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force

(Encyclopedia)force, commonly, a “push” or “pull,” more properly defined in physics as a quantity that changes the motion, size, or shape of a body. Force is a vector quantity, having both magnitude and dir...

Alma-Tadema, Sir Lawrence

(Encyclopedia)Alma-Tadema, Sir Lawrence ălˈmə-tădˈĭmə [key], 1836–1912, English painter, b. Friesland. He studied in Belgium, where he lived until 1869. In that year he went to England; there he became a c...

Gance, Abel

(Encyclopedia)Gance, Abel, 1889–1981, pioneering French filmmaker. He acted on the stage in the early 1900s and appeared on the silent screen. From 1911 he wrote and directed several films; his first important fi...

Outer Banks

(Encyclopedia)Outer Banks or the Banks, chain of sand barrier islands and peninsulas, c.175 mi (280 km), along the Atlantic coast of SE Va. and E N.C. Separated by inlets and enclosing several saltwater lagoons, or...

thunder

(Encyclopedia)thunder, sound produced along a path of a lightning flash, caused by the rapid heating and expansion of the adjacent air; lightning can heat air to temperatures as much as five times hotter than those...

exile, in politics and government

(Encyclopedia)exile, removal of a national from his or her country, or the civilized parts of it, for a long period of time or for life. Exile may be a forceful expulsion by the government or a voluntary removal by...

McCormack, John

(Encyclopedia)McCormack, John, 1884–1945, Irish-American tenor, b. Athlone, Ireland. He made his debut in London in 1907. In 1909, Oscar Hammerstein brought him to the United States. After his debut in New York C...

analog-to-digital conversion

(Encyclopedia)analog-to-digital or A/D conversion, the process of changing continuously varying data, such as voltage, current, or shaft rotation, into discrete digital quantities that represent the magnitude of th...

sonar

(Encyclopedia)sonar sōˈnär [key], device used underwater for locating submerged objects and for submarine communication by means of sound waves. The term sonar is an acronym for sound navigation ranging. The mai...

celestial mechanics

(Encyclopedia)celestial mechanics, the study of the motions of astronomical bodies as they move under the influence of their mutual gravitation. Celestial mechanics analyzes the orbital motions of planets, dwarf pl...