Biography
Laudation
Press Release
Chaim Leib Pekeris
(19081993)
Born June 15, 1908 in Alytus, Lithuania, the son of Samuel
and Chaya (Rivel) Pekeris.
Dr. Pekeris received a Bachelor of Science degree in 1929
and a Doctor of Science degree in 1934 from the Massachusetts
Institute of Technology. The following two years were spent
at M.I.T. and at Cambridge University as a Rockefeller Fellow.
He was a member of the faculty of M.I.T. from 1937 to 1941.
He then joined the Mathematical Physics Group of the Division
of War Research at Columbia University, heading the group
from 1945 to 1947. Following a year as a member of the Institute
for Advanced Study at Princeton, he went to Israel in 1949
to head the Department of Applied Mathematics at the newly
created Weizmann Institute of Science. When he relinquished
that post in 1973, he was honored with the title of Distinguished
Institute Professor.
Dr. Pekeris was elected to the National Academy of Sciences
of the U.S.A. in 1952 and to the Israel Academy of Sciences
and Humanities in 1961. He was also a foreign associate of the Royal
Astronomical Society, a foreign honorary member of the American
Academy of Arts and Sciences, and a foreign member of the
Academia Nazionale dei Lincei.
Among his awards and honors were the Rothschild Prize in mathematics
and an honorary degree from Brandeis University.
Dr. Pekeris was a pioneer in applying advanced mathematical
methods to a wide range of fundamental problems related to
the Earth, atmosphere and oceans. In each of the areas of
research in which he has worked he showed a facility for
selecting key problems for theoretical study which he
then proceeded to solve with unique mathematical insight.
His work furthered understanding of such diverse natural
phenomena as the Earth's free vibrations, the tides of both
the ocean and the atmosphere, the propagation of seismic and
electromagnetic pulses and the origin of the earth's magnetic
field. In molecular and atomic physics he made contributions
to the solution of the Boltzmann integral equation and to
spectroscopy of twoelectron atoms.
The solid Earth vibrates with certain characteristic frequencies
when excited by a large earthquake. The Earth continues to
vibrate in free oscillation for some time much as a bell continues
to ring after being struck. He calculated in detail the characteristics
of the various types of free vibrations which were later shown
to be in close agreement with seismograph observations made
after the Chilean earthquake of 1960.
The global behavior of ocean tides was first proposed as a
geophysical problem by the French mathematician, Laplace,
in 1775. The solution of the world ocean problem, involving
realistic shorelines and bottom topography was not possible
before the advent of the highspeed digital computer. At the
1960 General Assembly of the International Union of Geodesy
and Geophysics held in Helsinki, Dr. Pekeris presented the
first global numerical integration of the Laplace tidal equations.
The theory of tides in the atmosphere was also developed by
Dr. Pekeris with Sir G. I. Taylor during his fellowship at
Cambridge University.
Waterborne sound waves from explosions in shallow water
were investigated by Drs. Ewing and Worzel during World War
II. The waves showed marked frequency dispersion, with different
frequencies traveling at different speeds. Dr. Pekeris provided
a theoretical interpretation of these waves in terms of the
normalmode theory which he extended to cover the case of
explosive sound. This theory would provide a basis
for underwater sound transmission theory for many yearst to come.
In later years Pekeris devoted himself to explaining the origin
of the Earth's magnetic field in terms of the dynamo theory.
He has developed models of convective overturning in the Earth's
interior which act as a selfexcited dynamo to generate the
magnetic field of our planet.
Over the 61 years of his scientific activity, Dr. Pekeris published 145 papers in his many fields of interest.
He Died in Rehovot, Israel, on February 24, 1993.
