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quantum theory

(Encyclopedia)quantum theory, modern physical theory concerned with the emission and absorption of energy by matter and with the motion of material particles; the quantum theory and the theory of relativity togethe...

mangrove

(Encyclopedia)mangrove, large tropical evergreen tree, genus Rhizophora, that grows on muddy tidal flats and along protected ocean shorelines. Mangroves are most abundant in tropical Asia, Africa, and the islands o...

Roche limit

(Encyclopedia)Roche limit, the closest distance that a celestial body held together only by its own gravity can come to a planet without being pulled apart by the planet's tidal (gravitational) force. This distance...

New York Bay

(Encyclopedia)New York Bay, arm of the Atlantic Ocean at the mouth of the Hudson River, SE N.Y. and NE N.J., enclosed by the shores of NE New Jersey, E Staten Island, S Manhattan, and W Long Island (Brooklyn) and o...

electroencephalography

(Encyclopedia)electroencephalography əlĕkˌtrōĕnsĕfˌəlŏgˈrafē [key], science of recording and analyzing the electrical activity of the brain. Electrodes, placed on or just under the scalp, are linked to a...

hydrogen bomb

(Encyclopedia)hydrogen bomb or H-bomb, weapon deriving a large portion of its energy from the nuclear fusion of hydrogen isotopes. In an atomic bomb, uranium or plutonium is split into lighter elements that togethe...

Munk, Walter Heinrich

(Encyclopedia)Munk, Walter Heinrich, 1917–2019, American oceanographer and geophysicist, b. Vienna (then in Austria-Hungary), B.S. California Institute of Technology, 1939, Ph.D Univ. of California, Los Angeles, ...

Gomułka, Władysław

(Encyclopedia)Gomułka, Władysław vwädĭsˈwäf gəmo͝oˈkə [key], 1905–82, Polish Communist leader. Long a Communist, he helped establish the Polish Workers' party and was (1943–49) secretary of its centr...

Rohmer, Eric

(Encyclopedia)Rohmer, Eric, 1920–2010, French film director and writer, b. Jean-Marie Maurice Schérer. He was a founder (1950) of La Gazette du cinéma, cowrote (1957) a study of Alfred Hitchcock, and edited (19...

Singleton, Benjamin

(Encyclopedia)Singleton, Benjamin, c. 1809–c. 1900, African-American leader of post–Civil War black resettlement in the West, b. Davidson co. (now coextensive with Nashville), Tenn. He escaped slavery in 1846, ...