John F. Allen
John Frank "Jack" Allen , (born May 5, 1908 in Winnipeg , † April 22, 2001 in Elie , Fife , Scotland ) was a Canadian-British physicist who was one of the discoverers of superfluidity , for which Pyotr Kapiza received the Nobel Prize .
His father Frank Allen was a physics professor at the University of Manitoba , where Jack Allen also studied physics with a bachelor's degree in 1928. He then went to the University of Toronto , where he received his doctorate in 1933 under John McLennan on superconductivity . In Toronto he built a cryostat for low temperatures. After two years as a post-doctoral student at Caltech , he went to Cambridge University in 1935 , where he wanted to conduct research at the Royal Society's Moon Laboratory with the low-temperature physicist Pyotr Kapitsa, who was not allowed to leave the country after visiting the Soviet Union.
In 1937 he and his student Don Misener , who also came from Canada, discovered superfluidity independently of Kapitsa in Moscow at the Moon Laboratory of the Royal Society at Cambridge University . Allen and Misener published about it side by side with Kapitsa in the same issue of Nature in 1938. He also made early films about the strange properties of superfluids such as the fountain effect he discovered. When he demonstrated this in front of the Royal Society in London, HG Wells is said to have been so astonished that he crawled under the experiment table to look for the pump he suspected ( Ralph Fowler and Paul Dirac were also present ). His student Ernest Ganz detected the second sound in liquid helium, and he and his colleagues were on their way to further discoveries (third sound in thin superfluid films) when the Second World War broke out and instead looked at electronically adjustable fuzes for anti-aircraft shells and with oxygen generation for bomber crews.
In 1937 he invented O-rings as seals for vacuum technology and in 1947 indium rings for the same purpose at low temperatures. From 1947 to his retirement in 1978 he was a professor at the University of St. Andrews .
In 1949 he became a Fellow of the Royal Society and in 1948 the Royal Society of Edinburgh and the American Physical Society . He was chairman and founding member of the Standing Conference of Professors of Physics and the Committee of Scottish Professors of Physics , member of the British National Committee for Physics and 1966-1969 chairman of the Very Low Temperature Commission of the International Union of Pure and Applied Physics (IUPAP).
In 1933 he married Elfriede Hiebert. The marriage later divorced and he had an adopted son.
At the University of St. Andrews he later dealt with the history of scientific instruments preserved there and was a member of the St. Andrews Preservation Trust. He also dealt with the history of Scottish science and designed the plaque in memory of Nevil Maskelyne's determination of the gravitational constant at the Schiehallion . He was twice Dean of the Faculty of Science in St. Andrews and as such was involved in the establishment of the Faculty of Applied Science at Queens College in Dundee (then part of St. Andrews) and in 1966 in the construction of the new research building (Science Complex) in St. Andrews.
- Russell J. Donnelly: Obituary: John Frank Allen, Physics Today, Vol. 55, Jul. 2002, pp. 76-77, online
- Allan Griffin: Obituary: John Frank (Jack) Allen (1908-2001), Nature, Volume 411, 2002, p. 436
- JF Allen, AD Misener, Flow of liguid helium II, Nature, Volume 141, 1938, p. 75
|SURNAME||Allen, John F.|
|ALTERNATIVE NAMES||Allen, John Frank (full name); Allen, Jack (nickname)|
|BRIEF DESCRIPTION||Canadian-British physicist|
|DATE OF BIRTH||May 5, 1908|
|PLACE OF BIRTH||Winnipeg|
|DATE OF DEATH||April 22, 2001|
|Place of death||Elie , Fife , Scotland|