Renowned Physicist Robert B. Leighton Dies
PASADENA--Robert B. Leighton, a longtime physicist and astronomer at the
California Institute of Technology, died Sunday, March 9, 1997, after a
long illness. He was 77.
Widely known for his innovative design of scientific instruments such as
the Caltech Submillimeter Observatory on Mauna Kea, Hawaii, Leighton was
active in many areas of physics and astronomy during his career. His work
over the years spanned solid state physics, cosmic ray physics, the beginnings
of modern particle physics, solar physics, planetary photography, infrared
astronomy, and millimeter- and submillimeter-wave astronomy.
"In the latter four fields, his pioneering work opened up entirely
new scientific areas of research that subsequently developed into vigorous
scientific communities," said Charles Peck, professor of physics and
chair of the Division of Physics, Mathematics and Astronomy. "All of
us who knew Bob Leighton deeply admired him and miss him greatly."
In addition, he was a renowned teacher, having edited "The Feynman
Lectures in Physics" into their printed form, and authored a highly
influential text, "Principles of Modern Physics," and, for his
contemporaries, set a high standard of teaching quality. In addition, he
co-authored, with Caltech physics professor Robbie Vogt , a set of problems
to accompany the Feynman Lectures.
In 1948, Leighton's first scientific publication concerned the specific
heat of face-centered cubic crystals, but he had already been drawn into
Caltech's strong cosmic ray group under Nobel laureate Carl Anderson's
leadership. He played a key role in 1949 in showing that the mu-meson decay
products are two neutrinos and an electron, and he made the first
measurement of the energy spectrum of the decay electron (at the time, low
statistics experiments suggested that only one neutrino was involved). In
1950 he made the first observation of strange particle decays after the
initial discovery of two cases in England in 1947. Over the next seven
years, he elucidated many of the properties, e.g., mass, lifetime,
decay-modes and energies, of several of the new strange particles, in
particular, the lambda, the xi, and what were then called the theta
particles (K-mesons).
In the mid-1950s, Leighton became interested in the physics of the outer
layers of the Sun. With characteristic imagination and insight, he devised
Doppler-shift and Zeeman effect solar cameras. They were applied with
striking success to the investigation of magnetic and velocity fields on
the sun. With the Zeeman camera, Leighton and his students mapped
complicated patterns of the sun's magnetic field with excellent resolution.
Even more striking were his discoveries of a remarkable five-minute
oscillation in local surface velocities and of a "super-granulation
pattern" of horizontal convection currents in large cells of moving
material. These solar oscillations have subsequently been recognized as
internally trapped acoustic waves, opening up the field of solar
seismology, subsequently pursued by Caltech physics professor Ken
Libbrecht.
In the early 1960's, Leighton developed and fabricated a novel,
inexpensive infrared telescope. He and Caltech physics professor Gerry
Neugebauer used it to produce the first survey of the sky at 2.2 microns.
This survey revealed an unexpectedly large number of relatively cool
objects. Some of these have been found to be new stars still surrounded by
their dusty pre-stellar shells, while others are supergiant stars in the
last stages of their evolution, embedded in expanding dusty shells of
matter ejected by the stars themselves.During the middle 1960's Leighton
was the Team Leader at JPL for the Imaging Science Investigations on the
Mariner 4, 6, and 7 missions to Mars. As Team Leader and an experienced
experimental physicist, Leighton played a key role in forming and guiding
the development of JPL's first digital television system for use in deep
space. He also contributed to the first efforts at image processing and
enhancement techniques made possible by the digital form of the imaging
data.
Leighton also designed and built equipment earlier in his career that
was used to make images of the planets. These were considered the best
images of the planets until the era of space exploration with probes began
in the 1960s.
In the 1970's, Leighton's interest shifted to the development of large,
inexpensive dish antennae which could be used to pursue millimeter-wave
interferometry and submillimeter-wave astronomy. Once again, his remarkable
experimental abilities opened a new field of science at Caltech which
continues to be vigorously pursued at the Owens Valley Radio Observatory
(OVRO) and the Caltech Sub-millimeter Observatory (CSO) on Mauna Kea using
the "Leighton Dishes."
Born in Detroit, September 10, 1919, Dr. Leighton received his B.S. in
1941, his M.S. in 1944, and his Ph.D. in 1947, all from Caltech. He
continued here as a Research Fellow (1947-1949), Assistant Professor
(1949-1953), Associate Professor (1953-1959), Professor (1959-1984),
Valentine Professor of Physics (1984-1985), and Valentine Professor,
Emeritus (1985-1997). Bob served as Division Chair of Physics, Mathematics
and Astronomy from 1970 to 1975. He was a member of the American Physical
Society, Sigma Xi, the American Astronomical Society, the American Association
of Arts and Sciences, and the National Academy of Sciences.
He is survived by his wife, Marge Leighton of Pasadena; his former wife,
Alice Leighton of Seattle, Washington; their two sons, Alan of Bochum,
Germany and Ralph of Tiburon, California; and two grandchildren, Ian and
Nicole, both of Tiburon.Memorials may be made to the Los Angeles Library
Foundation at 630 West 5th Street, Los Angeles, California 90071.
Contact: Robert Tindol (818) 395-3631 tindol@caltech.edu
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