Columbia Encyclopedia

Search results

214 results found

Sparta

(Encyclopedia)Sparta spärˈtə [key], city of ancient Greece, capital of Laconia, on the Eurotas (Evrótas) River in the Peloponnesus. By the 6th cent. b.c., Sparta was the strongest Greek city. In the Persian ...

gravitation

(Encyclopedia)gravitation, the attractive force existing between any two particles of matter. The term gravitygravity is commonly used synonymously with gravitation, but in correct usage a definite distinction is...

infrared astronomy

(Encyclopedia)infrared astronomy, study of celestial objects by means of the infrared radiation they emit, in the wavelength range from about 1 micrometer to about 1 millimeter. All objects, from trees and building...

Tonga

(Encyclopedia)Tonga tŏngˈgə [key], officially Kingdom of Tonga, island kingdom (2015 est. pop. 106,000), 270 sq mi (699 sq km), South Pacific, c.2000 mi (3,220 km) NE of Sydney, Australia. Tonga is the only surv...

North Atlantic Treaty Organization

(Encyclopedia)North Atlantic Treaty Organization (NATO), established under the North Atlantic Treaty (Apr. 4, 1949) by Belgium, Canada, Denmark, France, Great Britain, Iceland, Italy, Luxembourg, the Netherlands, N...

blood

(Encyclopedia)blood, fluid pumped by the heart that circulates throughout the body via the arteries, veins, and capillaries (see circulatory system; heart). An adult male of average size normally has about 6 quarts...

calendar

(Encyclopedia)calendar [Lat., from Kalends], system of reckoning time for the practical purpose of recording past events and calculating dates for future plans. The calendar is based on noting ordinary and easily o...

Andes

(Encyclopedia)Andes ănˈdēz [key], mountain system, more than 5,000 mi (8,000 km) long, W South America. The ranges run generally parallel to the Pacific coast and extend from Tierra del Fuego northward, across t...

bee

(Encyclopedia)bee, name for flying insects of the superfamily Apoidea, in the same order as the ants and the wasps. Bees are characterized by their enlarged hind feet, typically equipped with pollen baskets of stif...

bat

(Encyclopedia)bat, winged mammal of the order Chiroptera, which includes 900–1,000 species classified in about 200 genera and 17 families. Bats range in size from a wingspread of over 5 ft (150 cm) to a wingsprea...