Science fiction is a genre of speculative fiction dealing with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, extraterrestrials in fiction. Science fiction explores the potential consequences of scientific other various innovations, has been called a "literature of ideas." "Science fiction" is difficult to define as it includes a wide range of concepts and themes. James Blish wrote: "Wells used the term to cover what we would today call'hard' science fiction, in which a conscientious attempt to be faithful to known facts was the substrate on which the story was to be built, if the story was to contain a miracle, it ought at least not to contain a whole arsenal of them."Isaac Asimov said: "Science fiction can be defined as that branch of literature which deals with the reaction of human beings to changes in science and technology." According to Robert A. Heinlein, "A handy short definition of all science fiction might read: realistic speculation about possible future events, based solidly on adequate knowledge of the real world and present, on a thorough understanding of the nature and significance of the scientific method."Lester del Rey wrote, "Even the devoted aficionado or fan—has a hard time trying to explain what science fiction is," and that the reason for there not being a "full satisfactory definition" is that "there are no delineated limits to science fiction."
Author and editor Damon Knight summed up the difficulty, saying "science fiction is what we point to when we say it." Mark C. Glassy described the definition of science fiction as U. S. Supreme Court Justice Potter Stewart did with the definition of pornography: "I know it when I see it." Science fiction had its beginnings in a time when the line between myth and fact was arguably more blurred than the present day. Written in the 2nd century CE by the satirist Lucian, A True Story contains many themes and tropes that are characteristic of contemporary science fiction, including travel to other worlds, extraterrestrial lifeforms, interplanetary warfare, artificial life; some consider it the first science-fiction novel. Some of the stories from The Arabian Nights, along with the 10th-century The Tale of the Bamboo Cutter and Ibn al-Nafis's 13th-century Theologus Autodidactus contain elements of science fiction. Products of the Age of Reason and the development of modern science itself, Johannes Kepler's Somnium, Francis Bacon's New Atlantis, Cyrano de Bergerac's Comical History of the States and Empires of the Moon and The States and Empires of the Sun, Margaret Cavendish's "The Blazing World", Jonathan Swift's Gulliver's Travels, Ludvig Holberg's Nicolai Klimii Iter Subterraneum and Voltaire's Micromégas are regarded as some of the first true science-fantasy works.
Indeed, Isaac Asimov and Carl Sagan considered Somnium the first science-fiction story. Following the 18th-century development of the novel as a literary form, Mary Shelley's books Frankenstein and The Last Man helped define the form of the science-fiction novel. Brian Aldiss has argued. Edgar Allan Poe wrote several stories considered science fiction, including "The Unparalleled Adventure of One Hans Pfaall" which featured a trip to the Moon. Jules Verne was noted for his attention to detail and scientific accuracy Twenty Thousand Leagues Under the Sea which predicted the contemporary nuclear submarine. In 1887, the novel El anacronópete by Spanish author Enrique Gaspar y Rimbau introduced the first time machine. Many critics consider H. G. Wells one of science fiction's most important authors, or "the Shakespeare of science fiction." His notable science-fiction works include The Time Machine, The Island of Doctor Moreau, The Invisible Man, The War of the Worlds. His science fiction imagined alien invasion, biological engineering and time travel.
In his non-fiction futurologist works he predicted the advent of airplanes, military tanks, nuclear weapons, satellite television, space travel, something resembling the World Wide Web. In 1912, Edgar Rice Burroughs published A Princess of Mars, the first of his three-decade-long planetary romance series of Barsoom novels, set on Mars and featuring John Carter as the hero. In 1926, Hugo Gernsback published the first American science-fiction magazine, Amazing Stories, in which he wrote: By'scientifiction' I mean the Jules Verne, H. G. Wells and Edgar Allan Poe type of story—a charming romance intermingled with scientific fact and prophetic vision... Not only do these amazing tales make tremendously interesting reading—they are always instructive, they supply knowledge... in a palatable form... New adventures pictured for us in the scientifiction of today are not at all impossible of realization tomorrow... Many great science stories destined to be of historical interest are still to be written...
Posterity will point to them as having blazed a new trail, not only in literature and fiction, but progress as well. In 1928, E. E. "Doc" Smith's first published work, The Skylark of Space, written in collaboration with Lee Hawkins Garby, appeared in Amazing Stories. It is called the first great space opera; the same year, Philip Francis Nowlan's original Buck Rogers story, Armageddon 2419 appeared in Amazing Stories. This was followed by the first serious science-fiction comic. In 1937, John W. Campbell became editor of Astounding Science Fiction, an event, sometimes conside
Library of Congress
The Library of Congress is the research library that serves the United States Congress and is the de facto national library of the United States. It is the oldest federal cultural institution in the United States; the Library is housed in three buildings on Capitol Hill in Washington, D. C.. The Library's functions are overseen by the Librarian of Congress, its buildings are maintained by the Architect of the Capitol; the Library of Congress has claimed to be the largest library in the world. Its "collections are universal, not limited by subject, format, or national boundary, include research materials from all parts of the world and in more than 450 languages."The Library of Congress moved to Washington in 1800 after sitting for 11 years in the temporary national capitals in New York City and Philadelphia. The small Congressional Library was housed in the United States Capitol for most of the 19th century until the early 1890s. Most of the original collection had been destroyed by the British in 1814 during the War of 1812, the library sought to restore its collection in 1815.
They bought Thomas Jefferson's entire personal collection of 6,487 books. After a period of slow growth, another fire struck the Library in its Capitol chambers in 1851, again destroying a large amount of the collection, including many of Jefferson's books. After the American Civil War, the Library of Congress grew in both size and importance, which sparked a campaign to purchase replacement copies for volumes, burned; the Library received the right of transference of all copyrighted works to deposit two copies of books, maps and diagrams printed in the United States. It began to build its collections, its development culminated between 1888 and 1894 with the construction of a separate, extensive library building across the street from the Capitol; the Library's primary mission is to research inquiries made by members of Congress, carried out through the Congressional Research Service. The Library is open to the public, although only high-ranking government officials and Library employees may check out books and materials.
James Madison is credited with the idea of creating a congressional library, first making such a proposition in 1783. The Library of Congress was subsequently established April 24, 1800 when President John Adams signed an act of Congress providing for the transfer of the seat of government from Philadelphia to the new capital city of Washington. Part of the legislation appropriated $5,000 "for the purchase of such books as may be necessary for the use of Congress... and for fitting up a suitable apartment for containing them." Books were ordered from London, the collection consisted of 740 books and three maps which were housed in the new United States Capitol. President Thomas Jefferson played an important role in establishing the structure of the Library of Congress. On January 26, 1802, he signed a bill that allowed the president to appoint the Librarian of Congress and establishing a Joint Committee on the Library to regulate and oversee it; the new law extended borrowing privileges to the President and Vice President.
The invading British army burned Washington in August 1814 during the War of 1812 and destroyed the Library of Congress and its collection of 3,000 volumes. These volumes had been left in the Senate wing of the Capitol. One of the few congressional volumes to survive was a government account book of receipts and expenditures for 1810, it was taken as a souvenir by British Admiral George Cockburn, whose family returned it to the United States government in 1940. Within a month, Thomas Jefferson offered to sell his personal library as a replacement. Congress accepted his offer in January 1815; some members of the House of Representatives opposed the outright purchase, including New Hampshire Representative Daniel Webster who wanted to return "all books of an atheistical and immoral tendency." Jefferson had spent 50 years accumulating a wide variety of books in several languages and on subjects such as philosophy, law, architecture, natural sciences, studies of classical Greece and Rome, modern inventions, hot air balloons, submarines, fossils and meteorology.
He had collected books on topics not viewed as part of a legislative library, such as cookbooks. However, he believed, he remarked: I do not know that it contains any branch of science which Congress would wish to exclude from their collection. Jefferson's collection was unique in that it was the working collection of a scholar, not a gentleman's collection for display. With the addition of his collection, the Library of Congress was transformed from a specialist's library to a more general one, his original collection was organized into a scheme based on Francis Bacon's organization of knowledge. He grouped his books into Memory and Imagination, which broke down into 44 more subdivisions; the Library followed Jefferson's organization scheme until the late 19th century, when librarian Herbert Putnam began work on a more flexible Library of Congress Classification structure that now applies to more than 138 million items. In 1851, a fire destroyed two thirds of the Jefferson collection, with only 2,000 books remaining.
By 2008, the Librarians of Congress had found replacements for all but 300 of the works that were in Jefferson's original collection. On December 22, 1851 the largest fire in the Library's history destroyed 35,000 books, about two–thi
The Soviet Union the Union of Soviet Socialist Republics, was a socialist state in Eurasia that existed from 1922 to 1991. Nominally a union of multiple national Soviet republics, its government and economy were centralized; the country was a one-party state, governed by the Communist Party with Moscow as its capital in its largest republic, the Russian Soviet Federative Socialist Republic. Other major urban centres were Leningrad, Minsk, Alma-Ata, Novosibirsk, it spanned over 10,000 kilometres east to west across 11 time zones, over 7,200 kilometres north to south. It had five climate zones: tundra, steppes and mountains; the Soviet Union had its roots in the 1917 October Revolution, when the Bolsheviks, led by Vladimir Lenin, overthrew the Russian Provisional Government which had replaced Tsar Nicholas II during World War I. In 1922, the Soviet Union was formed by a treaty which legalized the unification of the Russian, Transcaucasian and Byelorussian republics that had occurred from 1918. Following Lenin's death in 1924 and a brief power struggle, Joseph Stalin came to power in the mid-1920s.
Stalin committed the state's ideology to Marxism–Leninism and constructed a command economy which led to a period of rapid industrialization and collectivization. During his rule, political paranoia fermented and the Great Purge removed Stalin's opponents within and outside of the party via arbitrary arrests and persecutions of many people, resulting in at least 600,000 deaths. In 1933, a major famine struck the country. Before the start of World War II in 1939, the Soviets signed the Molotov–Ribbentrop Pact, agreeing to non-aggression with Nazi Germany, after which the USSR invaded Poland on 17 September 1939. In June 1941, Germany broke the pact and invaded the Soviet Union, opening the largest and bloodiest theatre of war in history. Soviet war casualties accounted for the highest proportion of the conflict in the effort of acquiring the upper hand over Axis forces at intense battles such as Stalingrad and Kursk; the territories overtaken by the Red Army became satellite states of the Soviet Union.
The post-war division of Europe into capitalist and communist halves would lead to increased tensions with the United States-led Western Bloc, known as the Cold War. Stalin died in 1953 and was succeeded by Nikita Khrushchev, who in 1956 denounced Stalin and began the de-Stalinization; the Cuban Missile Crisis occurred during Khrushchev's rule, among the many factors that led to his downfall in 1964. In the early 1970s, there was a brief détente of relations with the United States, but tensions resumed with the Soviet–Afghan War in 1979. In 1985, the last Soviet premier, Mikhail Gorbachev, sought to reform and liberalize the economy through his policies of glasnost and perestroika, which caused political instability. In 1989, Soviet satellite states in Eastern Europe overthrew their respective communist governments; as part of an attempt to prevent the country's dissolution due to rising nationalist and separatist movements, a referendum was held in March 1991, boycotted by some republics, that resulted in a majority of participating citizens voting in favor of preserving the union as a renewed federation.
Gorbachev's power was diminished after Russian President Boris Yeltsin's high-profile role in facing down a coup d'état attempted by Communist Party hardliners. In late 1991, Gorbachev resigned and the Supreme Soviet of the Soviet Union met and formally dissolved the Soviet Union; the remaining 12 constituent republics emerged as independent post-Soviet states, with the Russian Federation—formerly the Russian SFSR—assuming the Soviet Union's rights and obligations and being recognized as the successor state. The Soviet Union was a powerhouse of many significant technological achievements and innovations of the 20th century, including the world's first human-made satellite, the first humans in space and the first probe to land on another planet, Venus; the country had the largest standing military in the world. The Soviet Union was recognized as one of the five nuclear weapons states and possessed the largest stockpile of weapons of mass destruction, it was a founding permanent member of the United Nations Security Council as well as a member of the Organization for Security and Co-operation in Europe, the World Federation of Trade Unions and the leading member of the Council for Mutual Economic Assistance and the Warsaw Pact.
The word "Soviet" is derived from a Russian word сове́т meaning council, advice, harmony and all deriving from the proto-Slavic verbal stem of vět-iti, related to Slavic věst, English "wise", the root in "ad-vis-or", or the Dutch weten. The word sovietnik means "councillor". A number of organizations in Russian history were called "council". For example, in the Russian Empire the State Council, which functioned from 1810 to 1917, was referred to as a Council of Ministers after the revolt of 1905. During the Georgian Affair, Vladimir Lenin envisioned an expression of Great Russian ethnic chauvinism by Joseph Stalin and his supporters, calling for these nation-states to join Russia as semi-independent parts of a greater union, which he named as the Union of Soviet Republics of Europe and Asia. Stalin resisted the proposal, but accepted it, although with Lenin's agreement changed the name of the newly proposed sta
Space opera is a subgenre of science fiction that emphasizes space warfare, melodramatic adventure, interplanetary battles, chivalric romance, risk-taking. Set or in outer space, it involves conflict between opponents possessing advanced abilities, futuristic weapons, other sophisticated technology; the term has no relation to music, but is instead a play on the terms "soap opera" and "horse opera", the latter of, coined during the 1930s to indicate clichéd and formulaic Western movies. Space operas emerged in the 1930s and continue to be produced in literature, comics and video games. An early film, based on space opera comic strips was Flash Gordon created by Alex Raymond. In the late 1970s, the Star Wars franchise created by George Lucas brought a great deal of attention to the subgenre. After the convention-breaking "New Wave", followed by the enormous success of the Star Wars films, space opera became once again a critically acceptable subgenre. Throughout 1982–2002, the Hugo Award for best science fiction novel was given to a space opera nominee.
Space opera is defined as an adventure science-fiction story. The term "space opera" was coined in 1941 by fan writer and author Wilson Tucker as a pejorative term in an article in issue 36 of Le Zombie, a science fiction fanzine. At the time, serial radio dramas in the United States had become popularly known as soap operas because many were sponsored by soap manufacturers; the term "horse opera" had come into use to describe formulaic Western films. Tucker defined space opera as the science fiction equivalent: a "hacky, stinking, spaceship yarn". Fans and critics have noted that the plots of space operas have sometimes been taken from horse operas and translated into an outer space environment, as famously parodied on the back cover of the first issue of Galaxy Science Fiction. During the late 1920s and early 1930s, when the stories were printed in science-fiction magazines, the stories were referred to as "super-science epics". Beginning in the 1960s, accepted by the 1970s, the space opera was redefined, following Brian Aldiss' definition in Space Opera as – as paraphrased by Hartwell and Cramer – "the good old stuff".
Yet soon after his redefinition, it began to be challenged, for example, by the editorial practice and marketing of Judy-Lynn del Rey and in the reviews of her husband and colleague Lester del Rey. In particular, they disputed the claims that space operas were obsolete, Del Rey Books labeled reissues of earlier work of Leigh Brackett as space opera. By the early 1980s, space operas were again redefined, the label was attached to major popular culture works such as Star Wars. Only in the early 1990s did the term space opera began to be recognized as a legitimate genre of science fiction. Hartwell and Cramer define space opera as:... colorful, large-scale science fiction adventure and sometimes beautifully written focused on a sympathetic, heroic central character and plot action, set in the distant future, in space or on other worlds, characteristically optimistic in tone. It deals with war, military virtues, large-scale action, large stakes. Early works which preceded the subgenre contained many elements of.
They are today referred to as proto-space opera. Early proto-space opera was written by several 19th century French authors, for example, Les Posthumes by Nicolas-Edme Rétif, Star ou Psi de Cassiopée: Histoire Merveilleuse de l’un des Mondes de l’Espace by C. I. Defontenay and Lumen by Camille Flammarion. Not popular, proto-space operas were occasionally written during the late Victorian and Edwardian science-fiction era. Examples may be found in the works of Percy Greg, Garrett P. Serviss, George Griffith, Robert Cromie. One critic cites Robert William Cole's The Struggle for Empire: A Story of the Year 2236 as the first space opera; the novel depicts an interstellar conflict between solar men of Earth and a fierce humanoid race headquartered on Sirius. However, the idea for the novel arises out of a nationalistic genre of fiction popular from 1880 to 1914 called future-war fiction. Despite this early beginning, it was not until the late 1920s that the space opera proper began to appear in pulp magazines such as Amazing Stories.
In film, the genre began with the 1918 Danish film, Himmelskibet. Unlike earlier stories of space adventure, which either related the invasion of Earth by extraterrestrials, or concentrated on the invention of a space vehicle by a genius inventor, pure space opera took space travel for granted, skipped the preliminaries, launched straight into tales of derring-do among the stars. Early stories of this type include J. Schlossel's "Invaders from Outside", The Second Swarm and The Star Stealers, Ray Cummings' Tarrano the Conqueror, Edmond Hamilton's Across Space and Crashing Suns. Similar stories by other writers followed through 1929 and 1930. By 1931, the space opera was well established as a major subgenre of science fiction. However, the author cited most as the true father of the genre is E. E. "Doc" Smith. His first published work, The Skylark of Space, written in collaboration with Lee Hawkins Garby, is called the first great space opera, it merges the traditional tale of a scientist inventing a space-drive with planetary romance in the style of Edgar Rice Burroughs.
Smith's Lensman serie
Spaceflight is ballistic flight into or through outer space. Spaceflight can occur with spacecraft without humans on board. Yuri Gagarin of the Soviet Union was the first human to conduct a spaceflight. Examples of human spaceflight include the U. S. Apollo Moon landing and Space Shuttle programs and the Russian Soyuz program, as well as the ongoing International Space Station. Examples of unmanned spaceflight include space probes that leave Earth orbit, as well as satellites in orbit around Earth, such as communications satellites; these operate either by telerobotic control or are autonomous. Spaceflight is used in space exploration, in commercial activities like space tourism and satellite telecommunications. Additional non-commercial uses of spaceflight include space observatories, reconnaissance satellites and other Earth observation satellites. A spaceflight begins with a rocket launch, which provides the initial thrust to overcome the force of gravity and propels the spacecraft from the surface of the Earth.
Once in space, the motion of a spacecraft – both when unpropelled and when under propulsion – is covered by the area of study called astrodynamics. Some spacecraft remain in space indefinitely, some disintegrate during atmospheric reentry, others reach a planetary or lunar surface for landing or impact; the first theoretical proposal of space travel using rockets was published by Scottish astronomer and mathematician William Leitch, in an 1861 essay "A Journey Through Space". More well-known is Konstantin Tsiolkovsky's work, "Исследование мировых пространств реактивными приборами", published in 1903. Spaceflight became an engineering possibility with the work of Robert H. Goddard's publication in 1919 of his paper A Method of Reaching Extreme Altitudes, his application of the de Laval nozzle to liquid fuel rockets improved efficiency enough for interplanetary travel to become possible. He proved in the laboratory that rockets would work in the vacuum of space, his attempt to secure an Army contract for a rocket-propelled weapon in the first World War was defeated by the November 11, 1918 armistice with Germany.
Nonetheless, Goddard's paper was influential on Hermann Oberth, who in turn influenced Wernher von Braun. Von Braun became the first to produce modern rockets as guided weapons, employed by Adolf Hitler. Von Braun's V-2 was the first rocket to reach space, at an altitude of 189 kilometers on a June 1944 test flight. Tsiolkovsky's rocketry work was not appreciated in his lifetime, but he influenced Sergey Korolev, who became the Soviet Union's chief rocket designer under Joseph Stalin, to develop intercontinental ballistic missiles to carry nuclear weapons as a counter measure to United States bomber planes. Derivatives of Korolev's R-7 Semyorka missiles were used to launch the world's first artificial Earth satellite, Sputnik 1, on October 4, 1957, the first human to orbit the Earth, Yuri Gagarin in Vostok 1, on April 12, 1961. At the end of World War II, von Braun and most of his rocket team surrendered to the United States, were expatriated to work on American missiles at what became the Army Ballistic Missile Agency.
This work on missiles such as Juno I and Atlas enabled launch of the first US satellite Explorer 1 on February 1, 1958, the first American in orbit, John Glenn in Friendship 7 on February 20, 1962. As director of the Marshall Space Flight Center, Von Braun oversaw development of a larger class of rocket called Saturn, which allowed the US to send the first two humans, Neil Armstrong and Buzz Aldrin, to the Moon and back on Apollo 11 in July 1969. Over the same period, the Soviet Union secretly tried but failed to develop the N1 rocket to give them the capability to land one person on the Moon. Rockets are the only means capable of reaching orbit or beyond. Other non-rocket spacelaunch technologies have yet to remain short of orbital speeds. A rocket launch for a spaceflight starts from a spaceport, which may be equipped with launch complexes and launch pads for vertical rocket launches, runways for takeoff and landing of carrier airplanes and winged spacecraft. Spaceports are situated well away from human habitation for safety reasons.
ICBMs have various special launching facilities. A launch is restricted to certain launch windows; these windows depend upon the position of celestial orbits relative to the launch site. The biggest influence is the rotation of the Earth itself. Once launched, orbits are located within constant flat planes at a fixed angle to the axis of the Earth, the Earth rotates within this orbit. A launch pad is a fixed structure designed to dispatch airborne vehicles, it consists of a launch tower and flame trench. It is surrounded by equipment used to erect and maintain launch vehicles; the most used definition of outer space is everything beyond the Kármán line, 100 kilometers above the Earth's surface. The United States sometimes defines outer space as everything beyond 50 miles in altitude. Rockets are the only practical means of reaching space. Conventional airplane engines cannot reach space due to the lack of oxygen. Rocket engines expel propellant to provide forward thrust that generates enough delta-v to reach orbit.
For manned launch systems launch escape systems are fitted to allow astronauts to escape in the case of emergency. Many ways to reach space other than rockets have been proposed. Ideas such as the space elevator, momentum exchange tethers li
A gas giant is a giant planet composed of hydrogen and helium. Gas giants are sometimes known as failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System; the term "gas giant" was synonymous with "giant planet", but in the 1990s it became known that Uranus and Neptune are a distinct class of giant planet, being composed of heavier volatile substances. For this reason and Neptune are now classified in the separate category of ice giants. Jupiter and Saturn consist of hydrogen and helium, with heavier elements making up between 3 and 13 percent of the mass, they are thought to consist of an outer layer of molecular hydrogen surrounding a layer of liquid metallic hydrogen, with a molten rocky core. The outermost portion of their hydrogen atmosphere is characterized by many layers of visible clouds that are composed of water and ammonia; the layer of metallic hydrogen makes up the bulk of each planet, is referred to as "metallic" because the large pressure turns hydrogen into an electrical conductor.
The gas giants' cores are thought to consist of heavier elements at such high temperatures and pressures that their properties are poorly understood. The defining differences between a low-mass brown dwarf and a gas giant are debated. One school of thought is based on formation. Part of the debate concerns whether "brown dwarfs" must, by definition, have experienced nuclear fusion at some point in their history; the term gas giant was coined in 1952 by the science fiction writer James Blish and was used to refer to all giant planets. It is, something of a misnomer because throughout most of the volume of all giant planets, the pressure is so high that matter is not in gaseous form. Other than solids in the core and the upper layers of the atmosphere, all matter is above the critical point, where there is no distinction between liquids and gases; the term has caught on, because planetary scientists use "rock", "gas", "ice" as shorthands for classes of elements and compounds found as planetary constituents, irrespective of what phase the matter may appear in.
In the outer Solar System and helium are referred to as "gases". Because Uranus and Neptune are composed of, in this terminology, not gas, they are referred to as ice giants and separated from the gas giants. Gas giants can, theoretically, be divided into five distinct classes according to their modeled physical atmospheric properties, hence their appearance: ammonia clouds, water clouds, alkali-metal clouds, silicate clouds. Jupiter and Saturn are both class I. Hot Jupiters are class IV or V. A cold hydrogen-rich gas giant more massive than Jupiter but less than about 500 M⊕ will only be larger in volume than Jupiter. For masses above 500 M⊕, gravity will cause the planet to shrink. Kelvin–Helmholtz heating can cause a gas giant to radiate more energy than it receives from its host star. Although the words "gas" and "giant" are combined, hydrogen planets need not be as large as the familiar gas giants from the Solar System. However, smaller gas planets and planets closer to their star will lose atmospheric mass more via hydrodynamic escape than larger planets and planets farther out.
A gas dwarf could be defined as a planet with a rocky core that has accumulated a thick envelope of hydrogen and other volatiles, having as result a total radius between 1.7 and 3.9 Earth-radii. The smallest known extrasolar planet, a "gas planet" is Kepler-138d, which has the same mass as Earth but is 60% larger and therefore has a density that indicates a thick gas envelope. A low-mass gas planet can still have a radius resembling that of a gas giant if it has the right temperature. List of gravitationally rounded objects of the Solar System List of planet types Hot Jupiter
Virtual International Authority File
The Virtual International Authority File is an international authority file. It is a joint project of several national libraries and operated by the Online Computer Library Center. Discussion about having a common international authority started in the late 1990s. After a series of failed attempts to come up with a unique common authority file, the new idea was to link existing national authorities; this would present all the benefits of a common file without requiring a large investment of time and expense in the process. The project was initiated by the US Library of Congress, the German National Library and the OCLC on August 6, 2003; the Bibliothèque nationale de France joined the project on October 5, 2007. The project transitioned to being a service of the OCLC on April 4, 2012; the aim is to link the national authority files to a single virtual authority file. In this file, identical records from the different data sets are linked together. A VIAF record receives a standard data number, contains the primary "see" and "see also" records from the original records, refers to the original authority records.
The data are available for research and data exchange and sharing. Reciprocal updating uses the Open Archives Initiative Protocol for Metadata Harvesting protocol; the file numbers are being added to Wikipedia biographical articles and are incorporated into Wikidata. VIAF's clustering algorithm is run every month; as more data are added from participating libraries, clusters of authority records may coalesce or split, leading to some fluctuation in the VIAF identifier of certain authority records. Authority control Faceted Application of Subject Terminology Integrated Authority File International Standard Authority Data Number International Standard Name Identifier Wikipedia's authority control template for articles Official website VIAF at OCLC