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Nicholas of Cusa

(Encyclopedia)Nicholas of Cusa (Nicolaus Cusanus), 1401?–1464, German humanist, scientist, statesman, and philosopher, from 1448 cardinal of the Roman Catholic Church. The son of a fisherman, Nicholas was educate...

vortex

(Encyclopedia)vortex vôrˈtĕks [key], mass of fluid in whirling or rotary motion. To simplify the analysis, vortex motion usually describes motions in a frictionless fluid. In such cases the absence of friction w...

damp

(Encyclopedia)damp, in mining, any mixture of gases in an underground mine, especially oxygen-deficient or noxious gases. The term damp probably is derived from the German dampf, meaning fog or vapor. Several disti...

Sargon, king of Akkad

(Encyclopedia)Sargon särˈgŏn [key], king of Akkad in Mesopotamia (reigned c.2340–c.2305 b.c.). By conquest he established a great empire that included the whole of Mesopotamia and extended over Syria and Elam,...

Dalton's law

(Encyclopedia)Dalton's law [for John Dalton], physical law that states that the total pressure exerted by a homogeneous mixture of gases is equal to the sum of the partial pressures of the individual gases. The par...

Robert of Geneva

(Encyclopedia)Robert of Geneva, d. 1394, Genevan churchman, antipope (1378–94; see Schism, Great) with the name Clement VII. He was archbishop of Cambrai (1368) and was created (1371) a cardinal. He was subsequen...

Pisa, Council of

(Encyclopedia)Pisa, Council of, 1409, unrecognized council of the Roman Catholic Church. It was summoned to end the Great Schism (see Schism, Great) by members of the colleges of cardinals of the two rivals, Gregor...

inert gas

(Encyclopedia)inert gas or noble gas, any of the elements in Group 18 of the periodic table. In order of increasing atomic number they are: helium, neon, argon, krypton, xenon, and radon. They are colorless, odorle...

chemistry

(Encyclopedia)chemistry, branch of science concerned with the properties, composition, and structure of substances and the changes they undergo when they combine or react under specified conditions. Organic chemi...

nerve gas

(Encyclopedia)nerve gas, any of several poison gases intended for military use, e.g., tabun, sarin, soman, and VX. Nerve gases were first developed by Germany during World War II but were not used at that time. The...