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communications industry

(Encyclopedia)communications industry, broadly defined, the business of conveying information. Although communication by means of symbols and gestures dates to the beginning of human history, the term generally ref...

Uranus , in astronomy

(Encyclopedia)Uranus yo͝orāˈnəs, yo͝orˈə– [key], in astronomy, 7th planet from the sun, at a mean distance of 1.78 billion mi (2.87 billion km), with an orbit lying between those of Saturn and Neptune; its...

electromagnetic radiation

(Encyclopedia)CE5 Electromagnetic spectrum electromagnetic radiation, energy radiated in the form of a wave as a result of the motion of electric charges. A moving charge gives rise to a magnetic field, and if ...

Reagan, Ronald Wilson

(Encyclopedia)Reagan, Ronald Wilson rāˈgən [key], 1911–2004, 40th president of the United States (1981–89), b. Tampico, Ill. In 1932, after graduation from Eureka College, he became a radio announcer and spo...

painting

(Encyclopedia)painting, direct application of pigment to a surface to produce by tones of color or of light and dark some representation or decorative arrangement of natural or imagined forms. See also articles on ...

Joyce, James

(Encyclopedia)Joyce, James, 1882–1941, Irish novelist. Perhaps the most influential and significant novelist of the 20th cent., Joyce was a master of the English language, exploiting all of its resources. His nov...

uncertainty principle

(Encyclopedia)uncertainty principle, physical principle, enunciated by Werner Heisenberg in 1927, that places an absolute, theoretical limit on the combined accuracy of certain pairs of simultaneous, related measur...

Egyptian language

(Encyclopedia)Egyptian language, extinct language of ancient Egypt, a member of the Afroasiatic family of languages (see Afroasiatic languages). The development of ancient Egyptian is usually divided into four peri...

Xenophon

(Encyclopedia)Xenophon zĕnˈəfən [key], c.430 b.c.–c.355 b.c., Greek historian, b. Athens. He was one of the well-to-do young disciples of Socrates before leaving Athens to join the Greek force (the Ten Thousa...

Cepheid variables

(Encyclopedia)Cepheid variables sēˈfēĭd [key], class of variable stars that brighten and dim in an extremely regular fashion. The periods of the fluctuations (the time to complete one cycle from bright to dim a...