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1 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 -
2 Telecommunications
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3 Broadcasting
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4 Eccles, William Henry
[br]b. 23 August 1875 Ulverston, Cumbria, Englandd. 27 April 1966 Oxford, England[br]English physicist who made important contributions to the development of radio communications.[br]After early education at home and at private school, Eccles won a scholarship to the Royal College of Science (now Imperial College), London, where he gained a First Class BSc in physics in 1898. He then worked as a demonstrator at the college and studied coherers, for which he obtained a DSc in 1901. Increasingly interested in electrical engineering, he joined the Marconi Company in 1899 to work on oscillators at the Poole experimental radio station, but in 1904 he returned to academic life as Professor of Mathematics and Physics and Department Head at South West Polytechnic, Chelsea. There he discovered ways of using the negative resistance of galena-crystal detectors to generate oscillations and gave a mathematical description of the operation of the triode valve. In 1910 he became Reader in Engineering at University College, London, where he published a paper explaining the reflection of radio waves by the ionosphere and designed a 60 MHz short-wave transmitter. From 1916 to 1926 he was Professor of Applied Physics and Electrical Engineering at the Finsbury City \& Guilds College and a private consulting engineer. During the First World War he was a military scientific adviser and Secretary to the Joint Board of Scientific Societies. After the war he made many contributions to electronic-circuit development, many of them (including the Eccles-Jordan "flip-flop" patented in 1918 and used in binary counters) in conjunction with F.W.Jordan, about whom little seems to be known. Illness forced Eccles's premature academic retirement in 1926, but he remained active as a consultant for many years.[br]Principal Honours and DistinctionsFRS 1921. President, Institution of Electrical Engineers, 1926–7. President, Physical Society 1929. President, Radio Society of Great Britain.Bibliography1912, "On the diurnal variation of the electric waves occurring in nature and on the propagation of electric waves round the bend of the earth", Proceedings of the Royal Society 87:79. 1919, with F.W.Jordan, "Method of using two triode valves in parallel for generating oscillations", Electrician 299:3.1915, Handbook of Wireless Telegraphy.1921, Continuous Wave Wireless Telegraphy.Further Reading1971, "William Henry Eccles, 1875–1966", Biographical Memoirs of the Royal Society, London, 17.KF -
5 Hertz, Heinrich Rudolph
[br]b. 22 February 1857 Hamburg, Germanyd. 1 January 1894 Bonn, Germany[br]German physicist who was reputedly the first person to transmit and receive radio waves.[br]At the age of 17 Hertz entered the Gelehrtenschule of the Johaneums in Hamburg, but he left the following year to obtain practical experience for a year with a firm of engineers in Frankfurt am Main. He then spent six months at the Dresden Technical High School, followed by year of military service in Berlin. At this point he decided to switch from engineering to physics, and after a year in Munich he studied physics under Helmholtz at the University of Berlin, gaining his PhD with high honours in 1880. From 1883 to 1885 he was a privat-dozent at Kiel, during which time he studied the electromagnetic theory of James Clerk Maxwell. In 1885 he succeeded to the Chair in Physics at Karlsruhe Technical High School. There, in 1887, he constructed a rudimentary transmitter consisting of two 30 cm (12 in.) rods with metal balls separated by a 7.5 mm (0.3 in.) gap at the inner ends and metallic plates at the outer ends, the whole assembly being mounted at the focus of a large parabolic metal mirror and the two rods being connected to an induction coil. At the other side of his laboratory he placed a 70 cm (27½ in.) diameter wire loop with a similar air gap at the focus of a second metal mirror. When the induction coil was made to create a spark across the transmitter air gap, he found that a spark also occurred at the "receiver". By a series of experiments he was not only able to show that the invisible waves travelled in straight lines and were reflected by the parabolic mirrors, but also that the vibrations could be refracted like visible light and had a similar wavelength. By this first transmission and reception of radio waves he thus confirmed the theoretical predictions made by Maxwell some twenty years earlier. It was probably in his experiments with this apparatus in 1887 that Hertz also observed that the voltage at which a spark was able to jump a gap was significantly reduced by the presence of ultraviolet light. This so-called photoelectric effect was subsequently placed on a theoretical basis by Albert Einstein in 1905. In 1889 he became Professor of Physics at the University of Bonn, where he continued to investigate the nature of electric discharges in gases at low pressure until his death after a long and painful illness. In recognition of his measurement of radio and other waves, the international unit of frequency of an oscillatory wave, the cycle per second, is now universally known as the Hertz.[br]Principal Honours and DistinctionsRoyal Society Rumford Medal 1890.BibliographyMuch of Hertz's work, including his 1890 paper "On the fundamental equations of electrodynamics for bodies at rest", is recorded in three collections of his papers which are available in English translations by D.E.Jones et al., namely Electric Waves (1893), Miscellaneous Papers (1896) and Principles of Mechanics (1899).Further ReadingJ.G.O'Hara and W.Pricha, 1987, Hertz and the Maxwellians, London: Peter Peregrinus. J.Hertz, 1977, Heinrich Hertz, Memoirs, Letters and Diaries, San Francisco: San Francisco Press.R.Appleyard, 1930, Pioneers of Electrical Communication.See also: Heaviside, OliverKFBiographical history of technology > Hertz, Heinrich Rudolph
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6 Preece, Sir William Henry
[br]b. 15 February 1834 Bryn Helen, Gwynedd, Walesd. 6 November 1913 Penrhos, Gwynedd, Wales[br]Welsh electrical engineer who greatly furthered the development and use of wireless telegraphy and the telephone in Britain, dominating British Post Office engineering during the last two decades of the nineteenth century.[br]After education at King's College, London, in 1852 Preece entered the office of Edwin Clark with the intention of becoming a civil engineer, but graduate studies at the Royal Institution under Faraday fired his enthusiasm for things electrical. His earliest work, as connected with telegraphy and in particular its application for securing the safe working of railways; in 1853 he obtained an appointment with the Electric and National Telegraph Company. In 1856 he became Superintendent of that company's southern district, but four years later he moved to telegraph work with the London and South West Railway. From 1858 to 1862 he was also Engineer to the Channel Islands Telegraph Company. When the various telegraph companies in Britain were transferred to the State in 1870, Preece became a Divisional Engineer in the General Post Office (GPO). Promotion followed in 1877, when he was appointed Chief Electrician to the Post Office. One of the first specimens of Bell's telephone was brought to England by Preece and exhibited at the British Association meeting in 1877. From 1892 to 1899 he served as Engineer-in-Chief to the Post Office. During this time he made a number of important contributions to telegraphy, including the use of water as part of telegraph circuits across the Solent (1882) and the Bristol Channel (1888). He also discovered the existence of inductive effects between parallel wires, and with Fleming showed that a current (thermionic) flowed between the hot filament and a cold conductor in an incandescent lamp.Preece was distinguished by his administrative ability, some scientific insight, considerable engineering intuition and immense energy. He held erroneous views about telephone transmission and, not accepting the work of Oliver Heaviside, made many errors when planning trunk circuits. Prior to the successful use of Hertzian waves for wireless communication Preece carried out experiments, often on a large scale, in attempts at wireless communication by inductive methods. These became of historic interest only when the work of Maxwell and Hertz was developed by Guglielmo Marconi. It is to Preece that credit should be given for encouraging Marconi in 1896 and collaborating with him in his early experimental work on radio telegraphy.While still employed by the Post Office, Preece contributed to the development of numerous early public electricity schemes, acting as Consultant and often supervising their construction. At Worcester he was responsible for Britain's largest nineteenth-century public hydro-electric station. He received a knighthood on his retirement in 1899, after which he continued his consulting practice in association with his two sons and Major Philip Cardew. Preece contributed some 136 papers and printed lectures to scientific journals, ninety-nine during the period 1877 to 1894.[br]Principal Honours and DistinctionsCB 1894. Knighted (KCB) 1899. FRS 1881. President, Society of Telegraph Engineers, 1880. President, Institution of Electrical Engineers 1880, 1893. President, Institution of Civil Engineers 1898–9. Chairman, Royal Society of Arts 1901–2.BibliographyPreece produced numerous papers on telegraphy and telephony that were presented as Royal Institution Lectures (see Royal Institution Library of Science, 1974) or as British Association reports.1862–3, "Railway telegraphs and the application of electricity to the signaling and working of trains", Proceedings of the ICE 22:167–93.Eleven editions of Telegraphy (with J.Sivewright), London, 1870, were published by 1895.1883, "Molecular radiation in incandescent lamps", Proceedings of the Physical Society 5: 283.1885. "Molecular shadows in incandescent lamps". Proceedings of the Physical Society 7: 178.1886. "Electric induction between wires and wires", British Association Report. 1889, with J.Maier, The Telephone.1894, "Electric signalling without wires", RSA Journal.1898, "Aetheric telegraphy", Proceedings of the Institution of Electrical Engineers.Further ReadingJ.J.Fahie, 1899, History of Wireless Telegraphy 1838–1899, Edinburgh: Blackwood. E.Hawkes, 1927, Pioneers of Wireless, London: Methuen.E.C.Baker, 1976, Sir William Preece, F.R.S. Victorian Engineer Extraordinary, London (a detailed biography with an appended list of his patents, principal lectures and publications).D.G.Tucker, 1981–2, "Sir William Preece (1834–1913)", Transactions of the Newcomen Society 53:119–36 (a critical review with a summary of his consultancies).GW / KFBiographical history of technology > Preece, Sir William Henry
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Heaviside, Oliver — born May 18, 1850, London, Eng. died Feb. 3, 1925, Torquay, Devon English physicist. In 1902 he predicted the presence of the ionosphere. Since Arthur Kennelly (1861–1939) had made a similar prediction, the ionosphere was long known as the… … Universalium
Heaviside , Oliver — (1850–1925) British electronic engineer and physicist Heaviside, a Londoner, was a nephew of Charles Wheatstone. Being very deaf, he was hampered in school, and was largely self taught. He was interested in the transmission of electrical signals… … Scientists
Heaviside, Oliver — ► (1850 1925) Físico y matemático británico. En 1902 sugirió la existencia de una capa atmosférica fuertemente ionizada. * * * (18 may. 1850, Londres, Inglaterra–3 feb. 1925, Torquay, Devon). Físico inglés. En 1902 predijo la presencia de la… … Enciclopedia Universal
Heaviside — Oliver … Scientists
Oliver Heaviside — Heaviside redirects here. For other uses, see Heaviside (disambiguation). Oliver Heaviside Portrait by Francis Edwin Hodge … Wikipedia
Oliver Heaviside — hacia 1890 Nacimiento … Wikipedia Español
Oliver Heaviside — (* 18. Mai 1850 in London; † 3. Februar 1925 in Homefield bei Torquay) war ein britischer Mathematiker und Physiker, der wesentliche Beiträge zur Entwicklung des Elektromagnetismus lieferte. Inhaltsverzeichnis … Deutsch Wikipedia
Heaviside — Oliver Heaviside Oliver Heaviside (* 18. Mai 1850 in London; † 3. Februar 1925 in Homefield bei Torquay) war ein britischer Mathematiker und Physiker, der wesentliche Beiträge zur Entwicklung des Elektromagnetismus lieferte. Inhaltsverzeichnis … Deutsch Wikipedia
Oliver — Oliver, Joan Oliver, Joe Oliver, Miguel de los Santos * * * (as used in expressions) Cromwell, Oliver Davis, Benjamin O(liver), Jr. Ellsworth, Oliver Evans, Oliver Goldsmith … Enciclopedia Universal
Heaviside — Heaviside, Oliver Heaviside, capa de … Enciclopedia Universal
Heaviside-Schicht — Ionosphärenschichten (engl. Layer) in Abhängigkeit von der Tageszeit Die Kennelly Heaviside Schicht, auch E Schicht genannt, ist ein Teil der Ionosphäre der Erde. Sie ist eine der Schichten der Ionosphäre an denen kurzwellige Radiosignale… … Deutsch Wikipedia
