Sin-Itiro Tomonaga
Biography
Sin-Itiro Tomonaga was born in Tokyo, Japan, on March 31, 1906, the
eldest son of Sanjuro Tomonaga and Hide Tomonaga. In 1913 his family moved
to Kyoto when his father was appointed a professor of philosophy at Kyoto
Imperial University. From that time he was brought up in Kyoto. He is
a graduate of the Third Higher School, Kyoto, a renowned senior high school
which has educated a number of leading personalities in prewarJapan.
Tomonaga completed work for Rigakushi (bachelor's degree) in physics at
Kyoto Imperial University in 1929, with one of his intimate friends. Dr.
Hideki Yukawa, Nobel laureate. He was engaged in graduate work for three
years at the same university and was then appointed a research associate
by Dr. Yoshio Nishina at the Institute of Physical and Chemical Research,
Tokyo, where he started to work in a newly developed frontier of theoretical
physics quantum electrodynamics - under the guidance of Dr. Nishina. His
paper on the photoelectric pair creation is well-known.
Tomonaga stayed in Leipzig, Germany, from 1937 to 1939, to study
nuclear physics and the quantum field theory in collaboration
with the theoretical group of Dr. W. Heisenberg, where he
published a paper "Innere Reibung und
Wärmeleitfähigkeit der Kernmaterie", which was chosen
as the thesis for Rigakuhakushi (Doctor of Science) at Tokyo
Imperial University in December,1939.
In 1940, Dr. Tomonaga directed his attention to the meson theory and developed
the intermediate coupling theory in order to clarify the structure of
the meson cloud around the nucleon. He joined the faculty of Tokyo Bunrika
University (which was absorbed into the Tokyo University of Education
in 1949*) as Professor of Physics in 1941. It was in 1942 when he first
proposed the covariant formulation of the quantum field theory in which
the concept of the quantum state was generalized so as to be relativistically
covariant.
During the Second World War, Dr. Tomonaga was interested in
developing a theory of microwave systems. He solved the motion of
electrons in the magnetron and also developed a unified theory of
the systems consisting of wave guides and cavity
resonators.
As soon as the War was over, Tomonaga came back to academic
research again with a programme in which he was first to
summarize and extend the intermediate coupling theory and
secondly to apply the covariant field theory to actual physical
systems. His aim was to investigate the nature of field reaction
in the meson theory as well as in quantum electrodynamics. He was
confident, prior to the Lamb-Rutherford experiment, by means of a
model calculation that divergence difficulty in
quantumelectrodynamics could be overcome simply by handling the
infinite mass and charge due to field reactions in some way or
another. It was only a step further for him to develop the
renormalization theory with covariant formalism in his right hand
and experimental support in his left.
Dr. Tomonaga was invited to the Institute for Advanced Study,
Princeton, in 1949 where he was engaged in the investigation of a
one-dimensional fermion system. Thus he first succeeded in
clarifying the nature of collective oscillations of a
quantum-mechanical many-body system and opened a new frontier of
theoretical physics, modern many-body problem. In 1955, he
published an elementary theory of quantum mechanical collective
motions.
Dr. Tomonaga took the leadership in establishing the Institute
for Nuclear Study, University of Tokyo, in 1955. From 1956 to 1962 he
was appointed President of the Tokyo University of Education and
since 1963 he has been President of the Science Council of Japan
and Director of the Institute for Optical Research, Tokyo
University of Education. He occupies an important position in
various governmental committees for scientific research and
policymaking.
Tomonaga's honours and awards include the Japan Academy Prize
(1948); the Order of Culture (1952); the Lomonosov Medal,
U.S.S.R. (1964).
Dr. Tomonaga is a member of the Japan Academy, the Deutsche Akademie der
Naturforscher "Leopoldina" and a foreign member of the Royal Swedish Academy
of Science. He is a corresponding member of the Bayerische Akademie der
Wissenschaften and a foreign associate of the National Academy of Science
of U.S.A.
Tomonaga has published widely in scientific journals on such
subjects as quantum electrodynamics, the meson theory, nuclear
physics, cosmic rays, and the many-body problem. His book,
"Quantum Mechanics", was published in 1949 and translated into
English in 1963.
Tomonaga was married in 1940 to Ryoko Sekiguchi, daughter of Dr.
K. Sekiguchi, the former Director of the Tokyo Metropolitan
Observatory. They have two sons, Atsushi and Makoto and one
daughter. Their daughter was married in 1965 to Dr. Y. Nagashima,
research associate of the Physics Department, University of
Rochester.
From Nobel Lectures, Physics 1963-1970, Elsevier Publishing Company, Amsterdam, 1972
This autobiography/biography was first published in the book series Les Prix Nobel. It was later edited and republished in Nobel Lectures. To cite this document, always state the source as shown above.
* Tokyo University of Education was further reorganized and renamed as University of Tsukuba in 1973.
Sin-Itiro Tomonaga died on July 8, 1979.
Copyright © The Nobel Foundation 1965