| Sir John Turton Randall,DSc, FRSE | |
|---|---|
| Born | 23 March 1905 Newton-le-Willows, Lancashire, England |
| Died | 16 June 1984 (aged 79) Edinburgh, Scotland |
| Residence | UK |
| Citizenship | United Kingdom of Great Britain |
| Nationality | British |
| Fields | Experimental physicist and biophysicist |
| Institutions | GEC, The Cavendish Laboratory of the University of Cambridge, King's College in the University of London and Dept. of Zoology at the University of Edinburgh |
| Alma mater | University of Manchester and The Cavendish Laboratory of the University of Cambridge |
| Doctoral advisor | Nobel-prize winner, Sir-William Lawrence Bragg, Head of The Cavendish Laboratory |
| Doctoral students | 49 |
| Known for | High-power, multi-cavity magnetron for British and American radar stations in WWII, DNA structure determination, neutron diffraction studies of labelled proteins |
| Notable awards | Knight of the British Empire, FRSE John Price Wetherill Medal (1958) |
Sir John Turton Randall, FRS, FRSE, (23 March 1905 – 16 June 1984) was a British physicist and biophysicist, credited with radical improvement of the cavity magnetron, an essential component of centimetric wavelength radar, which was one of the keys to the Allied victory in the Second World War. It is also the key component of microwave ovens. He also led the King's College London team which worked on the structure of DNA; his deputy, Professor Maurice Wilkins, shared the 1962 Nobel Prize for Physiology or Medicine, together with James Watson and Francis Crick of the Cavendish Laboratory at the University of Cambridge, for the determination of the structure of DNA. His other staff included Rosalind Franklin, Raymond Gosling, Alex Stokes and Herbert Wilson, all involved in research on DNA.
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John Randall was born on 23 March 1905 at Newton-le-Willows, Lancashire, the only son and the first of the three children of Sidney Randall, nurseryman and seedsman, and his wife, Hannah Cawley, daughter of John Turton, colliery manager in the area. He was educated at the grammar school at Ashton-in-Makerfield and at the University of Manchester, where he was awarded a first-class honors degree in physics and a graduate prize in 1925, and an MSc in 1926. He married Doris, daughter of Josiah John Duckworth, a colliery surveyor, in 1928. They had one son.
From 1926 to 1937 Randall was employed on research by the General Electric Company at its Wembley laboratories, where he took a leading part in developing luminescent powders for use in discharge lamps. He also took an active interest in the mechanisms of such luminescence.
By 1937 he was recognized as the leading British worker in his field, and was awarded a Royal Society fellowship to the University of Birmingham, where he worked on the electron trap theory of phosphorescence in Professor Marcus Oliphant's physics faculty. When the war began in 1939 Randall transferred to the large group working on centimeter radar. At the time limited transmitter output was the greatest single obstacle in the development of this type of radar.
Simple two-pole magnetrons had been developed in the 1920s but gave relatively low power outputs. A more powerful multi-cavity resonant magnetron had been developed in 1935[1] by Hans Erich Hollmann in Berlin. By 1940 Randall and Dr Harry Boot produced a working prototype similar to Hollman's cavity magnetron, but added liquid cooling and a stronger cavity. However Randall and Boot soon managed to increase its power output 100-fold. As Prof. W. E.Burcham recollects:
John Randall and Harry Boot, two young physicists were assigned to the task. Within two months (21 February 1940) they had produced a new kind of magnetron, one with eight concentric cavities… Randall got the inspirational idea of using eight cavities when he researched the design of the original Hertz oscillator which was an open single ring. Randall saw that this structure could be extrapolated into a cylinder and then into eight resonating chambers[2]
In 1943 Randall left Oliphant's physical laboratory in Birmingham to teach for a year in the Cavendish Laboratory at Cambridge. In 1944 Randall was appointed professor of natural philosophy at University of St Andrews and began planning research in biophysics (with Maurice Wilkins) on a small Admiralty grant.
In 1946, John T Randall - who had as Ph.D. advisor the Nobel-Prize winning physicist, William Lawrence Bragg - was appointed Head of Physics Department at King’s College in London. He then moved to the Wheatstone chair of physics at King's College London, where the Medical Research Council set up the Biophysics Research Unit with Randall as the director (now known as Randall Division of Cell and Molecular Biophysics) at King's College London. During his term as Director the experimental work leading to the discovery of the structure of DNA was made there by Rosalind Franklin, Raymond Gosling, Maurice Wilkins, Alex Stokes and Herbert R. Wilson. He assigned Raymond Gosling as a PhD student to Dr. R. Franklin to work on DNA structure by X-ray diffraction.
Maurice Wilkins shared the 1962 Nobel Prize for Physiology and Medicine with James Watson and Francis Crick; Rosalind Franklin had already died from cancer in 1958.
In addition to the X-Ray diffraction work the unit conducted a wide-ranging programme of research by physicists, biochemists, and biologists. The use of new types of light microscopes led to the important proposal in 1954 of the sliding filament mechanism for muscle contraction. Randall was also successful in integrating the teaching of biosciences at King's College.
In 1951 he set up a large multidisciplinary group working under his personal direction to study the structure and growth of the connective tissue protein collagen. Their contribution helped to elucidate the three-chain structure of the collagen molecule. Randall himself specialized in using the electron microscope, first studying the fine structure of spermatozoa and then concentrating on collagen. In 1958 he began to study the structure of protozoa. He set up a new group to use the cilia of protozoa as a model system for the analysis of morphogenesis by correlating the structural and biochemical differences in mutants.
In 1970 he retired to Edinburgh University, where he formed a group which applied a range of new biophysical methods, such as coherent neutron diffraction studies of protein crystals in ionic solutions in heavy water, to study by neutron diffraction and scattering various biomolecular problems, such as the proton exchange of protein residues by deuterons.
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