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概要. 日本 のテレビ局において、1990年代前半では「情報番組」という呼称は「生活情報番組」およびニュースとワイドショーを合わせた「朝の情報番組」を表していた。. 朝の情報番組はワイドショーを制作している部署が番組を制作しているため、 報道局 ...
History of Wikipedia. The English edition of Wikipedia has grown to 6,822,233 articles. [1] Wikipedia, a free-content online encyclopedia written and maintained by a community of volunteers known as Wikipedians, began with its first edit on 15 January 2001, two days after the domain was registered. [2]
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History of television. Family watching TV, 1958. The 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 ...
- Discovery
- Exploration of Optical Qualities
- Proposed Applications
- Marconi and Radio Telegraphy
- Audio Transmission
- Radio Companies
- Technological Development
- Radio Telex
- Radio Navigation
- FM
In an 1864 presentation, published in 1865, James Clerk Maxwell proposed theories of electromagnetism and mathematical proofs demonstrating that light, radio and x-rays were all types of electromagnetic waves propagating through free space. Between 1886 and 1888 Heinrich Rudolf Hertzpublished the results of experiments wherein he was able to transm...
After their discovery many scientists and inventors experimented with transmitting and detecting "Hertzian waves" (it would take almost 20 years for the term "radio" to be universally adopted for this type of electromagnetic radiation). Maxwell's theory showing that light and Hertzian electromagnetic waves were the same phenomenon at different wave...
Between 1890 and 1892 physicists such as John Perry, Frederick Thomas Trouton and William Crookes proposed electromagnetic or Hertzian waves as a navigation aid or means of communication, with Crookes writing on the possibilities of wireless telegraphy based on Hertzian waves in 1892. Among physicist, what were perceived as technical limitations to...
In 1894, the young Italian inventor Guglielmo Marconi began working on the idea of building long-distance a wireless transmission systems based on the use of Hertzian waves (radio waves), a line of inquiry that he noted other inventors did not seem to be pursuing. Marconi read through the literature and used the ideas of others who were experimenti...
In the late 1890s, Canadian-American inventor Reginald Fessenden came to the conclusion that he could develop a far more efficient system than the spark-gap transmitter and coherer receiver combination. To this end he worked on developing a high-speed alternator (referred to as "an alternating-current dynamo") that generated "pure sine waves" and p...
British Marconi
Using various patents, the British Marconi company was established in 1897 by Guglielmo Marconi and began communication between coast radio stations and ships at sea. A year after, in 1898, they successfully introduced their first radio station in Chelmsford. This company, along with its subsidiaries Canadian Marconi and American Marconi, had a stranglehold on ship-to-shore communication. It operated much the way American Telephone and Telegraphoperated until 1983, owning all of its equipment...
Telefunken
The company Telefunken was founded on May 27, 1903, as "Telefunken society for wireless telefon" of Siemens & Halske (S & H) and the Allgemeine Elektrizitäts-Gesellschaft (General Electricity Company) as joint undertakings for radio engineering in Berlin. It continued as a joint venture of AEG and Siemens AG, until Siemens left in 1941. In 1911, Kaiser Wilhelm II sent Telefunken engineers to West Sayville, New York to erect three 600-foot (180-m) radio towers there. Nikola Tesla assisted in t...
Amplitude-modulated
The invention of amplitude-modulated (AM) radio, which allows more closely spaced stations to simultaneously send signals (as opposed to spark-gap radio, where each transmission occupies a wide bandwidth) is attributed to Reginald Fessenden, Valdemar Poulsen and Lee de Forest.
Crystal set receivers
The most common type of receiver before vacuum tubes was the crystal set, although some early radios used some type of amplification through electric current or battery. Inventions of the triode amplifier, motor-generator, and detector enabled audio radio. The use of amplitude modulation (AM), by which soundwaves can be transmitted over a continuous-wave radio signal of narrow bandwidth (as opposed to spark-gap radio, which sent rapid strings of damped-wave pulses that consumed much bandwidth...
Vacuum tubes
During the mid-1920s, amplifying vacuum tubes revolutionized radio receivers and transmitters. John Ambrose Fleming developed a vacuum tube diode. Lee de Forest placed a screen, added a "grid" electrode, creating the triode. Early radios ran the entire power of the transmitter through a carbon microphone. In the 1920s, the Westinghouse company bought Lee de Forest's and Edwin Armstrong's patent. During the mid-1920s, Amplifying vacuum tubes revolutionized radio receiversand transmitters. West...
Telegraphy did not go away on radio. Instead, the degree of automation increased. On land-lines in the 1930s, teletypewriters automated encoding, and were adapted to pulse-code dialing to automate routing, a service called telex. For thirty years, telex was the cheapest form of long-distance communication, because up to 25 telex channels could occu...
One of the first developments in the early 20th century was that aircraft used commercial AM radio stations for navigation, AM stations are still marked on U.S. aviation charts. Radio navigation played an important role during war time, especially in World War II. Before the discovery of the crystal oscillator, radio navigation had many limits.Howe...
In 1933, FM radio was patented by inventor Edwin H. Armstrong. FM uses frequency modulation of the radio wave to reduce static and interference from electrical equipment and the atmosphere. In 1937, W1XOJ, the first experimental FM radio station after Armstrong's W2XMN in Alpine, New Jersey, was granted a construction permit by the US Federal Commu...
Television ( TV) is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertising, entertainment, news, and sports.
Origin is an American science fiction drama series created by Mika Watkins that premiered on November 14, 2018, on YouTube Premium. Watkins also serves as a writer for the series and executive produces alongside Andy Harries , Rob Bullock, Suzanne Mackie, Josh Appelbaum , André Nemec , Jeff Pinkner , and Scott Rosenberg .
Wikipedia began as a complementary project for Nupedia, a free online English-language encyclopedia project whose articles were written by experts and reviewed under a formal process. It was founded on March 9, 2000, under the ownership of Bomis, a web portal company.
