Julian Schwinger – Biography
Julian Schwinger was born on
12th February 1918 in New York City. The principal direction of
his life was fixed at an early age by an intense awareness of
physics, and its study became an all-engrossing activity. To
judge by a first publication, he debuted as a professional
physicist at the age of sixteen. He was allowed to progress
rapidly through the public school system of New York City.
Through the kind interest of some friends, and especially
I.I. Rabi of Columbia
University, he transferred to that institution, where he
completed his college education. Although his thesis had been
written some two or three years earlier, it was in 1939 that he
received the Ph.D. degree.
For the next two years he was at the University of
California, Berkeley, first as a National Research Fellow and
then as assistant to J.R. Oppenheimer. The outbreak of the
Pacific war found Schwinger as an Instructor, teaching elementary
physics to engineering students at Purdue
University.
War activities were largely confined to the Radiation Laboratory
at the Massachusetts
Institute of Technology in Cambridge. Being a confirmed
solitary worker, he became the night research staff. More
scientific influences were also at work. He first approached
electromagnetic radar problems as a nuclear physicist, but soon
began to think of nuclear physics in the language of electrical
engineering. That would eventually emerge as the effective range
formulation of nuclear scattering. Then, being conscious of the
large microwave powers available, Schwinger began to think about
electron accelerators, which led to the question of radiation by
electrons in magnetic fields. In studying the latter problem he
was reminded, at the classical level, that the reaction of the
electron's field alters the properties of the particle, including
its mass. This would be significant in the intensive developments
of quantum electrodynamics, which were soon to follow.
With the termination of the war Dr. Schwinger accepted an
appointment as Associate Professor at Harvard University. Two
years later he became full Professor. That was also the year of
his marriage to Clarice Carrol of Boston.
In subsequent years, he worked in a number of directions, but
there was a pattern of concentration on general theoretical
questions rather than specific problems of immediate experimental
concern, which were nearer to the center ot hls earlier work. A
speculative approach to physics has its dangers, but it can have
its rewards. Schwinger was particularly pleased by an
anticipation, early in 1957, of the existence of two different
neutrinos associated, respectively, with the electron and the
muon. This has been confirmed experimentally only rather
recently. A related and somewhat earlier speculation, that all
weak interactions are transmitted by heavy, charged, unit-spin
particles still awaits a decisive experimental test. Schwinger's
policy of finding theoretical virtues in experimentally unknown
particles has culminated recently in a revived concern with
magnetically charged particles, which may also be involved in the
understanding of strong interactions.
In later years, Schwinger has followed his own advice about the
practical importance of a phenomenological theory of particles.
He has invented and systematically developed source theory, which
deals uniformly with strongly interacting particles, photons, and
gravitons, thus providing a general approach to all physical
phenomena. This work has been described in two volumes published
under the title "Particles, Sources, and Fields".
Awards and other honors include the first Einstein Prize (1951),
the U.S. National Medal of Science (1964), honorary D.Sc. degrees
from Purdue University (1961) and Harvard University (1962), and
the Nature of Light Award of the U.S. National Academy of
Sciences (1949). Prof. Schwinger is a member of the latter body,
and a sponsor of the Bulletin of the Atomic
Scientists.
From
Nobel Lectures. Physics 1963-1970, Elsevier Publishing Company, Amsterdam, 1972
This autobiography/biography was written
at the time of the award and later published in the book series Les
Prix Nobel/Nobel
Lectures. The information is sometimes updated with an addendum submitted
by the Laureate. To cite this document, always state the source as shown above.
Julian Schwinger died in 1994.
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