John F. Allen (physicist)
John F. Allen Superfluid phase of matter | |
---|---|
Scientific career | |
Fields | Physics |
Institutions | University of St Andrews |
Doctoral advisor | John McLennan |
John Frank Allen,
Life
Allen was born in Winnipeg; he was also known as Jack Allen. His father, Frank Allen, was a professor in physics at the University of Manitoba.[3] John Allen studied physics initially at the
He stayed in Cambridge until 1947, when he took up an appointment as a professor in natural philosophy at the University of St Andrews, Scotland in 1947.[10]
In 1949, he was elected a Fellow of the Royal Society.[11] During his tenure at the University of St Andrews, he was twice dean of the Faculty of Science, and oversaw the creation of a separate Faculty of Applied Science at Dundee as well as the development of the Science complex on the North Haugh in St Andrews, which opened in 1966.
He was chair of the Very Low Temperature Commission of the International Union of Pure and Applied Physics from 1966 to 1969 and member of the British National Committee for Physics of the Royal Society.[10]
In 1978, he retired, retaining emeritus status until his death. He died in St Andrews in Fife[12] of a stroke.[11]
Allen received an honorary doctorate from Heriot-Watt University in 1984.[13] The building of the School of Physics and Astronomy of the University of St Andrews is named after John Allen, as is the library in the J.F. Allen building.
Allen died of a stroke on 22 April 2001.[14]
Family
Allen married his wife, Elfriede Hiebert, in 1933. The two divorced later. They had one adopted son.[10]
Scientific work
During his work on low temperature physics, Allen developed a number of techniques that are still in use today. In 1937, he introduced the O-ring for use as a seal for vacuum systems.[2][11] He further invented in 1947 indium gaskets to create leak tight seals for low temperature applications.[4]
In 1937, Allen discovered
Allen also used a movie camera to film his experiments, such as the superfluid helium fountain, which he discovered in 1938 with the help of a pocket flashlight. Over a ten-year period Allen made a movie of the various two-fluid phenomena exhibited by liquid helium-4. The photography of these effects was a real challenge, because liquid helium-4 is essentially transparent. This unique colour movie (the fifth edition was completed in 1982) is one of Allen's great legacies to physics. His was an early user of moving images to document experiments and inform students and the general public.
At some stage (likely in 1984) he modified the long-running St. Andrews pitch drop experiment to bring its setup closer to that of the University of Queensland's similar pitch-drop experiment.[15]
Pictorial biography
-
J F Allen building, hosting the School of Physics and Astronomy of the University of St Andrews
-
Helium liquifier built by John F. Allen in 1952 at the University of St Andrews
See also
- Timeline of low-temperature technology
- Griffin, Allan (1999). "A Brief History of Our Understanding of BEC: From Bose to Beliaev". )
- John Allen's video on superfluid helium
References
- .
- ^ .
- doi:10.1038/209133b0.
- ^ a b c d "John Allen Eminent physicist who was the discoverer of superfluid helium". Herald Scotland. 28 April 2001.
- doi:10.1063/1.881467.
- ^ Pearce Wright (4 May 2001). "Obituary: John Allen". The Guardian.
- S2CID 4094549.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - S2CID 3997900.
- S2CID 119067574.
- ^ a b c d "Directory of Fellows of the Royal Society". Retrieved 21 August 2019.[permanent dead link]
- ^ S2CID 36121636.
- OCLC 83595094.
- ^ "Heriot-Watt University Edinburgh: Honorary Graduates" (PDF). Retrieved 21 August 2019.
- S2CID 36121636.
- ISSN 0028-6664. Retrieved 5 May 2023.
Professor Allen says he has altered his apparatus (which was too small to produce separate drips) so that it duplicates more precisely the experiment at Queensland