John Reynolds (physicist)

John Hamilton Reynolds (born April 3, 1923 in Cambridge (Massachusetts) , † November 4, 2000 in Berkeley ) was an American geophysicist .

life and work

Reynolds studied at Harvard University (Bachelor summa cum laude 1943) and interrupted his military service during World War II in the US Navy in the South Pacific at the University of Chicago , where he received his doctorate under Mark Inghram . He dealt there with mass spectrometers , where he was influenced by the Chicago physicists Harold C. Urey and Enrico Fermi . He applied mass spectrometry to geological and cosmic dating problems, such as meteorites .

In 1950 he became an assistant professor at the University of California, Berkeley , where he worked with the geological research group of John Verhoogen and his students. There he developed the first static (non-pumped) glass mass spectrometer for noble gases . With this he improved the potassium-argon dating in geology. Reynolds discovered isotopic anomalies in meteorites that indicated elements that predated the formation of the solar system . For example, in 1960 he found a xenon -129 anomaly, which he attributed to the decay of iodine 129 (half-life 16 million years), possibly originating from a supernova before the formation of the solar system.

He spent a sabbatical year at the University of São Paulo , where he helped set up a geochronological laboratory.

He was a member of the National Academy of Sciences (1968) and the American Academy of Arts and Sciences (1986). In 1965 he received the Wetherill Medal of the Franklin Institute , in 1967 the J. Lawrence Smith Medal of the National Academy of Sciences, in 1973 the NASA Exceptional Achievement Award and the Leonard Medal of the Meteoritical Society and in 1988 the Berkeley Citation. In 1987 he received an honorary doctorate from the University of Coimbra in Portugal.

His research also provided the basis for the paleomagnetic dating of Allan Cox , Richard Doell , Brent Dalrymple , all of whom came from Berkeley. His method also played an important role in dating the early human finds in the Olduvai Gorge .

literature

• William Glen: The road to Jamarillo. Critical years of revolution in earth science . Stanford University Press, Stanford, Calif. 1982, ISBN 0-8047-1119-4 .

Web links

• Obituary in Berkeley