History of televisionThe concept of television is the work of many individuals in the late 19th and early 20th centuries. The first practical transmissions of moving images over a radio system used mechanical rotating perforated disks to scan a scene into a time-varying signal that could be reconstructed at a receiver back into an approximation of the original image. Development of television was interrupted by the Second World War. After the end of the war, all-electronic methods of scanning and displaying images became standard.
History of videotelephonyBarely two years after the telephone was first patented in the United States in 1876 by Alexander Graham Bell, an early concept of a combined videophone and wide-screen television called a telephonoscope was conceptualized in the popular periodicals of the day. It was also mentioned in various early science fiction works such as Le Vingtième siècle. La vie électrique (The 20th century. The electrical life) and other works written by Albert Robida, and was also sketched in various cartoons by George du Maurier as a fictional invention of Thomas Edison.
History of the telephoneThis history of the telephone chronicles the development of the electrical telephone, and includes a brief overview of its predecessors. The first telephone patent was granted to Alexander Graham Bell in 1876. Before the invention of electromagnetic telephones, mechanical acoustic devices existed for transmitting speech and music over a greater distance. This distance was greater than that of normal direct speech. The earliest mechanical telephones were based on sound transmission through pipes or other physical media.
Timeline of the telephoneThis timeline of the telephone covers landline, radio, and cellular telephony technologies and provides many important dates in the history of the telephone. 1667: Robert Hooke creates an acoustic string telephone that conveys sounds over a taut extended wire by mechanical vibrations. 1844: Innocenzo Manzetti first suggests the idea of an electric "speaking telegraph", or telephone. 1849: Antonio Meucci demonstrates a communicating device to individuals in Havana.
Global networkA global network is any communication network which spans the entire Earth. The term, as used in this article refers in a more restricted way to bidirectional communication networks, and to technology-based networks. Early networks such as international mail and unidirectional communication networks, such as radio and television, are described elsewhere. The first global network was established using electrical telegraphy and global span was achieved in 1899. The telephony network was the second to achieve global status, in the 1950s.
History of broadcastingIt is generally recognized that the first radio transmission was made from a temporary station set up by Guglielmo Marconi in 1895 on the Isle of Wight. This followed on from pioneering work in the field by a number of people including Alessandro Volta, André-Marie Ampère, Georg Ohm and James Clerk Maxwell. The radio broadcasting of music and talk intended to reach a dispersed audience started experimentally around 1905–1906, and commercially around 1920 to 1923. VHF (very high frequency) stations started 30 to 35 years later.
History of radioThe early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting. Invention of radio In an 1864 presentation, published in 1865, James Clerk Maxwell proposed theories of electromagnetism, with mathematical proofs, that showed that light and predicted that radio and x-rays were all types of electromagnetic waves propagating through free space.
