Columbia Encyclopedia

Search results

500 results found

right of way

(Encyclopedia)right of way, in land and air traffic and in sea navigation, rules that determine precedence in the use of traffic lanes. The rules are framed in the simplest possible terms and with nearly absolute u...

polar front

(Encyclopedia)polar front, zone of transition between polar and tropical air masses. Its average position during the winter is at about 30° lat. and during the summer at about 60° lat. In the N Atlantic Ocean, fo...

Cartagena, city, Spain

(Encyclopedia)Cartagena, Lat. Carthago Nova, city, Murcia prov., SE Spain, on the Mediterranean Sea. A major seaport and naval base, it has a fine natural harbor,...

electroweak theory

(Encyclopedia)electroweak theory, a unified field theory that describes two of the fundamental forces in nature, electromagnetism (see electromagnetic radiation) and the weak interaction. The electroweak theory der...

perturbation

(Encyclopedia)perturbation pŭrˌtərbāˈshən [key], in astronomy and physics, small force or other influence that modifies the otherwise simple motion of some object. The term is also used for the effect produce...

evaporation

(Encyclopedia)evaporation, change of a liquid into vapor at any temperature below its boiling point. For example, water, when placed in a shallow open container exposed to air, gradually disappears, evaporating at ...

newton, unit of measure

(Encyclopedia)newton, abbr. N, unit of force in the mks system of units, which is based on the metric system; it is the force that produces an acceleration of 1 meter per second per second when exerted on a mass of...

dyne

(Encyclopedia)dyne dīn [key], unit of force in the cgs system of units, which is based on the metric system; an acceleration of 1 centimeter per second per second is produced when a force of 1 dyne is exerted on a...

Strategic Defense Initiative

(Encyclopedia)Strategic Defense Initiative (SDI), former U.S. government program responsible for research and development of a space-based system to defend the nation from attack by strategic ballistic missiles (se...

Lorient

(Encyclopedia)Lorient lôryăNˈ [key], town (1990 pop. 61,630), Morbihan dept., NW France, a port and naval station on the Atlantic Ocean. A great shipbuilding center, Lorient also produces textiles, furniture, an...