Tribute
to Dr. Hans A. Bethe
by Dr. Raymond L. Orbach
Director, Office of Science
U.S. Department of Energy
March 8, 2005
Nobel Laureate Hans A. Bethe died peacefully at home
in Ithaca, New York, at the age of 98 on March
6, 2005.
"A monumental
figure in the history of physics has passed
on,” said Dr. Raymond L. Orbach, Director
of the Department of Energy’s Office
of Science. “We have lost a giant among
giants. We shall all miss his remarkable scientific
insight and contributions, not only to physics,
but also to our nation and world. He will
long be remembered for his fundamental contributions
to our understanding of the properties of
matter, from the atomic nucleus, to materials,
to the cosmos."
Professor Bethe’s earliest work still
remains the cornerstone of many-body physics,
Dr. Orbach noted. The "Bethe ansatz"
serves as the basis of our understanding of
complex interacting systems, from the antiferromagnetic
ground state to the Kondo problem.
When he first came
to Cornell University from Germany via Cambridge,
England in 1935, he wrote a brilliant series
of papers on nuclear physics which became
known as “Bethe's Bible” and which,
according to Edward Teller, contained everything
there was to know about nuclear physics. In
1938, Bethe developed the carbon cycle, a
nuclear process for generating energy in the
Sun, and stars like it, by fusing hydrogen
into helium. For this work, Bethe was awarded
the Nobel Prize in Physics in 1967. (Neutrinos
are one byproduct of the carbon cycle, and
it was the determination to detect them that
started Raymond Davis on his quest, which
led eventually to a share of the Nobel Prize
in 2002.)
In 1943, Bethe joined the then secret Los
Alamos laboratory as head of the theoretical
division, and he played a key role in the
complex calculations leading to the design
of the atomic bomb. A brilliant man himself,
with the steadiness and determination of a
battleship, he kept a collection of brilliant
minds and idiosyncratic personalities, such
as Richard Feynman, John von Neumann and Edward
Teller firmly focused on the goals of the
Manhattan Project.
After the Second World War, Bethe returned
to Cornell to his first love, teaching and
research into the structure of atoms, molecules
and condensed matter, and the theory of quantum
electrodynamics. He did, however, maintain
his interest in matters of national security
and while he never regretted his role in developing
nuclear weapons, he had definite views on
the proper role for them in world affairs.
He served on the President's Science Advisory
Committee from 1956 to 1964.
In 1961, Bethe received the Fermi
Award from the Atomic Energy Commission,
the predecessor of the Department of Energy,"for
contributions to nuclear and theoretical physics,
to peaceful uses of atomic energy, and to
the security of the United States." (Fellow
Fermi Award recipients in following years
included Edward Teller (1962), Robert Oppenheimer
(1963), and Lise Meitner (1966).)
In recent years, Bethe’s interests turned
to nuclear astrophysics and the phenomenon
of supernova explosions. In his 90's, he was
still giving lectures to non-physicists about
quantum mechanics.
“Hans Bethe’s
passing marks the end of a prodigious group
of pioneers in the quantum nature of our world,”
said Dr. Orbach. “He symbolizes the
finest amongst us--a scientist with a deep
understanding of, and commitment to, scientific
discovery; and a world citizen who recognized
the importance of science and society, and
contributed so much to making this a better
world.”
Note: Hans
Bethe’s obituary and three
lectures he delivered in 1999 are available
on the Cornell
University web site.