title: Plate tectonics

text: It has generally been accepted that tectonic plates are able to move because of the relative density of oceanic lithosphere and the relative weakness of the asthenosphere. Dissipation of heat from the mantle is acknowledged to be the original source of the energy required to drive plate tectonics through convection or large scale upwelling and doming. The current view, though still a matter of some debate, asserts that as a consequence, a powerful source generating plate motion is the excess density of the oceanic lithosphere sinking in subduction zones. When the new crust forms at mid-ocean ridges, this oceanic lithosphere is initially less dense than the underlying asthenosphere, but it becomes denser with age as it conductively cools and thickens. The greater density of old lithosphere relative to the underlying asthenosphere allows it to sink into the deep mantle at subduction zones, providing most of the driving force for plate movement. The weakness of the asthenosphere allows the tectonic plates to move easily towards a subduction zone. Although subduction is thought to be the strongest force driving plate motions, it cannot be the only force since there are plates such as the North American Plate which are moving, yet are nowhere being subducted. The same is true for the enormous Eurasian Plate. The sources of plate motion are a matter of intensive research and discussion among scientists. One of the main points is that the kinematic pattern of the movement itself should be separated clearly from the possible geodynamic mechanism that is invoked as the driving force of the observed movement, as some patterns may be explained by more than one mechanism. In short, the driving forces advocated at the moment can be divided into three categories based on the relationship to the movement: mantle dynamics related, gravity related (main driving force accepted nowadays), and earth rotation related.


title: Plate tectonics

text: For much of the last quarter century, the leading theory of the driving force behind tectonic plate motions envisaged large scale convection currents in the upper mantle, which can be transmitted through the asthenosphere. This theory was launched by Arthur Holmes and some forerunners in the 1930s and was immediately recognized as the solution for the acceptance of the theory as originally discussed in the papers of Alfred Wegener in the early years of the century. However, despite its acceptance, it was long debated in the scientific community because the leading theory still envisaged a static Earth without moving continents up until the major breakthroughs of the early sixties.


title: Plate tectonics

text: Two- and three-dimensional imaging of Earth's interior (seismic tomography) shows a varying lateral density distribution throughout the mantle. Such density variations can be material (from rock chemistry), mineral (from variations in mineral structures), or thermal (through thermal expansion and contraction from heat energy). The manifestation of this varying lateral density is mantle convection from buoyancy forces.


title: Plate tectonics

text: How mantle convection directly and indirectly relates to plate motion is a matter of ongoing study and discussion in geodynamics. Somehow, this energy must be transferred to the lithosphere for tectonic plates to move. There are essentially two main types of forces that are thought to influence plate motion: friction and gravity.


title: Plate tectonics

text: Lately, the convection theory has been much debated, as modern techniques based on 3D seismic tomography still fail to recognize these predicted large scale convection cells. Alternative views have been proposed.


title: Plate tectonics

text: In the theory of plume tectonics followed by numerous researchers during the 1990s, a modified concept of mantle convection currents is used. It asserts that super plumes rise from the deeper mantle and are the drivers or substitutes of the major convection cells. These ideas find their roots in the early 1930s in the works of Beloussov and van Bemmelen, which were initially opposed to plate tectonics and placed the mechanism in a fixistic frame of verticalistic movements. Van Bemmelen later on modulated on the concept in his "Undulation Models" and used it as the driving force for horizontal movements, invoking gravitational forces away from the regional crustal doming.


title: Plate tectonics

text: The theories find resonance in the modern theories which envisage hot spots or mantle plumes which remain fixed and are overridden by oceanic and continental lithosphere plates over time and leave their traces in the geological record (though these phenomena are not invoked as real driving mechanisms, but rather as modulators).


title: Plate tectonics

text: The mechanism is still advocated to explain the break-up of supercontinents during specific geological epochs. It has followers amongst the scientists involved in the theory of Earth expansion.


title: Plate tectonics

text: Another theory is that the mantle flows neither in cells nor large plumes but rather as a series of channels just below Earth's crust, which then provide basal friction to the lithosphere. This theory, called "surge tectonics", was popularized during the 1980s and 1990s. Recent research, based on three-dimensional computer modeling, suggests that plate geometry is governed by a feedback between mantle convection patterns and the strength of the lithosphere.


title: Plate tectonics

text: Forces related to gravity are invoked as secondary phenomena within the framework of a more general driving mechanism such as the various forms of mantle dynamics described above. In modern views, gravity is invoked as the major driving force, through slab pull along subduction zones.


title: Plate tectonics

text: Gravitational sliding away from a spreading ridge is one of the proposed driving forces, it proposes plate motion is driven by the higher elevation of plates at ocean ridges. As oceanic lithosphere is formed at spreading ridges from hot mantle material, it gradually cools and thickens with age (and thus adds distance from the ridge). Cool oceanic lithosphere is significantly denser than the hot mantle material from which it is derived and so with increasing thickness it gradually subsides into the mantle to compensate the greater load. The result is a slight lateral incline with increased distance from the ridge axis.


title: Plate tectonics

text: This force is regarded as a secondary force and is often referred to as "ridge push". This is a misnomer as there is no force "pushing" horizontally, indeed tensional features are dominant along ridges. It is more accurate to refer to this mechanism as "gravitational sliding", since the topography across the whole plate can vary considerably and spreading ridges are only the most prominent feature. Other mechanisms generating this gravitational secondary force include flexural bulging of the lithosphere before it dives underneath an adjacent plate, producing a clear topographical feature that can offset, or at least affect, the influence of topographical ocean ridges. Mantle plumes and hot spots are also postulated to impinge on the underside of tectonic plates.


title: Plate tectonics

text: Slab pull: Current scientific opinion is that the asthenosphere is insufficiently competent or rigid to directly cause motion by friction along the base of the lithosphere. Slab pull is therefore most widely thought to be the greatest force acting on the plates. In this current understanding, plate motion is mostly driven by the weight of cold, dense plates sinking into the mantle at trenches. Recent models indicate that trench suction plays an important role as well. However, the fact that the North American Plate is nowhere being subducted, although it is in motion, presents a problem. The same holds for the African, Eurasian, and Antarctic plates.


title: Plate tectonics

text: Gravitational sliding away from mantle doming: According to older theories, one of the driving mechanisms of the plates is the existence of large scale asthenosphere/mantle domes which cause the gravitational sliding of lithosphere plates away from them (see the paragraph on Mantle Mechanisms). This gravitational sliding represents a secondary phenomenon of this basically vertically oriented mechanism. It finds its roots in the Undation Model of van Bemmelen. This can act on various scales, from the small scale of one island arc up to the larger scale of an entire ocean basin.


title: Plate tectonics

text: Alfred Wegener, being a meteorologist, had proposed tidal forces and centrifugal forces as the main driving mechanisms behind continental drift; however, these forces were considered far too small to cause continental motion as the concept was of continents plowing through oceanic crust. Therefore, Wegener later changed his position and asserted that convection currents are the main driving force of plate tectonics in the last edition of his book in 1929.


title: Plate tectonics

text: However, in the plate tectonics context (accepted since the seafloor spreading proposals of Heezen, Hess, Dietz, Morley, Vine, and Matthews (see below) during the early 1960s), the oceanic crust is suggested to be in motion "with" the continents which caused the proposals related to Earth rotation to be reconsidered. In more recent literature, these driving forces are:


title: Plate tectonics

text: For these mechanisms to be overall valid, systematic relationships should exist all over the globe between the orientation and kinematics of deformation and the geographical latitudinal and longitudinal grid of Earth itself. These systematic relations studies in the second half of the nineteenth century and the first half of the twentieth century underline exactly the opposite: that the plates had not moved in time, that the deformation grid was fixed with respect to Earth's equator and axis, and that gravitational driving forces were generally acting vertically and caused only local horizontal movements (the so-called pre-plate tectonic, "fixist theories"). Later studies (discussed below on this page), therefore, invoked many of the relationships recognized during this pre-plate tectonics period to support their theories (see the anticipations and reviews in the work of van Dijk and collaborators).


title: Plate tectonics

text: Of the many forces discussed above, tidal force is still highly debated and defended as a possible principal driving force of plate tectonics. The other forces are only used in global geodynamic models not using plate tectonics concepts (therefore beyond the discussions treated in this section) or proposed as minor modulations within the overall plate tectonics model.


title: Plate tectonics

text: In 1973, George W. Moore of the USGS and R. C. Bostrom presented evidence for a general westward drift of Earth's lithosphere with respect to the mantle. He concluded that tidal forces (the tidal lag or "friction") caused by Earth's rotation and the forces acting upon it by the Moon are a driving force for plate tectonics. As Earth spins eastward beneath the Moon, the Moon's gravity ever so slightly pulls Earth's surface layer back westward, just as proposed by Alfred Wegener (see above). In a more recent 2006 study, scientists reviewed and advocated these earlier proposed ideas. It has also been suggested recently in that this observation may also explain why Venus and Mars have no plate tectonics, as Venus has no moon and Mars' moons are too small to have significant tidal effects on the planet. In a recent paper, it was suggested that, on the other hand, it can easily be observed that many plates are moving north and eastward, and that the dominantly westward motion of the Pacific Ocean basins derives simply from the eastward bias of the Pacific spreading center (which is not a predicted manifestation of such lunar forces). In the same paper the authors admit, however, that relative to the lower mantle, there is a slight westward component in the motions of all the plates. They demonstrated though that the westward drift, seen only for the past 30 Ma, is attributed to the increased dominance of the steadily growing and accelerating Pacific plate. The debate is still open.


title: Plate tectonics

text: The vector of a plate's motion is a function of all the forces acting on the plate; however, therein lies the problem regarding the degree to which each process contributes to the overall motion of each tectonic plate.


title: Plate tectonics

text: The diversity of geodynamic settings and the properties of each plate result from the impact of the various processes actively driving each individual plate. One method of dealing with this problem is to consider the relative rate at which each plate is moving as well as the evidence related to the significance of each process to the overall driving force on the plate.


title: Plate tectonics

text: One of the most significant correlations discovered to date is that lithospheric plates attached to downgoing (subducting) plates move much faster than other types of plates. The Pacific plate, for instance, is essentially surrounded by zones of subduction (the so-called Ring of Fire) and moves much faster than the plates of the Atlantic basin, which are attached (perhaps one could say 'welded') to adjacent continents instead of subducting plates. It is thus thought that forces associated with the downgoing plate (slab pull and slab suction) are the driving forces which determine the motion of plates, except for those plates which are not being subducted. This view however has been contradicted by a recent study which found that the actual motions of the Pacific Plate and other plates associated with the East Pacific Rise do not correlate mainly with either slab pull or slab push, but rather with a mantle convection upwelling whose horizontal spreading along the bases of the various plates drives them along via viscosity-related traction forces. The driving forces of plate motion continue to be active subjects of on-going research within geophysics and tectonophysics.


title: Plate tectonics

text: Italian polymath Leonardo da Vinci was the first to theorize that mountains gradually rise from the oceans, explaining why they have fossils of marine life.


title: Plate tectonics

text: Around the start of the twentieth century, various theorists unsuccessfully attempted to explain the many geographical, geological, and biological continuities between continents. In 1912 the meteorologist Alfred Wegener described what he called continental drift, an idea that culminated fifty years later in the modern theory of plate tectonics.


title: Plate tectonics

text: Wegener expanded his theory in his 1915 book "The Origin of Continents and Oceans". Starting from the idea (also expressed by his forerunners) that the present continents once formed a single land mass (later called Pangaea), Wegener suggested that these separated and drifted apart, likening them to "icebergs" of low density sial floating on a sea of denser sima. Supporting evidence for the idea came from the dove-tailing outlines of South America's east coast and Africa's west coast Antonio Snider-Pellegrini had drawn on his maps, and from the matching of the rock formations along these edges. Confirmation of their previous contiguous nature also came from the fossil plants "Glossopteris" and "Gangamopteris", and the therapsid or mammal-like reptile "Lystrosaurus", all widely distributed over South America, Africa, Antarctica, India, and Australia. The evidence for such an erstwhile joining of these continents was patent to field geologists working in the southern hemisphere. The South African Alex du Toit put together a mass of such information in his 1937 publication "Our Wandering Continents", and went further than Wegener in recognising the strong links between the Gondwana fragments.


title: Plate tectonics

text: Wegener's work was initially not widely accepted, in part due to a lack of detailed evidence. Earth might have a solid crust and mantle and a liquid core, but there seemed to be no way that portions of the crust could move around. Many distinguished scientists of the time, such as Harold Jeffreys and Charles Schuchert, were outspoken critics of continental drift.


title: Plate tectonics

text: Despite much opposition, the view of continental drift gained support and a lively debate started between "drifters" or "mobilists" (proponents of the theory) and "fixists" (opponents). During the 1920s, 1930s and 1940s, the former reached important milestones proposing that convection currents might have driven the plate movements, and that spreading may have occurred below the sea within the oceanic crust. Concepts close to the elements now incorporated in plate tectonics were proposed by geophysicists and geologists (both fixists and mobilists) like Vening-Meinesz, Holmes, and Umbgrove. In 1941 Otto Ampferer described, in his publication "Thoughts on the motion picture of the Atlantic region", processes that anticipate what is now called seafloor spreading and subduction. One of the first pieces of geophysical evidence that was used to support the movement of lithospheric plates came from paleomagnetism. This is based on the fact that rocks of different ages show a variable magnetic field direction, evidenced by studies since the mid–nineteenth century. The magnetic north and south poles reverse through time, and, especially important in paleotectonic studies, the relative position of the magnetic north pole varies through time. Initially, during the first half of the twentieth century, the latter phenomenon was explained by introducing what was called "polar wander" (see apparent polar wander) (i.e., it was assumed that the north pole location had been shifting through time). An alternative explanation, though, was that the continents had moved (shifted and rotated) relative to the north pole, and each continent, in fact, shows its own "polar wander path". During the late 1950s it was successfully shown on two occasions that these data could show the validity of continental drift: by Keith Runcorn in a paper in 1956, and by Warren Carey in a symposium held in March 1956.


title: Plate tectonics

text: The second piece of evidence in support of continental drift came during the late 1950s and early 60s from data on the bathymetry of the deep ocean floors and the nature of the oceanic crust such as magnetic properties and, more generally, with the development of marine geology which gave evidence for the association of seafloor spreading along the mid-oceanic ridges and magnetic field reversals, published between 1959 and 1963 by Heezen, Dietz, Hess, Mason, Vine & Matthews, and Morley.


title: Plate tectonics

text: Simultaneous advances in early seismic imaging techniques in and around Wadati–Benioff zones along the trenches bounding many continental margins, together with many other geophysical (e.g. gravimetric) and geological observations, showed how the oceanic crust could disappear into the mantle, providing the mechanism to balance the extension of the ocean basins with shortening along its margins.


title: Plate tectonics

text: All this evidence, both from the ocean floor and from the continental margins, made it clear around 1965 that continental drift was feasible. The theory of plate tectonics was defined in a series of papers between 1965 and 1967. The theory revolutionized the Earth sciences, explaining a diverse range of geological phenomena and their implications in other studies such as paleogeography and paleobiology.


title: Plate tectonics

text: In the late 19th and early 20th centuries, geologists assumed that Earth's major features were fixed, and that most geologic features such as basin development and mountain ranges could be explained by vertical crustal movement, described in what is called the geosynclinal theory. Generally, this was placed in the context of a contracting planet Earth due to heat loss in the course of a relatively short geological time.


title: Plate tectonics

text: It was observed as early as 1596 that the opposite coasts of the Atlantic Ocean—or, more precisely, the edges of the continental shelves—have similar shapes and seem to have once fitted together.


title: Plate tectonics

text: Since that time many theories were proposed to explain this apparent complementarity, but the assumption of a solid Earth made these various proposals difficult to accept.


title: Plate tectonics

text: The discovery of radioactivity and its associated heating properties in 1895 prompted a re-examination of the apparent age of Earth. This had previously been estimated by its cooling rate under the assumption that Earth's surface radiated like a black body. Those calculations had implied that, even if it started at red heat, Earth would have dropped to its present temperature in a few tens of millions of years. Armed with the knowledge of a new heat source, scientists realized that Earth would be much older, and that its core was still sufficiently hot to be liquid.


title: Plate tectonics

text: By 1915, after having published a first article in 1912, Alfred Wegener was making serious arguments for the idea of continental drift in the first edition of "The Origin of Continents and Oceans". In that book (re-issued in four successive editions up to the final one in 1936), he noted how the east coast of South America and the west coast of Africa looked as if they were once attached. Wegener was not the first to note this (Abraham Ortelius, Antonio Snider-Pellegrini, Eduard Suess, Roberto Mantovani and Frank Bursley Taylor preceded him just to mention a few), but he was the first to marshal significant fossil and paleo-topographical and climatological evidence to support this simple observation (and was supported in this by researchers such as Alex du Toit). Furthermore, when the rock strata of the margins of separate continents are very similar it suggests that these rocks were formed in the same way, implying that they were joined initially. For instance, parts of Scotland and Ireland contain rocks very similar to those found in Newfoundland and New Brunswick. Furthermore, the Caledonian Mountains of Europe and parts of the Appalachian Mountains of North America are very similar in structure and lithology.


title: Plate tectonics

text: However, his ideas were not taken seriously by many geologists, who pointed out that there was no apparent mechanism for continental drift. Specifically, they did not see how continental rock could plow through the much denser rock that makes up oceanic crust. Wegener could not explain the force that drove continental drift, and his vindication did not come until after his death in 1930.


title: Plate tectonics

text: As it was observed early that although granite existed on continents, seafloor seemed to be composed of denser basalt, the prevailing concept during the first half of the twentieth century was that there were two types of crust, named "sial" (continental type crust) and "sima" (oceanic type crust). Furthermore, it was supposed that a static shell of strata was present under the continents. It therefore looked apparent that a layer of basalt (sial) underlies the continental rocks.


title: Plate tectonics

text: However, based on abnormalities in plumb line deflection by the Andes in Peru, Pierre Bouguer had deduced that less-dense mountains must have a downward projection into the denser layer underneath. The concept that mountains had "roots" was confirmed by George B. Airy a hundred years later, during study of Himalayan gravitation, and seismic studies detected corresponding density variations. Therefore, by the mid-1950s, the question remained unresolved as to whether mountain roots were clenched in surrounding basalt or were floating on it like an iceberg.


title: Plate tectonics

text: During the 20th century, improvements in and greater use of seismic instruments such as seismographs enabled scientists to learn that earthquakes tend to be concentrated in specific areas, most notably along the oceanic trenches and spreading ridges. By the late 1920s, seismologists were beginning to identify several prominent earthquake zones parallel to the trenches that typically were inclined 40–60° from the horizontal and extended several hundred kilometers into Earth. These zones later became known as Wadati–Benioff zones, or simply Benioff zones, in honor of the seismologists who first recognized them, Kiyoo Wadati of Japan and Hugo Benioff of the United States. The study of global seismicity greatly advanced in the 1960s with the establishment of the Worldwide Standardized Seismograph Network (WWSSN) to monitor the compliance of the 1963 treaty banning above-ground testing of nuclear weapons. The much improved data from the WWSSN instruments allowed seismologists to map precisely the zones of earthquake concentration worldwide.


title: Plate tectonics

text: Meanwhile, debates developed around the phenomenon of polar wander. Since the early debates of continental drift, scientists had discussed and used evidence that polar drift had occurred because continents seemed to have moved through different climatic zones during the past. Furthermore, paleomagnetic data had shown that the magnetic pole had also shifted during time. Reasoning in an opposite way, the continents might have shifted and rotated, while the pole remained relatively fixed. The first time the evidence of magnetic polar wander was used to support the movements of continents was in a paper by Keith Runcorn in 1956, and successive papers by him and his students Ted Irving (who was actually the first to be convinced of the fact that paleomagnetism supported continental drift) and Ken Creer.


title: Plate tectonics

text: This was immediately followed by a symposium in Tasmania in March 1956. In this symposium, the evidence was used in the theory of an expansion of the global crust. In this hypothesis, the shifting of the continents can be simply explained by a large increase in the size of Earth since its formation. However, this was unsatisfactory because its supporters could offer no convincing mechanism to produce a significant expansion of Earth. Certainly there is no evidence that the moon has expanded in the past 3 billion years; other work would soon show that the evidence was equally in support of continental drift on a globe with a stable radius.


title: Plate tectonics

text: During the thirties up to the late fifties, works by Vening-Meinesz, Holmes, Umbgrove, and numerous others outlined concepts that were close or nearly identical to modern plate tectonics theory. In particular, the English geologist Arthur Holmes proposed in 1920 that plate junctions might lie beneath the sea, and in 1928 that convection currents within the mantle might be the driving force. Often, these contributions are forgotten because:


title: Plate tectonics

text: In 1947, a team of scientists led by Maurice Ewing utilizing the Woods Hole Oceanographic Institution's research vessel "Atlantis" and an array of instruments, confirmed the existence of a rise in the central Atlantic Ocean, and found that the floor of the seabed beneath the layer of sediments consisted of basalt, not the granite which is the main constituent of continents. They also found that the oceanic crust was much thinner than continental crust. All these new findings raised important and intriguing questions.


title: Plate tectonics

text: The new data that had been collected on the ocean basins also showed particular characteristics regarding the bathymetry. One of the major outcomes of these datasets was that all along the globe, a system of mid-oceanic ridges was detected. An important conclusion was that along this system, new ocean floor was being created, which led to the concept of the "Great Global Rift". This was described in the crucial paper of Bruce Heezen (1960) based on his work with Marie Tharp, which would trigger a real revolution in thinking. A profound consequence of seafloor spreading is that new crust was, and still is, being continually created along the oceanic ridges. Therefore, Heezen advocated the so-called "expanding Earth" hypothesis of S. Warren Carey (see above). Therefore, the question remained as to how new crust was continuously added along the oceanic ridges without increasing the size of Earth. In reality, this question had been solved already by numerous scientists during the 1940s and the 1950s, like Arthur Holmes, Vening-Meinesz, Coates and many others: The crust in excess disappeared along what were called the oceanic trenches, where so-called "subduction" occurred. Therefore, when various scientists during the early 1960s started to reason on the data at their disposal regarding the ocean floor, the pieces of the theory quickly fell into place.


title: Plate tectonics

text: The question particularly intrigued Harry Hammond Hess, a Princeton University geologist and a Naval Reserve Rear Admiral, and Robert S. Dietz, a scientist with the U.S. Coast and Geodetic Survey who first coined the term "seafloor spreading". Dietz and Hess (the former published the same idea one year earlier in "Nature", but priority belongs to Hess who had already distributed an unpublished manuscript of his 1962 article by 1960) were among the small number who really understood the broad implications of sea floor spreading and how it would eventually agree with the, at that time, unconventional and unaccepted ideas of continental drift and the elegant and mobilistic models proposed by previous workers like Holmes.


title: Plate tectonics

text: In the same year, Robert R. Coats of the U.S. Geological Survey described the main features of island arc subduction in the Aleutian Islands. His paper, though little noted (and even ridiculed) at the time, has since been called "seminal" and "prescient". In reality, it actually shows that the work by the European scientists on island arcs and mountain belts performed and published during the 1930s up until the 1950s was applied and appreciated also in the United States.


title: Plate tectonics

text: If Earth's crust was expanding along the oceanic ridges, Hess and Dietz reasoned like Holmes and others before them, it must be shrinking elsewhere. Hess followed Heezen, suggesting that new oceanic crust continuously spreads away from the ridges in a conveyor belt–like motion. And, using the mobilistic concepts developed before, he correctly concluded that many millions of years later, the oceanic crust eventually descends along the continental margins where oceanic trenches—very deep, narrow canyons—are formed, e.g. along the rim of the Pacific Ocean basin. The important step Hess made was that convection currents would be the driving force in this process, arriving at the same conclusions as Holmes had decades before with the only difference that the thinning of the ocean crust was performed using Heezen's mechanism of spreading along the ridges. Hess therefore concluded that the Atlantic Ocean was expanding while the Pacific Ocean was shrinking. As old oceanic crust is "consumed" in the trenches (like Holmes and others, he thought this was done by thickening of the continental lithosphere, not, as now understood, by underthrusting at a larger scale of the oceanic crust itself into the mantle), new magma rises and erupts along the spreading ridges to form new crust. In effect, the ocean basins are perpetually being "recycled", with the forming of new crust and the destruction of old oceanic lithosphere occurring simultaneously. Thus, the new mobilistic concepts neatly explained why Earth does not get bigger with sea floor spreading, why there is so little sediment accumulation on the ocean floor, and why oceanic rocks are much younger than continental rocks.


title: Plate tectonics

text: Beginning in the 1950s, scientists like Victor Vacquier, using magnetic instruments (magnetometers) adapted from airborne devices developed during World War II to detect submarines, began recognizing odd magnetic variations across the ocean floor. This finding, though unexpected, was not entirely surprising because it was known that basalt—the iron-rich, volcanic rock making up the ocean floor—contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. This distortion was recognized by Icelandic mariners as early as the late 18th century. More importantly, because the presence of magnetite gives the basalt measurable magnetic properties, these newly discovered magnetic variations provided another means to study the deep ocean floor. When newly formed rock cools, such magnetic materials recorded Earth's magnetic field at the time.


title: Plate tectonics

text: As more and more of the seafloor was mapped during the 1950s, the magnetic variations turned out not to be random or isolated occurrences, but instead revealed recognizable patterns. When these magnetic patterns were mapped over a wide region, the ocean floor showed a zebra-like pattern: one stripe with normal polarity and the adjoining stripe with reversed polarity. The overall pattern, defined by these alternating bands of normally and reversely polarized rock, became known as magnetic striping, and was published by Ron G. Mason and co-workers in 1961, who did not find, though, an explanation for these data in terms of sea floor spreading, like Vine, Matthews and Morley a few years later.


title: Plate tectonics

text: The discovery of magnetic striping called for an explanation. In the early 1960s scientists such as Heezen, Hess and Dietz had begun to theorise that mid-ocean ridges mark structurally weak zones where the ocean floor was being ripped in two lengthwise along the ridge crest (see the previous paragraph). New magma from deep within Earth rises easily through these weak zones and eventually erupts along the crest of the ridges to create new oceanic crust. This process, at first denominated the "conveyer belt hypothesis" and later called seafloor spreading, operating over many millions of years continues to form new ocean floor all across the 50,000 km-long system of mid-ocean ridges.


title: Plate tectonics

text: Only four years after the maps with the "zebra pattern" of magnetic stripes were published, the link between sea floor spreading and these patterns was correctly placed, independently by Lawrence Morley, and by Fred Vine and Drummond Matthews, in 1963, now called the Vine–Matthews–Morley hypothesis. This hypothesis linked these patterns to geomagnetic reversals and was supported by several lines of evidence:


title: Plate tectonics

text: By explaining both the zebra-like magnetic striping and the construction of the mid-ocean ridge system, the seafloor spreading hypothesis (SFS) quickly gained converts and represented another major advance in the development of the plate-tectonics theory. Furthermore, the oceanic crust now came to be appreciated as a natural "tape recording" of the history of the geomagnetic field reversals (GMFR) of Earth's magnetic field. Today, extensive studies are dedicated to the calibration of the normal-reversal patterns in the oceanic crust on one hand and known timescales derived from the dating of basalt layers in sedimentary sequences (magnetostratigraphy) on the other, to arrive at estimates of past spreading rates and plate reconstructions.


title: Plate tectonics

text: After all these considerations, Plate Tectonics (or, as it was initially called "New Global Tectonics") became quickly accepted in the scientific world, and numerous papers followed that defined the concepts:


title: Plate tectonics

text: The Plate Tectonics Revolution was the scientific and cultural change which developed from the acceptance of the plate tectonics theory. The event was a paradigm shift and scientific revolution.


title: Plate tectonics

text: Continental drift theory helps biogeographers to explain the disjunct biogeographic distribution of present-day life found on different continents but having similar ancestors. In particular, it explains the Gondwanan distribution of ratites and the Antarctic flora.


title: Plate tectonics

text: Reconstruction is used to establish past (and future) plate configurations, helping determine the shape and make-up of ancient supercontinents and providing a basis for paleogeography.


title: Plate tectonics

text: Current plate boundaries are defined by their seismicity. Past plate boundaries within existing plates are identified from a variety of evidence, such as the presence of ophiolites that are indicative of vanished oceans.


title: Plate tectonics

text: Various types of quantitative and semi-quantitative information are available to constrain past plate motions. The geometric fit between continents, such as between west Africa and South America is still an important part of plate reconstruction. Magnetic stripe patterns provide a reliable guide to relative plate motions going back into the Jurassic period. The tracks of hotspots give absolute reconstructions, but these are only available back to the Cretaceous. Older reconstructions rely mainly on paleomagnetic pole data, although these only constrain the latitude and rotation, but not the longitude. Combining poles of different ages in a particular plate to produce apparent polar wander paths provides a method for comparing the motions of different plates through time. Additional evidence comes from the distribution of certain sedimentary rock types, faunal provinces shown by particular fossil groups, and the position of orogenic belts.


title: Plate tectonics

text: The movement of plates has caused the formation and break-up of continents over time, including occasional formation of a supercontinent that contains most or all of the continents. The supercontinent Columbia or Nuna formed during a period of and broke up about . The supercontinent Rodinia is thought to have formed about 1 billion years ago and to have embodied most or all of Earth's continents, and broken up into eight continents around . The eight continents later re-assembled into another supercontinent called Pangaea; Pangaea broke up into Laurasia (which became North America and Eurasia) and Gondwana (which became the remaining continents).


title: Plate tectonics

text: The Himalayas, the world's tallest mountain range, are assumed to have been formed by the collision of two major plates. Before uplift, they were covered by the Tethys Ocean.


title: Plate tectonics

text: Depending on how they are defined, there are usually seven or eight "major" plates: African, Antarctic, Eurasian, North American, South American, Pacific, and Indo-Australian. The latter is sometimes subdivided into the Indian and Australian plates.


title: Plate tectonics

text: There are dozens of smaller plates, the seven largest of which are the Arabian, Caribbean, Juan de Fuca, Cocos, Nazca, Philippine Sea, and Scotia.


title: Plate tectonics

text: The current motion of the tectonic plates is today determined by remote sensing satellite data sets, calibrated with ground station measurements.


title: Plate tectonics

text: The appearance of plate tectonics on terrestrial planets is related to planetary mass, with more massive planets than Earth expected to exhibit plate tectonics. Earth may be a borderline case, owing its tectonic activity to abundant water (silica and water form a deep eutectic).


title: Plate tectonics

text: Venus shows no evidence of active plate tectonics. There is debatable evidence of active tectonics in the planet's distant past; however, events taking place since then (such as the plausible and generally accepted hypothesis that the Venusian lithosphere has thickened greatly over the course of several hundred million years) has made constraining the course of its geologic record difficult. However, the numerous well-preserved impact craters have been used as a dating method to approximately date the Venusian surface (since there are thus far no known samples of Venusian rock to be dated by more reliable methods). Dates derived are dominantly in the range , although ages of up to have been calculated. This research has led to the fairly well accepted hypothesis that Venus has undergone an essentially complete volcanic resurfacing at least once in its distant past, with the last event taking place approximately within the range of estimated surface ages. While the mechanism of such an impressive thermal event remains a debated issue in Venusian geosciences, some scientists are advocates of processes involving plate motion to some extent.


title: Plate tectonics

text: One explanation for Venus's lack of plate tectonics is that on Venus temperatures are too high for significant water to be present. Earth's crust is soaked with water, and water plays an important role in the development of shear zones. Plate tectonics requires weak surfaces in the crust along which crustal slices can move, and it may well be that such weakening never took place on Venus because of the absence of water. However, some researchers remain convinced that plate tectonics is or was once active on this planet.


title: Plate tectonics

text: Mars is considerably smaller than Earth and Venus, and there is evidence for ice on its surface and in its crust.


title: Plate tectonics

text: In the 1990s, it was proposed that Martian Crustal Dichotomy was created by plate tectonic processes. Scientists today disagree, and think that it was created either by upwelling within the Martian mantle that thickened the crust of the Southern Highlands and formed Tharsis or by a giant impact that excavated the Northern Lowlands.


title: Plate tectonics

text: Observations made of the magnetic field of Mars by the "Mars Global Surveyor" spacecraft in 1999 showed patterns of magnetic striping discovered on this planet. Some scientists interpreted these as requiring plate tectonic processes, such as seafloor spreading. However, their data fail a "magnetic reversal test", which is used to see if they were formed by flipping polarities of a global magnetic field.


title: Plate tectonics

text: Some of the satellites of Jupiter have features that may be related to plate-tectonic style deformation, although the materials and specific mechanisms may be different from plate-tectonic activity on Earth. On 8 September 2014, NASA reported finding evidence of plate tectonics on Europa, a satellite of Jupiter—the first sign of subduction activity on another world other than Earth.


title: Plate tectonics

text: Titan, the largest moon of Saturn, was reported to show tectonic activity in images taken by the "Huygens" probe, which landed on Titan on January 14, 2005.


title: Plate tectonics

text: On Earth-sized planets, plate tectonics is more likely if there are oceans of water. However, in 2007, two independent teams of researchers came to opposing conclusions about the likelihood of plate tectonics on larger super-Earths with one team saying that plate tectonics would be episodic or stagnant and the other team saying that plate tectonics is very likely on super-earths even if the planet is dry.


title: Plate tectonics

text: Consideration of plate tectonics is a part of the search for extraterrestrial intelligence and extraterrestrial life.


title: Margot Robbie filmography

text: Margot Robbie is an Australian actress and producer who made her film debut in the 2008 film "Vigilante". Robbie then landed a role on the long-running Australian soap opera "Neighbours" (2008–2011, 2022). From 2011 until its cancellation in 2012, she portrayed a stewardess on the television series "Pan Am". Her breakout role was in the Martin Scorsese-directed "The Wolf of Wall Street" (2013) opposite Leonardo DiCaprio. In 2015, she acted alongside Will Smith in the comedy-drama "Focus". In the following year, Robbie played Harley Quinn in the DC Extended Universe film "Suicide Squad", later reprising the role in "Birds of Prey" (2020) and "The Suicide Squad" (2021). Also in 2016, she played Jane Porter in "The Legend of Tarzan". That year she also hosted an episode of "Saturday Night Live".


title: Margot Robbie filmography

text: For her starring role as Tonya Harding in the biopic "I, Tonya" (2017), she was nominated for the Academy Award for Best Actress. The following year, she portrayed Queen Elizabeth I in "Mary Queen of Scots", which garnered her a nomination for a Screen Actors Guild Award. That same year, Robbie voiced Flopsy Rabbit in "Peter Rabbit". She received a second Academy Award nomination, this time for Best Supporting Actress, for her performance as a Fox News employee in "Bombshell" (2019). Her portrayal of Sharon Tate in the Quentin Tarantino-directed "Once Upon a Time in Hollywood" (2019) garnered her a nomination for the BAFTA Award for Best Actress in a Supporting Role. Robbie later reprised the role of Quinn in "Birds of Prey" in 2020 and in "The Suicide Squad", the following year.


title: Margot Robbie filmography

text: Robbie has also produced several projects, including the Hulu television series "Dollface" (2019–2022), the film "Promising Young Woman" (2020), and the Netflix miniseries "Maid" (2021).


title: The Garden of Earthly Delights

text: The Garden of Earthly Delights is the modern title given to a triptych oil painting on oak panel painted by the Early Netherlandish master Hieronymus Bosch, between 1490 and 1510, when Bosch was between 40 and 60 years old. It has been housed in the Museo del Prado in Madrid, Spain since 1939.


title: The Garden of Earthly Delights

text: As little is known of Bosch's life or intentions, interpretations of his artistic intent behind the work range from an admonition of worldly fleshy indulgence, to a dire warning on the perils of life's temptations, to an evocation of ultimate sexual joy. The intricacy of its symbolism, particularly that of the central panel, has led to a wide range of scholarly interpretations over the centuries. Twentieth-century art historians are divided as to whether the triptych's central panel is a moral warning or a panorama of paradise lost.


title: The Garden of Earthly Delights

text: Bosch painted three large triptychs (the others are "The Last Judgment" of 1482 and "The Haywain Triptych" of 1516) that can be read from left to right and in which each panel was essential to the meaning of the whole. Each of these three works presents distinct, yet linked themes addressing history and faith. Triptychs from this period were generally intended to be read sequentially, the left and right panels often portraying Eden and the Last Judgment respectively, while the main subject was contained in the center piece. It is not known whether "The Garden" was intended as an altarpiece, but the general view is that the extreme subject matter of the inner center and right panels make it unlikely that it was intended to function in a church or monastery, but was instead commissioned by a lay patron.


title: The Garden of Earthly Delights

text: When the triptych's wings are closed, the design of the outer panels becomes visible. Rendered in a green–gray grisaille, these panels lack colour, probably because most Netherlandish triptychs were thus painted, but possibly indicating that the painting reflects a time before the creation of the sun and moon, which were formed, according to Christian theology, to "give light to the earth". The typical grisaille blandness of Netherlandish altarpieces served to highlight the splendid colour inside.


title: The Garden of Earthly Delights

text: The outer panels are generally thought to depict the creation of the world, showing greenery beginning to clothe the still-pristine Earth. God, wearing a crown similar to a papal tiara (a common convention in Netherlandish painting), is visible as a tiny figure at the upper left. Bosch shows God as the father sitting with a Bible on his lap, creating the Earth in a passive manner by divine fiat. Above him is inscribed a quote from Psalm 33 reading "Ipse dīxit, et facta sunt: ipse mandāvit, et creāta sunt"—"For he spoke and it was done; he commanded, and it stood fast". The Earth is encapsulated in a transparent sphere recalling the traditional depiction of the created world as a crystal sphere held by God or Christ. It hangs suspended in the cosmos, which is shown as an impermeable darkness, whose only other inhabitant is God himself.


title: The Garden of Earthly Delights

text: Despite the presence of vegetation, the earth does not yet contain human or animal life, indicating that the scene represents the events of the biblical Third Day. Bosch renders the plant life in an unusual fashion, using uniformly gray tints which make it difficult to determine whether the subjects are purely vegetable or perhaps include some mineral formations. Surrounding the interior of the globe is the sea, partially illuminated by beams of light shining through clouds. The exterior wings have a clear position within the sequential narrative of the work as a whole. They show an unpopulated earth composed solely of rock and plants, contrasting sharply with the inner central panel which contains a paradise teeming with lustful humanity.


title: The Garden of Earthly Delights

text: Scholars have proposed that Bosch used the outer panels to establish a Biblical setting for the inner elements of the work, and the exterior image is generally interpreted as set in an earlier time than those in the interior. As with Bosch's "Haywain Triptych", the inner centerpiece is flanked by heavenly and hellish imagery. The scenes depicted in the triptych are thought to follow a chronological order: flowing from left-to-right they represent Eden, the garden of earthly delights, and Hell. God appears as the creator of humanity in the left hand wing, while the consequences of humanity's failure to follow his will are shown in the right.


title: The Garden of Earthly Delights

text: However, in contrast to Bosch's two other complete triptychs, "The Last Judgment" (around 1482) and "The Haywain" (after 1510), God is absent from the central panel. Instead, this panel shows humanity acting with apparent free will as naked men and women engage in various pleasure-seeking activities. According to some interpretations, the right hand panel is believed to show God's penalties in a hellscape.


title: The Garden of Earthly Delights

text: Art historian Charles de Tolnay believed that, through the seductive gaze of Adam, the left panel already shows God's waning influence upon the newly created earth. This view is reinforced by the rendering of God in the outer panels as a tiny figure in comparison to the immensity of the earth. According to Hans Belting, the three inner panels seek to broadly convey the Old Testament notion that, before the Fall, there was no defined boundary between good and evil; humanity in its innocence was unaware of consequence.


title: The Garden of Earthly Delights

text: The left panel (sometimes known as the "Joining of Adam and Eve") depicts a scene from the paradise of the Garden of Eden commonly interpreted as the moment when God presents Eve to Adam. The painting shows Adam waking from a deep sleep to find God holding Eve by her wrist and giving the sign of his blessing to their union. God is younger-looking than on the outer panels, blue-eyed and with golden curls. His youthful appearance may be a device by the artist to illustrate the concept of Christ as the incarnation of the Word of God. God's right hand is raised in blessing, while he holds Eve's wrist with his left. According to the work's most controversial interpreter, the 20th-century folklorist and art historian Wilhelm Fraenger:


title: The Garden of Earthly Delights

text: As though enjoying the pulsation of the living blood and as though too he were setting a seal on the eternal and immutable communion between this human blood and his own. This physical contact between the Creator and Eve is repeated even more noticeably in the way Adam's toes touch the Lord's foot. Here is the stressing of a rapport: Adam seems indeed to be stretching to his full length in order to make contact with the Creator. And the billowing out of the cloak around the Creator's heart, from where the garment falls in marked folds and contours to Adam's feet, also seems to indicate that here a current of divine power flows down, so that this group of three actually forms a closed circuit, a complex of magical energy ...


title: The Garden of Earthly Delights

text: Eve avoids Adam's gaze, although, according to Walter S. Gibson, she is shown "seductively presenting her body to Adam". Adam's expression is one of amazement, and Fraenger has identified three elements to his seeming astonishment. Firstly, there is surprise at the presence of the God. Secondly, he is reacting to an awareness that Eve is of the same nature as himself, and has been created from his own body. Finally, from the intensity of Adam's gaze, it can be concluded that he is experiencing sexual arousal and the primal urge to reproduce for the first time.


title: The Garden of Earthly Delights

text: The surrounding landscape is populated by hut-shaped forms, some of which are made from stone, while others are at least partially organic. Behind Eve rabbits, symbolising fecundity, play in the grass, and a dragon tree opposite is thought to represent eternal life. The background reveals several animals that would have been exotic to contemporaneous Europeans, including a giraffe, a monkey riding an elephant, and a lion that has killed and is about to devour his prey. In the foreground, from a large hole in the ground, emerge birds and winged animals, some of which are realistic, some fantastic. Behind a fish, a person clothed in a short-sleeved hooded jacket and with a duck's beak holds an open book as if reading.


title: The Garden of Earthly Delights

text: To the left of the area a cat holds a small lizard-like creature in its jaws. Belting observes that, despite the fact that the creatures in the foreground are fantastical imaginings, many of the animals in the mid and background are drawn from contemporary travel literature, and here Bosch is appealing to "the knowledge of a humanistic and aristocratic readership". Erhard Reuwich's pictures for Bernhard von Breydenbach's 1486 "Pilgrimages to the Holy Land" were long thought to be the source for both the elephant and the giraffe, though more recent research indicates the mid-15th-century humanist scholar Cyriac of Ancona's travelogues served as Bosch's exposure to these exotic animals.


title: The Garden of Earthly Delights

text: According to art historian Virginia Tuttle, the scene is "highly unconventional [and] cannot be identified as any of the events from the Book of Genesis traditionally depicted in Western art". Some of the images contradict the innocence expected in the Garden of Eden. Tuttle and other critics have interpreted the gaze of Adam upon his wife as lustful, and indicative of the Christian belief that humanity was doomed from the beginning. Gibson believes that Adam's facial expression betrays not just surprise but also expectation. According to a belief common in the Middle Ages, before the Fall Adam and Eve would have copulated without lust, solely to reproduce. Many believed that the first sin committed after Eve tasted the forbidden fruit was carnal lust. On a tree to the right a snake curls around a tree trunk, while to its right a mouse creeps; according to Fraenger, both animals are universal phallic symbols.


title: The Garden of Earthly Delights

text: The skyline of the center panel (220 × 195 cm, 87 × 77 in) matches exactly with that of the left wing, while the positioning of its central pool and the lake behind it echoes the lake in the earlier scene. The center image depicts the expansive "garden" landscape which gives the triptych its name. The panel shares a common horizon with the left wing, suggesting a spatial connection between the two scenes. The garden is teeming with male and female nudes, together with a variety of animals, plants and fruit.


title: The Garden of Earthly Delights

text: The setting is not the paradise shown in the left panel, but neither is it based in the terrestrial realm. Fantastic creatures mingle with the real; otherwise ordinary fruits appear engorged to a gigantic size. The figures are engaged in diverse amorous sports and activities, both in couples and in groups. Gibson describes them as behaving "overtly and without shame", while art historian Laurinda Dixon writes that the human figures exhibit "a certain adolescent sexual curiosity".


title: The Garden of Earthly Delights

text: Many of the numerous human figures revel in an innocent, self-absorbed joy as they engage in a wide range of activities; some appear to enjoy sensory pleasures, others play unselfconsciously in the water, and yet others cavort in meadows with a variety of animals, seemingly at one with nature. In the middle of the background, a large blue globe resembling a fruit pod rises in the middle of a lake. Visible through its circular window is a man holding his right hand close to his partner's genitals, and the bare buttocks of yet another figure hover in the vicinity. According to Fraenger, the eroticism of the center frame could be considered either as an allegory of spiritual transition or a playground of corruption.


title: The Garden of Earthly Delights

text: On the right-hand side of the foreground stand a group of four figures, three white- and one black-skinned. The white-skinned figures, two males and one female, are covered from head to foot in light-brown body hair. Scholars generally agree that these hirsute figures represent wild or primeval humanity, but disagree on the symbolism of their inclusion. Art historian Patrik Reuterswärd, for example, posits that they may be seen as "the noble savage" who represents "an imagined alternative to our civilized life", imbuing the panel with "a more clear-cut primitivistic note". Writer Peter Glum, in contrast, sees the figures as intrinsically connected with whoredom and lust.


title: The Garden of Earthly Delights

text: In a cave to their lower right, a male figure points towards a reclining female who is also covered in hair. The pointing man is the only clothed figure in the panel, and as Fraenger observes, "he is clothed with emphatic austerity right up to his throat". In addition, he is one of the few human figures with dark hair. According to Fraenger:


title: The Garden of Earthly Delights

text: The way this man's dark hair grows, with the sharp dip in the middle of his high forehead, as though concentrating there all the energy of the masculine M, makes his face different from all the others. His coal-black eyes are rigidly focused in a gaze that expresses compelling force. The nose is unusually long and boldly curved. The mouth is wide and sensual, but the lips are firmly shut in a straight line, the corners strongly marked and tightened into final points, and this strengthens the impression—already suggested by the eyes—of a strong controlling will. It is an extraordinarily fascinating face, reminding us of faces of famous men, especially of Machiavelli's; and indeed the whole aspect of the head suggests something Mediterranean, as though this man had acquired his frank, searching, superior air at Italian academies.


title: The Garden of Earthly Delights

text: The pointing man has variously been described as either the patron of the work (Fraenger in 1947), as an advocate of Adam denouncing Eve (Dirk Bax in 1956), as Saint John the Baptist in his camel's skin (Isabel Mateo Goméz in 1963), or as a self-portrait. The woman below him lies within a semicylindrical transparent shield, while her mouth is sealed, devices implying that she bears a secret. To their left, a man crowned by leaves lies on top of what appears to be an actual but gigantic strawberry, and is joined by a male and female who contemplate another equally huge strawberry.


title: The Garden of Earthly Delights

text: There is no perspectival order in the foreground; instead it comprises a series of small motifs wherein proportion and terrestrial logic are abandoned. Bosch presents the viewer with gigantic ducks playing with tiny humans under the cover of oversized fruit; fish walking on land while birds dwell in the water; a passionate couple encased in an amniotic fluid bubble; and a man inside of a red fruit staring at a mouse in a transparent cylinder.


title: The Garden of Earthly Delights

text: The pools in the fore and background contain bathers of both sexes. In the central circular pool, the sexes are mostly segregated, with several females adorned by peacocks and fruit. Four women carry cherry-like fruits on their heads, perhaps a symbol of pride at the time, as has been deduced from the contemporaneous saying: "Don't eat cherries with great lords—they'll throw the pits in your face."


title: The Garden of Earthly Delights

text: The women are surrounded by a parade of naked men riding horses, donkeys, unicorns, camels and other exotic or fantastic creatures. Several men show acrobatics while riding, apparently acts designed to gain the females' attention, which highlights the attraction felt between the two sexes as groups. The two outer springs also contain both men and women cavorting with abandon. Around them, birds infest the water while winged fish crawl on land. Humans inhabit giant shells. All are surrounded by oversized fruit pods and eggshells, and both humans and animals feast on strawberries and cherries.


title: The Garden of Earthly Delights

text: The impression of a life lived without consequence, or what art historian Hans Belting describes as "unspoilt and pre-moral existence", is underscored by the absence of children and old people. According to the second and third chapters of Genesis, Adam and Eve's children were born after they were expelled from Eden. This has led some commentators, in particular Belting, to theorise that the panel represents the world if the two had not been driven out "among the thorns and thistles of the world". In Fraenger's view, the scene illustrates "a utopia, a garden of divine delight before the Fall, or—since Bosch could not deny the existence of the dogma of original sin—a millennial condition that would arise if, after expiation of Original Sin, humanity were permitted to return to Paradise and to a state of tranquil harmony embracing all Creation."


title: The Garden of Earthly Delights

text: In the high distance of the background, above the hybrid stone formations, four groups of people and creatures are seen in flight. On the immediate left a human male rides on a chthonic solar eagle-lion. The human carries a triple-branched tree of life on which perches a bird; according to Fraenger "a symbolic bird of death". Fraenger believes the man is intended to represent a genius, "he is the symbol of the extinction of the duality of the sexes, which are resolved in the ether into their original state of unity".


title: The Garden of Earthly Delights

text: To their right a knight with a dolphin tail sails on a winged fish. The knight's tail curls back to touch the back of his head, which references the common symbol of eternity: the snake biting its own tail. On the immediate right of the panel, a winged youth soars upwards carrying a fish in his hands and a falcon on his back. According to Belting, in these passages Bosch's "imagination triumphs ... the ambivalence of [his] visual syntax exceeds even the enigma of content, opening up that new dimension of freedom by which painting becomes art." Fraenger titled his chapter on the high background "The Ascent to Heaven", and wrote that the airborne figures were likely intended as a link between "what is above" and "what is below", just as the left and right hand panels represent "what was" and "what will be".


title: The Garden of Earthly Delights

text: The right panel (220 × 97.5 cm, 87 × 38.4 in) illustrates Hell, the setting of a number of Bosch paintings. Bosch depicts a world in which humans have succumbed to temptations that lead to evil and reap eternal damnation. The tone of this final panel strikes a harsh contrast to those preceding it. The scene is set at night, and the natural beauty that adorned the earlier panels is noticeably absent. Compared to the warmth of the center panel, the right wing possesses a chilling quality—rendered through cold colourisation and frozen waterways—and presents a tableau that has shifted from the paradise of the center image to a spectacle of cruel torture and retribution.


title: The Garden of Earthly Delights

text: In a single, densely detailed scene, the viewer is made witness to cities on fire in the background; war, torture chambers, infernal taverns, and demons in the midground; and mutated animals feeding on human flesh in the foreground. The nakedness of the human figures has lost all its eroticism, and many now attempt to cover their genitalia and breasts with their hands, ashamed by their nakedness.


title: The Garden of Earthly Delights

text: Large explosions in the background throw light through the city gates and spill into the water in the midground; according to writer Walter S. Gibson, "their fiery reflection turning the water below into blood". The light illuminates a road filled with fleeing figures, while hordes of tormentors prepare to burn a neighbouring village. A short distance away, a rabbit carries an impaled and bleeding corpse, while a group of victims above are thrown into a burning lantern. The foreground is populated by a variety of distressed or tortured figures. Some are shown vomiting or excreting, others are crucified by harp and lute, in an allegory of music, thus sharpening the contrast between pleasure and torture. A choir sings from a score inscribed on a pair of buttocks, part of a group that has been described as the "Musicians' Hell".


title: The Garden of Earthly Delights

text: The focal point of the scene is the "Tree-Man", whose cavernous torso is supported by what could be contorted arms or rotting tree trunks. His head supports a disk populated by demons and victims parading around a huge set of bagpipes—often used as a dual sexual symbol—reminiscent of human scrotum and penis. The tree-man's torso is formed from a broken eggshell, and the supporting trunk has thorn-like branches which pierce the fragile body. A grey figure in a hood bearing an arrow jammed between his buttocks climbs a ladder into the tree-man's central cavity, where nude men sit in a tavern-like setting. The tree-man gazes outwards beyond the viewer, his conspiratorial expression a mix of wistfulness and resignation. Belting wondered if the tree-man's face is a self-portrait, citing the figure's "expression of irony and the slightly sideways gaze [which would] then constitute the signature of an artist who claimed a bizarre pictorial world for his own personal imagination".


title: The Garden of Earthly Delights

text: Many elements in the panel incorporate earlier iconographical conventions depicting hell. However, Bosch is innovative in that he describes hell not as a fantastical place, but as a realistic world containing many elements from day-to-day human life.


title: The Garden of Earthly Delights

text: Animals are shown punishing humans, subjecting them to nightmarish torments that may symbolise the seven deadly sins, matching the torment to the sin. Sitting on an object that may be a toilet or a throne, the panel's centerpiece is a gigantic bird-headed monster feasting on human corpses, which he excretes through a cavity below him, into the transparent chamber pot on which he sits. The monster is sometimes referred to as the "Prince of Hell", a name derived from the cauldron he wears on his head, perhaps representing a debased crown. At his feet, a female has her face reflected on the buttocks of a demon. Further to the left, next to a hare-headed demon, a group of naked persons around a toppled gambling table are being massacred with swords and knives. Other brutal violence is shown by a knight torn down and eaten up by a pack of wolves to the right of the tree-man.


title: The Garden of Earthly Delights

text: During the Middle Ages, sexuality and lust were seen, by some, as evidence of humanity's fall from grace. In the eyes of some viewers, this sin is depicted in the left-hand panel through Adam's, allegedly lustful, gaze towards Eve, and it has been proposed that the center panel was created as a warning to the viewer to avoid a life of sinful pleasure. According to this view, the penalty for such sins is shown in the right panel of the triptych. In the lower right-hand corner, a man is approached by a pig wearing the veil of a nun. The pig is shown trying to seduce the man to sign legal documents.


title: The Garden of Earthly Delights

text: Lust is further said to be symbolised by the gigantic musical instruments and by the choral singers in the left foreground of the panel. Musical instruments often carried erotic connotations in works of art of the period, and lust was referred to in moralising sources as the "music of the flesh". There has also been the view that Bosch's use of music here might be a rebuke against traveling minstrels, often thought of as purveyors of bawdy song and verse.


title: The Garden of Earthly Delights

text: The dating of "The Garden of Earthly Delights" is uncertain. Ludwig von Baldass (1917) considered the painting to be an early work by Bosch. However, since De Tolnay (1937) consensus among 20th-century art historians placed the work in 1503–1504 or even later. Both early and late datings were based on the "archaic" treatment of space. Dendrochronology dates the oak of the panels between the years 1460 and 1466, providing an earliest date ("terminus post quem") for the work.


title: The Garden of Earthly Delights

text: Wood used for panel paintings during this period customarily underwent a lengthy period of storage for seasoning purposes, so the age of the oak might be expected to predate the actual date of the painting by several years. Internal evidence, specifically the depiction of a pineapple (a "New World" fruit), suggests that the painting itself postdates Columbus' voyages to the Americas, between 1492 and 1504. The dendrochronological research brought Vermet to reconsider an early dating and, consequently, to dispute the presence of any "New World" objects, stressing the presence of African ones instead.


title: The Garden of Earthly Delights

text: "The Garden" was first documented in 1517, one year after the artist's death, when Antonio de Beatis, a canon from Molfetta, Italy, described the work as part of the decoration in the town palace of the Counts of the House of Nassau in Brussels. The palace was a high-profile location, a house often visited by heads of state and leading court figures. The prominence of the painting has led some to conclude that the work was commissioned, and not "solely ... a flight of the imagination". A description of the triptych in 1605 called it the "strawberry painting", because the fruit of the strawberry tree ("madroño" in Spanish) features prominently in the center panel. Early Spanish writers referred to the work as "La Lujuria" ("Lust").


title: The Garden of Earthly Delights

text: The aristocracy of the Burgundian Netherlands, influenced by the humanist movement, were the most likely collectors of Bosch's paintings, but there are few records of the location of his works in the years immediately following his death. It is probable that the patron of the work was Engelbrecht II of Nassau, who died in 1504, or his successor Henry III of Nassau-Breda, the governor of several of the Habsburg provinces in the Low Countries. De Beatis wrote in his travel journal that "there are some panels on which bizarre things have been painted. They represent seas, skies, woods, meadows, and many other things, such as people crawling out of a shell, others that bring forth birds, men and women, white and blacks doing all sorts of different activities and poses."


title: The Garden of Earthly Delights

text: Because the triptych was publicly displayed in the palace of the House of Nassau, it was visible to many, and Bosch's reputation and fame quickly spread across Europe. The work's popularity can be measured by the numerous surviving copies—in oil, engraving and tapestry—commissioned by wealthy patrons, as well as by the number of forgeries in circulation after his death. Most are of the central panel only and do not deviate from the original. These copies were usually painted on a much smaller scale, and they vary considerably in quality. Many were created a generation after Bosch, and some took the form of wall tapestries.


title: The Garden of Earthly Delights

text: The De Beatis description, only rediscovered by Steppe in the 1960s, cast new light on the commissioning of a work that was previously thought—since it has no central religious image—to be an atypical altarpiece. Many Netherlandish diptychs intended for private use are known, and even a few triptychs, but the Bosch panels are unusually large compared with these and contain no donor portraits. Possibly they were commissioned to celebrate a wedding, as large Italian paintings for private houses frequently were. Nevertheless, "The Garden"s bold depictions do not rule out a church commission, such was the contemporaneous fervor to warn against immorality. In 1566, the triptych served as the model for a tapestry that hangs at El Escorial monastery near Madrid.


title: The Garden of Earthly Delights

text: Upon the death of Henry III, the painting passed into the hands of his nephew William the Silent, the founder of the House of Orange-Nassau and leader of the Dutch Revolt against Spain. In 1568, however, the Duke of Alba confiscated the picture and brought it to Spain, where it became the property of one Don Fernando, the Duke's illegitimate son and heir and the Spanish commander in the Netherlands. Philip II acquired the painting at auction in 1591; two years later he presented it to El Escorial. A contemporaneous description of the transfer records the gift on 8 July 1593 of a "painting in oils, with two wings depicting the variety of the world, illustrated with grotesqueries by Hieronymus Bosch, known as 'Del Madroño'".


title: The Garden of Earthly Delights

text: After an unbroken 342 years at El Escorial, the work moved to the Museo del Prado in 1939, along with other works by Bosch. The triptych was not particularly well-preserved; the paint of the middle panel especially had flaked off around joints in the wood. However, recent restoration works have managed to recover and maintain it in a very good state of quality and preservation. The painting is normally on display in a room with other works by Bosch.


title: The Garden of Earthly Delights

text: Little is known for certain of the life of Hieronymus Bosch or of the commissions or influences that may have formed the basis for the iconography of his work. His birthdate, education and patrons remain unknown. There is no surviving record of Bosch's thoughts or evidence as to what attracted and inspired him to such an individual mode of expression. Through the centuries art historians have struggled to resolve this question yet conclusions remain fragmentary at best. Scholars have debated Bosch's iconography more extensively than that of any other Netherlandish artist. His works are generally regarded as enigmatic, leading some to speculate that their content refers to contemporaneous esoteric knowledge since lost to history.


title: The Garden of Earthly Delights

text: Although Bosch's career flourished during the High Renaissance, he lived in an area where the beliefs of the medieval Church still held moral authority. He would have been familiar with some of the new forms of expression, especially those in Southern Europe, although it is difficult to attribute with certainty which artists, writers and conventions had a bearing on his work.


title: The Garden of Earthly Delights

text: José de Sigüenza is credited with the first extensive critique of "The Garden of Earthly Delights", in his 1605 "History of the Order of St. Jerome". He argued against dismissing the painting as either heretical or merely absurd, commenting that the panels "are a satirical comment on the shame and sinfulness of mankind". The art historian Carl Justi observed that the left and center panels are drenched in tropical and oceanic atmosphere, and concluded that Bosch was inspired by "the news of recently discovered Atlantis and by drawings of its tropical scenery, just as Columbus himself, when approaching terra firma, thought that the place he had found at the mouth of the Orinoco was the site of the Earthly Paradise".


title: The Garden of Earthly Delights

text: The period in which the triptych was created was a time of adventure and discovery, when tales and trophies from the New World sparked the imagination of poets, painters and writers. Although the triptych contains many unearthly and fantastic creatures, Bosch still appealed in his images and cultural references to an elite humanist and aristocratic audience. Bosch reproduces a scene from Martin Schongauer's engraving "Flight into Egypt".


title: The Garden of Earthly Delights

text: Conquest in Africa and the East provided both wonder and terror to European intellectuals, as it led to the conclusion that Eden could never have been an actual geographical location. "The Garden" references exotic travel literature of the 15th century through the animals, including lions and a giraffe, in the left panel. The giraffe has been traced to Cyriac of Ancona, a travel writer known for his visits to Egypt during the 1440s. The exoticism of Cyriac's sumptuous manuscripts may have inspired Bosch's imagination.


title: The Garden of Earthly Delights

text: The charting and conquest of this new world made real regions previously only idealised in the imagination of artists and poets. At the same time, the certainty of the old biblical paradise began to slip from the grasp of thinkers into the realms of mythology. In response, treatment of the Paradise in literature, poetry and art shifted towards a self-consciously fictional Utopian representation, as exemplified by the writings of Thomas More (1478–1535).


title: The Garden of Earthly Delights

text: Albrecht Dürer was an avid student of exotic animals, and drew many sketches based on his visits to European zoos. Dürer visited 's-Hertogenbosch during Bosch's lifetime, and it is likely the two artists met, and that Bosch drew inspiration from the German's work.


title: The Garden of Earthly Delights

text: Attempts to find sources for the work in literature from the period have not been successful. Art historian Erwin Panofsky wrote in 1953 that, "In spite of all the ingenious, erudite and in part extremely useful research devoted to the task of "decoding Jerome Bosch", I cannot help feeling that the real secret of his magnificent nightmares and daydreams has still to be disclosed. We have bored a few holes through the door of the locked room; but somehow we do not seem to have discovered the key." The humanist Desiderius Erasmus has been suggested as a possible influence; the writer lived in 's-Hertogenbosch in the 1480s, and it is likely he knew Bosch. Glum remarked on the triptych's similarity of tone with Erasmus's view that theologians "explain (to suit themselves) the most difficult mysteries ... is it a possible proposition: God the Father hates the Son? Could God have assumed the form of a woman, a devil, an ass, a gourd, a stone?"


title: The Garden of Earthly Delights

text: Because only bare details are known of Bosch's life, interpretation of his work can be an extremely difficult area for academics as it is largely reliant on conjecture. Individual motifs and elements of symbolism may be explained, but so far relating these to each other and to his work as a whole has remained elusive. The enigmatic scenes depicted on the panels of the inner triptych of "The Garden of Earthly Delights" have been studied by many scholars, who have often arrived at contradictory interpretations. Analyses based on symbolic systems ranging from the alchemical, astrological, and heretical to the folkloric and subconscious have all attempted to explain the complex objects and ideas presented in the work. Until the early 20th century, Bosch's paintings were generally thought to incorporate attitudes of Medieval didactic literature and sermons. Charles De Tolnay wrote that


title: The Garden of Earthly Delights

text: The oldest writers, Dominicus Lampsonius and Karel van Mander, attached themselves to his most evident side, to the subject; their conception of Bosch, inventor of fantastic pieces of devilry and of infernal scenes, which prevails today (1937) in the public at large, and prevailed with historians until the last quarter of the 19th century.


title: The Garden of Earthly Delights

text: Generally, his work is described as a warning against lust, and the central panel as a representation of the transience of worldly pleasure. In 1960, the art historian Ludwig von Baldass wrote that Bosch shows "how sin came into the world through the Creation of Eve, how fleshly lusts spread over the entire earth, promoting all the Deadly Sins, and how this necessarily leads straight to Hell". De Tolnay wrote that the center panel represents "the nightmare of humanity", where "the artist's purpose above all is to show the evil consequences of sensual pleasure and to stress its ephemeral character". Supporters of this view hold that the painting is a sequential narrative, depicting mankind's initial state of innocence in Eden, followed by the subsequent corruption of that innocence, and finally its punishment in Hell. At various times in its history, the triptych has been known as "La Lujuria", "The Sins of the World" and "The Wages of Sin".


title: The Garden of Earthly Delights

text: Proponents of this idea point out that moralists during Bosch's era believed that it was woman's—ultimately Eve's—temptation that drew men into a life of lechery and sin. This would explain why the women in the center panel are very much among the active participants in bringing about the Fall. At the time, the power of femininity was often rendered by showing a female surrounded by a circle of males. A late 15th-century engraving by Israhel van Meckenem shows a group of men prancing ecstatically around a female figure. The Master of the Banderoles's 1460 work the "Pool of Youth" similarly shows a group of females standing in a space surrounded by admiring figures.


title: The Garden of Earthly Delights

text: This line of reasoning is consistent with interpretations of Bosch's other major moralising works which hold up the folly of man; the "Death and the Miser" and the "Haywain". Although according to the art historian Walter Bosing, each of these works is rendered in a manner that it is difficult to believe "Bosch intended to condemn what he painted with such visually enchanting forms and colors". Bosing concludes that a medieval mindset was naturally suspicious of material beauty, in any form, and that the sumptuousness of Bosch's description may have been intended to convey a false paradise, teeming with transient beauty.


title: The Garden of Earthly Delights

text: In 1947, Wilhelm Fränger argued that the triptych's center panel portrays a joyous world when mankind will experience a rebirth of the innocence enjoyed by Adam and Eve before their fall. In his book "The Millennium of Hieronymus Bosch", Fränger wrote that Bosch was a member of the heretical sect known as the Adamites—who were also known as the "Homines intelligentia" and Brethren and Sisters of the Free Spirit. This radical group, active in the area of the Rhine and the Netherlands, strove for a form of spirituality immune from sin even in the flesh, and imbued the concept of lust with a paradisical innocence.


title: The Garden of Earthly Delights

text: Fränger believed "The Garden of Earthly Delights" was commissioned by the order's Grand Master. Later critics have agreed that, because of their obscure complexity, Bosch's "altarpieces" may well have been commissioned for non-devotional purposes. The "Homines intelligentia" cult sought to regain the innocent sexuality enjoyed by Adam and Eve before the Fall. Fränger writes that the figures in Bosch's work "are peacefully frolicking about the tranquil garden in vegetative innocence, at one with animals and plants and the sexuality that inspires them seems to be pure joy, pure bliss." Fränger argued against the notion that the hellscape shows the retribution handed down for sins committed in the center panel. Fränger saw the figures in the garden as peaceful, naive, and innocent in expressing their sexuality, and at one with nature. In contrast, those being punished in Hell comprise "musicians, gamblers, desecrators of judgment and punishment".


title: The Garden of Earthly Delights

text: Examining the symbolism in Bosch's art—"the freakish riddles … the irresponsible phantasmagoria of an ecstatic"—Fränger concluded that his interpretation applied to Bosch's three altarpieces only: "The Garden of Earthly Delights", "The Temptation of Saint Anthony", and the "Haywain Triptych". Fränger distinguished these pieces from the artist's other works and argued that despite their anti-cleric polemic, they were nevertheless all altarpieces, probably commissioned for the devotional purposes of a mystery cult. While commentators accept Fränger's analysis as astute and broad in scope, they have often questioned his final conclusions. These are regarded by many scholars as hypothesis only, and built on an unstable foundation and what can only be conjecture. Critics argue that artists during this period painted not for their own pleasure but for commission, while the language and secularization of a post-Renaissance mind-set projected onto Bosch would have been alien to the late-Medieval painter.


title: The Garden of Earthly Delights

text: Fränger's thesis stimulated others to examine "The Garden" more closely. Writer Carl Linfert also senses the joyfulness of the people in the center panel, but rejects Fränger's assertion that the painting is a "doctrinaire" work espousing the "guiltless sexuality" of the Adamite sect. While the figures engage in amorous acts without any suggestion of the forbidden, Linfert points to the elements in the center panel suggesting death and temporality: some figures turn away from the activity, seeming to lose hope in deriving pleasure from the passionate frolicking of their cohorts. Writing in 1969, E. H. Gombrich drew on a close reading of Genesis and the Gospel According to Saint Matthew to suggest that the central panel is, according to Linfert, "the state of mankind on the eve of the Flood, when men still pursued pleasure with no thought of the morrow, their only sin the unawareness of sin."


title: The Garden of Earthly Delights

text: Because Bosch was such a unique and visionary artist, his influence has not spread as widely as that of other major painters of his era. However, there have been instances of later artists incorporating elements of "The Garden of Earthly Delights" into their own work. Pieter Bruegel the Elder (c. 1525–1569) in particular directly acknowledged Bosch as an important influence and inspiration, and incorporated many elements of the inner right panel into several of his most popular works. Bruegel's "Mad Meg" depicts a peasant woman leading an army of women to pillage Hell, while his "The Triumph of Death" (c. 1562) echoes the monstrous Hellscape of "The Garden", and utilizes, according to the Royal Museum of Fine Arts Antwerp, the same "unbridled imagination and the fascinating colours".


title: The Garden of Earthly Delights

text: While the Italian court painter Giuseppe Arcimboldo () did not create Hellscapes, he painted a body of strange and "fantastic" vegetable portraits—generally heads of people composed of plants, roots, webs and various other organic matter. These strange portraits rely on and echo a motif that was in part inspired by Bosch's willingness to break from strict and faithful representations of nature.


title: The Garden of Earthly Delights

text: David Teniers the Younger () was a Flemish painter who quoted both Bosch and Bruegel throughout his career in such works as his versions of the "Temptation of St Anthony", the "Rich Man in Hell" and his version of "Mad Meg".


title: The Garden of Earthly Delights

text: During the early 20th century, Bosch's work enjoyed a popular resurrection. The early surrealists' fascination with dreamscapes, the autonomy of the imagination, and a free-flowing connection to the unconscious brought about a renewed interest in his work. Bosch's imagery struck a chord with Joan Miró and Salvador Dalí in particular. Both knew his paintings firsthand, having seen "The Garden of Earthly Delights" in the Museo del Prado, and both regarded him as an art-historical mentor. Miró's "The Tilled Field" contains several parallels to Bosch's "Garden": similar flocks of birds; pools from which living creatures emerge; and oversize disembodied ears all echo the Dutch master's work. Dalí's 1929 "The Great Masturbator" is similar to an image on the right side of the left panel of Bosch's "Garden", composed of rocks, bushes and little animals resembling a face with a prominent nose and long eyelashes.


title: The Garden of Earthly Delights

text: When André Breton wrote his first Surrealist Manifesto in 1924, his historical precedents as inclusions named only Gustave Moreau, Georges Seurat, and Uccello. However, the Surrealist movement soon rediscovered Bosch and Bruegel, who quickly became popular among the Surrealist painters. René Magritte and Max Ernst both were inspired by Bosch's "The Garden of Earthly Delights".


title: Grace and Frankie

text: Grace and Frankie is an American comedy television series created by Marta Kauffman and Howard J. Morris for Netflix. The series stars Jane Fonda and Lily Tomlin as the eponymous Grace Hanson and Frankie Bergstein, two aging women who form an unlikely friendship after their husbands reveal they are in love with each other and plan to get married. Sam Waterston, Martin Sheen, Brooklyn Decker, Ethan Embry, June Diane Raphael, and Baron Vaughn co-star in supporting roles.


title: Grace and Frankie

text: The series premiered on Netflix on May 8, 2015. The second through sixth seasons were released from 2016 to 2020. The seventh and final season premiered on August 13, 2021 with four episodes, and the final twelve released on April 29, 2022.


title: Grace and Frankie

text: "Grace and Frankie" received mixed reviews upon its debut, but its second and subsequent seasons have been met with a largely positive reception from television critics. It has received several accolades, including five Primetime Emmy Award nominations for Outstanding Lead Actress in a Comedy Series and a Golden Globe Award nomination for Best Actress – Television Series Musical or Comedy.


title: Grace and Frankie

text: The series follows Grace Hanson, a sharp-tongued, retired cosmetics mogul, and Frankie Bergstein, a quirky artist and hippie, whose long-term husbands, Robert and Sol, are successful divorce lawyers in San Diego, California. Grace and Frankie's lives are turned upside down when Robert and Sol announce they are in love with each other and are leaving their wives. Now the women, who have never particularly liked each other, are forced to live together as they navigate family drama, medical scares, business ventures, and romantic turmoil on their road to becoming best friends.


title: Grace and Frankie

text: In March 2014, Netflix finalized a deal for a 13-episode straight-to-series order for "Grace and Frankie", with Jane Fonda and Lily Tomlin attached to star in the lead roles. The series was written and created by Marta Kauffman and Howard J. Morris, who also serve as executive producers alongside Fonda, Tomlin, Paula Weinstein and Tate Taylor, and Skydance Productions' Dana Goldberg, David Ellison, and Marcy Ross. It premiered on May 8, 2015, with all 13 episodes released simultaneously.


title: Grace and Frankie

text: On May 26, 2015, Netflix renewed the series for a second season which premiered on May 6, 2016. On December 10, 2015, the series was renewed for a third season which premiered on March 24, 2017. On April 12, 2017, the series was renewed for a fourth season, which premiered on January 19, 2018. On February 15, 2018, the series was renewed for a fifth season, which premiered on January 18, 2019. The sixth season was announced on January 15, 2019, and premiered on January 15, 2020.


title: Grace and Frankie

text: On September 4, 2019, the series was renewed for a seventh and final season consisting of 16 episodes. On March 12, 2020, production was halted on the final season, due to the COVID-19 pandemic. Jane Fonda indicated in an interview that production planned to resume filming in January 2021. Production was delayed again and resumed in June 2021. The seventh and final season premiered on August 13, 2021, when the first four episodes of the season were made available. The remaining 12 episodes of the season was released on April 29, 2022.


title: Grace and Frankie

text: Casting announcements began in June 2014, with Martin Sheen cast in the role of Robert, Grace's husband. The following month, Sam Waterston was cast in the role of Sol, Frankie's husband. June Diane Raphael and Baron Vaughn were then added to the cast, with Raphael cast in the role of Brianna, Grace and Robert's elder daughter, who rebels against Grace's decorum. Vaughn signed onto the role of Nwabudike, Frankie and Sol's son. Shortly afterwards, Ethan Embry and Brooklyn Decker were cast in the remaining roles on the series. Embry joined in the role of Coyote, Frankie and Sol's recovering drugaddicted son, while Decker signed onto the role of Mallory, Grace and Robert's younger daughter. In October 2015, it was announced Sam Elliott would appear in the second season as Grace's love interest. In April 2017, it was reported Lisa Kudrow will appear in the fourth season as Sheree, Grace's manicurist. In February 2018, the same day as the fifth season was commissioned, RuPaul was confirmed to appear in the fifth season as a rival of Grace and Frankie. Dolly Parton was confirmed to appear in a guest starring role in the final season, making it a full reunion of the cast of "9 to 5".


title: Grace and Frankie

text: Production on season one of "Grace and Frankie" began in Los Angeles, California, in early August 2014, and ended in late November. Production on season two of the series began in July 2015, and ended in November the same year. Production on final season ended in November 2021.


title: Grace and Frankie

text: The first season of "Grace and Frankie" received mixed reviews from critics. On the review aggregator website Rotten Tomatoes it has a rating of 57%, based on 40 reviews, with an average rating of 6.42/10. The site's critical consensus reads, ""Grace and Frankie"'s stellar cast adds an undeniable appeal, although its sloppy dialogue and clichéd sitcom setup will still leave most viewers wanting." On Metacritic the season has a score of 58 out of 100, based on 27 critics, indicating "mixed or average reviews".


title: Grace and Frankie

text: The second season received a more positive reception from critics. On Rotten Tomatoes, it has a rating of 91%, based on 11 reviews, with an average rating of 7.34/10. The site's critical consensus reads, ""Grace & Frankie" gets better with age in a heartwarming, character driven second season full of humor that is both fun and obnoxious." On Metacritic, the season has a score of 62 out of 100, based on 6 critics, indicating "generally favourable reviews".


title: Grace and Frankie

text: The third, fourth, and fifth season each have 100% ratings on Rotten Tomatoes with average ratings of 7.5/10, 8.42/10, and 6.33/10 respectively. The site's critical consensus for season five reads, "Five seasons in, "Grace & Frankie" remain blissfully at the top of their game, thanks to Jane Fonda and Lily Tomlin's undeniable bond."


title: Grace and Frankie

text: After the series' debut, Fonda and Tomlin expressed displeasure once it became public that their salaries were just equal to those of Waterston and Sheen, even though "the show is not 'Sol and Robert', it's 'Grace and Frankie,'" in the words of Tomlin, and contended this constituted a significant pay inequity. Shortly thereafter, Waterston and Sheen went on the record to support their co-stars' demands for a salary increase, with Waterston being quoted as saying: "I think they're being cheated". After fans of the series gathered nearly 200,000 signatures on a petition protesting the disparity, the two actresses issued a public statement backing away from criticism, saying: "This just reminds us to be mindful of how things come across in interviews. We appreciate everyone's support and the attention to this issue, but the structure of "Grace and Frankie" is fair, and we couldn't be happier to work with Skydance, Netflix and the great cast of this show." Fonda and Tomlin made a statement to "TheWrap" clarifying they were never displeased with the salaries to begin with and they had in actuality "made a joke in an interview about our salaries, which was taken out of context."


title: Electromagnetic radiation

text: In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. All of these waves form part of the electromagnetic spectrum.


title: Electromagnetic radiation

text: Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields. Depending on the frequency of oscillation, different wavelengths of electromagnetic spectrum are produced. In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted "c". In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength. Electromagnetic waves of different frequency are called by different names since they have different sources and effects on matter. In order of increasing frequency and decreasing wavelength these are: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.