You are using an outdated browser. Please upgrade your browser to improve your experience and security.
  • Fisher, Harry Conway (American cartoonist)

    Bud Fisher, American cartoonist and creator of the comic strip Mutt and Jeff. After attending the University of Chicago, Fisher worked as a journalist in San Francisco, where for the San Francisco Chronicle he originated Mr. Mutt in 1907. Soon he added Jeff, the short one of the pair and usually

  • Fisher, Herbert Albert Laurens (British historian and government official)

    Herbert Albert Laurens Fisher, British historian, educator, government official, and author who was an influential representative of the historical liberalism of his time. Fisher became a fellow of New College, Oxford, in 1888 and tutor and lecturer in modern history in 1891. While at New College

  • Fisher, Irving (American economist)

    Irving Fisher, American economist best known for his work in the field of capital theory. He also contributed to the development of modern monetary theory. Fisher was educated at Yale University (B.A., 1888; Ph.D., 1891), where he remained to teach mathematics (1892–95) and economics (1895–1935).

  • Fisher, Jeff (American football coach)

    Tennessee Titans: …to head coach defensive coordinator Jeff Fisher, who would go on to have the longest coaching tenure in team history and oversee the franchise’s most successful period.

  • Fisher, John Arbuthnot Fisher, 1st Baron (British admiral)

    John Arbuthnot Fisher, 1st Baron Fisher, British admiral and first sea lord whose reforms between 1904 and 1910 ensured the dominance of the Royal Navy during World War I. Fisher entered the navy at age 13. He was a midshipman in the Crimean War and in China (1859–60), where he took part in the

  • Fisher, Joseph (American government official)

    World Heritage site: The international conservation movement: American officials Joseph Fisher and Russell Train spearheaded the effort to create such a body, and in 1965 they recommended to the White House Conference on International Cooperation

  • Fisher, Kate (American plainswoman)

    Kate Elder, plainswoman and frontier prostitute of the old American West, companion and possible wife of Doc Holliday (q.v.). Nothing is known of her background before she turned up in a Fort Griffin, Texas, saloon in the fall of 1877, working as a barroom prostitute. There she met Holliday, with

  • Fisher, M. F. K. (American author)

    M.F.K. Fisher, American writer whose compelling style, wit, and interest in the gastronomical made her one of the major American writers on the subject of food. In her 15 celebrated books, Fisher created a new genre: the food essay. Seeing food as a cultural metaphor, she proved to be both an

  • Fisher, Mary Frances Kennedy (American author)

    M.F.K. Fisher, American writer whose compelling style, wit, and interest in the gastronomical made her one of the major American writers on the subject of food. In her 15 celebrated books, Fisher created a new genre: the food essay. Seeing food as a cultural metaphor, she proved to be both an

  • Fisher, Morris (American athlete)

    Morris Fisher, American rifle shooter who won five Olympic gold medals during the 1920s. At the 1920 Olympics in Antwerp, Fisher, apparently feeling the pressure of the competition in the three-position free rifle event, took 20 minutes before firing his first shot at the target, which was placed

  • Fisher, Roger Dummer (American academic)

    Roger Dummer Fisher, American academic (born May 28, 1922, Winnetka, Ill.—died Aug. 25, 2012, Hanover, N.H.), pioneered the field of “principled negotiation” as a Harvard University law professor, best-selling author, and expert adviser to individuals, organizations, and governments dealing with

  • Fisher, Rudolph (American writer)

    Rudolph Fisher, American short-story writer and novelist associated with the Harlem Renaissance whose fiction realistically depicted black urban life in the North, primarily Harlem. Fisher was raised chiefly in Providence, R.I., where he received B.A. and M.A. degrees from Brown University. He

  • Fisher, Rudolph John Chauncey (American writer)

    Rudolph Fisher, American short-story writer and novelist associated with the Harlem Renaissance whose fiction realistically depicted black urban life in the North, primarily Harlem. Fisher was raised chiefly in Providence, R.I., where he received B.A. and M.A. degrees from Brown University. He

  • Fisher, Saint John (English priest)

    Saint John Fisher, ; canonized May 19, 1935; feast day July 9), English humanist, martyr, and prelate, who, devoted to the pope and to the Roman Catholic church, resisted King Henry VIII of England by refusing to recognize royal supremacy and the abolition of papal jurisdiction over the English

  • Fisher, Samuel (British author)

    Benedict de Spinoza: Association with Collegiants and Quakers: …would have been aided by Samuel Fisher, a member of the Quaker mission who had studied Hebrew at the University of Oxford. Fisher, it seems, shared Spinoza’s skepticism of the historical accuracy of the Bible. In 1660 he published a book in English of more than 700 pages, Rusticus ad…

  • Fisher, Sir R. A. (British geneticist and statistician)

    Sir Ronald Aylmer Fisher, British statistician and geneticist who pioneered the application of statistical procedures to the design of scientific experiments. In 1909 Fisher was awarded a scholarship to study mathematics at the University of Cambridge, from which he graduated in 1912 with a B.A. in

  • Fisher, Sir Ronald Aylmer (British geneticist and statistician)

    Sir Ronald Aylmer Fisher, British statistician and geneticist who pioneered the application of statistical procedures to the design of scientific experiments. In 1909 Fisher was awarded a scholarship to study mathematics at the University of Cambridge, from which he graduated in 1912 with a B.A. in

  • Fisher, Terence (British director)

    Horror of Dracula: Production notes and credits:

  • Fisher, William August (Soviet spy)

    Rudolf Abel, Soviet intelligence officer, convicted in the United States in 1957 for conspiring to transmit military secrets to the Soviet Union. He was exchanged in 1962 for the American aviator Francis Gary Powers, who had been imprisoned as a spy in the Soviet Union since 1960. Genrich Fischer

  • Fisheries, Bureau of (United States government agency)

    Arctic National Wildlife Refuge: It is managed by the U.S. Fish and Wildlife Service, with headquarters in Fairbanks. One of the great pristine and largely undisturbed wilderness areas of North America, the refuge has been the subject of much controversy because of the potential hydrocarbon reserves within it.

  • fisherman bat (mammal)

    bulldog bat: The greater bulldog, or fisherman, bat (N. leporinus) is considerably larger, with a length of 11–12 cm (4.3–4.7 inches) and a wingspan of up to 70 cm (27.5 inches). Greater bulldog bats weigh about twice that of the lesser. The short fur of both ranges in…

  • Fisherman Consigning a Ring to the Doge (work by Bordone)

    Paris Bordone: His finest historical painting is Fisherman Consigning a Ring to the Doge (1534–35), and he first gained public attention after he won the competition to create it. The painting is characterized by typically bright colours, heavy Titianesque figures, and complex architectural motifs derived from the work of Sebastiano Serlio. Bordone’s…

  • fisherman’s anchor (nautical device)

    anchor: It is known as a stock anchor in the United States and as a fisherman’s anchor in the United Kingdom.

  • fisherman’s bend (knot)

    knot: The fisherman’s, or anchor, bend is an especially strong and simple knot that will not jam or slip under strain and can be untied easily. The knot is used to attach a rope to a ring, hook, anchor, or other object. It is made by taking…

  • Fisherman’s Invocation, The (poetry by Okara)

    Gabriel Okara: …includes a collection of poems, The Fisherman’s Invocation (1978), and two books for children, Little Snake and Little Frog (1981) and An Adventure to Juju Island (1992).

  • fisherman’s ring (Roman Catholicism)

    Fisherman’s ring, the pope’s signet ring; it shows St. Peter as a fisherman and has the reigning pope’s name inscribed around the border. Used since the 13th century as a seal for private letters and since the 15th century for papal briefs, it is one of two papal seals, the other being the leaden

  • fishery

    Fishery, harvesting of fish, shellfish, and sea mammals as a commercial enterprise, or the location or season of commercial fishing. Fisheries range from small family operations relying on traditional fishing methods to large corporations using large fleets and the most advanced technology.

  • Fishes (constellation and astrological sign)

    Pisces, (Latin: “Fishes”) in astronomy, zodiacal constellation in the northern sky between Aries and Aquarius, at about 1 hour right ascension and 15° north declination. The vernal equinox, the point where the Sun’s annual apparent path takes it north of the celestial equator and from which

  • fishfly (insect)

    Mayfly, (order Ephemeroptera), any member of a group of insects known for their extremely short life spans and emergence in large numbers in the summer months. Other common names for the winged stages are shadfly, sandfly, dayfly, fishfly, and drake. The aquatic immature stage, called a nymph or

  • Fishguard (Wales, United Kingdom)

    Pembrokeshire: Fishguard and Goodwick, both located at the head of Fishguard Bay in northern Pembrokeshire, are popular resort areas, and there is regular ferry service between Fishguard and Rosslare, Ireland. The county’s Norman castles and seaside resorts draw many visitors, and tourism is important to the…

  • fishhook (device)

    fishing: Early history: …was the predecessor of the fishhook: a gorge—that is, a piece of wood, bone, or stone 1 inch (2.5 cm) or so in length, pointed at both ends and secured off-centre to the line. The gorge was covered with some kind of bait. When a fish swallowed the gorge, a…

  • fishhook cactus (plant)

    Fishhook cactus, any hook-spined species of the family Cactaceae. The name is especially applied to various small cacti of the genera Sclerocactus and Mammillaria but also to species from other genera, such as Ferocactus (see barrel cactus). Some of their hooked spines are strong enough to have

  • fishing (food production)

    conservation: Fishing: Overfishing is the greatest threat to the biodiversity of the world’s oceans, and contemporary information published for fisheries in the United States can serve as an example of the magnitude of the problem. Congress requires the National Marine Fisheries Service (NMFS) to report regularly…

  • fishing (recreation)

    Fishing, the sport of catching fish, freshwater or saltwater, typically with rod, line, and hook. Like hunting, fishing originated as a means of providing food for survival. Fishing as a sport, however, is of considerable antiquity. An Egyptian angling scene from about 2000 bce shows figures

  • fishing bank

    Canada: Fishing: …shallowest water are known as fishing banks; there plankton, on which fish feed, thrive because the sunlight penetrates to the seafloor. The most important of these fishing banks is the Grand Banks of Newfoundland. Bradelle Bank, Sable Bank, Georges Bank (shared with the United States), and a number of other…

  • fishing bulldog bat (mammal)

    bulldog bat: The greater bulldog, or fisherman, bat (N. leporinus) is considerably larger, with a length of 11–12 cm (4.3–4.7 inches) and a wingspan of up to 70 cm (27.5 inches). Greater bulldog bats weigh about twice that of the lesser. The short fur of both ranges in…

  • fishing cat (mammal)

    Fishing cat, (species Felis viverrina), tropical cat of the family Felidae, found in India and Southeast Asia. The coat of the fishing cat is pale gray to deep brownish gray and marked with dark spots and streaks. The adult animal stands about 40 cm (16 inches) at the shoulder, weighs 8–11 kg

  • fishing eagle (bird)

    Sea eagle, any of various large fish-eating eagles (especially in the genus Haliaeetus), of which the bald eagle is best known. Sea eagles (sometimes called fish eagles or fishing eagles) live along rivers, big lakes, and tidewaters throughout the world except South America. Some reach 1 metre (3.3

  • fishing industry

    Commercial fishing, the taking of fish and other seafood and resources from oceans, rivers, and lakes for the purpose of marketing them. In the early 21st century about 250 million people were directly employed by the commercial fishing industry, and an estimated one billion people depended on fish

  • fishing line (fishing tackle)

    fishing: Early history: Horsehair fishing lines gave way to lines made of silk, cotton, or linen. The average angler could cast three times farther with these lines, and this increased distance helped spur the development of artificial lures. With longer casting capabilities and more line, a considerable tangle (called an…

  • fishing lure (fishing)

    fishing: Methods: …but grew to use artificial lures—pieces of metal or painted plastic designed to imitate a fish’s natural prey—as well as metal spoons and spinners. The lures are cast in likely fish-rich areas and are retrieved in a manner that allows them to effect a swimming action in the water. Lures…

  • fishing owl (bird)

    Fish owl, any of several species of owls of the family Strigidae (order Strigiformes). They live near water and eat fish as well as small mammals and birds. The several Asian species are of the genus Ketupa; the several African species are of the genus Scotopelia. The brown fish owl (K.

  • fishing reel

    fishing: Early history: …the invention of the fishing reel.

  • fishing rod

    fishing: Early history: …of the line to a rod, at first probably a stick or tree branch, made it possible to fish from the bank or shore and even to reach over vegetation bordering the water.

  • fishing tackle (equipment)

    fishing: Early history: …large part the history of tackle, as the equipment for fishing is called.

  • fishing, commercial

    Commercial fishing, the taking of fish and other seafood and resources from oceans, rivers, and lakes for the purpose of marketing them. In the early 21st century about 250 million people were directly employed by the commercial fishing industry, and an estimated one billion people depended on fish

  • Fishke der krumer (novel by Abramovitsh)

    Yiddish literature: The classic writers: Fishke der krumer (1869; Fishke the Lame), in contrast, is a brilliantly executed short novel. As the narrative moves between Mendele and several other characters, a panorama of Jewish life unfolds. The short novel portrays the misfortunes of itinerant beggars such as the title character. At the same time,…

  • Fishke the Lame (novel by Abramovitsh)

    Yiddish literature: The classic writers: Fishke der krumer (1869; Fishke the Lame), in contrast, is a brilliantly executed short novel. As the narrative moves between Mendele and several other characters, a panorama of Jewish life unfolds. The short novel portrays the misfortunes of itinerant beggars such as the title character. At the same time,…

  • Fishkill Landing (New York, United States)

    Beacon: …17th-century villages of Matteawan and Fishkill Landing were united in 1913. The name was inspired by the fires that blazed atop Mount Beacon during the American Revolution to warn George Washington of British troop movements; the mountain was later a resort, and the Mount Beacon Incline Railway (operated 1901–72) ascended…

  • fishmeal

    Fish meal, coarsely ground powder made from the cooked flesh of fish. Though formerly important as a fertilizer, fish meal is now primarily used in animal feed—especially for poultry, swine, mink, farm-raised fish, and pets. Certain species of oily fish, such as menhaden, anchovy, herring, and

  • Fishmonger’s Fiddle (work by Coppard)

    A.E. Coppard: …collections of stories followed, including Fishmonger’s Fiddle (1925), which contained what is perhaps his best story, “The Higgler.” The charm of his stories lay in his poetic feeling for the countryside and in his amusing and dramatic presentation of rustic characters.

  • Fishmongers Company (British company)

    Billingsgate: …time the gentlemen of the Fishmongers Company, their boots silvered with scales, exercised their functions there, maintaining it as London’s principal fish market. Market activities were moved in 1982 to large modernized premises at the north of the peninsular Isle of Dogs (in Tower Hamlets), where they now neighbour the…

  • Fishpond (California, United States)

    Barstow, city, San Bernardino county, south-central California, U.S. Located in the Mojave Desert, the city lies at a junction of pioneer trails. It was founded in 1880 during a silver-mining rush and was first called Fishpond and then Waterman Junction. It was renamed in 1886 to honour William

  • Fishta, Gjergi (Albanian writer)

    Albanian literature: …authors of the time were Gjergj Fishta, Faik Konitza (Konica), and Fan S. Noli. Fishta—a native of Shkod?r, the literary centre of northern Albania—was a powerful satirist but is best known for his long ballad Lahuta e malcís (1937; The Highland Lute), which celebrates the valour and virtues of Albanian…

  • fishtail kick (swimming)

    swimming: Strokes: …used was abandoned for a fishtail (dolphin) kick, depending only on up-and-down movement of the legs. Later swimmers used two dolphin kicks to one arm pull. Breathing is done in sprint competition by raising the head every second or third stroke.

  • Fisk Jubilee Singers (American singing group)

    Fisk Jubilee Singers, group of African American singers established (1871) at Fisk University in Nashville, Tennessee. It is one of the earliest and most-famous black vocal groups, known for the performance of slave spirituals. Originally known as the Fisk Free Colored School, Fisk University was

  • Fisk University (college, Nashville, Tennessee, United States)

    Fisk University, private, coeducational institution of higher learning in Nashville, Tennessee, U.S. One of the most notable historically black colleges, it is affiliated with the United Church of Christ. It offers undergraduate degree programs in business administration; humanities and fine arts,

  • Fisk, Carlton (American baseball player)

    Carlton Fisk, professional baseball player who played for 24 seasons in the American major leagues between 1969 and 1993. Fisk was one of the most durable catchers in the history of the game. Playing with the Boston Red Sox and the Chicago White Sox, Fisk caught 2,226 games, a record that stood

  • Fisk, Carlton Ernest (American baseball player)

    Carlton Fisk, professional baseball player who played for 24 seasons in the American major leagues between 1969 and 1993. Fisk was one of the most durable catchers in the history of the game. Playing with the Boston Red Sox and the Chicago White Sox, Fisk caught 2,226 games, a record that stood

  • Fisk, Clinton B. (American politician)

    Freedmen's Bureau: Clinton B. Fisk of the Tennessee Freedmen’s Bureau, who gave the school its original facilities in a former Union army barracks. Howard University, founded in 1867 through an act by the U.S. Congress, was named for Maj. Gen. Howard.

  • Fisk, Fidelia (American missionary)

    Fidelia Fiske, American missionary to Persia who worked with considerable success to improve women’s education and health in and around Orumiyeh (Urmia), in present-day Iran. Fidelia Fisk (she later restored the ancestral final e) early exhibited a serious interest in religion. She was said to have

  • Fisk, James (American financier)

    James Fisk, flamboyant American financier, known as the “Barnum of Wall Street,” who joined Jay Gould in securities manipulations and railroad raiding. Fisk worked successively as a circus hand, waiter, peddler, dry-goods salesman, stockbroker, and corporate official. In 1866 he formed Fisk and

  • Fisk, James Brown (American physicist)

    James Brown Fisk, American physicist who, as an electronic research engineer at Bell Laboratories, helped develop microwave magnetrons for high-frequency radar during World War II. At age 17, Fisk entered the Massachusetts Institute of Technology (M.I.T.), where he went on to obtain a bachelor’s

  • Fisk, Pudge (American baseball player)

    Carlton Fisk, professional baseball player who played for 24 seasons in the American major leagues between 1969 and 1993. Fisk was one of the most durable catchers in the history of the game. Playing with the Boston Red Sox and the Chicago White Sox, Fisk caught 2,226 games, a record that stood

  • Fisk, Robert (British journalist and author)

    Robert Fisk, British journalist and best-selling author known for his coverage of the Middle East. Fisk earned a B.A. in English literature at Lancaster University in 1968 and a Ph.D. in political science from Trinity College, Dublin, in 1985. He began his journalism career in 1972 as the Belfast

  • Fisk, Wilbur (American educator)

    Wilbur Fisk, American educator and Methodist clergyman, principal founder of Wesleyan Academy and Wesleyan University in Connecticut. Fisk studied at Peacham Academy and the University of Vermont and graduated from Brown University in 1815 (he received an M.A. in 1818). Licensed as a local preacher

  • fiskal (Russian government agent)

    Russia: The Petrine state: …a network of agents (fiskaly) who acted as tax inspectors, investigators, and personal representatives of the emperor.

  • Fiske, Bradley Allen (United States naval officer)

    Bradley Allen Fiske, U.S. naval officer and inventor whose new instruments greatly improved the efficiency and effectiveness of late 19th-century warships. Fiske graduated from the U.S. Naval Academy in 1874. As the navigator of the gunboat Petrel, he used one of his inventions, a stadimeter range

  • Fiske, Fidelia (American missionary)

    Fidelia Fiske, American missionary to Persia who worked with considerable success to improve women’s education and health in and around Orumiyeh (Urmia), in present-day Iran. Fidelia Fisk (she later restored the ancestral final e) early exhibited a serious interest in religion. She was said to have

  • Fiske, Harrison Grey (American playwright, theatrical manager, and journalist)

    Harrison Grey Fiske, American playwright, theatrical manager, and journalist who with his wife, Minnie Maddern Fiske, produced some of the most significant plays of the emerging realist drama, particularly those of Henrik Ibsen. In love with the stage, Fiske became a dramatic critic in his teens

  • Fiske, Helen Maria (American author)

    Helen Hunt Jackson, American poet and novelist best known for her novel Ramona. She was the daughter of Nathan Fiske, a professor at Amherst (Mass.) College. She lived the life of a young army wife, traveling from post to post, and after the deaths of her first husband, Captain Edward Hunt, and her

  • Fiske, John (American historian)

    John Fiske, American historian and philosopher who popularized European evolutionary theory in the United States. After graduating from Harvard Law School in 1865, Fiske briefly practiced law in Boston before turning to writing. In 1860 he had encountered Herbert Spencer’s adaptation of the

  • Fiske, Minnie Maddern (American actress)

    Minnie Maddern Fiske, American actress who became one of the leading exemplars of realism on the American stage, especially through her performances in Henrik Ibsen’s plays. Fiske made her New York debut at the age of five and for the next few years played children’s roles—e.g., Eva in Uncle Tom’s

  • Fiskenaesset (Greenland)

    Precambrian: Granulite-gneiss rock types: Such complexes occur at Fiskenaesset in western Greenland, in the Limpopo belt of southern Africa, and in southern India. These complexes may have formed at an oceanic ridge in a magma chamber that also fed the basaltic lavas, or they may be parts of oceanic plateaus. In many cases,…

  • Fiskerne (work by Ewald)

    Johannes Ewald: Of his dramatic works, only Fiskerne (1779; “The Fishermen”), an operetta, is still performed. His greatest work in prose is his posthumously published memoirs, in which lyrically pathetic chapters about his lost Arendse intermingle with humorous passages. He is known best as a lyric poet, especially for his great personal…

  • Fiskiekylen (stream, Pennsylvania-Delaware, United States)

    Brandywine Creek, stream in southeastern Pennsylvania and western Delaware, U.S., rising in two branches in Chester county, Pennsylvania, which join near Coatesville. It flows about 20 miles (32 km) southeast past Chadds Ford and through Delaware to join the Christina River just above its

  • fissile core (nuclear physics)

    nuclear weapon: Critical mass and the fissile core: As is indicated above, the minimum mass of fissile material necessary to sustain a chain reaction is called the critical mass. This quantity depends on the type, density, and shape of the fissile material and the degree to which surrounding materials reflect neutrons…

  • fissile material (nuclear physics)

    Fissile material, in nuclear physics, any species of atomic nucleus that can undergo the fission reaction. The principal fissile materials are uranium-235 (0.7 percent of naturally occurring uranium), plutonium-239, and uranium-233, the last two being artificially produced from the fertile m

  • fission (physics)

    thermonuclear warhead: Basic two-stage design: …a two-stage design, featuring a fission or boosted-fission primary (also called the trigger) and a physically separate component called the secondary. Both primary and secondary are contained within an outer metal case. Radiation from the fission explosion of the primary is contained and used to transfer energy to compress and…

  • fission (metaphysics)

    personal identity: Fission and special concern: Because such “fission” cases seem to constitute examples of psychological continuity without personal identity, they have been regarded as a challenge to the psychological view. They also seem to provide examples of quasi-memory that is not memory: the fission products would quasi-remember the past of the original…

  • fission barrier (physics)

    nuclear fission: Structure and stability of nuclear matter: …opposing tendencies set up a barrier in the potential energy of the system, as indicated in Figure 2.

  • fission bomb (fission device)

    Atomic bomb, weapon with great explosive power that results from the sudden release of energy upon the splitting, or fission, of the nuclei of a heavy element such as plutonium or uranium. When a neutron strikes the nucleus of an atom of the isotopes uranium-235 or plutonium-239, it causes that

  • fission fragment (physics)

    radioactivity: The nature of radioactive emissions: …less common forms of radioactivity, fission fragments, neutrons, or protons may be emitted. Fission fragments are themselves complex nuclei with usually between one-third and two-thirds the charge Z and mass A of the parent nucleus. Neutrons and protons are, of course, the basic building blocks of complex nuclei, having approximately…

  • fission hypothesis (astronomy)

    Moon: Origin and evolution: In fission theories a fluid proto-Earth began rotating so rapidly that it flung off a mass of material that formed the Moon. Although persuasive, the theory eventually failed when examined in detail; scientists could not find a combination of properties for a spinning proto-Earth that would…

  • fission product (physics)

    Fission product, in physics, any of the lighter atomic nuclei formed by splitting heavier nuclei (nuclear fission), including both the primary nuclei directly produced (fission fragments) and the nuclei subsequently generated by their radioactive decay. The fission fragments are highly unstable

  • fission yeast (order of fungi)

    fungus: Annotated classification: Order Schizosaccharomycetales (fission yeasts) Saprotrophic in fruit juice; asexual reproduction by fission; asci fuse to form groups of 4 or 8 ascospores; example genus is Schizosaccharomyces. Subphylum Saccharomycotina (true yeasts) Saprotrophic on plants and animals, including

  • fission, nuclear (physics)

    Nuclear fission, subdivision of a heavy atomic nucleus, such as that of uranium or plutonium, into two fragments of roughly equal mass. The process is accompanied by the release of a large amount of energy. In nuclear fission the nucleus of an atom breaks up into two lighter nuclei. The process may

  • fission, spontaneous (physics)

    Spontaneous fission, type of radioactive decay in which certain unstable nuclei of heavier elements split into two nearly equal fragments (nuclei of lighter elements) and liberate a large amount of energy. Spontaneous fission, discovered (1941) by the Russian physicists G.N. Flerov and K.A.

  • fission-track dating (geochronology)

    Fission-track dating, method of age determination that makes use of the damage done by the spontaneous fission of uranium-238, the most abundant isotope of uranium. The fission process results in the release of several hundred million electron volts of energy and produces a large amount of

  • fissionable material (nuclear physics)

    Fissile material, in nuclear physics, any species of atomic nucleus that can undergo the fission reaction. The principal fissile materials are uranium-235 (0.7 percent of naturally occurring uranium), plutonium-239, and uranium-233, the last two being artificially produced from the fertile m

  • Fissipedia (mammal suborder)

    carnivore: Critical appraisal: …them in two suborders, the Fissipedia (“split-footed”) and Pinnipedia (“feather-footed”), of the single order Carnivora. This more conservative taxonomy is followed in this article.

  • fissure (pathology)

    coloboma: Frequently several structures are fissured: the choroid (the pigmented middle layer of the wall of the eye), the retina (the light-sensitive layer of tissue that lines the back and sides of the eye), the ciliary body (the source of the aqueous humour and the site of the ciliary muscle,…

  • fissure of Rolando

    brain: Two major furrows—the central sulcus and the lateral sulcus—divide each cerebral hemisphere into four sections: the frontal, parietal, temporal, and occipital lobes. The central sulcus, also known as the fissure of Rolando, also separates the cortical motor area (which is anterior to the fissure) from the cortical sensory…

  • fissure of Sylvius (anatomy)

    Franciscus Sylvius: …(1641) the deep cleft (Sylvian fissure) separating the temporal (lower), frontal, and parietal (top rear) lobes of the brain.

  • fissure vein (geology)

    vein: There are two distinct types: fissure veins and ladder veins.

  • fissure vent (geology)

    volcano: Fissure vents: These features constitute the surface trace of dikes (underground fractures filled with magma). Most dikes measure about 0.5 to 2 metres (1.5 to 6.5 feet) in width and several kilometres in length. The dikes that feed fissure vents reach the surface from depths…

  • fissure, cerebral (anatomy)

    human nervous system: Morphological development: …the massive growth of the cerebral hemispheres over the sides of the midbrain and of the cerebellum at the hindbrain; and the formations of convolutions (sulci and gyri) in the cerebral cortex and folia of the cerebellar cortex. The central and calcarine sulci are discernible by the fifth fetal month,…

  • Fissurella (mollusk genus)

    gastropod: Size range and diversity of structure: …a limpet shape, as in Fissurella. Often a number of such shell shapes can be found among species within a single family, but such marine families as the Terebridae, Conidae, and Cypraeidae are conservative in shape. Shells of different species vary markedly in thickness, and those of many species bear…

  • Fissurellidae (mollusk)

    gastropod: Classification: …Japan, Australia, and South Africa; keyhole limpets (Fissurellidae) in intertidal rocky areas. Superfamily Patellacea (Docoglossa) Conical-shelled limpets, without slits or holes, found in rocky shallow waters (Acmaeidae and Patellidae). Superfamily Trochacea

  • fist hatchet (tool)

    Acheulean industry: …characteristic Acheulean tools are termed hand axes and cleavers. Considerable improvement in the technique of producing hand axes occurred over the long period; anthropologists sometimes distinguish each major advance in method by a separate number or name. Early Acheulean tool types are called Abbevillian (especially in Europe); the last Acheulean…

Check out Britannica's new site for parents!
Subscribe Today!
色色影院-色色影院app下载