Columbia Encyclopedia
Search results
171 results found
density
(Encyclopedia)density, ratio of the mass of a substance to its volume, expressed, for example, in units of grams per cubic centimeter or pounds per cubic foot. The density of a pure substance varies little from sam...optical density
(Encyclopedia)optical density: see refraction. ...specific gravity
(Encyclopedia)specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the t...Archimedes' principle
(Encyclopedia)Archimedes' principle, principle that states that a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid. The principle applies to both floating and submerged bo...mirage
(Encyclopedia)mirage mĭräzhˈ [key], atmospheric optical illusion in which an observer sees in the distance a nonexistent body of water or an image, sometimes distorted, of some object or of a complete scene. Exa...osteoporosis
(Encyclopedia)osteoporosis ŏsˌtēōˌpərōˈsĭs [key], disorder in which the normal replenishment of old bone tissue is severely disrupted, resulting in weakened bones and increased risk of fracture; osteopenia...tesla
(Encyclopedia)tesla tĕsˈlə [key], unit of magnetic flux density: see under weber. ...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...Persichetti, Vincent
(Encyclopedia)Persichetti, Vincent, 1915–87, American composer, b. Philadelphia. Persichetti taught at the Philadelphia Conservatory and at Juilliard. His music is notable for polytonal combinations, contrapuntal...arteriosclerosis
(Encyclopedia)arteriosclerosis ärtĭrˌēōsklərōˈsis [key], general term for a condition characterized by thickening, hardening, and loss of elasticity of the walls of the blood vessels. These changes are freq...Browse by Subject
- Earth and the Environment +-
- History +-
- Literature and the Arts +-
- Medicine +-
- People +-
- Philosophy and Religion +-
- Places +-
- Africa
- Asia
- Australia and Oceania
- Britain, Ireland, France, and the Low Countries
- Commonwealth of Independent States and the Baltic Nations
- Germany, Scandinavia, and Central Europe
- Latin America and the Caribbean
- Oceans, Continents, and Polar Regions
- Spain, Portugal, Italy, Greece, and the Balkans
- United States, Canada, and Greenland
- Plants and Animals +-
- Science and Technology +-
- Social Sciences and the Law +-
- Sports and Everyday Life +-
