Pronunciation and etymology.

In American English, "lichen" is pronounced the same as the verb "liken" (). In British English, both this pronunciation and one rhyming with "kitchen" ) are used.  English "lichen" derives from

Growth forms.

Lichens grow in a wide range of shapes and forms (morphologies). The shape of a lichen is usually determined by the organization of the fungal filaments. The nonreproductive tissues, or vegetative body parts, are called the "thallus". Lichens are grouped by thallus type, since the thallus is usually the most visually prominent part of the lichen. Thallus growth forms typically correspond to a few basic internal structure types. Common names for lichens often come from a growth form or color that is typical of a lichen genus.  Common groupings of lichen thallus growth forms are:  There are variations in growth types in a single lichen species, grey areas between the growth type descriptions, and overlapping between growth types, so some authors might describe lichens using different growth type descriptions.  When a crustose lichen gets old, the center may start to crack up like old-dried paint, old-broken asphalt paving, or like the polygonal "islands" of cracked-up mud in a dried lakebed. This is called being rimose or areolate, and the "island" pieces separated by the cracks are called areolas. The areolas appear separated, but are (or were) connected by an underlying "prothallus" or "hypothallus". When a crustose lichen grows from a center and appears to radiate out, it is called crustose placodioid. When the edges of the areolas lift up from the substrate, it is called squamulose.  These growth form groups are not precisely defined. Foliose lichens may sometimes branch and appear to be fruticose. Fruticose lichens may have flattened branching parts and appear leafy. Squamulose lichens may appear where the edges lift up. Gelatinous lichens may appear leafy when dry. Means of telling them apart in these cases are in the sections below.  Structures involved in reproduction often appear as discs, bumps, or squiggly lines on the surface of the thallus. The thallus is not always the part of the lichen that is most visually noticeable. Some lichens can grow "inside" solid rock between the grains (endolithic lichens), with only the sexual fruiting part visible growing outside the rock. These may be dramatic in color or appearance. Forms of these sexual parts are not in the above growth form categories. The most visually noticeable reproductive parts are often circular, raised, plate-like or disc-like outgrowths, with crinkly edges, and are described in sections below.

Color.

Lichens come in many colors. Coloration is usually determined by the photosynthetic component. Special pigments, such as yellow usnic acid, give lichens a variety of colors, including reds, oranges, yellows, and browns, especially in exposed, dry habitats. In the absence of special pigments, lichens are usually bright green to olive gray when wet, gray or grayish-green to brown when dry. This is because moisture causes the surface skin (cortex) to become more transparent, exposing the green photobiont layer. Different colored lichens covering large areas of exposed rock surfaces, or lichens covering or hanging from bark can be a spectacular display when the patches of diverse colors "come to life" or "glow" in brilliant displays following rain.  Different colored lichens may inhabit different adjacent sections of a rock face, depending

Internal structure and growth forms.

A lichen consists of a simple photosynthesizing organism, usually a green alga or cyanobacterium, surrounded by filaments of a fungus. Generally, most of a lichen's bulk is made of interwoven fungal filaments, although in filamentous and gelatinous lichens this is not the case. The fungus is called a "mycobiont". The photosynthesizing organism is called a "photobiont". Algal photobionts are called "phycobionts". Cyanobacteria photobionts are called "cyanobionts".  The part of a lichen that is not involved in reproduction, the "body" or "vegetative tissue" of a lichen, is called the "thallus". The thallus form is very different from any form where the fungus or alga are growing separately. The thallus is made up of filaments of the fungus called "hyphae". The filaments grow by branching then rejoining to create a mesh, which is called being

Physiology.

Symbiotic relation.

A lichen is a composite organism that emerges from algae or cyanobacteria living among the filaments (hyphae) of the fungi in a mutually beneficial symbiotic relationship. The fungi benefit from the carbohydrates produced by the algae or cyanobacteria via photosynthesis. The algae or cyanobacteria benefit by being protected from the environment by the filaments of the fungi, which also gather moisture and nutrients from the environment, and (usually) provide an anchor to it. Although some photosynthetic partners in a lichen can survive outside the lichen, the lichen symbiotic association extends the ecological range of both partners, whereby most descriptions of lichen associations describe them as symbiotic. However, while symbiotic, the relationship is probably not mutualistic, since the algae

Ecology.

Lichen associations may be examples of mutualism, commensalism or even parasitism, depending on the species. There is evidence to suggest that the lichen symbiosis is parasitic or commensalistic, rather than mutualistic. The photosynthetic partner can exist in nature independently of the fungal partner, but not vice versa. Photobiont cells are routinely destroyed in the course of nutrient exchange. The association is able to continue because reproduction of the photobiont cells matches the rate at which they are destroyed. The fungus surrounds the algal cells, often enclosing them within complex fungal tissues unique to lichen associations. In many species the fungus penetrates the algal cell wall, forming penetration pegs (haustoria) similar to those produced by pathogenic fungi that feed on a host. Cyanobacteria in laboratory settings can grow faster when they are alone rather than when they are part of a lichen.

Miniature ecosystem and holobiont theory.

Symbiosis in lichens is so well-balanced that lichens have been considered to be relatively self-contained miniature ecosystems in and of themselves. It is thought that lichens may be even more complex symbiotic systems that include non-photosynthetic bacterial communities performing other functions as partners in a holobiont.  Many lichens are very sensitive to environmental disturbances and can be used to cheaply assess air pollution, ozone depletion, and metal contamination. Lichens have been used in making dyes, perfumes, and in traditional medicines. A few lichen species

Lichenicolous fungi.

Some fungi can only be found living "on" lichens as obligate parasites. These are referred to as lichenicolous fungi, and are a different species from the fungus living inside the lichen; thus they are not considered to be part of the lichen.

Reaction to water.

Moisture makes the cortex become more transparent. This way, the algae can conduct photosynthesis when moisture

Metabolites, metabolite structures and bioactivity.

Lichens can show intense antioxidant activity. Secondary metabolites are often deposited as crystals in the apoplast. Secondary metabolites are thought to

Growth rate.

Lichens often have a regular but very slow growth rate of less than a millimeter per year.

Life span.

Lichens may be long-lived, with some considered to be among the oldest living organisms. Lifespan is difficult to measure because what defines the "same" individual lichen is not precise. Lichens grow

Response to environmental stress.

Unlike simple dehydration in plants and animals, lichens may experience a "complete" loss of body water in dry periods. Lichens are capable of surviving extremely low levels of water content (poikilohydric). They quickly absorb water when it becomes available again, becoming soft and fleshy. Reconfiguration of membranes following a period of dehydration requires several minutes or more.  In tests, lichen survived and showed remarkable results on the adaptation capacity of photosynthetic activity within the simulation time

Reproduction and dispersal.

Vegetative reproduction.

Many lichens reproduce asexually, either by a piece breaking off and growing on its own (vegetative reproduction) or through the dispersal of diaspores containing a few algal cells surrounded by fungal cells. Because of the relative lack of differentiation in the thallus, the line between diaspore formation and vegetative reproduction is often blurred. Fruticose lichens can easily fragment, and new lichens can grow from

Sexual reproduction.

Structures involved in reproduction often appear as discs, bumps, or squiggly lines on the surface of the thallus. Only the fungal partner in a lichen reproduces sexually. Many lichen fungi reproduce sexually like other fungi, producing spores formed by meiosis and fusion of gametes. Following dispersal, such fungal spores must meet with a compatible algal partner before a functional lichen can form.  Some lichen fungi belong to Basidiomycetes ("basidiolichens") and produce mushroom-like reproductive structures resembling those of their nonlichenized

Taxonomy and classification.

Lichens are classified by the fungal component. Lichen species are given the same scientific name (binomial name) as the fungus species in the lichen. Lichens are being integrated into the classification schemes for fungi. The alga bears its own scientific name, which bears no relationship to that of the lichen or fungus. There are about 13,500–17,000 identified lichen species. Nearly 20% of known fungal species are associated with lichens.  ""Lichenized fungus"" may refer to the entire lichen, or to just the fungus. This may cause confusion without context. A particular fungus species may form lichens with different algae species, giving rise to what appear to be different lichen species, but which are still classified (as of 2014) as the same lichen species.  Formerly, some lichen taxonomists placed lichens in their own division, the "Mycophycophyta", but this practice is no longer accepted because the components belong to separate lineages. Neither the ascolichens nor the basidiolichens form monophyletic lineages in their respective fungal phyla, but they do form several major solely or primarily lichen-forming groups within each phylum. Even more unusual than basidiolichens is the fungus "Geosiphon pyriforme", a member of the Glomeromycota that is unique in that it encloses a cyanobacterial symbiont inside its cells. "Geosiphon" is not usually considered to be a lichen, and its peculiar symbiosis was not recognized for many years. The genus is more closely allied to endomycorrhizal genera. Fungi from Verrucariales also form marine lichens with the brown algae "Petroderma maculiforme", and have a symbiotic relationship with seaweed like (rockweed) and Blidingia minima, where the algae are the dominant components. The fungi is thought to help the rockweeds to resist desiccation when exposed to air. In addition, lichens can also use yellow-green algae (Heterococcus) as their symbiotic partner.  Lichens independently emerged from fungi associating with algae and cyanobacteria multiple times throughout history.

Fungi.

The fungal component of a lichen is called the "mycobiont". The mycobiont may be an Ascomycete or Basidiomycete. The associated lichens are called either ascolichens or basidiolichens, respectively. Living as a symbiont in a lichen appears to be a successful way for a fungus to derive essential nutrients, since about 20% of all fungal species have acquired this mode of life.  Thalli produced by a given fungal symbiont with its differing partners

Photobionts.

The photosynthetic partner in a lichen is called a "photobiont". The photobionts in lichens come from a variety of simple prokaryotic and eukaryotic organisms. In the majority of lichens the photobiont is a green alga (Chlorophyta) or a cyanobacterium. In some lichens both types are present. Algal photobionts are called "phycobionts", while cyanobacterial photobionts are called "cyanobionts". According to one source, about 90% of all known lichens have phycobionts, and about 10% have cyanobionts, while another source states that two thirds of lichens

Controversy over classification method and species names.

There are about 20,000 known lichen species. But what is meant by "species" is different from what is meant by biological species in plants, animals, or fungi, where being the same species implies that there is a common ancestral lineage. Because lichens are combinations of members of two or even three different biological kingdoms, these components "must" have a "different" ancestral lineage from each other. By convention, lichens are still called "species" anyway, and are classified according to the species of their fungus, not the species of the algae or cyanobacteria. Lichens are given the same scientific name (binomial name) as the fungus in them, which may cause some confusion. The alga bears its own scientific name, which has no relationship to the name of the lichen or fungus.  Depending on context, "lichenized fungus" may refer to the entire lichen, or to the fungus when it is in the lichen, which can be grown in culture in isolation from the algae or cyanobacteria. Some algae and cyanobacteria are found naturally

Diversity.

The largest number of lichenized fungi occur in the Ascomycota, with about 40% of species forming such an association. Some of these lichenized fungi occur in orders with nonlichenized fungi that live as saprotrophs or plant parasites (for example, the Leotiales, Dothideales, and Pezizales). Other lichen fungi occur in only five orders in which

Identification methods.

Lichen identification uses growth form and reactions to chemical tests.  The outcome of the "Pd test" is called "Pd", which is also used as

Evolution and paleontology.

The fossil record for lichens is poor. The extreme habitats that lichens dominate, such as tundra, mountains, and deserts, are not ordinarily conducive to producing fossils. There are fossilized lichens embedded in amber. The fossilized "Anzia" is found in pieces of amber in northern Europe and dates back approximately 40 million years. Lichen fragments are also found in fossil leaf beds, such as "Lobaria" from Trinity County in northern California, USA, dating back to the early to middle Miocene.  The oldest fossil lichen in which both symbiotic partners have been recovered is "Winfrenatia",an early zygomycetous (Glomeromycotan) lichen symbiosis that may have involved controlled parasitism, is permineralized in the Rhynie Chert of Scotland, dating from early Early Devonian, about 400 million years ago. The slightly older fossil "Spongiophyton" has also been interpreted as a lichen on morphological and isotopic grounds, although the isotopic basis is decidedly shaky. It has been demonstrated that Silurian-Devonian fossils "Nematothallus" and "Prototaxites" were lichenized. Thus

Ecology and interactions with environment.

Substrates and habitats.

Lichens cover about 7% of the planet's surface and grow on and in a wide range of substrates and habitats, including some of the most extreme conditions on earth. They are abundant growing on bark, leaves, and hanging from branches "living on thin air" (epiphytes) in rain forests and in temperate woodland. They grow on bare rock, walls, gravestones, roofs, and exposed soil surfaces. They can survive in some of the most extreme environments on Earth: arctic tundra, hot dry deserts,

Lichens and soils.

In addition to distinct physical mechanisms by which lichens break down raw stone, recent studies indicate lichens attack stone chemically, entering newly chelated minerals into the ecology.The lichen exudates, which have powerful chelating capacity, the widespread occurrence of mineral neoformation, particularly metal oxalates, together with the characteristics of weathered substrates, all confirm the significance of lichens as chemical

Ecological interactions.

Lichens are pioneer species, among the first living things to grow on bare rock or areas denuded of life by a disaster. Lichens may have to compete with plants for access to sunlight, but because of their small size and slow growth, they thrive in places where higher plants have difficulty growing. Lichens are often the first to settle in places lacking soil, constituting the sole vegetation in some extreme environments such as those found at high mountain elevations and at high latitudes. Some survive in the tough conditions of deserts, and others on frozen soil of the Arctic regions.  A major ecophysiological advantage of lichens is that they are poikilohydric ("poikilo"- variable, "hydric"- relating to water), meaning that though they have little control over the status of their hydration, they can tolerate irregular and extended periods of severe desiccation. Like some mosses, liverworts, ferns, and a few "resurrection plants", upon desiccation, lichens enter a metabolic suspension or stasis (known as cryptobiosis) in which the cells of the lichen symbionts are dehydrated to a degree that halts most biochemical activity. In this cryptobiotic state, lichens can survive wider extremes

Effects of air pollution.

If lichens are exposed to air pollutants at all times, without any deciduous parts, they are unable to avoid the accumulation of pollutants. Also lacking stomata and a cuticle, lichens may absorb aerosols and gases over the entire thallus surface from which they may readily diffuse to the photobiont layer. Because lichens do not possess roots, their primary source of most elements is the air, and therefore elemental levels in lichens often reflect the accumulated composition of ambient air. The processes by which atmospheric deposition occurs include fog and dew, gaseous absorption, and dry deposition. Consequently, many environmental studies with lichens emphasize their feasibility as effective biomonitors of atmospheric quality.  Not all lichens

Human use.

Food.

Lichens are eaten by many different cultures across the world. Although some lichens are only eaten in times of famine, others are a staple food or even a delicacy. Two obstacles are often encountered when eating lichens: lichen polysaccharides are generally indigestible to humans, and lichens usually contain mildly toxic secondary compounds that should be removed before eating. Very few lichens are poisonous, but those high in vulpinic acid or usnic acid are toxic. Most poisonous lichens are

Lichenometry.

Lichenometry is a technique used to determine the age of exposed rock surfaces based on the size of lichen thalli. Introduced by Beschel in the 1950s, the technique has found many applications. it is used in archaeology, palaeontology, and geomorphology. It uses the presumed regular but slow rate of lichen growth to determine the age of exposed rock. Measuring the diameter (or other size measurement) of the largest lichen

Biodegradation.

Lichens have been shown to degrade polyester resins, as can be seen in archaeological

As dyes.

Many lichens produce secondary compounds, including pigments that reduce harmful amounts of sunlight and powerful toxins that reduce herbivory or kill bacteria. These compounds are very useful for lichen identification, and have had economic importance as dyes such as cudbear or primitive antibiotics.  The pH indicator (indicated acidic or basic) in the litmus test is a dye extracted from the

Traditional medicine and research.

Historically in traditional medicine of Europe, "Lobaria pulmonaria" was collected in large quantities as "Lungwort", due to its lung-like appearance (the "doctrine of signatures" suggesting that herbs can treat body parts that they physically resemble). Similarly, "Peltigera leucophlebia" was used as a supposed cure for thrush, due to

Aesthetic appeal.

Colonies of lichens may be spectacular in appearance, dominating the surface of the visual landscape as part of the aesthetic appeal to visitors of Yosemite National Park and Sequoia National Park. Orange and

In literature.

In early Midrashic literature, the Hebrew word "vayilafeth" in Ruth 3:8 is explained as referring to Ruth entwining herself around Boaz like lichen. The tenth century Arab physician,

History.

Although lichens had been recognized as organisms for quite some time, it was not until 1867, when Swiss botanist Simon Schwendener proposed his dual theory of lichens, that lichens are a combination of fungi with algae or cyanobacteria, whereby the true nature of the lichen association began to emerge. Schwendener's hypothesis, which at the time lacked experimental evidence, arose from his extensive analysis of the anatomy and development in lichens, algae, and fungi using a light microscope. Many of the leading lichenologists at the time, such as James Crombie and Nylander, rejected Schwendener's hypothesis because the common consensus was that all living organisms were autonomous.  Other prominent biologists, such as Heinrich Anton de Bary, Albert Bernhard Frank, Melchior Treub and Hermann Hellriegel were not so quick to reject Schwendener's ideas and the concept soon spread into other areas of study, such as microbial, plant, animal and human pathogens. When the complex relationships between pathogenic microorganisms and their hosts were finally identified, Schwendener's hypothesis began to gain popularity. Further experimental proof of the dual nature of lichens was obtained when Eugen Thomas published his results in 1939 on the first successful re-synthesis experiment.  In the 2010s, a new facet of the fungi-algae partnership was discovered. Toby Spribille and colleagues found that many types of lichen that were long thought to be ascomycete-algae pairs were actually ascomycete-basidiomycete-algae trios.

A lichen ( or, sometimes in the UK,, ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. Lichens have different properties from those of its component organisms. Lichens come in many colors, sizes, and forms and are sometimes plant-like, but lichens are not plants. Lichens may have tiny, leafless branches (fruticose), flat leaf-like structures (foliose), flakes that lie on the surface like peeling paint (crustose), a powder-like appearance (leprose), or other growth forms.

Les lichens (), appelés aussi champignons lichénisés ou champignons lichénisants, sont des organismes composites résultant d'une symbiose entre au moins un champignon hétérotrophe appelé mycobionte, généralement prépondérant dans la plupart des genres, et des cellules microscopiques possédant de la chlorophylle (algue verte ou cyanobactérie autotrophe pour le carbone) nommées « photobiontes ». Ils sont classés dans le phylum des "Fungi".


Early life and education.

Childhood.

Gödel was born April 28, 1906, in Brünn, Austria-Hungary (now Brno, Czech Republic) into the German family of Rudolf Gödel (1874–1929), the manager of a textile factory, and Marianne Gödel (née Handschuh, 1879–1966). Throughout his life, Gödel would remain close to his mother; their correspondence was frequent and wide-ranging. At the time of his birth the city had a German-speaking majority which included his parents. His father was Catholic and his mother was Protestant and the children were raised Protestant. The ancestors of Kurt Gödel were often active in Brünn's cultural life. For example, his grandfather Joseph Gödel was a famous singer of that time and for some years a member of the (Men's Choral Union of Brünn).  Gödel automatically became a Czechoslovak citizen at age 12 when the Austro-Hungarian Empire collapsed, following its defeat in the World War I. (According to his classmate, like many residents of the predominantly German, "Gödel considered himself always Austrian and an exile in Czechoslovakia".) In February 1929 he was granted release from his Czechoslovakian citizenship and then, in April, granted Austrian citizenship. When Germany annexed Austria in 1938, Gödel automatically became a German citizen at age 32. After World War II (1948), at the age of 42, he became an American citizen.  In his family, young Kurt was known as ("Mr. Why") because of his insatiable curiosity. According to his brother Rudolf, at the age of six or seven Kurt suffered from rheumatic fever; he completely recovered, but for the rest of his life he remained convinced that his heart had suffered permanent damage. Beginning at age four, Gödel suffered from "frequent episodes of poor health", which would continue for his entire life.  Gödel attended the, a Lutheran school in Brünn from 1912 to 1916, and was enrolled in the from 1916 to 1924, excelling with honors in all his subjects, particularly in mathematics, languages and religion. Although Kurt had first excelled in languages, he later became more interested in history and mathematics. His interest in mathematics increased when in 1920 his older brother Rudolf (born 1902) left for Vienna to go to medical school at the University of Vienna. During his teens, Kurt studied Gabelsberger shorthand, Goethe's "Theory of Colours" and criticisms of Isaac Newton, and the writings of Immanuel Kant.

Studying in Vienna.

At the age of 18, Gödel joined his brother in Vienna and entered the University of Vienna. By that time, he had already mastered university-level mathematics. Although initially intending to study theoretical physics, he also attended courses on mathematics and philosophy. During this time, he adopted ideas of mathematical realism. He read Kant's, and participated in the Vienna Circle with Moritz Schlick, Hans Hahn, and Rudolf Carnap. Gödel then studied number theory, but when he took part in a seminar run by Moritz Schlick which studied Bertrand Russell's book "Introduction to Mathematical Philosophy", he became interested in mathematical logic. According to Gödel, mathematical logic was "a science prior to all others, which contains the ideas and principles underlying all sciences."  Attending a lecture by David Hilbert in Bologna on completeness and consistency of mathematical systems may have set Gödel's life course. In 1928, Hilbert and Wilhelm Ackermann published ("Principles of Mathematical Logic"), an introduction to first-order logic in which the problem of completeness was posed: "Are the axioms of a formal system sufficient to derive every statement that is true in all models of the system?"  This problem became the topic that Gödel chose for his doctoral work. In 1929, at the age of 23, he completed his doctoral dissertation under Hans Hahn's supervision. In it, he established his eponymous completeness theorem regarding the first-order predicate calculus. He was awarded his doctorate in 1930, and his thesis (accompanied by some additional work) was published by the Vienna Academy of Science.

Career.

Incompleteness theorem.

In 1930 Gödel attended the Second Conference on the Epistemology of the Exact Sciences, held in Königsberg, 5–7 September. Here he delivered his incompleteness theorems.  Gödel published his incompleteness theorems in (called in English "On Formally Undecidable Propositions of and Related Systems"). In that article, he proved for any computable axiomatic system that is powerful enough to describe the arithmetic of the natural numbers (e.g., the Peano axioms or Zermelo–Fraenkel set theory with the axiom of choice), that: These theorems ended a half-century of attempts, beginning with the work of Frege and culminating in and Hilbert's formalism, to find a set of axioms sufficient for all mathematics.  In hindsight, the basic idea at the heart of the incompleteness theorem is rather simple. Gödel essentially constructed a formula that claims that it is unprovable in a given formal system. If it were provable, it would be false. Thus there will always be at least one true but unprovable statement. That is, for any computably enumerable set of axioms for arithmetic (that is, a set that can in principle be printed out by an idealized computer with unlimited resources), there is a formula that is true of arithmetic, but which is not provable in that system. To make this precise, however, Gödel needed to produce a method to encode (as natural numbers) statements, proofs, and the concept of provability; he did this using a process known as Gödel numbering.  In his two-page paper (1932) Gödel refuted the finite-valuedness of intuitionistic logic. In the proof, he implicitly used what has later become known as Gödel–Dummett intermediate logic (or Gödel fuzzy logic).

Mid-1930s: further work and U.S. visits.

Gödel earned his habilitation at Vienna in 1932, and in 1933 he became a (unpaid lecturer) there. In 1933 Adolf Hitler came to power in Germany, and over the following years the Nazis rose in influence in Austria, and among Vienna's mathematicians. In June 1936, Moritz Schlick, whose seminar had aroused Gödel's interest in logic, was assassinated by one of his former students, Johann Nelböck. This triggered "a severe nervous crisis" in Gödel. He developed paranoid symptoms, including a fear of being poisoned, and spent several months in a sanitarium for nervous diseases.  In 1933, Gödel first traveled to the U.S., where he met Albert Einstein, who became a good friend. He delivered an address to the annual meeting of the American Mathematical Society. During this year, Gödel also developed the ideas of computability and recursive functions to the point where he was able to present a lecture on general recursive functions and the concept of truth. This work was developed in number theory, using Gödel numbering.  In 1934, Gödel gave a series of lectures at the Institute for Advanced Study (IAS) in Princeton, New Jersey, entitled "On undecidable propositions of formal mathematical systems". Stephen Kleene, who had just completed his PhD at Princeton, took notes of these lectures that have been subsequently published.  Gödel visited the IAS again in the autumn of 1935. The travelling and the hard work had exhausted him and the next year he took a break to recover from a depressive episode. He returned to teaching in 1937. During this time, he worked on the proof of consistency of the axiom of choice and of the continuum hypothesis; he went on to show that these hypotheses cannot be disproved from the common system of axioms of set theory.  He married Adele Nimbursky (née Porkert, 1899–1981), whom he had known for over 10 years, on September 20, 1938. Their relationship had been opposed by his parents on the grounds that she was a divorced dancer, six years older than he was.  Subsequently, he left for another visit to the United States, spending the autumn of 1938 at the IAS and publishing "Consistency of the axiom of choice and of the generalized continuum-hypothesis with the axioms of set theory," a classic of modern mathematics. In that work he introduced the constructible universe, a model of set theory in which the only sets that exist are those that can be constructed from simpler sets. Gödel showed that both the axiom of choice (AC) and the generalized continuum hypothesis (GCH) are true in the constructible universe, and therefore must be consistent with the Zermelo–Fraenkel axioms for set theory (ZF). This result has had considerable consequences for working mathematicians, as it means they can assume the axiom of choice when proving the Hahn–Banach theorem. Paul Cohen later constructed a model of ZF in which AC and GCH are false; together these proofs mean that AC and GCH are independent of the ZF axioms for set theory.  Godel spent the spring of 1939 at the University of Notre Dame.

Princeton, Einstein, U.S. citizenship.

After the Anschluss on 12 March 1938, Austria had become a part of Nazi Germany. Germany abolished the title, so Gödel had to apply for a different position under the new order. His former association with Jewish members of the Vienna Circle, especially with Hahn, weighed against him. The University of Vienna turned his application down.  His predicament intensified when the German army found him fit for conscription. World War II started in September 1939. Before the year was up, Gödel and his wife left Vienna for Princeton. To avoid the difficulty of an Atlantic crossing, the Gödels took the Trans-Siberian Railway to the Pacific, sailed from Japan to San Francisco (which they reached on March 4, 1940), then crossed the US by train to Princeton. There Gödel accepted a position at the Institute for Advanced Study (IAS), which he had previously visited during 1933–34.  Albert Einstein was also living at Princeton during this time. Gödel and Einstein developed a strong friendship, and were known to take long walks together to and from the Institute for Advanced Study. The nature of their conversations was a mystery to the other Institute members. Economist Oskar Morgenstern recounts that toward the end of his life Einstein confided that his "own work no longer meant much, that he came to the Institute merely... to have the privilege of walking home with Gödel".  Gödel and his wife, Adele, spent the summer of 1942 in Blue Hill, Maine, at the Blue Hill Inn at the top of the bay. Gödel was not merely vacationing but had a very productive summer of work. Using [volume 15] of Gödel's still-unpublished [working notebooks], John W. Dawson Jr. conjectures that Gödel discovered a proof for the independence of the axiom of choice from finite type theory, a weakened form of set theory, while in Blue Hill in 1942. Gödel's close friend Hao Wang supports this conjecture, noting that Gödel's Blue Hill notebooks contain his most extensive treatment of the problem.  On December 5, 1947, Einstein and Morgenstern accompanied Gödel to his U.S. citizenship exam, where they acted as witnesses. Gödel had confided in them that he had discovered an inconsistency in the U.S. Constitution that could allow the U.S. to become a dictatorship. Einstein and Morgenstern were concerned that their friend's unpredictable behavior might jeopardize his application. The judge turned out to be Phillip Forman, who knew Einstein and had administered the oath at Einstein's own citizenship hearing. Everything went smoothly until Forman happened to ask Gödel if he thought a dictatorship like the Nazi regime could happen in the U.S. Gödel then started to explain his discovery to Forman. Forman understood what was going on, cut Gödel off, and moved the hearing on to other questions and a routine conclusion.  Gödel became a permanent member of the Institute for Advanced Study at Princeton in 1946. Around this time he stopped publishing, though he continued to work. He became a full professor at the Institute in 1953 and an emeritus professor in 1976.  During his many years at the Institute, Gödel's interests turned to philosophy and physics. In 1949, he demonstrated the existence of solutions involving closed timelike curves, to Einstein's field equations in general relativity. He is said to have given this elaboration to Einstein as a present for his 70th birthday. His "rotating universes" would allow time travel to the past and caused Einstein to have doubts about his own theory. His solutions are known as the Gödel metric (an exact solution of the Einstein field equation).  He studied and admired the works of Gottfried Leibniz, but came to believe that a hostile conspiracy had caused some of Leibniz's works to be suppressed. To a lesser extent he studied Immanuel Kant and Edmund Husserl. In the early 1970s, Gödel circulated among his friends an elaboration of Leibniz's version of Anselm of Canterbury's ontological proof of God's existence. This is now known as Gödel's ontological proof.

Awards and honours.

Gödel was awarded (with Julian Schwinger) the first Albert Einstein Award in 1951, and was also awarded the National Medal of Science, in 1974. Gödel was elected a Foreign Member of the Royal Society (ForMemRS) in 1968. He was a Plenary Speaker of the ICM in 1950 in Cambridge, Massachusetts. The Gödel Prize, an annual prize for outstanding papers in the area of theoretical computer science, is named after him.

Later life and death.

Later in his life, Gödel suffered periods of mental instability and illness. He had an obsessive fear of being poisoned; he would eat only food that his wife, Adele, prepared for him. Late in 1977, she was hospitalized for six months and could subsequently no longer prepare her husband's food. In her absence, he refused to eat, eventually starving to death. He weighed when he died. His death certificate reported that he died of "malnutrition and inanition caused by personality disturbance" in Princeton Hospital on January 14, 1978. He was buried in Princeton Cemetery. Adele's death followed in 1981.

Personal life.

Religious views.

Gödel was a convinced theist, in the Christian tradition. He held the notion that God was personal.  He believed firmly in an afterlife, stating: "Of course this supposes that there are many relationships which today's science and received wisdom haven't any inkling of. But I am convinced of this [the afterlife], independently of any theology." It is "possible today to perceive, by pure reasoning" that it "is entirely consistent with known facts." "If the world is rationally constructed and has meaning, then there must be such a thing [as an afterlife]."  In an unmailed answer to a questionnaire, Gödel described his religion as "baptized Lutheran (but not member of any religious congregation). My belief is "theistic", not pantheistic, following Leibniz rather than Spinoza." Describing religion(s) in general, Gödel said: "Religions are, for the most part, bad—but religion is not". According to his wife Adele, "Gödel, although he did not go to church, was religious and read the Bible in bed every Sunday morning", while of Islam, he said, "I like Islam: it is a consistent [or consequential] idea of religion and open-minded."

Legacy.

The Kurt Gödel Society, founded in 1987, was named in his honor. It is an international organization for the promotion of research in the areas of logic, philosophy, and the history of mathematics. The University of Vienna hosts the Kurt Gödel Research Center for Mathematical Logic. The Association for Symbolic Logic has invited an annual Kurt Gödel lecturer each year since 1990. Gödel's Philosophical Notebooks are edited at the Kurt Gödel Research Centre which is situated at the Berlin-Brandenburg Academy of Sciences and Humanities in Germany.  Five volumes of Gödel's collected works have been published. The first two include Gödel's publications; the third includes unpublished manuscripts from Gödel's, and the final two include correspondence.  A biography of Gödel was published by John Dawson in 2005: "Logical Dilemmas: The Life and Work of Kurt Gödel" (A. K. Peters, Wellesley, MA, ). Gödel was also one of four mathematicians examined in the 2008 BBC documentary entitled "Dangerous Knowledge" by David Malone.  Douglas Hofstadter wrote a popular book in 1979 called to celebrate the work and ideas of Gödel, along with those of artist M. C. Escher and composer Johann Sebastian Bach. The book partly explores the ramifications of the fact that Gödel's incompleteness theorem can be applied to any Turing-complete computational system, which may include the human brain.

Bibliography.

Important publications.

In German:  In English:  In English translation:

Kurt Friedrich Gödel (; ; April 28, 1906 – January 14, 1978) was an Austro-Hungarian-born Austrian logician, mathematician, and analytic philosopher. Considered along with Aristotle and Gottlob Frege to be one of the most significant logicians in history, Gödel had an immense effect upon scientific and philosophical thinking in the 20th century, a time when others such as Bertrand Russell, Alfred North Whitehead, and David Hilbert were analyzing the use of logic and set theory to understand the foundations of mathematics pioneered by Georg Cantor.

Kurt Gödel, né le à Brünn et mort le à Princeton (New Jersey), est un logicien et mathématicien autrichien naturalisé américain.


Origin.

According to cocktail historian David Wondrich, the margarita is merely a popular Mexican and American drink, the Daisy ("margarita" is Spanish for "daisy"), remade with tequila instead of brandy, which became popular during Prohibition as people drifted over the border for alcohol. There is an account from 1936 of Iowa newspaper editor James Graham finding such a cocktail in Tijuana, years before any of the other margarita "creation myths".  1937 Cafe Royal Cocktail Book contains a recipe for a Picador using the same concentrations of tequila, triple sec and lime juice as a margarita. One of the earliest stories is of the margarita being invented in 1938 by Carlos "Danny" Herrera at his restaurant Rancho La Gloria, halfway between Tijuana and Rosarito, Baja California, created for customer and former Ziegfeld dancer Marjorie King, who was allergic to many spirits, but not to tequila. This story was related by Herrera and also by bartender Albert Hernandez, acknowledged for popularizing a margarita in San Diego after 1947, at the La Plaza restaurant in La Jolla.  There are also claims that the margarita was first mixed in Juárez, Chihuahua at Tommy's Place Bar on July 4, 1942 by Francisco "Pancho" Morales. Morales later left bartending in Mexico to become a US citizen, where he worked as a milkman for 25 years. Mexico's official news agency Notimex and many experts have said Morales has the strongest claim to having invented the margarita.  Others say the inventor was Dallas socialite Margarita Sames, when she concocted the drink for her guests at her Acapulco, Guerrero vacation home in 1948. Tommy Hilton reportedly attended, bringing the drink back to the Hilton chain of hotels. However, Jose Cuervo was already running ad campaigns for the margarita three years earlier, in 1945, with the slogan, "Margarita: It's more than a girl's name." According to Jose Cuervo, the cocktail was invented in 1938 by a bartender in honor of Mexican showgirl Rita de la Rosa. Another common origin tale begins the cocktail's history at the legendary Balinese Room in Galveston, Texas where, in 1948, head bartender Santos Cruz created the margarita for singer Peggy (Margaret) Lee. He supposedly named it after the Spanish version of her name, Margarita.  The first known publication of a margarita recipe was in the December 1953 issue of "Esquire", with a recipe calling for an ounce of tequila, a dash of triple sec and the juice of half a lime or lemon. A recipe for a tequila-based cocktail first appeared in the 1930 book "My New Cocktail Book" by G.F. Steele. Without noting a specific recipe or inventor, a drink called the Tequila Daisy was mentioned in the "Syracuse Herald" as early as 1936. Margarita is Spanish for Daisy, which is a nickname for Margaret.  A later, certainly false, story is that the margarita was invented in October 1961, at a party in Houston, Texas, by party goer Robert James "Rusty" Thomson while acting as bartender. He concocted a mixture of equal parts tequila, Controy orange liqueur, lime, and crushed ice in a salt-rimmed glass. However, Thomson's recipe was made with Damiana Liqueur, not Cointreau orange liqueur. It is said that the idea was an experiment after running out of rum while making frozen daiquiris.

Variations.

The IBA (IBA Official list of Cocktails) standard is 10:4:3, that is tequila:triple sec:fresh lime juice.  The "Original Margarita" recipe as given by Cointreau on their website has slightly more of their own sweet liqueur: 1 part white tequila, part Cointreau, and part fresh squeezed lime juice.

Flavored tequila.

Apple-cinnamon tequila, triple sec, cranberry juice, fresh lime juice, and an apple wedge or lemon twist for garnish combine to form the Cranberry Margarita With Apple-Cinnamon Tequila, a fall seasonal drink.

Flavored liqueurs.

Besides Cointreau, other orange-flavored liqueurs that might be used include Grand Marnier (yielding the "Cadillac Margarita"), Gran Gala, other brands of triple sec, or blue curaçao (yielding the "blue margarita"). When sweeter fruit juices or freshly puréed fruits are added to the margarita, the orange-flavored liqueur is often reduced or eliminated entirely. In addition to orange-flavored liqueurs, secondary liqueurs may occasionally be added to a cocktail, including melon-flavored or black raspberry-flavored. Other flavors include pineapple and watermelon.

Fresh lime juice.

Freshly squeezed lime juice is the key ingredient. The most common lime in the United States is the thick-skinned Persian lime. However, margaritas in Mexico are generally made with Mexican limes (Key limes). These are small, thin-skinned limes and have more tart and an often bitter flavor compared to Persian limes.

Frozen margarita.

The frozen margarita is a margarita served as an ice slush, similar to other tropical-inspired frozen mixed drinks like the hurricane or piña colada. The ingredients can be processed with ice in a kitchen blender, or for larger output, a slush or soft-serve ice cream machine is used: a cooled, horizontal cylinder has a rotating impeller which churns the mix so it will not freeze solid, and the thick half-frozen slush is dispensed from a spout. Frozen margaritas were first served in La Jolla, when Albert Hernandez Sr. stopped using crushed ice and instead combined the ingredients in a blender in 1947. The dedicated frozen margarita machine was introduced by Mariano Martinez in Dallas in 1971.  A lemonade or limeade margarita can be quickly whipped up by using frozen lemonade or limeade concentrate in place of lime juice.

Fruit sodas and sports drinks.

Fruity sodas such as fruit punch, lime, pineapple, or mandarin orange Jarritos, or sports drinks such as blue or orange Gatorade, can substitute for triple sec. A margarita made with orange soda and beer is a sunrise beer margarita; if it is made with carbonated fruit punch soda, it is a sunset margarita. The variant that uses grapefruit soda is called a Paloma.

Other fruits and vegetables.

Alternate fruits and juice mixtures can also be used in a margarita. Fruits like mango, peach, strawberry, banana, melon, raspberry, or avocado are suitable for creating this drink. Orange juice and pomegranate juice (poured down the inner side of the glass) can make a sunset margarita (so named because the orange is at the top and the red at the bottom). Many recipes call for a splash of orange juice. These days, margarita can be prepared in many different ways. When the word "margarita" is used by itself, it typically refers to the lime or lemon juice margarita, but when other juices are used, the fruits are typically added as adjectives in the name; with lime juice or lemon juice added to give it a characteristic margarita flavor (a wedge of lime is often added to the glass). Other varieties of margarita include fruit margarita, top-shelf margarita and virgin margarita.  Coconut cream, coconut milk, and coconut water can also be added to margaritas, e.g. skinny margaritas that substitute, e.g., pineapple juice for liqueurs.  Margaritas can also be made with vegetables such as carrots, beets, cucumber, and celery.

Beer cocktails.

A beermarita (or Coronarita) is a beer cocktail that has a bottle of Corona beer or other light-flavored beer poured upside down into a margarita on the rocks.

Skinny.

A skinny margarita is a two-ingredient cocktail that leaves out the liqueur and only has tequila and a hint of Rose's lime juice, shaken over ice and served optionally with salt.

Related drinks.

A margarita with vodka substituted for tequila is a kamikaze.

Glass.

Margaritas may be served in a variety of glasses, most notably the eponymous margarita glass, a variant of the classic champagne coupe; this is particularly associated with blended fruit margaritas, and the glass is also used for dishes such as guacamole or shrimp cocktails. In formal settings margaritas are often served in a standard cocktail glass, while in informal settings, particularly with ice, margaritas may be served in an old fashioned glass.

Popularity.

The margarita cocktail was the "Drink of the Month" in "Esquire" magazine, December 1953, pg. 76:  It was further popularized by the 1977 song "Margaritaville" by Jimmy Buffett, and in 2004 it was described as "the most popular mixed drink in America".  Another reason that has been given for the margarita's popularity is that it feels more complete than a drink that only has sweet and sour flavors, since it engages a third primary taste, salty.

A margarita is a cocktail consisting of tequila, orange liqueur, and lime juice often served with salt on the rim of the glass. The drink is served shaken with ice (on the rocks), blended with ice (frozen margarita), or without ice (straight up). Although it has become acceptable to serve a margarita in a wide variety of glass types, ranging from cocktail and wine glasses to pint glasses and even large schooners, the drink is traditionally served in the eponymous margarita glass, a stepped-diameter variant of a cocktail glass or champagne coupe.

La Margarita est un cocktail à base de tequila, inventé par des Américains au Mexique. C'est un "before lunch" qui serait une version du cocktail daisy (qui signifie « marguerite » en français, « "margarita" » en espagnol) dans lequel on remplaça le brandy par de la téquila durant la prohibition, période où les Américains ouvrirent des bars au Mexique et au Canada dans les zones frontalières.


Origin.

Robert "Rosebud" Butt claims to have invented the Long Island iced tea as an entry in a contest to create a new mixed drink with triple sec in 1972 while he worked at the Oak Beach Inn on Long Island, New York.  A slightly different drink is claimed to have been invented in the 1920s during Prohibition in the United States by an "Old Man Bishop" in a local community named Long Island in Kingsport, Tennessee. The drink was then perfected by Ransom Bishop, Old Man Bishop's son. This drink included whiskey and maple syrup, and varied quantities of the five liquors, rather than the modern one with cola and five equal portions of the five liquors.

Variations.

The popularity of the Long Island has spawned its own family of highballs. Many drinks remain popular in their own right in numerous locales throughout the United States, while owing their existence to the success of the original Long Island iced tea. An example of a variation to the Long Island is the Grateful Dead (also variously known as the Purple Rain or the Black Superman), which uses the same mix as a Long Island but the Triple Sec is replaced with a shot of Chambord and the cola replaced with lemon-lime soda. The Adios Motherfucker is considered a variation of the Long Island Iced Tea with Blue Curaçao substituting the Triple Sec and lemon-lime soda substituting the cola; it has a distinctive blue color. See Blue Hawaiian. If cranberry juice is substituted for cola, the result is a Long Beach Iced Tea and has a reddish color. If Midori is substituted for the Coca-Cola the result is a Tokyo Iced Tea and has a greenish color. In the Western United States, Long Island Iced Tea is often made without Tequila. For the original recipe, one must order a Texas Tea instead.

A Long Island iced tea is a type of alcoholic mixed drink typically made with vodka, tequila, light rum, triple sec, gin, and a splash of cola, which gives the drink the same amber hue as its namesake. A popular version mixes equal parts vodka, tequila, gin, rum, triple sec, with parts sour mix and a splash of cola. Lastly, it is decorated with the lemon and straw, after stirring with bar spoon smoothly.

Le Long Island iced tea ou LIIT ou Long Island (littéralement « thé glacé Long Island », en anglais) est un cocktail à base de tequila, gin, vodka, rhum, liqueur d'oranges, et cola. Ce cocktail officiel de l'IBA tient son nom de sa ressemblance à du thé glacé (bien qu'il n'en contienne pas).


Early life and education.

Eric Hobsbawm was born in 1917 in Alexandria, Egypt. His father was Leopold Percy Hobsbaum (né Obstbaum), a Jewish merchant from the East End of London of Polish Jewish descent. His mother was Nelly Hobsbaum (née Grün), who was from a middle-class Austrian Jewish family. His early childhood was spent in Vienna, Austria and Berlin, Germany. A clerical error at birth altered his surname from Hobsbaum to Hobsbawm. Although the family lived in German-speaking countries, he grew up speaking English as his first language.  In 1929, when Hobsbawm was 12, his father died, and he started contributing to his family's support by working as an "au pair" and English tutor. Upon the death of their mother in 1931, he and his sister Nancy were adopted by their maternal aunt, Gretl, and paternal uncle, Sidney, who married and had a son named Peter. Hobsbawm was a student at the Prinz Heinrich-Gymnasium Berlin (today Friedrich-List-School) when the Nazi Party came to power in 1933. That year the family moved to London, where Hobsbawm enrolled in St Marylebone Grammar School (now defunct). His migration from Germany created the false belief that Hobsbawm was a refugee, which persisted throughout his life, while he was actually British by birth because of his father's nationality.  Hobsbawm attended King's College, Cambridge, from 1936, where he joined the Communist Party "in the form of the university's Socialist Club." He also took a double-starred first in History and was elected to the Cambridge Apostles. He received a doctorate (PhD) in History from Cambridge University for his dissertation on the Fabian Society. During the Second World War, he served in the Royal Engineers and the Army Educational Corps.

Academia.

MI5 opened a personal file on Hobsbawm in 1942 and their monitoring of his activities was to affect the progress of his career for many years. In 1945, he applied to the BBC for a full-time post making educational broadcasts to help servicemen adjust to civilian life after a long period in the forces and was considered "a most suitable candidate". The appointment was swiftly vetoed by MI5 who believed Hobsbawm was unlikely "to lose any opportunity he may get to disseminate propaganda and obtain recruits for the Communist party”. In 1947, he became a lecturer in history at Birkbeck College, University of London which, unusually at the time, lacked any inclination towards anti-communism among staff or students. He became reader in 1959, professor between 1970 and 1982 and an emeritus professor of history in 1982. He was a Fellow of King's College, Cambridge, from 1949 to 1955. Hobsbawm said there was a weaker version of McCarthyism that took hold in Britain and affected Marxist academics: "you didn't get promotion for 10 years, but nobody threw you out". Hobsbawm was also denied a lectureship at Cambridge by political enemies, and, given that he was also blocked for a time from a professorship at Birkbeck for the same reasons, spoke of his good fortune at having got a post at Birkbeck in 1948 before the Cold War really started to take off. Conservative commentator David Pryce-Jones has questioned the existence of such career obstacles.  Hobsbawm helped found the academic journal "Past & Present" in 1952. He was a visiting professor at Stanford in the 1960s. In 1970s, he was appointed professor and in 1976 he became a Fellow of the British Academy. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1971 and a Fellow of the Royal Society of Literature in 2006.  Hobsbawm formally retired from Birkbeck in 1982, becoming Emeritus Professor of History, and was appointed as president of Birkbeck in 2002. He remained as visiting professor at The New School for Social Research in Manhattan between 1984 and 1997. He was, until his death, professor emeritus in the New School for Social Research in the Political Science Department. A polyglot, he spoke German, English, French, Spanish and Italian fluently, and read Portuguese and Catalan.

Works.

Hobsbawm wrote extensively on many subjects as one of Britain's most prominent historians. As a Marxist historiographer he has focused on analysis of the "dual revolution" (the political French Revolution and the British Industrial Revolution). He saw their effect as a driving force behind the predominant trend towards liberal capitalism today. Another recurring theme in his work was social banditry, which Hobsbawm placed in a social and historical context, thus countering the traditional view of it being a spontaneous and unpredictable form of primitive rebellion. He also coined the term "long nineteenth century", which begins with the French Revolution in 1789 and ends with the start of the Great War in 1914.  He published numerous essays in various intellectual journals, dealing with subjects such as barbarity in the modern age, the troubles of labour movements, and the conflict between anarchism and communism. Among his final publications were "Globalisation, Democracy and Terrorism" (2007), "On Empire" (2008) and the collection of essays "How to Change the World: Marx and Marxism 1840–2011" (2011).  Outside his academic historical writing, Hobsbawm wrote a regular column about Jazz for the "New Statesman" (under the pseudonym Francis Newton, taken from the name of Billie Holiday's communist trumpet player, Frankie Newton), and from time to time over other forms of popular music such as with his "Beatles and before" article. He had become interested in Jazz during the 1930s when it was officially frowned upon by the Communist Party.

Politics.

Hobsbawm joined the "" (Association of Socialist Pupils), an offshoot of the Young Communist League of Germany, in Berlin in 1931, and the British Communist Party in 1936. He was a member of the Communist Party Historians Group from 1946 until its demise and subsequently president of its successor, the Socialist History Society until his death. The Soviet invasion of Hungary in 1956 led thousands of its members to leave the British Communist Party – but Hobsbawm, unique among his colleagues, remained in the party, but was distrusted by its leadership and ceased political work by the end of the 1950s. He signed a historians' letter of protest against the Soviet invasion of Hungary and was strongly in favour of the Prague spring.  Hobsbawm was later a leading light of the Eurocommunist faction in the CPGB that began to gather strength after 1968, when the CPGB criticised the Soviet crushing of the Prague Spring and the French CP failing to support the May students in Paris. In "The Forward March of Labour Halted?" (originally a Marx Memorial Lecture, "The British Working Class One Hundred Years after Marx", that was delivered to a small audience of fellow Marxists in March 1978 before being published in "Marxism Today" in September 1978), he argued that the working class was inevitably losing its central role in society, and that left-wing parties could no longer appeal only to this class; a controversial viewpoint in a period of trade union militancy. Hobsbawm supported Neil Kinnock's transformation of the British Labour Party from 1983 (the party received just 28 per cent of the vote in that year's elections, just 2 per cent more than the Social Democratic Party/Liberal Alliance), and, though not close to Kinnock, came to be referred to as "Neil Kinnock's Favourite Marxist". His interventions in Kinnock's remaking of the Labour Party helped prepare the ground for the Third Way, New Labour, and Tony Blair, whom Hobsbawm later derisively referred to as "Thatcher in trousers". Until the cessation of publication in 1991, he contributed to the magazine "Marxism Today". A third of the 30 reprints of "Marxism Today" feature articles that appeared in "The Guardian" during the 1980s were articles or interviews by or with Hobsbawm, making him by far the most popular of all contributors.  In addition to his association with the CPGB, Hobsbawm also developed close ties to the largest Communist Party in the western world, the Italian Communist Party (PCI), of which he declared himself a "spiritual member". He developed contacts with Italian left-wing academics and intellectuals in the early 1950s, which led to him encountering the work of Antonio Gramsci, whose writings were a key influence on Hobsbawm's work on the history of subaltern groups, emphasising their agency as well as structural factors. Hobsbawm spoke favourably about PCI general secretary Enrico Berlinguer's strategy of Historic Compromise in the 1970s, seeking rapprochement with the Catholic Church and the Christian Democrats, providing passive support to the latter in government in order to bring the Communists into the political mainstream by accepting Italy's position as a member of NATO, thus being able to build broader alliances and convince wider sections of society of its legitimacy as a potential governing force.  From the 1960s, his politics took a more moderate turn, as Hobsbawm came to recognise that his hopes were unlikely to be realised, and no longer advocated "socialist systems of the Soviet type". Until the day of his death, however, he remained firmly entrenched on the Left, maintaining that the long-term outlooks for humanity were 'bleak'. "I think we ought to get out of that 20th-century habit of thinking of systems as mutually exclusive: you’re either socialist or you’re capitalist, or whatever," Hobsbawm stated in 2009 in regards to the emergence of a new historical system. "There are plenty of people who still think so. I think very few attempts have been made to build a system on the total assumption of social ownership and social management. At its peak the Soviet system tried it. And in the past 20 or 30 years, the capitalist system has also tried it. In both cases, the results demonstrate that it won’t work. So it seems to me the problem isn’t whether this market system disappears, but exactly what the nature of the mixture between market economy and public economy is and, above all, in my view, what the social objectives of that economy are. One of the worst things about the politics of the past 30 years is that the rich have forgotten to be afraid of the poor – of most of the people in the world."

Communism and Russia.

Hobsbawm stressed that since communism was not created, the sacrifices were in fact not justified—a point he emphasised in "Age of Extremes": Elsewhere he insisted: With regard to the 1930s, he wrote that  He claimed that the demise of the USSR was "traumatic not only for communists but for socialists everywhere".

Miscellaneous views.

Regarding the Queen, Hobsbawm stated that constitutional monarchy in general has "proved a reliable framework for liberal-democratic regimes" and "is likely to remain useful". On the nuclear attacks on Japan in World War II, he adhered to the view that "there was even less sign of a crack in Japan's determination to fight to the end [compared with that of Nazi Germany], which is why nuclear arms were dropped on Hiroshima and Nagasaki to ensure a rapid Japanese surrender". He also believed there was an ancillary political, non-military reason for the bombings: "perhaps the thought that it would prevent America's ally the USSR from establishing a claim to a major part in Japan's defeat was not absent from the minds of the US government either." Hobsbawm is also quoted as saying that, next to sex, there is nothing so physically intense as 'participation in a mass demonstration at a time of great public exaltation'.

Praise and criticism.

In 1994, Neal Ascherson said of Hobsbawm: "No historian now writing in English can match his overwhelming command of fact and source. But the key word is 'command'. Hobsbawm's capacity to store and retrieve detail has now reached a scale normally approached only by large archives with big staffs". In 2002, Hobsbawm was described by right-leaning magazine "The Spectator" as "arguably our greatest living historian—not only Britain's, but the world's", while Niall Ferguson wrote: "That Hobsbawm is one of the great historians of his generation is undeniable... His quartet of books beginning with "The Age of Revolution" and ending with "The Age of Extremes" constitute the best starting point I know for anyone who wishes to begin studying modern history. Nothing else produced by the British Marxist historians will endure as these books will." In 2003, "The New York Times" described him as "one of the great British historians of his age, an unapologetic Communist and a polymath whose erudite, elegantly written histories are still widely read in schools here and abroad". James Joll wrote in "The New York Review of Books" that "Eric Hobsbawm's nineteenth century trilogy is one of the great achievements of historical writing in recent decades". Ian Kershaw said that Hobsbawm's take on the twentieth century, his 1994 book, "The Age of Extremes", consisted of "masterly analysis". Meanwhile, Tony Judt, while praising Hobsbawm's vast knowledge and graceful prose, cautioned that Hobsbawm's bias in favour of the USSR, communist states and communism in general, and his tendency to disparage any nationalist movement as passing and irrational, weakened his grasp of parts of the 20th century.  With regard to the impact of his Marxist outlook and sympathies on his scholarship, Ben Pimlott saw it as "a tool not a straitjacket; he's not dialectical or following a party line", although Judt argued that it has "prevented his achieving the analytical distance he does on the 19th century: he isn't as interesting on the Russian revolution because he can't free himself completely from the optimistic vision of earlier years. For the same reason he's not that good on fascism".  British historian David Pryce-Jones conceded that Hobsbawm was "no doubt intelligent and industrious, and he might well have made a notable contribution as a historian", but also charged that Hobsbawm, as a professional historian who has "steadily corrupted knowledge into propaganda, and scorns the concept of objective truth", was "neither a historian nor professional." After reading "Age of Extremes", Kremlinologist Robert Conquest concluded that Hobsbawm suffers from a "massive reality denial" regarding the USSR, and John Gray, though praising his work on the nineteenth century, has described Hobsbawm's writings on the post-1914 period as "banal in the extreme. They are also highly evasive. A vast silence surrounds the realities of communism, a refusal to engage which led the late Tony Judt to conclude that Hobsbawm had 'provincialised himself'. It is a damning judgement".  In a 1994 interview on BBC television with Canadian academic Michael Ignatieff, he shocked viewers when he said that the deaths of millions of Soviet citizens under Stalin would have been worth it if a genuinely communist society had been the result. Hobsbawm argued that, "In a period in which, as you might imagine, mass murder and mass suffering are absolutely universal, the chance of a new world being born in great suffering would still have been worth backing" but, unfortunately, "the Soviet Union was not the beginning of the World Revolution". The following year, when asked the same question on BBC Radio 4's "Desert Island Discs", if "the sacrifice of millions of lives" would have been worth the future communist society, he replied: "That's what we felt when we fought the Second World War". He repeated what he had already said to Michael Ignatieff, when he asked the rhetorical question, "Do people now say we shouldn't have had World War II, because more people died in World War II than died in Stalin's terror?".  Tony Judt was of the opinion that Hobsbawm "clings to a pernicious illusion of the late Enlightenment: that if one can promise a benevolent outcome it would be worth the human cost. But one of the great lessons of the 20th century is that it's not true. For such a clear-headed writer, he appears blind to the sheer scale of the price paid. I find it tragic, rather than disgraceful." Neil Ascherson believes that, "Eric is not a man for apologising or feeling guilty. He does feel bad about the appalling waste of lives in Soviet communism. But he refuses to acknowledge that he regrets anything. He's not that kind of person." Hobsbawm himself, in his autobiography, wrote that he desires "historical understanding... not agreement, approval or sympathy".  The 1930s aside, Hobsbawm was criticised for never relinquishing his Communist Party membership. Whereas people like Arthur Koestler left the Party after seeing the friendly reception of Nazi foreign minister Joachim von Ribbentrop in Moscow during the years of the Molotov–Ribbentrop Pact (1939–1941), Hobsbawm stood firm even after the Soviet invasions of Hungary and Czechoslovakia. In his review of Hobsbawm's 2002 memoirs, "Interesting Times", Niall Ferguson wrote:  In those memoirs, Hobsbawn wrote: "The dream of the October Revolution is still there somewhere inside me... I have abandoned, nay, rejected it, but it has not been obliterated. To this day, I notice myself treating the memory and tradition of the USSR with an indulgence and tenderness." Reviewing the book, David Caute wrote: "One keeps asking of Hobsbawm: didn't you know what Deutscher and Orwell knew? Didn't you know about the induced famine, the horrors of collectivisation, the false confessions, the terror within the Party, the massive forced labour of the gulag? As Orwell himself documented, a great deal of evidence was reliably knowable even before 1939, but Hobsbawm pleads that much of it was not reliably knowable until Khrushchev's denunciation of Stalin in 1956."  Reviewing Hobsbawm's 2011 "How to Change the World" in the "Wall Street Journal", Michael Moynihan argued: Reviewing the same book, Francis Wheen argued in a similar vein: "When writing about how the anti-fascist campaigns of the 1930s brought new recruits to the communist cause, he cannot even bring himself to mention the Hitler-Stalin pact, referring only to 'temporary episodes such as 1939–41'. The Soviet invasion of Hungary and the crushing of the Prague Spring are skipped over."  David Evanier, in an article published in the American neoconservative magazine "The Weekly Standard", called Hobsbawm "Stalin's cheerleader", writing: "One can learn almost nothing about the history of communism from Hobsbawm's "Interesting Times"—nothing about the show trials, the torture and execution of millions, the Communist betrayal of Spain."  An alternative conservative assessment of Hobsbawm came from Matthew Walther in "National Review". While critical of Hobsbawm for his communist sympathies and his purported views about Israel, Walther wrote that "There is no denying his [Hobsbawm's] intelligence and erudition" and concluded that "if Hobsbawm is read 50 or 100 years from now, it will probably be despite rather than because of his politics."  In 2008, the historian Tony Judt summed up Hobsbawm's career thus: "Eric J. Hobsbawm was a brilliant historian in the great English tradition of narrative history. On everything he touched he wrote much better, had usually read much more, and had a broader and subtler understanding than his more fashionable emulators. If he had not been a lifelong Communist he would be remembered simply as one of the great historians of the 20th century".  After Hobsbawm died in October 2012, Mark Mazower wrote of his historical writings being "about trends, social forces, large-scale change over vast distances. Telling that kind of history in a way that is as compelling as a detective story is a real challenge of style and composition: in the tetralogy, Hobsbawm shows how to do it."

Personal life.

Hobsbawm's friend, historian Donald Sassoon, wrote that: "Hobsbawm was not a Jewish historian; he was an historian who happened to be Jewish." His first marriage was to Muriel Seaman in 1943. They divorced in 1951. His second marriage was to Marlene Schwarz, with whom he had two children, Julia Hobsbawm and Andy Hobsbawm. Julia is chief executive of Hobsbawm Media and Marketing and a visiting professor of public relations at the College of Communication, University of the Arts London. He also had an out-of-wedlock son, Joshua Bennathan, who died in November 2014.

Death.

In the early hours of 1 October 2012, Hobsbawm died at the Royal Free Hospital in London. His daughter Julia confirmed that he died of pneumonia, while suffering complications from leukemia. She said,  Following Hobsbawm's death reactions included praise for his "sheer academic productivity and prowess" and "tough reasoning" in "The Guardian". Reacting to news of Hobsbawm's death, Ed Miliband called him "an extraordinary historian, a man passionate about his politics... He brought history out of the ivory tower and into people's lives".  He was cremated at Golders Green Crematorium and his ashes were interred in Highgate Cemetery. A memorial service for Hobsbawm was held at the New School in October 2013.

Impact.

Owing to his status as a widely read and prominent Communist historian, and the fact that his ideology had influenced his work, Hobsbawm has been credited with spreading Marxist thought around the globe. His writings reached particular prominence in India and Brazil in the 1960s and 1970s at a time of lively debate about these countries' political and social future. Emile Chabal, in an essay for "Aeon", wrote: "In the period from the early 1960s to the late ’80s, Marxists in noncommunist countries were increasingly able to participate in a transnational discussion over the past and future of capitalism, and the most promising agents of revolutionary change. Hobsbawm played a starring role in these discussions – and, occasionally, set the agenda."

Eric John Ernest Hobsbawm (; 9 June 1917 – 1 October 2012) was a British historian of the rise of industrial capitalism, socialism and nationalism. A life-long Marxist, his socio-political convictions influenced the character of his work. His best-known works include his trilogy about what he called the "long 19th century" ("", "" and ""), "The Age of Extremes" on the short 20th century, and an edited volume that introduced the influential idea of "invented traditions".

Eric Hobsbawm, né le à Alexandrie et mort le à Londres, est un historien britannique. Membre à partir de 1936 du Parti communiste de Grande-Bretagne, il collabora jusqu'en 1991 à la revue "Marxism Today". Il a beaucoup travaillé sur la question des nations et des nationalismes en Europe au et au ainsi que sur l'invention des traditions par les nations. Hobsbawm a introduit la notion de « Long » pour qualifier la période allant de 1789 (Révolution française) à 1914 (veille de la Première Guerre mondiale), période marquée par des conflits issus de la Révolution.


Description.

The leaves are arranged either spirally, in decussate pairs (opposite pairs, each pair at 90° to the previous pair) or in decussate whorls of three or four, depending on the genus. On young plants, the leaves are needle-like, becoming small and scale-like on mature plants of many genera; some genera and species retain needle-like leaves throughout their lives. Old leaves are mostly not shed individually, but in small sprays of foliage (cladoptosis); exceptions are leaves on the shoots that develop into branches. These leaves eventually fall off individually when the bark starts to flake. Most are evergreen with the leaves persisting 2–10 years, but three genera ("Glyptostrobus", "Metasequoia" and "Taxodium") are deciduous or include deciduous species. The seed cones are either woody, leathery, or (in "Juniperus") berry-like and fleshy, with one to several ovules per scale. The bract scale and ovuliferous scale are fused together except at the apex, where the bract scale is often visible as a short spine (often called an umbo) on the ovuliferous scale. As with the foliage, the cone scales are arranged spirally, decussate (opposite) or whorled, depending on the genus. The seeds are mostly small and somewhat flattened, with two narrow wings, one down each side of the seed; rarely (e.g. "Actinostrobus") triangular in section with three wings; in some genera (e.g. "Glyptostrobus" and "Libocedrus"), one of the wings is significantly larger than the other, and in some others (e.g. "Juniperus", "Microbiota", "Platycladus", and "Taxodium") the seed is larger and wingless. The seedlings usually have two cotyledons, but in some species up to six. The pollen cones are more uniform in structure across the family, 1–20 mm long, with the scales again arranged spirally, decussate (opposite) or whorled, depending on the genus; they may be borne singly at the apex of a shoot (most genera), in the leaf axils ("Cryptomeria"), in dense clusters ("Cunninghamia" and "Juniperus drupacea"), or on discrete long pendulous panicle-like shoots ("Metasequoia" and "Taxodium").  Cupressaceae is a widely distributed conifer family, with a near-global range in all continents except for Antarctica, stretching from 71°N in arctic Norway ("Juniperus communis") south to 55°S in southernmost Chile ("Pilgerodendron uviferum"), while "Juniperus indica" reaches 5200 m altitude in Tibet, the highest altitude reported for any woody plant. Most habitats on land are occupied, with the exceptions of polar tundra and tropical lowland rainforest (though several species are important components of temperate rainforests and tropical highland cloud forests); they are also rare in deserts, with only a few species able to tolerate severe drought, notably "Cupressus dupreziana" in the central Sahara. Despite the wide overall distribution, many genera and species show very restricted relictual distributions, and many are endangered species.

Classification.

The family Cupressaceae is now widely regarded as including the Taxodiaceae, previously treated as a distinct family, but now shown not to differ from the Cupressaceae in any consistent characteristics. The one exception in the former Taxodiaceae is the genus "Sciadopitys", which is genetically distinct from the rest of the Cupressaceae, and is now treated in its own family, Sciadopityaceae.  The family is divided into seven subfamilies, based on genetic and morphological analysis as follows: A 2010 study of "Actinostrobus" and "Callitris" places the three species of "Actinostrobus" within an expanded "Callitris" based on analysis of 42 morphological and anatomical characters.

Superlatives.

The family is notable for including the largest, tallest, and stoutest individual trees in the world, and also the second longest lived species in the world:  In addition to the above, many other members of the family list among the tallest, most massive, stoutest and most long-lived tree species in the world, including Taiwania, sugi, western redcedar, incense cedar, Tibetan cypress, and Formosan cypress among others.

Uses.

Many of the species are important timber sources, especially in the genera "Calocedrus", "Chamaecyparis", "Cryptomeria", "Cunninghamia", "Cupressus", "Sequoia", "Taxodium", and "Thuja". These and several other genera are also important in horticulture. Junipers are among the most important evergreen shrubs, groundcovers and small evergreen trees, with hundreds of cultivars selected, including plants with blue, grey, or yellow foliage. "Chamaecyparis" and "Thuja" also provide hundreds of dwarf cultivars as well as trees, including Lawson's cypress and the infamous hybrid Leyland cypress. Dawn redwood is widely planted as an ornamental tree because of its excellent horticultural qualities, rapid growth and status as a living fossil. giant sequoia is a popular ornamental tree and is occasionally grown for timber. Giant sequoia, Leyland cypress, and Arizona cypress are grown to a small extent as Christmas trees.  Sugi ("Cryptomeria japonica") is the national tree of Japan, and ahuehuete ("Taxodium mucronatum") the national tree of Mexico. Coast redwood and giant sequoia were jointly designated the state tree of California and are famous California tourist attractions. Redwood National and State Parks and several parks including Giant Sequoia National Monument protect almost half the remaining stands of Coast Redwoods and Giant sequoias. Bald cypress is the state tree of Louisiana. Bald cypress, often festooned with Spanish moss, of southern swamps are another tourist attraction. They can be seen at Big Cypress National Preserve in Florida. Bald cypress "knees" are often sold as knick knacks, made into lamps or carved to make folk art. Monterey cypress is another famous picturesque tree often visited by tourists and photographers.  Baton Rouge, Louisiana ("red stick") was named after the decay-resistant red wood of "Juniperus virginiana", used by Native Americans in the region for waymarking. Its heartwood is fragrant and used in clothes chests, drawers and closets to repel moths. It is a source of juniper oil used in perfumes and medicines. The wood is also used as long lasting fenceposts and for bows. The fleshy cones of "Juniperus communis" are used to flavour gin.  "Calocedrus decurrens" is the main wood used to make wooden pencils and is also used for cupboards and chests. In China, cypress wood known as "baimu" or "bomu", was carved into furniture, using notably "Cupressus funebris", and particularly in tropical areas, Fujian cypress and the aromatic wood of "Glyptostrobus pensilis". Native Americans and early European explorers used "Thuja" leaves as a cure for scurvy. Distillation of "Fokienia" roots produces an essential oil called pemou oil used in medicine and cosmetics.  Recent progress on Endophyte Biology in Cupressaceae, by the groups of Jalal Soltani (Bu-Ali Sina University) and Elizabeth Arnold (Arizona University) have revealed prevalent symbioses of endophytes and endofungal bacteria with family Cupressaceae. Furthermore, current and potential uses of Cupressaceous trees's endophytes in agroforestry and medicine is shown by both groups.

Disease vectors.

The pollen of many genera of Cupressaceae is allergenic, causing major hay fever problems in areas where they are abundant, most notably by "Cryptomeria japonica" ("sugi") pollen in Japan. Highly allergenic species of cypress with an OPALS allergy scale rating of 8 or higher include: "Taxodium", "Cupressus", "Callitris", "Chamaecyparis", and the males and monoicous variants of "Austrocedrus" and "Widdringtonia". However, the females of some species have a very low potential for causing allergies (an OPALS allergy scale rating of 2 or lower) including "Austrocedrus" females and "Widdringtonia" females.  Several genera are an alternate host of "Gymnosporangium" rust, which damages apples and other related trees in the subfamily Maloideae.

Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdioecious or (rarely) dioecious trees and shrubs up to tall. The bark of mature trees is commonly orange- to red- brown and of stringy texture, often flaking or peeling in vertical strips, but smooth, scaly or hard and square-cracked in some species.

La famille des Cupressaceae (Cupressacées, aussi nommées Cupressinées), regroupe des plantes gymnospermes. Le contenu de cette famille a beaucoup changé entre classification classique et classification phylogénétique. La famille, qui inclut les cyprès, est référencée parmi les émetteurs de pollens allergisants selon le Réseau National de Surveillance Aérobiologique.