John Hamilton Reynolds[2] (April 3, 1923 – November 4, 2000) was an American physicist and a specialist in mass spectrometry.[3]
John Hamilton Reynolds | |
|---|---|
| Born | April 3, 1923 Cambridge, Massachusetts, United States |
| Died | November 4, 2000 (aged 77) Berkeley, California, United States |
| Alma mater | Harvard University, University of Chicago |
| Known for | Discovery of excess meteoritic 129Xe |
| Awards | John Price Wetherill Medal (1965) J. Lawrence Smith Medal (1967) Leonard Medal (1973)[1] |
| Scientific career | |
| Fields | Geophysics |
| Institutions | University of Chicago, University of California, Berkeley |
| Doctoral advisor | Mark Inghram |
Life
editJohn H. Reynolds was born April 3, 1923 in Cambridge, Massachusetts, United States. He studied first at Harvard University and, after serving in the Navy during World War II, at the University of Chicago. There, he was influenced by his Ph.D. thesis advisor Mark Inghram and by two other famous physicists, Harold Urey and Enrico Fermi. He specialized in mass spectrometry and utilized this method to determine isotope ratios needed for the radiometric dating of geologically and cosmologically relevant samples.
In 1950 he was appointed as professor to the University of California, Berkeley where he continued his research on isotope ratios in meteorites, leading to the discovery in 1960 that the Richardton meteorite and other meteorites had an excess of xenon-129,[4][5][6] thought to be a result of the beta decay of iodine-129 in the early Solar System.[7] He was helped by a new all-glass spectrometer that he had designed, which allowed gas samples to be run through it multiple times, helping to increase the odds of detection and alleviate the low sensitivity problems plaguing earlier attempts by other researchers on other meteorites.[8] Unlike many scientific discoveries, the significance of the discovery was well and widely understood at the time.[8]
His improvement of potassium-argon dating was also adopted by several institutions.[3][9]
Reynolds was a Guggenheim Fellow for the academic years 1956–1957 and 1986–1987.[10] He was elected to the National Academy of Sciences in 1968.[1] He died of pneumonia on November 4, 2000, in Berkeley, California, United States.[3]
References
edit- ^ a b Kennedy, B. Mack; Podosek, Frank A. (April 2001). "John H. Reynolds (1923-2000)" (PDF). The Geochemical News, Newsletter of the Geochemical Society (107): 10–11.
- ^ The Leonard Medal, Meteoritics 8 (1973), pp. 291–293.
- ^ a b c John H. Reynolds, Physics: Berkeley, Bruce A. Bolt, Richard E. Packard, and P. Buford Price, in University of California: In Memoriam, 2000, edited by Micki Conklin, University of California Academic Senate, 2000. Accessed on line October 24, 2007.
- ^ J. H. Reynolds (1960). "Isotopic Composition of Primordial Xenon". Physical Review Letters. 4 (7): 351–354. Bibcode:1960PhRvL...4..351R. doi:10.1103/PhysRevLett.4.351.
- ^ J. H. Reynolds (1960). "Determination of the Age of the Elements". Physical Review Letters. 4 (1): 8–10. Bibcode:1960PhRvL...4....8R. doi:10.1103/PhysRevLett.4.8.
- ^ Saxon, Wolfgang (20 November 2000). "John Hamilton Reynolds, 77; Improved Study of Cosmic Ages". The New York Times. Retrieved 25 December 2012.
- ^ Alan P. Dickin (1997). Radiogenic Isotope Geology. Cambridge University Press. p. 400. ISBN 978-0-521-59891-0.
- ^ a b Pratt, Sarah E. (25 September 2015). "Benchmarks: January 1, 1960: The Discovery of "Extinct Radioactivity" The quest to date the elements that formed the solar system". Earth Magazine. Retrieved 2024-08-26.
- ^ Office of the Home Secretary; National Academy of Sciences (2004). Biographical Memoirs. National Academies Press. p. 248. ISBN 978-0-309-10363-3.
- ^ "John Hamilton Reynolds". John Simon Guggenheim Memorial Foundation.