Columbia Encyclopedia

Search results

472 results found

Brown, Trisha

(Encyclopedia)Brown, Trisha, 1936–2017, American dancer and choreographer acclaimed for having revolutionized modern dance in the late 20th cent., b. Aberdeen, Wash. After studying dance at Mills College (B.A., 1...

Pluto, in astronomy

(Encyclopedia)Pluto, in astronomy, a dwarf planet and the first Kuiper belt, or transneptunian, object (see comet) to be discovered (1930) by astronomers. Pluto has an elliptical orbit usually lying beyond that of ...

nicotine

(Encyclopedia)nicotine, C10H14N2, poisonous, pale yellow, oily liquid alkaloid with a pungent odor and an acrid taste. It turns brown on exposure to air. Nicotine, a naturally occurring constituent of tobacco, is t...

nonlinear dynamics

(Encyclopedia)nonlinear dynamics, study of systems governed by equations in which a small change in one variable can induce a large systematic change; the discipline is more popularly known as chaos (see chaos theo...

titanium

(Encyclopedia)titanium tītāˈnēəm, tĭ– [key] [from Titan], metallic chemical element; symbol Ti; at. no. 22; at. wt. 47.867; m.p. 1,675℃; b.p. 3,260℃; sp. gr. 4.54 at 20℃; valence +2, +3, or +4. Titani...

chain reaction

(Encyclopedia)CE5 Chain reaction: A neutron (n) strikes the uranium nucleus (U-235), causing it to split into fission products A and B and release two neutrons. These neutrons can in turn cause further fissions....

sodium

(Encyclopedia)sodium, a metallic chemical element; symbol Na [Lat. natrium]; at. no. 11; at. wt. 22.98977; m.p. 97.81℃; b.p. 892.9℃; sp. gr. 0.971 at 20℃; valence +1. Sodium is a soft, silver-white metal. Ext...

plating

(Encyclopedia)plating, application of a plate, or coat, of metal to a surface for decoration, reflection of light, protection against corrosion, or increased wearing quality. The practice is of ancient origin: gild...

nuclear reactor

(Encyclopedia)CE5 Power reactor system nuclear reactor, device for producing controlled release of nuclear energy. Reactors can be used for research or for power production. A research reactor is designed to pr...

mining

(Encyclopedia)mining, extraction of solid mineral resources from the earth. These resources include ores, which contain commercially valuable amounts of metals, such as iron and aluminum; precious stones, such as d...