Columbia Encyclopedia

Search results

458 results found

continental drift

(Encyclopedia)CE5 Continental drift (arrows indicate the directions of motion of the landmasses) A. Proposed reconstruction of the supercontinent Pangaea indicating the major present landmasses B. Proposed recon...

friction

(Encyclopedia)friction, resistance offered to the movement of one body past another body with which it is in contact. In certain situations friction is desired. Without friction the wheels of a locomotive could not...

parallax

(Encyclopedia)CE5 The trigonometric parallax of a star, expressed by the angle θ, is a measure of its apparent motion against the background of more distant stars as a result of the earth's motions in its orbit...

differential

(Encyclopedia)differential, in the automobile, a set of gears used on the driving (usually rear) axle. The two wheels on the driving axle must be interconnected in order to receive their energy from the same source...

horology

(Encyclopedia)horology hōrŏlˈəjē [key], science of measuring time and technology of constructing instruments for its measurement or recording. Early measurements of the passage of time were based on observatio...

Halley, Edmond

(Encyclopedia)Halley, Edmond hălˈē, hôˈlē [key], 1656–1742, English astronomer and mathematician. He is particularly noted as the first astronomer to predict the return of a comet and the first to point out...

Hollywood

(Encyclopedia)Hollywood. 1 Community (2020 population 35,757) within the city of Los Angeles, S Calif., on the slopes of the Santa Monica Mts.; inc. 1903, ...

minstrel show

(Encyclopedia)minstrel show, stage entertainment by white performers made up as blacks. Thomas Dartmouth Rice, who gave (c.1828) the first solo performance in blackface and introduced the song-and-dance act Jim Cro...

acetic acid

(Encyclopedia)acetic acid əsēˈtĭk [key], CH3CO2H, colorless liquid that has a characteristic pungent odor, boils at 118℃, and is miscible with water in all proportions; it is a weak organic carboxylic acid (s...

magnetic pole

(Encyclopedia)magnetic pole, the two roughly opposite ends of the planet where the earth's magnetic intensity is the greatest, as the north and south magnetic poles. For the magnetic north, it is the direction from...