in Antigua and Barbuda
References
Works cited
Further reading
Nicholson, Desmond V., Antigua, Barbuda, and Redonda: A Historical Sketch, St. Johns, Antigua: Antigua and Barbuda Museum, 1991.
Dyde, Brian, A History of Antigua: The Unsuspected Isle, London: Macmillan Caribbean, 2000.
Gaspar, David Barry – Bondmen & Rebels: A Study of Master-Slave Relations in Antigua, with Implications for Colonial America.
Harris, David R. – Plants, Animals, and Man in the Outer Leeward Islands, West Indies. An Ecological Study of Antigua, Barbuda, and Anguilla.
Henry, Paget – Peripheral Capitalism and Underdevelopment in Antigua.
Lazarus-Black, Mindie – Legitimate Acts and Illegal Encounters: Law and Society in Antigua and Barbuda.
Riley, J. H. – Catalogue of a Collection of Birds from Barbuda and Antigua, British West Indies.
Rouse, Irving and Birgit Faber Morse – Excavations at the Indian Creek Site, Antigua, West Indies.
Thomas Hearne. Southampton.
External links
Antigua and Barbuda, United States Library of Congress
Antigua and Barbuda. The World Factbook. Central Intelligence Agency.
Antigua and Barbuda from UCB Libraries GovPubs
Antigua and Barbuda from the BBC News
World Bank's country data profile for Antigua and Barbuda
ArchaeologyAntigua.org – 2010March13 source of archaeological information for Antigua and Barbuda
Antigua & Barbuda Official Business Hub
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953 | https://en.wikipedia.org/wiki/Azincourt | Azincourt | Azincourt ( ; ) is a commune in the Pas-de-Calais department in northern France. It is situated north-west of Saint-Pol-sur-Ternoise on the D71 road between Hesdin and Fruges. It is often erroneously known as Agincourt ( ) in English, as the village had never been called as such throughout its history, however, there is a village that is named "Agincourt", located in the Meurthe-et-Moselle department in Eastern France.
The Late Medieval Battle of Azincourt between the English and the French took place in the commune in 1415.
Toponym
The name is attested as Aisincurt in 1175, derived from a Germanic masculine name Aizo, Aizino and the early Northern French word curt (which meant a farm with a courtyard; derived from the Late Latin cortem). The name has no etymological link with Agincourt, Meurthe-et-Moselle (attested as Egincourt 875), which is derived separately from another Germanic male name *Ingin-.
History
Azincourt is known for being near the site of the battle fought on 25 October 1415 in which the army led by King Henry V of England defeated the forces led by Charles d'Albret on behalf of Charles VI of France, which has gone down in history as the Battle of Agincourt. According to M. Forrest, the French knights were so encumbered by their armour that they were exhausted even before the start of the battle.
After he became king in 1509, Henry VIII is purported to have commissioned an English translation of a Life of Henry V so that he could emulate him, on the grounds that he thought that launching a campaign against France would help him to impose himself on the European stage. In 1513, Henry VIII crossed the English Channel, stopping by at Azincourt.
The battle, as was the tradition, was named after a nearby castle called Azincourt. The castle has since disappeared and the settlement now known as Azincourt adopted the name in the seventeenth century.
John Cassell wrote in 1857 that "the village of Azincourt itself is now a group of dirty farmhouses and wretched cottages, but where the hottest of the battle raged, between that village and the commune of Tramecourt, there still remains a wood precisely corresponding with the one in which Henry placed his ambush; and there are yet existing the foundations of the castle of Azincourt, from which the king named the field."
Population
Sights
The original battlefield museum in the village featured model knights made out of Action Man figures. This has now been replaced by the Centre historique médiéval d'Azincourt (CHM)a more professional museum, conference centre and exhibition space incorporating laser, video, slide shows, audio commentaries, and some interactive elements. The museum building is shaped like a longbow similar to those used at the battle by archers under King Henry.
Since 2004 a large medieval festival organised by the local community, the CHM, The Azincourt Alliance, and various other UK societies commemorating the battle, local history and medieval life, arts and crafts has been held in the village. Prior to this date the festival was held in October, but due to the inclement weather and local heavy clay soil (like the battle) making the festival difficult, it was moved to the last Sunday in July.
International relations
Azincourt is twinned with Middleham, United Kingdom.
See also
Communes of the Pas-de-Calais department
The neighbourhood of Agincourt, Toronto, Canada, named for Azincourt, not Agincourt, Meurthe-et-Moselle
References
Communes of Pas-de-Calais
Artois |
957 | https://en.wikipedia.org/wiki/Apiaceae | Apiaceae | Apiaceae () or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus Apium and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plants, with more than 3,800 species in about 446 genera, including such well-known and economically important plants as ajwain, angelica, anise, asafoetida, caraway, carrot, celery, chervil, coriander, cumin, dill, fennel, lovage, cow parsley, parsley, parsnip and sea holly, as well as silphium, a plant whose exact identity is unclear and which may be extinct.
The family Apiaceae includes a significant number of phototoxic species, such as giant hogweed, and a smaller number of highly poisonous species, such as poison hemlock, water hemlock, spotted cowbane, fool's parsley, and various species of water dropwort.
Description
Most Apiaceae are annual, biennial or perennial herbs (frequently with the leaves aggregated toward the base), though a minority are woody shrubs or small trees such as Bupleurum fruticosum. Their leaves are of variable size and alternately arranged, or with the upper leaves becoming nearly opposite. The leaves may be petiolate or sessile. There are no stipules but the petioles are frequently sheathing and the leaves may be perfoliate. The leaf blade is usually dissected, ternate, or pinnatifid, but simple and entire in some genera, e.g. Bupleurum. Commonly, their leaves emit a marked smell when crushed, aromatic to fetid, but absent in some species.
The defining characteristic of this family is the inflorescence, the flowers nearly always aggregated in terminal umbels, that may be simple or more commonly compound, often umbelliform cymes. The flowers are usually perfect (hermaphroditic) and actinomorphic, but there may be zygomorphic flowers at the edge of the umbel, as in carrot (Daucus carota) and coriander, with petals of unequal size, the ones pointing outward from the umbel larger than the ones pointing inward. Some are andromonoecious, polygamomonoecious, or even dioecious (as in Acronema), with a distinct calyx and corolla, but the calyx is often highly reduced, to the point of being undetectable in many species, while the corolla can be white, yellow, pink or purple. The flowers are nearly perfectly pentamerous, with five petals and five stamens.
There is often variation in the functionality of the stamens even within a single inflorescence. Some flowers are functionally staminate (where a pistil may be present but has no ovules capable of being fertilized) while others are functionally pistillate (where stamens are present but their anthers do not produce viable pollen). Pollination of one flower by the pollen of a different flower of the same plant (geitonogamy) is common. The gynoecium consists of two carpels fused into a single, bicarpellate pistil with an inferior ovary. Stylopodia support two styles and secrete nectar, attracting pollinators like flies, mosquitoes, gnats, beetles, moths, and bees. The fruit is a schizocarp consisting of two fused carpels that separate at maturity into two mericarps, each containing a single seed. The fruits of many species are dispersed by wind but others such as those of Daucus spp., are covered in bristles, which may be hooked in sanicle Sanicula europaea and thus catch in the fur of animals. The seeds have an oily endosperm and often contain essential oils, containing aromatic compounds that are responsible for the flavour of commercially important umbelliferous seed such as anise, cumin and coriander. The shape and details of the ornamentation of the ripe fruits are important for identification to species level.
Taxonomy
Apiaceae was first described by John Lindley in 1836. The name is derived from the type genus Apium, which was originally used by Pliny the Elder circa 50 AD for a celery-like plant. The alternative name for the family, Umbelliferae, derives from the inflorescence being generally in the form of a compound umbel. The family was one of the first to be recognized as a distinct group in Jacques Daleschamps' 1586 Historia generalis plantarum. With Robert Morison's 1672 Plantarum umbelliferarum distribution nova it became the first group of plants for which a systematic study was published.
The family is solidly placed within the Apiales order in the APG III system. It is closely related to Araliaceae and the boundaries between these families remain unclear. Traditionally groups within the family have been delimited largely based on fruit morphology, and the results from this have not been congruent with the more recent molecular phylogenetic analyses. The subfamilial and tribal classification for the family is currently in a state of flux, with many of the groups being found to be grossly paraphyletic or polyphyletic.
Classification and phylogeny
Prior to molecular phylogenetic studies, the family was subdivided primarily based on fruit characteristics. Molecular phylogenetic analyses from the mid-1990s onwards have shown that fruit characters evolved in parallel many times, so that using them in classification resulted in units that were not monophyletic. In 2004, it was proposed that Apiaceae should be divided into four subfamilies:
Apioideae Seem.
Azorelloideae G.M.Plunkett & Lowry
Mackinlayoideae G.M.Plunkett & Lowry
Saniculoideae Burnett
Apioideae is by far the largest subfamily with about 90% of the genera. Most subsequent studies have supported this division, although leaving some genera unplaced. A 2021 study suggested the relationships shown in the following cladogram.
The Platysace clade and the genera Klotzschia and Hermas fell outside the four subfamilies. It was suggested that they could be accommodated in subfamilies of their own. Phlyctidocarpa was formerly placed in the subfamily Apioideae, but if kept there makes Apioideae paraphyletic. It could be placed in an enlarged Saniculoideae, or restored to Apioideae if the latter were expanded to include Saniculoideae.
The subfamilies can be further divided into tribes and clades, with many clades falling outside formally recognized tribes.
Genera
The number of genera accepted by sources varies. , Plants of the World Online (PoWO) accepted 444 genera, while GRIN Taxonomy accepted 462. The PoWO genera are not a subset of those in GRIN; for example, Haloselinum is accepted by PoWO but not by GRIN, while Halosciastrum is accepted by GRIN but not by PoWO, which treats it as a synonym of Angelica. The Angiosperm Phylogeny Website had an "approximate list" of 446 genera.
Ecology
The black swallowtail butterfly, Papilio polyxenes, uses the family Apiaceae for food and host plants for oviposition. The 22-spot ladybird is also commonly found eating mildew on these plants.
Uses
Many members of this family are cultivated for various purposes. Parsnip (Pastinaca sativa), carrot (Daucus carota) and Hamburg parsley (Petroselinum crispum) produce tap roots that are large enough to be useful as food. Many species produce essential oils in their leaves or fruits and as a result are flavourful aromatic herbs. Examples are parsley (Petroselinum crispum), coriander (Coriandrum sativum), culantro, and dill (Anethum graveolens). The seeds may be used in cuisine, as with coriander (Coriandrum sativum), fennel (Foeniculum vulgare), cumin (Cuminum cyminum), and caraway (Carum carvi).
Other notable cultivated Apiaceae include chervil (Anthriscus cerefolium), angelica (Angelica spp.), celery (Apium graveolens), arracacha (Arracacia xanthorrhiza), sea holly (Eryngium spp.), asafoetida (Ferula asafoetida), galbanum (Ferula gummosa), cicely (Myrrhis odorata), anise (Pimpinella anisum), lovage (Levisticum officinale), and hacquetia (Sanicula epipactis).
Cultivation
Generally, all members of this family are best cultivated in the cool-season garden; they may not grow at all if the soils are too warm. Almost every widely cultivated plant of this group is a considered useful as a companion plant. One reason is that the tiny flowers, clustered into umbels, are well suited for ladybugs, parasitic wasps, and predatory flies, which drink nectar when not reproducing. They then prey upon insect pests on nearby plants. Some of the members of this family considered "herbs" produce scents that are believed to mask the odours of nearby plants, thus making them harder for insect pests to find.
Other uses
The poisonous members of the Apiaceae have been used for a variety of purposes globally. The poisonous Oenanthe crocata has been used as an aid in suicides, and arrow poisons have been made from various other family species.
Daucus carota has been used as coloring for butter.
Dorema ammoniacum, Ferula galbaniflua, and Ferula moschata (sumbul) are sources of incense.
The woody Azorella compacta Phil. has been used in South America for fuel.
Toxicity
Many species in the family Apiaceae produce phototoxic substances (called furanocoumarins) that sensitize human skin to sunlight. Contact with plant parts that contain furanocoumarins, followed by exposure to sunlight, may cause phytophotodermatitis, a serious skin inflammation. Phototoxic species include Ammi majus, Notobubon galbanum, the parsnip (Pastinaca sativa) and numerous species of the genus Heracleum, especially the giant hogweed (Heracleum mantegazzianum). Of all the plant species that have been reported to induce phytophotodermatitis, approximately half belong to the family Apiaceae.
The family Apiaceae also includes a smaller number of poisonous species, including poison hemlock, water hemlock, spotted cowbane, fool's parsley, and various species of water dropwort.
Some members of the family Apiaceae, including carrot, celery, fennel, parsley and parsnip, contain polyynes, an unusual class of organic compounds that exhibit cytotoxic effects.
References
Further reading
Constance, L. (1971). "History of the classification of Umbelliferae (Apiaceae)." in Heywood, V. H. [ed.], The biology and chemistry of the Umbelliferae, 1–11. Academic Press, London.
Cronquist, A. (1968). The Evolution and Classification of Flowering Plants. Boston: Houghton Mifflin.
French, D. H. (1971). "Ethnobotany of the Umbelliferae." in Heywood, V. H. [ed.], The biology and chemistry of the Umbelliferae, 385–412. Academic Press, London.
Hegnauer, R. (1971) "Chemical Patterns and Relationships of Umbelliferae." in Heywood, V. H. [ed.], The biology and chemistry of the Umbelliferae, 267–277. Academic Press, London.
Heywood, V. H. (1971). "Systematic survey of Old World Umbelliferae." in Heywood, V. H. [ed.], The biology and chemistry of the Umbelliferae, 31–41. Academic Press, London.
Judd, W. S. et al. (1999). Plant Systematics: A Phylogenetic Approach. Sunderland, MA: Sinauer Associates, Inc.
Nieto Feliner, Gonzalo; Jury, Stephen Leonard & Herrero Nieto, Alberto (eds.) Flora iberica. Plantas vasculares de la Península Ibérica e Islas Baleares. Vol. X. "Araliaceae-Umbelliferae" (2003) Madrid: Real Jardín Botánico, CSIC (in Spanish).
External links
Umbelliferae at The Families of Flowering Plants (DELTA)
Apiaceae at Discover Life
Umbellifer Resource Centre at the Royal Botanic Garden Edinburgh
Umbellifer Information Server at Moscow State University
Asterid families |
958 | https://en.wikipedia.org/wiki/Axon | Axon | An axon (from Greek ἄξων áxōn, axis) or nerve fiber (or nerve fibre: see spelling differences) is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons (pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and acquired neurological disorders that affect both the peripheral and central neurons. Nerve fibers are classed into three typesgroup A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated. These groups include both sensory fibers and motor fibers. Another classification groups only the sensory fibers as Type I, Type II, Type III, and Type IV.
An axon is one of two types of cytoplasmic protrusions from the cell body of a neuron; the other type is a dendrite. Axons are distinguished from dendrites by several features, including shape (dendrites often taper while axons usually maintain a constant radius), length (dendrites are restricted to a small region around the cell body while axons can be much longer), and function (dendrites receive signals whereas axons transmit them). Some types of neurons have no axon and transmit signals from their dendrites. In some species, axons can emanate from dendrites known as axon-carrying dendrites. No neuron ever has more than one axon; however in invertebrates such as insects or leeches the axon sometimes consists of several regions that function more or less independently of each other.
Axons are covered by a membrane known as an axolemma; the cytoplasm of an axon is called axoplasm. Most axons branch, in some cases very profusely. The end branches of an axon are called telodendria. The swollen end of a telodendron is known as the axon terminal which joins the dendrite or cell body of another neuron forming a synaptic connection. Axons make contact with other cellsusually other neurons but sometimes muscle or gland cellsat junctions called synapses. In some circumstances, the axon of one neuron may form a synapse with the dendrites of the same neuron, resulting in an autapse. At a synapse, the membrane of the axon closely adjoins the membrane of the target cell, and special molecular structures serve to transmit electrical or electrochemical signals across the gap. Some synaptic junctions appear along the length of an axon as it extends; these are called en passant ("in passing") synapses and can be in the hundreds or even the thousands along one axon. Other synapses appear as terminals at the ends of axonal branches.
A single axon, with all its branches taken together, can target multiple parts of the brain and generate thousands of synaptic terminals. A bundle of axons make a nerve tract in the central nervous system, and a fascicle in the peripheral nervous system. In placental mammals the largest white matter tract in the brain is the corpus callosum, formed of some 200 million axons in the human brain.
Anatomy
Axons are the primary transmission lines of the nervous system, and as bundles they form nerves. Some axons can extend up to one meter or more while others extend as little as one millimeter. The longest axons in the human body are those of the sciatic nerve, which run from the base of the spinal cord to the big toe of each foot. The diameter of axons is also variable. Most individual axons are microscopic in diameter (typically about one micrometer (μm) across). The largest mammalian axons can reach a diameter of up to 20 μm. The squid giant axon, which is specialized to conduct signals very rapidly, is close to 1 millimeter in diameter, the size of a small pencil lead. The numbers of axonal telodendria (the branching structures at the end of the axon) can also differ from one nerve fiber to the next. Axons in the central nervous system (CNS) typically show multiple telodendria, with many synaptic end points. In comparison, the cerebellar granule cell axon is characterized by a single T-shaped branch node from which two parallel fibers extend. Elaborate branching allows for the simultaneous transmission of messages to a large number of target neurons within a single region of the brain.
There are two types of axons in the nervous system: myelinated and unmyelinated axons. Myelin is a layer of a fatty insulating substance, which is formed by two types of glial cells: Schwann cells and oligodendrocytes. In the peripheral nervous system Schwann cells form the myelin sheath of a myelinated axon. Oligodendrocytes form the insulating myelin in the CNS. Along myelinated nerve fibers, gaps in the myelin sheath known as nodes of Ranvier occur at evenly spaced intervals. The myelination enables an especially rapid mode of electrical impulse propagation called saltatory conduction.
The myelinated axons from the cortical neurons form the bulk of the neural tissue called white matter in the brain. The myelin gives the white appearance to the tissue in contrast to the grey matter of the cerebral cortex which contains the neuronal cell bodies. A similar arrangement is seen in the cerebellum. Bundles of myelinated axons make up the nerve tracts in the CNS. Where these tracts cross the midline of the brain to connect opposite regions they are called commissures. The largest of these is the corpus callosum that connects the two cerebral hemispheres, and this has around 20 million axons.
The structure of a neuron is seen to consist of two separate functional regions, or compartmentsthe cell body together with the dendrites as one region, and the axonal region as the other.
Axonal region
The axonal region or compartment, includes the axon hillock, the initial segment, the rest of the axon, and the axon telodendria, and axon terminals. It also includes the myelin sheath. The Nissl bodies that produce the neuronal proteins are absent in the axonal region. Proteins needed for the growth of the axon, and the removal of waste materials, need a framework for transport. This axonal transport is provided for in the axoplasm by arrangements of microtubules and intermediate filaments known as neurofilaments.
Axon hillock
The axon hillock is the area formed from the cell body of the neuron as it extends to become the axon. It precedes the initial segment. The received action potentials that are summed in the neuron are transmitted to the axon hillock for the generation of an action potential from the initial segment.
Axonal initial segment
The axonal initial segment (AIS) is a structurally and functionally separate microdomain of the axon. One function of the initial segment is to separate the main part of an axon from the rest of the neuron; another function is to help initiate action potentials. Both of these functions support neuron cell polarity, in which dendrites (and, in some cases the soma) of a neuron receive input signals at the basal region, and at the apical region the neuron's axon provides output signals.
The axon initial segment is unmyelinated and contains a specialized complex of proteins. It is between approximately 20 and 60 μm in length and functions as the site of action potential initiation. Both the position on the axon and the length of the AIS can change showing a degree of plasticity that can fine-tune the neuronal output. A longer AIS is associated with a greater excitability. Plasticity is also seen in the ability of the AIS to change its distribution and to maintain the activity of neural circuitry at a constant level.
The AIS is highly specialized for the fast conduction of nerve impulses. This is achieved by a high concentration of voltage-gated sodium channels in the initial segment where the action potential is initiated. The ion channels are accompanied by a high number of cell adhesion molecules and scaffold proteins that anchor them to the cytoskeleton. Interactions with ankyrin-G are important as it is the major organizer in the AIS.
Axonal transport
The axoplasm is the equivalent of cytoplasm in the cell. Microtubules form in the axoplasm at the axon hillock. They are arranged along the length of the axon, in overlapping sections, and all point in the same directiontowards the axon terminals. This is noted by the positive endings of the microtubules. This overlapping arrangement provides the routes for the transport of different materials from the cell body. Studies on the axoplasm has shown the movement of numerous vesicles of all sizes to be seen along cytoskeletal filamentsthe microtubules, and neurofilaments, in both directions between the axon and its terminals and the cell body.
Outgoing anterograde transport from the cell body along the axon, carries mitochondria and membrane proteins needed for growth to the axon terminal. Ingoing retrograde transport carries cell waste materials from the axon terminal to the cell body. Outgoing and ingoing tracks use different sets of motor proteins. Outgoing transport is provided by kinesin, and ingoing return traffic is provided by dynein. Dynein is minus-end directed. There are many forms of kinesin and dynein motor proteins, and each is thought to carry a different cargo. The studies on transport in the axon led to the naming of kinesin.
Myelination
In the nervous system, axons may be myelinated, or unmyelinated. This is the provision of an insulating layer, called a myelin sheath. The myelin membrane is unique in its relatively high lipid to protein ratio.
In the peripheral nervous system axons are myelinated by glial cells known as Schwann cells. In the central nervous system the myelin sheath is provided by another type of glial cell, the oligodendrocyte. Schwann cells myelinate a single axon. An oligodendrocyte can myelinate up to 50 axons.
The composition of myelin is different in the two types. In the CNS the major myelin protein is proteolipid protein, and in the PNS it is myelin basic protein.
Nodes of Ranvier
Nodes of Ranvier (also known as myelin sheath gaps) are short unmyelinated segments of a myelinated axon, which are found periodically interspersed between segments of the myelin sheath. Therefore, at the point of the node of Ranvier, the axon is reduced in diameter. These nodes are areas where action potentials can be generated. In saltatory conduction, electrical currents produced at each node of Ranvier are conducted with little attenuation to the next node in line, where they remain strong enough to generate another action potential. Thus in a myelinated axon, action potentials effectively "jump" from node to node, bypassing the myelinated stretches in between, resulting in a propagation speed much faster than even the fastest unmyelinated axon can sustain.
Axon terminals
An axon can divide into many branches called telodendria (Greek for 'end of tree'). At the end of each telodendron is an axon terminal (also called a synaptic bouton, or terminal bouton). Axon terminals contain synaptic vesicles that store the neurotransmitter for release at the synapse. This makes multiple synaptic connections with other neurons possible. Sometimes the axon of a neuron may synapse onto dendrites of the same neuron, when it is known as an autapse.
Axonal varicosities
In the normally developed brain, along the shaft of some axons are located pre-synaptic boutons also known as axonal varicosities and these have been found in regions of the hippocampus that function in the release of neurotransmitters. However, axonal varicosities are also present in neurodegenerative diseases where they interfere with the conduction of an action potential. Axonal varicosities are also the hallmark of traumatic brain injuries. Axonal damage is usually to the axon cytoskeleton disrupting transport. As a consequence protein accumulations such as amyloid-beta precursor protein can build up in a swelling resulting in a number of varicosities along the axon.
Action potentials
Most axons carry signals in the form of action potentials, which are discrete electrochemical impulses that travel rapidly along an axon, starting at the cell body and terminating at points where the axon makes synaptic contact with target cells. The defining characteristic of an action potential is that it is "all-or-nothing"every action potential that an axon generates has essentially the same size and shape. This all-or-nothing characteristic allows action potentials to be transmitted from one end of a long axon to the other without any reduction in size. There are, however, some types of neurons with short axons that carry graded electrochemical signals, of variable amplitude.
When an action potential reaches a presynaptic terminal, it activates the synaptic transmission process. The first step is rapid opening of calcium ion channels in the membrane of the axon, allowing calcium ions to flow inward across the membrane. The resulting increase in intracellular calcium concentration causes synaptic vesicles (tiny containers enclosed by a lipid membrane) filled with a neurotransmitter chemical to fuse with the axon's membrane and empty their contents into the extracellular space. The neurotransmitter is released from the presynaptic nerve through exocytosis. The neurotransmitter chemical then diffuses across to receptors located on the membrane of the target cell. The neurotransmitter binds to these receptors and activates them. Depending on the type of receptors that are activated, the effect on the target cell can be to excite the target cell, inhibit it, or alter its metabolism in some way. This entire sequence of events often takes place in less than a thousandth of a second. Afterward, inside the presynaptic terminal, a new set of vesicles is moved into position next to the membrane, ready to be released when the next action potential arrives. The action potential is the final electrical step in the integration of synaptic messages at the scale of the neuron.
Extracellular recordings of action potential propagation in axons has been demonstrated in freely moving animals. While extracellular somatic action potentials have been used to study cellular activity in freely moving animals such as place cells, axonal activity in both white and gray matter can also be recorded. Extracellular recordings of axon action potential propagation is distinct from somatic action potentials in three ways: 1. The signal has a shorter peak-trough duration (~150μs) than of pyramidal cells (~500μs) or interneurons (~250μs). 2. The voltage change is triphasic. 3. Activity recorded on a tetrode is seen on only one of the four recording wires. In recordings from freely moving rats, axonal signals have been isolated in white matter tracts including the alveus and the corpus callosum as well hippocampal gray matter.
In fact, the generation of action potentials in vivo is sequential in nature, and these sequential spikes constitute the digital codes in the neurons. Although previous studies indicate an axonal origin of a single spike evoked by short-term pulses, physiological signals in vivo trigger the initiation of sequential spikes at the cell bodies of the neurons.
In addition to propagating action potentials to axonal terminals, the axon is able to amplify the action potentials, which makes sure a secure propagation of sequential action potentials toward the axonal terminal. In terms of molecular mechanisms, voltage-gated sodium channels in the axons possess lower threshold and shorter refractory period in response to short-term pulses.
Development and growth
Development
The development of the axon to its target, is one of the six major stages in the overall development of the nervous system. Studies done on cultured hippocampal neurons suggest that neurons initially produce multiple neurites that are equivalent, yet only one of these neurites is destined to become the axon. It is unclear whether axon specification precedes axon elongation or vice versa, although recent evidence points to the latter. If an axon that is not fully developed is cut, the polarity can change and other neurites can potentially become the axon. This alteration of polarity only occurs when the axon is cut at least 10 μm shorter than the other neurites. After the incision is made, the longest neurite will become the future axon and all the other neurites, including the original axon, will turn into dendrites. Imposing an external force on a neurite, causing it to elongate, will make it become an axon. Nonetheless, axonal development is achieved through a complex interplay between extracellular signaling, intracellular signaling and cytoskeletal dynamics.
Extracellular signaling
The extracellular signals that propagate through the extracellular matrix surrounding neurons play a prominent role in axonal development. These signaling molecules include proteins, neurotrophic factors, and extracellular matrix and adhesion molecules.
Netrin (also known as UNC-6) a secreted protein, functions in axon formation. When the UNC-5 netrin receptor is mutated, several neurites are irregularly projected out of neurons and finally a single axon is extended anteriorly. The neurotrophic factorsnerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NTF3) are also involved in axon development and bind to Trk receptors.
The ganglioside-converting enzyme plasma membrane ganglioside sialidase (PMGS), which is involved in the activation of TrkA at the tip of neutrites, is required for the elongation of axons. PMGS asymmetrically distributes to the tip of the neurite that is destined to become the future axon.
Intracellular signaling
During axonal development, the activity of PI3K is increased at the tip of destined axon. Disrupting the activity of PI3K inhibits axonal development. Activation of PI3K results in the production of phosphatidylinositol (3,4,5)-trisphosphate (PtdIns) which can cause significant elongation of a neurite, converting it into an axon. As such, the overexpression of phosphatases that dephosphorylate PtdIns leads into the failure of polarization.
Cytoskeletal dynamics
The neurite with the lowest actin filament content will become the axon. PGMS concentration and f-actin content are inversely correlated; when PGMS becomes enriched at the tip of a neurite, its f-actin content is substantially decreased. In addition, exposure to actin-depolimerizing drugs and toxin B (which inactivates Rho-signaling) causes the formation of multiple axons. Consequently, the interruption of the actin network in a growth cone will promote its neurite to become the axon.
Growth
Growing axons move through their environment via the growth cone, which is at the tip of the axon. The growth cone has a broad sheet-like extension called a lamellipodium which contain protrusions called filopodia. The filopodia are the mechanism by which the entire process adheres to surfaces and explores the surrounding environment. Actin plays a major role in the mobility of this system. Environments with high levels of cell adhesion molecules (CAMs) create an ideal environment for axonal growth. This seems to provide a "sticky" surface for axons to grow along. Examples of CAMs specific to neural systems include N-CAM, TAG-1an axonal glycoproteinand MAG, all of which are part of the immunoglobulin superfamily. Another set of molecules called extracellular matrix-adhesion molecules also provide a sticky substrate for axons to grow along. Examples of these molecules include laminin, fibronectin, tenascin, and perlecan. Some of these are surface bound to cells and thus act as short range attractants or repellents. Others are difusible ligands and thus can have long range effects.
Cells called guidepost cells assist in the guidance of neuronal axon growth. These cells that help axon guidance, are typically other neurons that are sometimes immature. When the axon has completed its growth at its connection to the target, the diameter of the axon can increase by up to five times, depending on the speed of conduction required.
It has also been discovered through research that if the axons of a neuron were damaged, as long as the soma (the cell body of a neuron) is not damaged, the axons would regenerate and remake the synaptic connections with neurons with the help of guidepost cells. This is also referred to as neuroregeneration.
Nogo-A is a type of neurite outgrowth inhibitory component that is present in the central nervous system myelin membranes (found in an axon). It has a crucial role in restricting axonal regeneration in adult mammalian central nervous system. In recent studies, if Nogo-A is blocked and neutralized, it is possible to induce long-distance axonal regeneration which leads to enhancement of functional recovery in rats and mouse spinal cord. This has yet to be done on humans. A recent study has also found that macrophages activated through a specific inflammatory pathway activated by the Dectin-1 receptor are capable of promoting axon recovery, also however causing neurotoxicity in the neuron.
Length regulation
Axons vary largely in length from a few micrometers up to meters in some animals. This emphasizes that there must be a cellular length regulation mechanism allowing the neurons both to sense the length of their axons and to control their growth accordingly. It was discovered that motor proteins play an important role in regulating the length of axons. Based on this observation, researchers developed an explicit model for axonal growth describing how motor proteins could affect the axon length on the molecular level. These studies suggest that motor proteins carry signaling molecules from the soma to the growth cone and vice versa whose concentration oscillates in time with a length-dependent frequency.
Classification
The axons of neurons in the human peripheral nervous system can be classified based on their physical features and signal conduction properties. Axons were known to have different thicknesses (from 0.1 to 20 μm) and these differences were thought to relate to the speed at which an action potential could travel along the axonits conductance velocity. Erlanger and Gasser proved this hypothesis, and identified several types of nerve fiber, establishing a relationship between the diameter of an axon and its nerve conduction velocity. They published their findings in 1941 giving the first classification of axons.
Axons are classified in two systems. The first one introduced by Erlanger and Gasser, grouped the fibers into three main groups using the letters A, B, and C. These groups, group A, group B, and group C include both the sensory fibers (afferents) and the motor fibers (efferents). The first group A, was subdivided into alpha, beta, gamma, and delta fibersAα, Aβ, Aγ, and Aδ. The motor neurons of the different motor fibers, were the lower motor neuronsalpha motor neuron, beta motor neuron, and gamma motor neuron having the Aα, Aβ, and Aγ nerve fibers, respectively.
Later findings by other researchers identified two groups of Aa fibers that were sensory fibers. These were then introduced into a system (Lloyd classification) that only included sensory fibers (though some of these were mixed nerves and were also motor fibers). This system refers to the sensory groups as Types and uses Roman numerals: Type Ia, Type Ib, Type II, Type III, and Type IV.
Motor
Lower motor neurons have two kind of fibers:
Different sensory receptors innervate different types of nerve fibers. Proprioceptors are innervated by type Ia, Ib and II sensory fibers, mechanoreceptors by type II and III sensory fibers and nociceptors and thermoreceptors by type III and IV sensory fibers.
Autonomic
The autonomic nervous system has two kinds of peripheral fibers:
Clinical significance
In order of degree of severity, injury to a nerve in the peripheral nervous system can be described as neurapraxia, axonotmesis, or neurotmesis.
Concussion is considered a mild form of diffuse axonal injury. Axonal injury can also cause central chromatolysis. The dysfunction of axons in the nervous system is one of the major causes of many inherited and acquired neurological disorders that affect both peripheral and central neurons.
When an axon is crushed, an active process of axonal degeneration takes place at the part of the axon furthest from the cell body. This degeneration takes place quickly following the injury, with the part of the axon being sealed off at the membranes and broken down by macrophages. This is known as Wallerian degeneration. Dying back of an axon can also take place in many neurodegenerative diseases, particularly when axonal transport is impaired, this is known as Wallerian-like degeneration. Studies suggest that the degeneration happens as
a result of the axonal protein NMNAT2, being prevented from reaching all of the axon.
Demyelination of axons causes the multitude of neurological symptoms found in the disease multiple sclerosis.
Dysmyelination is the abnormal formation of the myelin sheath. This is implicated in several leukodystrophies, and also in schizophrenia.
A severe traumatic brain injury can result in widespread lesions to nerve tracts damaging the axons in a condition known as diffuse axonal injury. This can lead to a persistent vegetative state. It has been shown in studies on the rat that axonal damage from a single mild traumatic brain injury, can leave a susceptibility to further damage, after repeated mild traumatic brain injuries.
A nerve guidance conduit is an artificial means of guiding axon growth to enable neuroregeneration, and is one of the many treatments used for different kinds of nerve injury.
Terminology
Some general dictionaries define "nerve fiber" as any neuronal process, including both axons and dendrites. However, medical sources generally use "nerve fiber" to refer to the axon only.
History
German anatomist Otto Friedrich Karl Deiters is generally credited with the discovery of the axon by distinguishing it from the dendrites. Swiss Rüdolf Albert von Kölliker and German Robert Remak were the first to identify and characterize the axon initial segment. Kölliker named the axon in 1896. Louis-Antoine Ranvier was the first to describe the gaps or nodes found on axons and for this contribution these axonal features are now commonly referred to as the nodes of Ranvier. Santiago Ramón y Cajal, a Spanish anatomist, proposed that axons were the output components of neurons, describing their functionality. Joseph Erlanger and Herbert Gasser earlier developed the classification system for peripheral nerve fibers, based on axonal conduction velocity, myelination, fiber size etc. Alan Hodgkin and Andrew Huxley also employed the squid giant axon (1939) and by 1952 they had obtained a full quantitative description of the ionic basis of the action potential, leading to the formulation of the Hodgkin–Huxley model. Hodgkin and Huxley were awarded jointly the Nobel Prize for this work in 1963. The formulae detailing axonal conductance were extended to vertebrates in the Frankenhaeuser–Huxley equations. The understanding of the biochemical basis for action potential propagation has advanced further, and includes many details about individual ion channels.
Other animals
The axons in invertebrates have been extensively studied. The longfin inshore squid, often used as a model organism has the longest known axon. The giant squid has the largest axon known. Its size ranges from 0.5 (typically) to 1 mm in diameter and is used in the control of its jet propulsion system. The fastest recorded conduction speed of 210 m/s, is found in the ensheathed axons of some pelagic Penaeid shrimps and the usual range is between 90 and 200 meters/s (cf 100–120 m/s for the fastest myelinated vertebrate axon.)
In other cases as seen in rat studies an axon originates from a dendrite; such axons are said to have "dendritic origin". Some axons with dendritic origin similarly have a "proximal" initial segment that starts directly at the axon origin, while others have a "distal" initial segment, discernibly separated from the axon origin. In many species some of the neurons have axons that emanate from the dendrite and not from the cell body, and these are known as axon-carrying dendrites. In many cases, an axon originates at an axon hillock on the soma; such axons are said to have "somatic origin". Some axons with somatic origin have a "proximal" initial segment adjacent the axon hillock, while others have a "distal" initial segment, separated from the soma by an extended axon hillock.
See also
Electrophysiology
Ganglionic eminence
Giant axonal neuropathy
Neuronal tracing
Pioneer axon
Single-unit recording
References
External links
"Slide 3 Spinal cord"
Neurohistology |
960 | https://en.wikipedia.org/wiki/Aramaic%20alphabet | Aramaic alphabet | The ancient Aramaic alphabet was used to write the Aramaic languages spoken by ancient Aramean pre-Christian tribes throughout the Fertile Crescent. It was also adopted by other peoples as their own alphabet when empires and their subjects underwent linguistic Aramaization during a language shift for governing purposes — a precursor to Arabization centuries later — including among the Assyrians and Babylonians who permanently replaced their Akkadian language and its cuneiform script with Aramaic and its script, and among Jews, but not Samaritans, who adopted the Aramaic language as their vernacular and started using the Aramaic alphabet, which they call "Square Script", even for writing Hebrew, displacing the former Paleo-Hebrew alphabet. The modern Hebrew alphabet derives from the Aramaic alphabet, in contrast to the modern Samaritan alphabet, which derives from Paleo-Hebrew.
The letters in the Aramaic alphabet all represent consonants, some of which are also used as matres lectionis to indicate long vowels. Writing systems, like the Aramaic, that indicate consonants but do not indicate most vowels other than by means of matres lectionis or added diacritical signs, have been called abjads by Peter T. Daniels to distinguish them from alphabets such as the Greek alphabet, that represent vowels more systematically. The term was coined to avoid the notion that a writing system that represents sounds must be either a syllabary or an alphabet, which would imply that a system like Aramaic must be either a syllabary, as argued by Ignace Gelb, or an incomplete or deficient alphabet, as most other writers had said before Daniels. Daniels put forward, this is a different type of writing system, intermediate between syllabaries and 'full' alphabets.
The Aramaic alphabet is historically significant since virtually all modern Middle Eastern writing systems can be traced back to it. That is primarily due to the widespread usage of the Aramaic language after it was adopted as both a lingua franca and the official language of the Neo-Assyrian and Neo-Babylonian Empires, and their successor, the Achaemenid Empire. Among the descendant scripts in modern use, the Jewish Hebrew alphabet bears the closest relation to the Imperial Aramaic script of the 5th century BC, with an identical letter inventory and, for the most part, nearly identical letter shapes. By contrast the Samaritan Hebrew script is directly descended from Proto-Hebrew/Phoenician script, which was the ancestor of the Aramaic alphabet. The Aramaic alphabet was also an ancestor to the Nabataean alphabet, which had the Arabic alphabet as a descendant.
History
The earliest inscriptions in the Aramaic language use the Phoenician alphabet. Over time, the alphabet developed into the Aramaic alphabet by the 8th century BC. It was used to write the Aramaic languages spoken by ancient Aramean pre-Christian tribes throughout the Fertile Crescent. It was also adopted by other peoples as their own alphabet when empires and their subjects underwent linguistic Aramaization during a language shift for governing purposes — a precursor to Arabization centuries later.
These include the Assyrians and Babylonians, who permanently replaced their Akkadian language and its cuneiform script with Aramaic and its script, and among Jews, but not Samaritans, who adopted the Aramaic language as their vernacular and started using the Aramaic alphabet even for writing Hebrew, displacing the former Paleo-Hebrew alphabet. The modern Hebrew alphabet derives from the Aramaic alphabet, in contrast to the modern Samaritan alphabet, which derives from Paleo-Hebrew.
Achaemenid Empire (The First Persian Empire)
Around 500 BC, following the Achaemenid conquest of Mesopotamia under Darius I, Old Aramaic was adopted by the Persians as the "vehicle for written communication between the different regions of the vast Persian empire with its different peoples and languages. The use of a single official language, which modern scholarship has dubbed as Official Aramaic, Imperial Aramaic or Achaemenid Aramaic, can be assumed to have greatly contributed to the astonishing success of the Achaemenid Persians in holding their far-flung empire together for as long as they did."
Imperial Aramaic was highly standardised. Its orthography was based more on historical roots than any spoken dialect and was influenced by Old Persian. The Aramaic glyph forms of the period are often divided into two main styles, the "lapidary" form, usually inscribed on hard surfaces like stone monuments, and a cursive form whose lapidary form tended to be more conservative by remaining more visually similar to Phoenician and early Aramaic. Both were in use through the Achaemenid Persian period, but the cursive form steadily gained ground over the lapidary, which had largely disappeared by the 3rd century BC.
For centuries after the fall of the Achaemenid Empire in 331 BC, Imperial Aramaic, or something near enough to it to be recognisable, remained an influence on the various native Iranian languages. The Aramaic script survived as the essential characteristics of the Iranian Pahlavi writing system.
30 Aramaic documents from Bactria have been recently discovered, an analysis of which was published in November 2006. The texts, which were rendered on leather, reflect the use of Aramaic in the 4th century BC, in the Persian Achaemenid administration of Bactria and Sogdiana.
The widespread usage of Achaemenid Aramaic in the Middle East led to the gradual adoption of the Aramaic alphabet for writing Hebrew. Formerly, Hebrew had been written using an alphabet closer in form to that of Phoenician, the Paleo-Hebrew alphabet.
Aramaic-derived scripts
Since the evolution of the Aramaic alphabet out of the Phoenician one was a gradual process, the division of the world's alphabets into the ones derived from the Phoenician one directly, and the ones derived from Phoenician via Aramaic, is somewhat artificial. In general, the alphabets of the Mediterranean region (Anatolia, Greece, Italy) are classified as Phoenician-derived, adapted from around the 8th century BC. Those of the East (the Levant, Persia, Central Asia, and India) are considered Aramaic-derived, adapted from around the 6th century BC from the Imperial Aramaic script of the Achaemenid Empire.
After the fall of the Achaemenid Empire, the unity of the Imperial Aramaic script was lost, diversifying into a number of descendant cursives.
The Hebrew and Nabataean alphabets, as they stood by the Roman era, were little changed in style from the Imperial Aramaic alphabet. Ibn Khaldun (1332–1406) alleges that not only the old Nabataean writing was influenced by the "Syrian script" (i.e. Aramaic), but also the old Chaldean script.
A cursive Hebrew variant developed from the early centuries AD. It remained restricted to the status of a variant used alongside the noncursive. By contrast, the cursive developed out of the Nabataean alphabet in the same period soon became the standard for writing Arabic, evolving into the Arabic alphabet as it stood by the time of the early spread of Islam.
The development of cursive versions of Aramaic led to the creation of the Syriac, Palmyrene and Mandaic alphabets, which formed the basis of the historical scripts of Central Asia, such as the Sogdian and Mongolian alphabets.
The Old Turkic script is generally considered to have its ultimate origins in Aramaic, in particular via the Pahlavi or Sogdian alphabets, as suggested by V. Thomsen, or possibly via Kharosthi (cf., Issyk inscription).
Brahmi script was also possibly derived or inspired by Aramaic. Brahmic family of scripts includes Devanagari.
Languages using the alphabet
Today, Biblical Aramaic, Jewish Neo-Aramaic dialects and the Aramaic language of the Talmud are written in the modern-Hebrew alphabet, distinguished from the Old Hebrew script. In classical Jewish literature, the name given to the modern-Hebrew script was "Ashurit", the ancient Assyrian script, a script now known widely as the Aramaic script. It is believed that during the period of Assyrian dominion, that Aramaic script and language received official status.
Syriac and Christian Neo-Aramaic dialects are today written in the Syriac alphabet, which script has superseded the more ancient Assyrian script and now bears its name. Mandaic is written in the Mandaic alphabet. The near-identical nature of the Aramaic and the classical Hebrew alphabets caused Aramaic text to be typeset mostly in the standard Hebrew script in scholarly literature.
Maaloula
In Maaloula, one of few surviving communities in which a Western Aramaic dialect is still spoken, an Aramaic Language Institute was established in 2006 by Damascus University that teaches courses to keep the language alive.
Unlike Classical Syriac, which has a rich literary tradition in Syriac-Aramaic script, Western Neo-Aramaic was solely passed down orally for generations until 2006 and was not utilized in a written form.
Therefore, the Language Institute's chairman, George Rizkalla (Rezkallah), undertook the writing of a textbook in Western Neo-Aramaic. Being previously unwritten, Rizkalla opted for the Hebrew alphabet. In 2010, the institute's activities were halted due to concerns that the square Maalouli-Aramaic alphabet used in the program bore a resemblance to the square script of the Hebrew alphabet. As a result, all signs featuring the square Maalouli script were subsequently removed. The program stated that they would instead use the more distinct Syriac-Aramaic alphabet, although use of the Maalouli alphabet has continued to some degree. Al Jazeera Arabic also broadcast a program about Western Neo-Aramaic and the villages in which it is spoken with the square script still in use.
Letters
Unicode
The Imperial Aramaic alphabet was added to the Unicode Standard in October 2009, with the release of version 5.2.
The Unicode block for Imperial Aramaic is U+10840–U+1085F:
The Syriac Aramaic alphabet was added to the Unicode Standard in September 1999, with the release of version 3.0.
The Syriac Abbreviation (a type of overline) can be represented with a special control character called the Syriac Abbreviation Mark (U+070F). The Unicode block for Syriac Aramaic is U+0700–U+074F:
See also
Syriac alphabet
Mandaic alphabet
References
Sources
Byrne, Ryan. "Middle Aramaic Scripts". Encyclopaedia of Language and Linguistics. Elsevier. (2006)
Daniels, Peter T., et al. eds. The World's Writing Systems. Oxford. (1996)
Coulmas, Florian. The Writing Systems of the World. Blackwell Publishers Ltd, Oxford. (1989)
Rudder, Joshua. Learn to Write Aramaic: A Step-by-Step Approach to the Historical & Modern Scripts. n.p.: CreateSpace Independent Publishing Platform, 2011. 220 pp. . Includes a wide variety of Aramaic scripts.
Ancient Hebrew and Aramaic on Coins, reading and transliterating Proto-Hebrew, online edition (Judaea Coin Archive).
External links
Comparison of Aramaic to related alphabets
Omniglot entry
8th-century BC establishments
Obsolete writing systems
Persian scripts
Right-to-left writing systems
Abjad writing systems |
966 | https://en.wikipedia.org/wiki/American%20shot | American shot | "American shot" or "cowboy shot" is a translation of a phrase from French film criticism, , and refers to a medium-long ("knee") film shot of a group of characters, who are arranged so that all are visible to the camera. The usual arrangement is for the actors to stand in an irregular line from one side of the screen to the other, with the actors at the end coming forward a little and standing more in profile than the others. The purpose of the composition is to allow complex dialogue scenes to be played out without changes in camera position. In some literature, this is simply referred to as a 3/4 shot.
One of the other main reasons why French critics called it "American shot" was its frequent use in the western genre. This was because a shot that started at knee level would reveal the weapon of a cowboy, usually holstered at their waist. It is actually the closest the camera can get to an actor while keeping both their face and their holstered gun in frame.
The French critics thought it was characteristic of American films of the 1930s or 1940s; however, it was mostly characteristic of cheaper American movies, such as Charlie Chan mysteries where people collected in front of a fireplace or at the foot of the stairs in order to explain what happened a few minutes ago.
Howard Hawks legitimized this style in his films, allowing characters to act, even when not talking, when most of the audience would not be paying attention. It became his trademark style.
References
Cinematography |