Columbia Encyclopedia

Search results

177 results found

interference

(Encyclopedia)CE5 Constructive interference: Two crests or two troughs meet and combine (A, B, C). Destructive interference: A crest and a trough meet and cancel each other (D, E, F). interference, in physics, ...

tunnel

(Encyclopedia)tunnel, underground passage usually made without removing the overlying rock or soil. Although tunnels are approximately horizontal, they must be built with sufficient gradient for proper drainage. Tu...

observatory

(Encyclopedia)observatory, scientific facility especially equipped to detect and record naturally occurring scientific phenomena. Although geological and meteorological observatories exist, the term is generally ap...

telephone

(Encyclopedia)CE5 Hand telephone telephone, device for communicating sound, especially speech, usually by means of wires in an electric circuit. The telephones now in general use evolved from the device invente...

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...

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...

Xinjiang

(Encyclopedia)Xinjiang shĭnˈjyängˈ, sĭnˈkyăng [key] [Chinese,=new frontier], officially Xinjiang Uygur Autonomous Region (Mandarin Xinjiang Uygur Zizhiqu), autonomous region (2010 pop. 21,813,334), c.637,000...

battery, electric

(Encyclopedia)CE5 Lead storage cell: At the lead-dioxide electrode, electrons from the circuit combine with lead dioxide and sulfuric acid to form lead sulfate and water. At the spongy-lead electrode, lead react...

Franklin, Benjamin

(Encyclopedia)Franklin, Benjamin, 1706–90, American statesman, printer, scientist, and writer, b. Boston. The only American of the colonial period to earn a European reputation as a natural philosopher, he is bes...

dinosaur

(Encyclopedia)dinosaur dīˈnəsôr [key] [Gr., = terrible lizard], extinct land reptile of the Mesozoic era. The dinosaurs, which were egg-laying animals, ranged in length from 21⁄2 ft (91 cm) to about 127 f...