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Galois, Évariste

(Encyclopedia)Galois, Évariste āvärēstˈ gälwäˈ [key], 1811–32, French mathematician. At the age of 17 he had evolved original concepts on the theory of algebra. He made important contributions to the theo...

global warming

(Encyclopedia)global warming, the gradual increase of the temperature of the earth's lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution. Global warming and its effects,...

Jerusalem, Latin Kingdom of

(Encyclopedia)Jerusalem, Latin Kingdom of, feudal state created by leaders of the First Crusade (see Crusades) in the areas they had wrested from the Muslims in Syria and Palestine. In 1099, after their capture of ...

will-o'-the-wisp

(Encyclopedia)will-o'-the-wisp, phenomenon known also as ignis fatuus and jack-o'-lantern. It is seen at night as a pale, flickering light over marshland. There is no generally accepted explanation for it; it may r...

septic tank

(Encyclopedia)septic tank, underground sedimentation tank in which sewage is retained for a short period while it is decomposed and purified by bacterial action. The organic matter in the sewage settles to the bott...

expansion

(Encyclopedia)expansion, in physics, increase in volume resulting from an increase in temperature. Contraction is the reverse process. When heat is applied to a body, the rate of vibration and the distances between...

Compton, Karl Taylor

(Encyclopedia)Compton, Karl Taylor, 1887–1954, American physicist, b. Wooster, Ohio, grad. College of Wooster (Ph.B., 1908), Princeton (Ph.D., 1912); brother of A. H. Compton. He taught at Princeton from 1915 to ...

correspondence principle

(Encyclopedia)correspondence principle, physical principle, enunciated by Niels Bohr in 1923, according to which the predictions of the quantum theory must correspond to the predictions of the classical theories of...

safety lamp

(Encyclopedia)safety lamp, oil lamp designed for safe use in mines and other places where flammable gases such as firedamp (see damp) may be present. Its invention (c.1816) is usually attributed to Sir Humphry Davy...

Fisher, Irving

(Encyclopedia)Fisher, Irving, 1867–1947, American economist, b. Saugerties, N.Y., Ph.D. Yale, 1891. He began teaching at Yale in 1890 and was active there until 1935. His earliest work was in mathematics, and he ...