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Victor Appleton Biography & Facts

Sir Edward Victor Appleton (6 September 1892 – 21 April 1965) was an English physicist, Nobel Prize winner (1947) and pioneer in radiophysics. He was awarded the Nobel Prize in Physics "for his investigations of the physics of the upper atmosphere especially for the discovery of the so-called Appleton layer". He studied, and was also employed as a lab technician, at Bradford College from 1909 to 1911. He won the Nobel Prize in Physics in 1947 for his seminal work proving the existence of the ionosphere during experiments carried out in 1924. Biography Appleton was born in Bradford, West Riding of Yorkshire, the son of Peter Appleton, a warehouseman, and Mary Wilcock, and was educated at Hanson Grammar School. In 1911, aged 18, he was awarded a scholarship to attend St John's College, Cambridge, where he graduated with First Class Honours in Natural Science with Physics in 1913. He was also a member of Isaac Newton University Lodge. In 1915 he married his first wife, Jessie Appleton (formerly Longson), with whom he had two children. Three years after her death he married Helen Lennie (m. 1965). During the First World War he joined the West Riding Regiment, and later transferred to the Royal Engineers. After returning from active service in the First World War, Appleton became assistant demonstrator in experimental physics at the Cavendish Laboratory in 1920. In 1922 he was initiated into Freemasonry. He was professor of physics at King's College London (1924–1936) and professor of natural philosophy at the University of Cambridge (1936–1939). From 1939 to 1949 he was secretary of the Department of Scientific and Industrial Research. Knighted in 1941, he received the 1947 Nobel Prize in Physics for his contributions to the knowledge of the ionosphere, which led to the development of radar. From 1949 until his death in 1965, Appleton was Principal and Vice-Chancellor of the University of Edinburgh. From 1960 he was involved with the University's plans for a CDA (Comprehensive Development Area) which would have demolished 125 acres of Edinburgh's historic southside, resulting in the loss of many homes and businesses. This University-led project blighted the area for a decade before being abandoned in the mid 1970s. One recent study describes Appleton as a megalomaniac in his desire to carry out these plans. In 1956, the BBC invited him to deliver the annual Reith Lectures. Across a series of six radio broadcasts, titled Science and the Nation, he explored the many facets of scientific activity in Britain at the time. Sir Edward died on 21 April 1965 at Edinburgh and is buried in Edinburgh's Morningside Cemetery with his wife Helen Lennie (d. 1983). The grave lies towards the extreme western side near the new housing to the north-west. Works Appleton had observed that the strength of the radio signal from a transmitter on a frequency such as the medium wave band and over a path of a hundred miles or so was constant during the day but that it varied during the night. This led him to believe that it was possible that two radio signals were being received. One was travelling along the ground, and another was reflected by a layer in the upper atmosphere. The fading or variation in strength of the overall radio signal received resulted from the interference pattern of the two signals. The existence of a reflecting atmospheric layer was not in itself a completely new idea. Balfour Stewart had suggested the idea in the late 19th century to explain rhythmic changes in the Earth's magnetic field. More recently, in 1902, Oliver Heaviside and Arthur E. Kennelly had suggested such an electromagnetic-reflecting stratum, now called the Kennelly–Heaviside layer, may explain the success Marconi had in transmitting his signals across the Atlantic. Calculations had shown that natural bending of the radio waves was not sufficient to stop them from simply "shooting off" into empty space before they reached the receiver. Appleton thought the best place to look for evidence of the ionosphere was in the variations he believed it was causing around sunset in radio signal receptions. It was sensible to suggest these variations were due to the interference of two waves but an extra step to show that the second wave causing the interference (the first being the ground wave) was coming down from the ionosphere. The experiment he designed had two methods to show ionospheric influence and both allowed the height of the lower boundary of reflection (thus the lower boundary of the reflecting layer) to be determined. The first method was called frequency modulation and the second was to calculate the angle of arrival of the reflected signal at the receiving aerial. The frequency modulation method exploits the fact that there is a path difference between the ground wave and the reflected wave, meaning they travel different distances from sender to receiver. Let the distance AC travelled by the ground wave be h and the distance ABC travelled by the reflected wave h'. The path difference is: h ′ − h = D {\displaystyle h'-h=D} The wavelength of the transmitted signal is λ. The number of wavelengths difference between the paths h and h' is: h − h ′ λ = D λ = N {\displaystyle {\frac {h-h'}{\lambda }}={\frac {D}{\lambda }}=N} If N is an integer number, then constructive interference will occur, this means a maximum signal will be achieved at the receiving end. If N is an odd integer number of half wavelengths, then destructive interference will occur and a minimum signal will be received. Let us assume we are receiving a maximum signal for a given wavelength λ. If we start to change λ, this is the process called frequency modulation, N will no longer be a whole number and destructive interference will start to occur, meaning the signal will start to fade. Now we keep changing λ until a maximum signal is once again received. The means that for our new value λ', our new value N' is also an integer number. If we have lengthened λ then we know that N' is one less than N. Thus: N − N ′ = D λ − D λ ′ = 1 {\displaystyle N-N'={\frac {D}{\lambda }}-{\frac {D}{\lambda '}}=1} Rearranging for D gives: D = h − h ′ = .... Discover the Victor Appleton popular books. Find the top 100 most popular Victor Appleton books.