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modem
modem [ mo dulator/ dem odulator], an external device or internal electronic circuitry used to transmit and receive digital data over a communications line normally used for analog signals. A modem attached to a computer converts digital data to an analog signal that it uses to modulate a carrier...
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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 invented by Alexander Graham Bell and patented by him in 1876 and 1877. Although Bell is recognized as the inventor, his telephone...
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radio
radio transmission or reception of electromagnetic radiation in the radio frequency range. The term is commonly applied also to the equipment used, especially to the radio receiver.
Uses of Radio Waves
The prime purpose of radio is to convey information from one place to another throu...
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cable television
cable television the transmission of televised images to viewers by means of coaxial cables. Cable systems receive the television signal, which is sent out over cables to individual subscribers, by a common antenna (CATV) or satellite dish. Early cable systems developed in the late 1940s to improve...
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Babylon
Babylon residential village (1990 pop. 12,249), Suffolk co., SE N.Y., on Long Island, on Great South Bay; settled 1689, inc. 1893. The first U.S. wireless station was built there by Marconi.
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Guglielmo Marconi, Marchese
Guglielmo Marconi, Marchese , 1874-1937, Italian physicist, celebrated for his development of wireless telegraphy (see radio ). In the field of electromagnetic waves he correlated and improved inventions of H. R. Hertz , Édouard Branly, and other scientists and invented a practical antenna....
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Karl Ferdinand Braun
Karl Ferdinand Braun , 1850-1918, German physicist. Braun taught at the Univ. of Marburg, Strasbourg Univ., Karlsruhe's Technische Hochschule, and the Univ. of Tübingen before being named director of Physics institute at Strasbourg in 1895. He conducted researches in electricity (an electromete...
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Lee De Forest
Lee De Forest 1873-1961, American inventor, b. Council Bluffs, Iowa, grad. Yale, 1896. He was a pioneer in the development of wireless telegraphy, sound pictures, and television. His triode (1906) made practicable transcontinental telephony, both wire and wireless, and led to the foundation of the ...
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Glace Bay
Glace Bay , town (1991 pop. 19,501), E Cape Breton Island, N.S., Canada. Exploitation of its coal mines began toward the end of the 19th cent., but declined in the 1960s; the last mine in the region closed in 2001. Its mines extended for several miles under the sea and were among the best equipped i...
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gear
gear toothed wheel, cylinder, or cone that transmits motion from one part of a machine to another; it is one of the oldest means of transmitting motion. When the teeth of two gears are meshed, turning one gear will cause the other to rotate. In most cases both gears are mounted on shafts so that wh...
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