Columbia Encyclopedia

Search results

139 results found

laser

(Encyclopedia)CE5 Ordinary light sources produce incoherent light, while a laser produces a beam of coherent light. laser [acronym for light amplification by stimulated emission of radiation], device for the cr...

Corea, Chick

(Encyclopedia) Corea, Chick (Armando Anthony), 1941-2021, American jazz pianist, composer, and bandleader, b. Chelsea, Ma. Corea’s father was a bandleader in Boston...

apparition

(Encyclopedia)apparition, spiritualistic manifestation of a person or object in which a form not actually present is seen with such intensity that belief in its reality is created. The ancient and widespread belief...

oscillator, electronic

(Encyclopedia)oscillator, electronic ŏsˈəlāˌtər [key], electronic circuit that produces an output signal of a specific frequency. An oscillator generally consists of an amplifier having part of its output ret...

personal digital assistant

(Encyclopedia)personal digital assistant (PDA), lightweight, hand-held computer designed for use as a personal organizer with communications capabilities; also called a handheld. A typical PDA has no keyboard, rely...

divination

(Encyclopedia)divination, practice of foreseeing future events or obtaining secret knowledge through communication with divine sources and through omens, oracles, signs, and portents. It is based on the belief in r...

cathode-ray tube

(Encyclopedia)CE5 Cathode-ray tube cathode-ray tube (CRT), special-purpose electron tube in which electrons are accelerated by high-voltage anodes, formed into a beam by focusing electrodes, and projected towar...

calcium hydroxide

(Encyclopedia)calcium hydroxide, Ca(OH)2, colorless crystal or white powder. It is prepared by reacting calcium oxide (lime) with water, a process called slaking, and is also known as hydrated lime or slaked lime. ...

Baykal

(Encyclopedia)Baykal or Baikal both: bīkälˈ [key], lake, 12,160 sq mi (31,494 sq km), SE Siberian Russia. It is the largest freshwater lake of Eurasia, with a width up to 50 mi (80 km) and a length of c.395 mi (...

Monte Albán

(Encyclopedia)Monte Albán mōnˈtā älbänˈ [key], ancient city, c.7 mi (11.3 km) from Oaxaca, SW Mexico, capital of the Zapotec. Monte Albán was built on an artificially leveled, rocky promontory above the Val...