Chaim L. Pekeris

Chaim Leib Pekeris (born June 15, 1908 in Alytus , Lithuania , † February 24, 1993 in Rehovot ) was an Israeli physicist and applied mathematician who dealt in particular with geophysics and atomic physics .

Life

Pekeris came to the USA in 1925 with his two brothers (made possible by an uncle who was already successful in the furniture industry there) where he studied at the Massachusetts Institute of Technology , with a bachelor's degree in meteorology in 1929 and a doctorate in geophysics with Carl in 1933 -Gustaf Rossby ( The development and present status of the theory of heat balance in the atmosphere ). During this time he was also on a study visit to Oslo. He was then an instructor at MIT and turned to geophysics under Louis B. Slichter (1896–1978).

In 1938 he became a US citizen. He stayed at MIT until 1941 when he moved to Columbia University's Hudson Laboratories for military research. In 1946 he was at the Institute for Advanced Study and was a Guggenheim Fellow. At the same time he was active in the procurement of military equipment for the nascent state of Israel.

In 1948 he went to Israel, where he was at the Weizmann Institute from 1949 and founded and headed its department of applied mathematics. He was involved in the development of the first digital computer in Israel, the WEIZAC , and led the first geophysical exploration of Israel, which also led to the discovery of crude oil at Heletz .

In 1973 he retired. He died of a fall from the stairs of his house.

During his time at MIT in the 1930s, he dealt with mantle convection, which came into question as a mechanism for plate tectonics, with natural oscillations of the atmosphere and stars, the propagation of sound pulses and the inverse problem of electrical conductivity in rocks. He continued his work on pulse propagation in the Second World War in military research on sonar, which later earned him the title of Honorary Admiral in the US Navy. After the war he dealt with atomic physics and theoretical seismology as well as hydrodynamics. For example, he derived the critical Reynolds number (onset of turbulence) for flow in a circular pipe. In atomic physics he published fundamental work on the calculation of the ground state of helium, which was based on a variation method by Egil Hylleraas . He theoretically investigated the natural vibration modes of the earth, which could be verified after the great earthquake in Chile in 1960 and developed synthetic seismograms for layered media, calculated with the Weizac and Golem computers in Israel. He also performed computer calculations in his investigations into atomic physics and in the numerical simulation of tides.

In 1974 he received the Vetlesen Prize and in 1980 the gold medal of the Royal Astronomical Society . He was a member of the National Academy of Sciences (1952), the American Academy of Arts and Sciences (1971) and the American Philosophical Society (1974). In 1981 he received the Israel Prize for Physics. In 1972 he became a member of the Accademia dei Lincei .

Fonts

• Thermal convection in the interior of the Earth , Mon. Not. R. Astron. Soc. Geophys. Suppl. 3, 1935, pp. 343-367
• Inverse Boundary Problem in Seismology , Physics, Volume 5, 1934, pp. 307-316
• Atmospheric Oscillations , Proc. Roy. Soc. A, Volume 158, 1937, pp. 650-671 (and Nature, Volume 138, 1936, p. 642)
• Non-radial oscillations of stars , astrophys. J., Volume 88, 1938, pp. 189-199
• The propagation of an SH pulse in a layered medium , Transactions American Geophysical Union I, Report Papers, 1941, p. 392
• Stability of laminar flow through a straight pipe of circular cross section to infinitesimal disturbances which are symmetrical about the axis of the pipe , Proc. Nat. Acad. Sci. USA, Vol. 34, 1948, pp. 285-295
• Theory of propagation of explosive sound in shallow water , Geol. Soc. At the. Memoir 27, 1948
• The zero-point energy of helium , Phys. Rev., Vol. 79, 1950, pp. 884-885
• The seismic surface pulse , Proc. Natl. Acad. Sci. USA, Vol. 41, 1955, pp. 469-480
• with IM Longman Ray theory solution of the problem of propagation of explosive sound in a layered liquid , J. Acoust. Soc. Am., Vol. 31 1958, pp. 323-328.
• Ground state of two-electron atoms , Phys. Rev., Vol. 112, 1958, pp. 1649-1658
• with Z. Alterman, H. Jarosch Oscillations of the Earth , Proc. R. Soc. A, Vol. 252, 1959, pp. 80-95.
• 1 ¹ S and 2 ³ S states of helium , Phys. Rev., Vol. 115, 1959, pp. 1216-1221
• 1 ¹ S, 2 ¹ S, and 2 ³ S states of H ^{-} and of He , Phys. Rev., Vol. 126, 1962, pp. 1470-1476
• with Y. Accad Dynamics of the liquid core of the Earth , Philos. Trans. Royal Soc. A, Vol. 273, 1972, pp. 237-260

Web links

• Obituary at the National Academy of Sciences by Freeman Gilbert