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Lorentz contraction

(Encyclopedia)Lorentz contraction lôrˈĕnts [key], in physics, contraction or foreshortening of a moving body in the direction of its motion, proposed by H. A. Lorentz on theoretical grounds and based on an earli...

uncertainty principle

(Encyclopedia)uncertainty principle, physical principle, enunciated by Werner Heisenberg in 1927, that places an absolute, theoretical limit on the combined accuracy of certain pairs of simultaneous, related measur...

barbiturate

(Encyclopedia)barbiturate bärbĭchˈərātˌ [key], any one of a group of drugs that act as depressants on the central nervous system. High doses depress both nerve and muscle activity and inhibit oxygen consumpti...

Dyson, Sir Frank Watson

(Encyclopedia)Dyson, Sir Frank Watson dīˈsən [key], 1868–1939, English astronomer, b. Ashby-de-la-Zouch, grad. Cambridge. He was astronomer royal of Scotland (1905–10) and of England (from 1910). As director...

color index

(Encyclopedia)color index, in astronomy, difference in an object's brightness as recorded between any two well-defined bands of the electromagnetic spectrum by using optical filters of different colors. If blue and...

Civilis

(Encyclopedia)Civilis (Julius Civilis) sĭvīˈlĭs [key], fl. a.d. 70, Batavian chief who chose the unsettled period at the fall of Nero to raise a revolt in Germany, which quickly spread to Gaul (a.d. 69–70). I...

irony

(Encyclopedia)irony, figure of speech in which what is stated is not what is meant. The user of irony assumes that his reader or listener understands the concealed meaning of his statement. Perhaps the simplest for...

intaglio

(Encyclopedia)intaglio ĭntălˈyō, –tälˈ– [key], design cut into stone or other material or etched or engraved in a metal plate, producing a concave, instead of a convex, effect. It is the reverse of a reli...

Haldane, John Scott

(Encyclopedia)Haldane, John Scott, 1860–1936, British scientist, b. Edinburgh; father of John Burdon Sanderson Haldane. He made many important contributions to mine safety, investigating principally the action of...

Goyen, Jan Josephszoon van

(Encyclopedia)Goyen, Jan Josephszoon van yän yōˈzəfsōn vän gōˈyən [key], 1596–1656, Dutch landscape painter. He studied at Leiden and Haarlem. In 1631 he settled at The Hague. His typically Dutch landsca...