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chromosphere

(Encyclopedia)chromosphere krōˈməsfērˌ [key] [Gr.,=color sphere], layer of rarefied, transparent gases in the solar atmosphere; it measures 6,000 mi (9,700 km) in thickness and lies between the photosphere (th...

echo, in acoustics

(Encyclopedia)echo, reflection of a sound wave back to its source in sufficient strength and with a sufficient time lag to be separately distinguished. If a sound wave returns within 1⁄10 sec, the human ear is in...

magnetron

(Encyclopedia)magnetron măgˈnĭtrŏnˌ [key], vacuum tube oscillator (see electron tube) that generates high-power electromagnetic signals in the microwave frequency range. Its operation is based on the combined ...

Arecibo Observatory

(Encyclopedia)Arecibo Observatory, radio-astronomy facility located near Arecibo, Puerto Rico, part of the National Astronomy and Ionosphere Center. Conceived by, designed by, and built under the supervision of Wil...

Kawasaki disease

(Encyclopedia)Kawasaki disease or Kawasaki syndrome, acute illness characterized by inflammation of the blood vessels that primarily affects young children; it is more common in boys and children of Asian descent. ...

resistance, in electricity

(Encyclopedia)resistance, property of an electric conductor by which it opposes a flow of electricity and dissipates electrical energy away from the circuit, usually as heat. Optimum resistance is provided by a con...

SETI

(Encyclopedia)SETI sĕtˈē [key] [Search for ExtraTerrestrial Intelligence], name given to a series of independent programs to detect radio signals from civilizations beyond the solar system. Modern SETI efforts c...

data communications

(Encyclopedia)data communications, application of telecommunications technology to the problem of transmitting data, especially to, from, or between computers. In popular usage, it is said that data communications ...

mutiny

(Encyclopedia)mutiny, concerted disobedient or seditious action by persons in military or naval service, or by sailors on commercial vessels. Mutiny may range from a combined refusal to obey orders to active revolt...

Cadillac, Antoine de la Mothe

(Encyclopedia)Cadillac, Antoine de la Mothe Fr. äNtwänˈ də lä môt kädēyäkˈ [key], c.1658–1730, French colonial governor in North America, founder of Detroit. Of the minor Gascon nobility, he came to Ame...