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1 Appleton, Sir Edward Victor
[br]b. 6 September 1892 Bradford, Englandd. 21 April 1965 Edinburgh, Scotland[br]English physicist awarded the Nobel Prize for Physics for his discovery of the ionospheric layer, named after him, which is an efficient reflector of short radio waves, thereby making possible long-distance radio communication.[br]After early ambitions to become a professional cricketer, Appleton went to St John's College, Cambridge, where he studied under J.J.Thompson and Ernest Rutherford. His academic career interrupted by the First World War, he served as a captain in the Royal Engineers, carrying out investigations into the propagation and fading of radio signals. After the war he joined the Cavendish Laboratory, Cambridge, as a demonstrator in 1920, and in 1924 he moved to King's College, London, as Wheatstone Professor of Physics.In the following decade he contributed to developments in valve oscillators (in particular, the "squegging" oscillator, which formed the basis of the first hard-valve time-base) and gained international recognition for research into electromagnetic-wave propagation. His most important contribution was to confirm the existence of a conducting ionospheric layer in the upper atmosphere capable of reflecting radio waves, which had been predicted almost simultaneously by Heaviside and Kennelly in 1902. This he did by persuading the BBC in 1924 to vary the frequency of their Bournemouth transmitter, and he then measured the signal received at Cambridge. By comparing the direct and reflected rays and the daily variation he was able to deduce that the Kennelly- Heaviside (the so-called E-layer) was at a height of about 60 miles (97 km) above the earth and that there was a further layer (the Appleton or F-layer) at about 150 miles (240 km), the latter being an efficient reflector of the shorter radio waves that penetrated the lower layers. During the period 1927–32 and aided by Hartree, he established a magneto-ionic theory to explain the existence of the ionosphere. He was instrumental in obtaining agreement for international co-operation for ionospheric and other measurements in the form of the Second Polar Year (1932–3) and, much later, the International Geophysical Year (1957–8). For all this work, which made it possible to forecast the optimum frequencies for long-distance short-wave communication as a function of the location of transmitter and receiver and of the time of day and year, in 1947 he was awarded the Nobel Prize for Physics.He returned to Cambridge as Jacksonian Professor of Natural Philosophy in 1939, and with M.F. Barnett he investigated the possible use of radio waves for radio-location of aircraft. In 1939 he became Secretary of the Government Department of Scientific and Industrial Research, a post he held for ten years. During the Second World War he contributed to the development of both radar and the atomic bomb, and subsequently served on government committees concerned with the use of atomic energy (which led to the establishment of Harwell) and with scientific staff.[br]Principal Honours and DistinctionsKnighted (KCB 1941, GBE 1946). Nobel Prize for Physics 1947. FRS 1927. Vice- President, American Institute of Electrical Engineers 1932. Royal Society Hughes Medal 1933. Institute of Electrical Engineers Faraday Medal 1946. Vice-Chancellor, Edinburgh University 1947. Institution of Civil Engineers Ewing Medal 1949. Royal Medallist 1950. Institute of Electrical and Electronics Engineers Medal of Honour 1962. President, British Association 1953. President, Radio Industry Council 1955–7. Légion d'honneur. LLD University of St Andrews 1947.Bibliography1925, joint paper with Barnett, Nature 115:333 (reports Appleton's studies of the ionosphere).1928, "Some notes of wireless methods of investigating the electrical structure of the upper atmosphere", Proceedings of the Physical Society 41(Part III):43. 1932, Thermionic Vacuum Tubes and Their Applications (his work on valves).1947, "The investigation and forecasting of ionospheric conditions", Journal of theInstitution of Electrical Engineers 94, Part IIIA: 186 (a review of British work on the exploration of the ionosphere).with J.F.Herd \& R.A.Watson-Watt, British patent no. 235,254 (squegging oscillator).Further ReadingWho Was Who, 1961–70 1972, VI, London: A. \& C.Black (for fuller details of honours). R.Clark, 1971, Sir Edward Appleton, Pergamon (biography).J.Jewkes, D.Sawers \& R.Stillerman, 1958, The Sources of Invention.KFBiographical history of technology > Appleton, Sir Edward Victor
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2 Appleton
m.Appleton, Sir Edward Victor Appleton. -
3 Telecommunications
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4 Heaviside, Oliver
[br]b. 18 May 1850 London, Englandd. 2 February 1925 Torquay, Devon, England[br]English physicist who correctly predicted the existence of the ionosphere and its ability to reflect radio waves.[br]Brought up in poor, almost Dickensian, circumstances, at the age of 13 years Heaviside, a nephew by marriage of Sir Charles Wheatstone, went to Camden House Grammar School. There he won a medal for science, but he was forced to leave because his parents could not afford the fees. After a year of private study, he began his working life in Newcastle in 1870 as a telegraph operator for an Anglo-Dutch cable company, but he had to give up after only four years because of increasing deafness. He therefore proceeded to spend his time studying theoretical aspects of electrical transmission and communication, and moved to Devon with his parents in 1889. Because the operation of many electrical circuits involves transient phenomena, he found it necessary to develop what he called operational calculus (which was essentially a form of the Laplace transform calculus) in order to determine the response to sudden voltage and current changes. In 1893 he suggested that the distortion that occurred on long-distance telephone lines could be reduced by adding loading coils at regular intervals, thus creating a matched-transmission line. Between 1893 and 1912 he produced a series of writings on electromagnetic theory, in one of which, anticipating a conclusion of Einstein's special theory of relativity, he put forward the idea that the mass of an electric charge increases with its velocity. When it was found that despite the curvature of the earth it was possible to communicate over very great distances using radio signals in the so-called "short" wavebands, Heaviside suggested the presence of a conducting layer in the ionosphere that reflected the waves back to earth. Since a similar suggestion had been made almost at the same time by Arthur Kennelly of Harvard, this layer became known as the Kennelly-Heaviside layer.[br]Principal Honours and DistinctionsFRS 1891. Institution of Electrical Engineers Faraday Medal 1924. Honorary PhD Gottingen. Honorary Member of the American Association for the Advancement of Science.Bibliography1872. "A method for comparing electro-motive forces", English Mechanic (July).1873. Philosophical Magazine (February) (a paper on the use of the Wheatstone Bridge). 1889, Electromagnetic Waves.1892, Electrical Papers.1893–1912, Electromagnetic Theory.Further ReadingI.Catt (ed.), 1987, Oliver Heaviside, The Man, St Albans: CAM Publishing.P.J.Nahin, 1988, Oliver Heaviside, Sage in Solitude: The Life and Works of an Electrical Genius of the Victorian Age, Institute of Electrical and Electronics Engineers, New York.J.B.Hunt, The Maxwellians, Ithaca: Cornell University Press.See also: Appleton, Sir Edward VictorKF -
5 Broadcasting
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6 Jansky, Karl Guthe
[br]b. 22 October 1905 Norman, Oklahoma, USAd. 14 February 1950 Red Bank, New Jersey, USA[br]American radio engineer who discovered stellar radio emission.[br]Following graduation from the University of Wisconsin in 1928 and a year of postgraduate study, Jansky joined Bell Telephone Laboratories in New Jersey with the task of establishing the source of interference to telephone communications by radio. To this end he constructed a linear-directional short-wave antenna and eventually, in 1931, he concluded that the interference actually came from the stars, the major source being the constellation Sagittarius in the direction of the centre of the Milky Way. Although he continued to study the propagation of short radio waves and the nature of observed echoes, it was left to others to develop the science of radioastronomy and to use the creation of echoes for radiolocation. Although he received no scientific award for his discovery, Jansky's name is primarily honoured by its use as the unit of stellar radio-emission strength.[br]Bibliography1935, "Directional studies of atmospherics at high frequencies", Proceedings of the Institute of Radio Engineers 23:1,158.1935, "A note on the sources of stellar interference", Proceedings of the Institute of RadioEngineers.1937, "Minimum noise levels obtained on short-wave radio receiving systems", Proceedings of the Institute of Radio Engineers 25:1,517.1941, "Measurements of the delay and direction of arrival of echoes from nearby short-wave transmitters", Proceedings of the Institute of Radio Engineers 29:322.Further ReadingP.C.Mahon, 1975, BellLabs, Mission Communication. The Story of the Bell Labs.W.I.Sullivan (ed.), 1984, The Early Years of Radio-Astronomy: Reflections 50 Years after Jansky's Discovery, Cambridge: Cambridge University Press.See also: Appleton, Sir Edward VictorKF -
7 Kennelly, Arthur Edwin
[br]b. 17 December 1871 Colaba, Bombay, Indiad. 18 June 1939 Boston, Massachusetts, USA[br]Anglo-American electrical engineer who predicted the ionosphere and developed mathematical analysis for electronic circuits.[br]As a young man, Kennelly worked as office boy for a London engineering society, as an electrician and on a cable-laying ship. In 1887 he went to work for Thomas Edison at West Orange, New Jersey, USA, becoming his chief assistant. In 1894, with Edwin J.Houston, he formed the Philadelphia company of Houston and Kennelly, but eight years later he took up the Chair of Electrical Engineering at Harvard, a post he held until his retirement in 1930. In 1902 he noticed that the radio signals received by Marconi in Nova Scotia from the transmitter in England were stronger than predicted and postulated a reflecting ionized layer in the upper atmosphere. Almost simultaneously the same prediction was made in England by Heaviside, so the layer became known as the Kennelly-Heaviside layer. Throughout most of his working life Kennelly was concerned with the application of mathematical techniques, particularly the use of complex theory, to the analysis of electrical circuits. With others he also contributed to an understanding of the high-frequency skin-effect in conductors.[br]Principal Honours and DistinctionsPresident, American Institute of Electrical Engineers 1898–1900. President, Institution of Electrical Engineers 1916. Institute of Electrical and Electronics Engineers Medal of Honour 1932; Edison Medal 1933.Bibliography1915, with F.A.Laws \& P.H.Pierce "Experimental research on the skin effect in conductors", Transactions of the American Institute of Electrical Engineers 34:1,953.1924, Hyperbolic Functions as Applied to Electrical Engineering.1924, Check Atlas of Complex Hyperbolic \& Circular Functions (both on mathematics for circuit analysis).Further ReadingK.Davies, 1990, Ionospheric Radio, London: Peter Peregrinus. See also Appleton, Sir Edward Victor.KF -
8 Tuve, Merle Antony
[br]b. 27 June 1901 Canton, South Dakota, USAd. 20 May 1982 Bethesda, Maryland, USA[br]American physicist and geophysicist who developed radio exploration of the ionosphere and made contributions to seismology and atomic physics.[br]After BS and AM degrees from the University of Minnesota, Tuve gained a PhD in physics from Johns Hopkins University in 1926. He then joined the Department of Terrestrial Magnetism at the Carnegie Institute, Washington, DC, where with Breit he established by experiment the existence and characteristics of the ionosphere. He also studied gamma and beta rays, artificial radioactivity and atomic transmutation, verified the existence of the neutron and measured nuclear binding forces. During the Second World War he performed military research, producing a proximity fuse for use against the VI flying bomb. He returned to Carnegie in 1946 as Director of the Department of Terrestrial Magnetism, where he remained until 1966, making many contributions to the study of the earth and space.[br]Principal Honours and DistinctionsAmerican Association for the Advancement of Science Prize for atomic and nuclear research 1931. National Academy of Science 1946. Research Corporation Award 1947. Comstock Prize 1948. National Academy of Science Barnard Medal 1955. Presidential Medal of Merit and Distinguished Service Member of the Carnegie Institute 1966.Bibliography1926, with G.Breit, "A test of the existence of the conducting layer", Physical Review 28:554 (gives an account of the early ionospheric studies).See also: Appleton, Sir Edward VictorKF
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Appleton,Sir Edward Victor — Appleton, Sir Edward Victor. 1892 1965. British physicist. He won a 1947 Nobel Prize for his discovery of the F layer of the ionosphere. * * * … Universalium
Appleton, Sir Edward Victor — ▪ British physicist born Sept. 6, 1892, Bradford, Yorkshire, Eng. died April 21, 1965, Edinburgh, Scot. British winner of the Nobel Prize for Physics in 1947 for his discovery of the so called Appleton layer of the ionosphere, which is a… … Universalium
Appleton , Sir Edward Victor — (1892–1965) British physicist Appleton was born in Bradford and studied physics at Cambridge University from 1910 to 1913. During World War I, while he was serving in the Royal Engineers, he developed the interest in radio that was to influence… … Scientists
Appleton, Sir Edward Victor — ► (1892 1965) Físico británico. Fue premio Nobel de Física en 1947 por sus trabajos sobre la ionosfera … Enciclopedia Universal
Edward Victor Appleton — Sir Edward Victor Appleton (* 6. September 1892 in Bradford; † 21. April 1965 in Edinburgh) war ein englischer Physiker. Nachdem Appleton vom aktiven Dienst aus dem Ersten Weltkrieg zurückgekehrt war, wurde er 1920 Assistent für Ex … Deutsch Wikipedia
Sir Edward Victor Appleton — noun English physicist remembered for his studies of the ionosphere (1892 1966) • Syn: ↑Appleton, ↑Edward Appleton • Instance Hypernyms: ↑physicist … Useful english dictionary
Edward Victor Appleton — Sir Edward Victor Appleton, físico inglés, nacido el 6 de septiembre de 1892 en Bradford, fallecido el 21 de de abril de 1965. Después de volver del servicio activo en la Primera Guerra Mundial, ingresó al laboratorio de Cavendish (1920) como… … Enciclopedia Universal
Edward Victor Appleton — Infobox Scientist name = Sir Edward Appleton imagesize = 120px caption = Edward Victor Appleton in army uniform, taken in World War I. birth date = birth date|1892|9|6 birth place = Bradford, West Yorkshire, England death date = death date and… … Wikipedia
Edward Victor Appleton — Retrato de 1947. Sir Edward Victor Appleton, GBE, KCB(Bradford, 6 de septiembre de 1892 Edimburgo, 21 de abril de 1965), físico inglés, premio Nobel de física en 1947. Contenido … Wikipedia Español
Appleton — Appleton, Sir Edward Victor ► C. de E.U.A., en el estado de Wisconsin; 57 143 h … Enciclopedia Universal
Appleton — noun 1. English physicist remembered for his studies of the ionosphere (1892 1966) • Syn: ↑Edward Appleton, ↑Sir Edward Victor Appleton • Instance Hypernyms: ↑physicist 2. a town in eastern Wisconsin • Instance Hypernyms: ↑ … Useful english dictionary