Columbia Encyclopedia

Search results

500 results found

Kelvin, William Thomson, 1st Baron

(Encyclopedia)Kelvin, William Thomson, 1st Baron, 1824–1907, British mathematician and physicist, b. Belfast. He was professor of natural philosophy at the Univ. of Glasgow (1846–99). He is known especially for...

plasma

(Encyclopedia)plasma, in physics, fully ionized gas of low density, containing approximately equal numbers of positive and negative ions (see electron and ion). It is electrically conductive and is affected by magn...

kinetic-molecular theory of gases

(Encyclopedia)kinetic-molecular theory of gases, physical theory that explains the behavior of gases on the basis of the following assumptions: (1) Any gas is composed of a very large number of very tiny particles ...

blackbody

(Encyclopedia)blackbody, in physics, an ideal black substance that absorbs all and reflects none of the radiant energy falling on it. Lampblack, or powdered carbon, which reflects less than 2% of the radiation fall...

International System of Units

(Encyclopedia)International System of Units, officially called the Système International d'Unités, or SI, system of units adopted by the 11th General Conference on Weights and Measures (1960). It is based on the ...

thermodynamics

(Encyclopedia)thermodynamics, branch of science concerned with the nature of heat and its conversion to mechanical, electric, and chemical energy. Historically, it grew out of efforts to construct more efficient he...

Réaumur, René Antoine Ferchault de

(Encyclopedia)Réaumur, René Antoine Ferchault de rāˈəmyo͝or, Fr. rənāˈ äNtwänˈ fĕrshōˈ də rāōmürˈ [key], 1683–1757, French physicist and naturalist. He invented an alcohol thermometer (1731) a...

incubator

(Encyclopedia)incubator, apparatus for the maintenance of controlled conditions in which eggs can be hatched artificially. Incubator houses with double walls of mud, a fireroom, and several compartments each holdin...

hydrometer

(Encyclopedia)hydrometer hīdrŏmˈətər [key], device used to determine directly the specific gravity of a liquid. It usually consists of a thin glass tube closed at both ends, with one end enlarged into a bulb t...

ice cream

(Encyclopedia)ice cream, sweet frozen dessert, made from milk fat and solids, sugar, flavoring, a stabilizer (usually gelatin), and sometimes eggs, fruits, or nuts. The mix is churned at freezing temperature to att...
 

Browse by Subject