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The timeline of radio lists within the history of radio, the technology and events that produced instruments that use radio waves and activities that people undertook. Later, the history is dominated by programming and contents, which is closer to general history. ==Origins and developments== Although the title "inventor of radio" is popularly attributed to Guglielmo Marconi, his was just the practical application of 80 years of scientific advancement in the field including the predictions of Michael Faraday, the theoretical work of James Clerk Maxwell, and the experimental demonstrations of Heinrich Rudolf Hertz.〔(G. R. M. Garratt, The Early History of Radio: From Faraday to Marconi, The Institution of Engineering and Technology - 1994, page 1 )〕 * 1789-1791: Luigi Galvani notices a spark generated nearby causes a convulsion in a frog's leg being touched by a scalpel.〔T. K. Sarkar, Robert Mailloux, Arthur A. Oliner, M. Salazar-Palma, Dipak L. Sengupta , History of Wireless, John Wiley & Sons - 2006, pages 258-261〕 In different experiments, he notices contractions in frogs' legs caused by lightning and a luminous discharge from a charged Leyden jar that disappeared over time and was renewed whenever a spark occurred nearby.〔http://www.scienzagiovane.unibo.it/English/scientists/galvani-3.html〕〔http://www.jstor.org/stable/227753?seq=1#page_scan_tab_contents〕 * 1820: Hans Christian Ørsted discovers the relationship between electricity and magnetism in a very simple experiment. He demonstrates that a wire carrying a current was able to deflect a magnetized compass needle. * 1831: Michael Faraday begins a series of experiments in which he discovers electromagnetic induction. The relation was mathematically modeled by Faraday's law, which subsequently becomes one of the four Maxwell equations. Faraday proposes that electromagnetic forces extended into the empty space around the conductor, but does not complete his work involving that proposal. *1835: Peter Samuel Munk observes the permanent increase of the electrical conductivity of a mixture of loose metal filings in a glass tube with two metal plugs in it resulting from the passage of a discharge current of a Leyden jar through it. This is an early example of the coherer effect.〔http://arxiv.org/pdf/cond-mat/0407773.pdf〕〔http://scans.library.utoronto.ca/pdf/9/18/elementarymanual00flem/elementarymanual00flem.pdf〕 *1842: Joseph Henry publishes his experimental results showing the oscillatory nature of the discharge in leyden jars and describes how a generated spark could magnetize a needle surrounded by a coil up to 220 feet away. He also describes how a lightning strike 8 miles away magnetized a needle surrounded by a coil, an effect that was most probably caused by radio waves. He considered both of these effects to be due to electromagnetic induction at the time.〔Albert E. Moyer, Joseph Henry: The rise of an American scientist, Smithsonian institution press - 1994, pages 172-176〕〔T. K. Sarkar, Robert Mailloux, Arthur A. Oliner, M. Salazar-Palma, Dipak L. Sengupta , History of Wireless, John Wiley & Sons - 2006, pages 258-261〕〔(Henry & Radio - Princeton University )〕 *1852: Samuel Alfred Varley notices a remarkable fall in the resistance of masses of metallic filings under the action of atmospheric electrical discharges.〔http://scans.library.utoronto.ca/pdf/9/18/elementarymanual00flem/elementarymanual00flem.pdf〕 *1864: James Clerk Maxwell predicts the existence of electromagnetic waves in his paper 'a dynamical theory of the electromagnetic field'.〔T. K. Sarkar, Robert Mailloux, Arthur. A. Oliner, M. Salazar-Palma, Dipak L. Sengupta, History of Wireless - 2006, page 260〕〔web.pdx.edu/~bseipel/Lecture%20notes%206-%20203%20EMwaves.pdf〕〔G. R. M. Garratt, The Early History of Radio: From Faraday to Marconi, IET - 1994, page 27〕 * 1871: Edwin Houston, while setting up a large sparking Ruhmkorff coil to be used in a demonstration, notices he can draw sparks from metal objects throughout the room. He attributes this to induction.〔W. Bernard Carlson, Innovation as a Social Process: Elihu Thomson and the Rise of General Electric, Cambridge University Press - 2003, page 59〕 * 1875: While experimenting with an acoustic telegraph, Thomas Edison notices an electromagnet producing unusual sparks. He finds this strange sparking could be conducted 25 miles along telegraph wires and be detected a few feet from the wire. To prove it was not electromagnetic induction he set up an experiment where he shows sparks in a spark detector but no effect in a gold-leaf electroscope and a galvanometer along the same line. On 28 November 1875 he announces to the press what he termes a new "etheric force".〔(ieeeghn.org, IEEE Global History Network, Etheric Force )〕〔W. Bernard Carlson, Innovation as a Social Process: Elihu Thomson and the Rise of General Electric, Cambridge University Press - 2003, pages 57-58〕 * December 1875: Edwin Houston, with the help of Elihu Thomson, conducts an improved version Edison's experiment at Central High School in Philadelphia, Pennsylvania using a Ruhmkorff coil and a spark detector. Thompson notices he can draw sparks from metal objects throughout the building and looks on the phenomenon as a possible new form of communication. Houston publishes his results, concluding that the phenomenon they and Edison produced was simply an induction phenomenon he had identified in 1871, claiming Edison was miss-identifying a rapidly switching polarity.〔W. Bernard Carlson, Innovation as a Social Process: Elihu Thomson and the Rise of General Electric, Cambridge University Press - 2003, pages 60〕 * 1878: David E. Hughes notices that sparks generated by a induction balance causes noise in an improved telephone microphone he was developing. He rigs up a portable version of his receiver and, carrying it down a street, finds the sparking can be detected at some distance. * 1879: German physicist Hermann von Helmholtz proposes the "Berlin Prize" for anyone who could experimentally prove a key aspect of Maxwell's electromagnetic theory thinking his star student, Heinrich Rudolf Hertz, could win the prize. Hertz declines working on the prize, seeing no way to produce a test apparatus. * 1880: David Hughes demonstrates his discovery to the Royal Society, but is told it is merely induction. * 1884: During his time as a lecturer in theoretical physics at the University of Kiel Heinrich Hertz produces an analysis of Maxwell's equations showing they did have more validity than the then prevalent "action at a distance" theories. * 1884: Temistocle Calzecchi-Onesti at Fermo in Italy discovers that metal filings between two brass plates clump together in reaction to electric sparks occurring at a distance. He thinks it could be used for detecting lightning. His little noticed paper is published in an Italian journal and he does not pursue the phenomenon further. (Considered an early type of "coherer"). * 1885: Edison takes out a patent〔(edison.rutgers.edu, patent 00465971 )〕 on a system of wireless communication between ships via electrostatic induction through sea water. The system proves to be too short range to be practical.〔(earlyradiohistory.us, THOMAS H. WHITE, UNITED STATES EARLY RADIO HISTORY, s e c t i o n 5, Radio at Sea (1891-1922) )〕 * 1886 to 1888: After noticing how discharging an electric current into a coil produced a spark in a second nearby coil, Heinrich Hertz sees a way to build a test apperatus to solve von Helmholtz "Berlin Prize" problem. Hertz conducts a series of experiments that validates Maxwell's theory of electromagnetic radiation and proves that it can traveling through free space (radio). He demonstrates the radiation has the properties of visible light, the properties of waves (now called Transverse waves), and discovers that the electromagnetic equations could be reformulated into a partial differential equation called the wave equation. * Spring 1888: British physicist Sir Oliver Lodge conducts experiments that seem to show electromagnetic waves traveling along wires. He took this as a way to prove Maxwell's electromagnetic theory but learns of Hertz' published proofs at the same time. * 1885 to 1892: Murray, Kentucky farmer Nathan Stubblefield conducts wireless transmissions some claim to be radio, but his devices seem to have worked by induction transmission rather than radio transmission. * 1890: French physicist and inventor Edouard Branly does a thorough investigation of metal filings in an evacuated tube and how they are sensitive to electric sparks at a distance. (an effect later to be called the coherer by Lodge) *1891: Irish physicist Frederick Thomas Trouton suggests using a fast rotating alternator as a wireless transmitter and suggest the new "Hertzian waves" could be used to replace light houses with "electric houses" that would operate in fog.〔(earlyradiohistory.us, THOMAS H. WHITE, UNITED STATES EARLY RADIO HISTORY, Alternator-Transmitter Development (1891-1922) )〕〔(earlyradiohistory.us, THOMAS H. WHITE, UNITED STATES EARLY RADIO HISTORY, s e c t i o n 5, Radio at Sea (1891-1922) )〕 * February 1892: British chemist and physicist William Crookes publishes an article suggesting "Hertzian waves" (radio waves) could be, and he claimed already were being used in wireless telegraphy.〔(Howard B. Rockman, Intellectual Property Law for Engineers and Scientists , page 196' )〕 * July 1892: Elihu Thompson writes that "signalling or telegraphing for moderate distances without wires, and even through dense fog may be an accomplished fact soon".〔(earlyradiohistory.us, THOMAS H. WHITE, UNITED STATES EARLY RADIO HISTORY, s e c t i o n 5, Radio at Sea (1891-1922) )〕 * 1892: Branly's filing tube comes to light when it is described by Dr. Dawson Turner at a meeting of the British Association in Edinburgh.〔Sungook Hong, Wireless: From Marconi's Black-box to the Audion, page 4〕〔(E C Green , The Development of the Coherer And Some Theories of Coherer Action, Scientific American: Supplement, Volume 84 - 1917, page 268 )〕 * 1892: Scottish electrical engineer and astronomer George Forbes suggests Branly's filing tube may react in the presence of Hertzian waves. * 1893: Nikola Tesla delivers a lecture "On Light and other High Frequency Phenomena" before the ''Franklin Institute'' in Philadelphia and the ''National Electric Light Association'' St Louis. Tesla did not think air-born radio waves existed〔W. Bernard Carlson, Tesla: Inventor of the Electrical Age, page 127〕 but saw wireless and electromagnetic phenomenon as a promising wireless lighting and power distribution system with communication as a side aspect.〔(Radio: Brian Regal, The Life Story of a Technology, page 22 )〕 * March 1893: American physicist Amos Dolbear predicts telegraphing without wires using "A beam of Hertzian rays" in ''Donahoe's Magazine''.〔(earlyradiohistory.us, THOMAS H. WHITE, UNITED STATES EARLY RADIO HISTORY, s e c t i o n 5, Radio at Sea (1891-1922) )〕 * 1893: physicist W.B. Croft exhibits Branly's experiments at a meeting of the Physical Society in London. It is unclear to Croft and others whether the filings in the Branly filing tube are reacting to sparks or the light from the sparks. George Minchin notices the () tube may be reacting to Hertzian waves the same way his solar cell does and writes the paper "''The Action of Electromagnetic Radiation on Films containing Metallic Powders''".〔Sungook Hong, Wireless: From Marconi's Black-box to the Audion, page 4〕〔(E C Green , The Development of the Coherer And Some Theories of Coherer Action, Scientific American: Supplement, Volume 84 - 1917, page 268 )〕 These papers are read by Lodge who sees a way to build a much improved Herzian wave detector. * 1893: Irish physicist George Francis FitzGerald publishes a formula for the radiating power of electromagnetic waves from a loop antenna that seems to show these (radio) waves would only ever have a useful range of 1/2 mile, a value Oliver Lodge agrees with.〔T. K. Sarkar, Robert Mailloux, Arthur A. Oliner, M. Salazar-Palma, Dipak L. Sengupta , History of Wireless, John Wiley & Sons - 2006, page 263〕 * 1 January 1894: Heinrich Rudolf Hertz dies. * 1 June 1894: Oliver Lodge delivers a memorial lecture on Hertz where he demonstrates the optical properties of "Hertzian waves" (radio), including transmitting them over a short distance, using an improved version of Branly's filing tube, which Lodge has named the "coherer", as a detector. He also demonstrates controlling frequency by changing inductance and capacitance in his circuits.〔(Howard B. Rockman, Intellectual Property Law for Engineers and Scientists , page 196' )〕 * November 1894: In Calcutta the Indian physicist Jagdish Chandra Bose, building on Lodges published work, uses radio wave transmissions to ignite gunpowder and rang a bell at a distance. * May 1895: After reading about Lodge's demonstrations, the Russian physicist Alexander Popov builds a "Hertzian wave" (radio wave) based lightning detector using a coherer. * 1895: Marconi pursues the idea of building a wireless telegraphy system using Hertzian waves (radio). This is considered to be the first development of a radio system specifically for communication.〔(【引用サイトリンク】title=U.S. Supreme Court )〕 * 1896: Alexander Popov demonstrates the transmission of signals between building at the University of St. Petersburg. * 1896: Marconi was awarded a patent for radio with British Patent 12039, ''Improvements in Transmitting Electrical Impulses and Signals and in Apparatus There-for''. This is the initial patent for radio based wireless telegraphy. * 1896: Bose goes to London on a lecture tour and meets Marconi, who was conducting wireless experiments for the British post office. * 1897: Marconi establishes a radio station on the Isle of Wight, England. In the U.S. during 1897, Tesla applies for several wireless power patents. Those two patents were issued in early 1900. * 1897: Although Australia's first officially recognised broadcast was made in 1906, some sources claim that there were transmissions in Australia in 1897, either conducted solely by Professor William Henry Bragg of Adelaide University〔http://www.wia.org.au/members/history/research/documents/WIA%20MAIN%20T-%20LINE-Nov%202013%20EXTENDED.pdf〕〔Bernard Harte, ''When Radio Was The Cat's Whiskers'', 2002, privately published Dural, NSW〕 or by Prof. Bragg in conjunction with G.W. Selby of Melbourne.〔Mimi Colligan, ''Golden Days of Radio'', Australia Post, 1991〕 * 1898: Marconi opened the first radio factory, on Hall Street, Chelmsford, England, employing around 50 people. * 1899: Bose announced his invention of the "iron-mercury-iron coherer with telephone detector" in a paper presented at Royal Society, London. * 1899: Tesla experiments with wireless power in Colorado Springs. He listens to static from thunderstorms trying to determine values for what he believes is a native electrical charge and frequency of the Earth. Using sensitive electromagnetic receivers he picks up repeating signals he thinks may be from beings on another planet. An alternative explanation is that Tesla may have heard Marconi's wireless telegraphy demonstrations in Europe. * 1900: Reginald Fessenden makes a weak transmission of voice over the airwaves. * July 1901: Tesla begins construction of his Wardenclyffe Tower wireless transmission facility. The project runs out of funding by 1905 and is never completed. * December 1901: Marconi claims to have received in St. John's, Newfoundland a radio signal transmitted from Poldhu in Cornwall (UK). * February 1902: Marconi starts conducting more organized and documented tests sailing on board the ''SS Philadelphia'' west from Great Britain recording signals sent daily from the Poldhu station showing reception up to 2,100 miles (3,400 km). * December 1902: the Marconi station in Glace Bay, Nova Scotia, Canada transmits the first signal from North America back to Great Britain. * 1904: The U.S. Patent Office reversed its decision, awarding Marconi a patent for the invention of radio. * 1906: In Australia, Ernest Fisk (later Sir Ernest) of AWA – Amalgamated Wireless (Australasia) conducted an isolated experiment in which music was broadcast. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Timeline of radio」の詳細全文を読む スポンサード リンク
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