VAL LOGSDON FITCH
 I
was born the youngest of three children, on a cattle ranch in Cherry
County, Nebraska, not far from the South Dakota border, on March 10, 1923.
This is a very sparsely populated part of the United States and remote
from any center of population. It seems incredible by modern standards
that by the age of 20 my father, Fred Fitch, had acquired a ranch of more
than 4 square miles and had persuaded a local school teacher, Frances
Logsdon, to marry and join him in living there. They moved to the ranch
just 20 years after the battle of Wounded Knee, which occurred about 40
miles northwest. I mention this because our living close to their
reservation made the Sioux Indians very much a part of our environment. My
father, while not fluent, spoke their language. They recognized his
friendly interest on their behalf by making him an honorary chief.
Not long after my birth my father was badly injured when a horse he was
riding fell with him. He subsequently had to give up the physically
strenuous activity associated with running a ranch and raising cattle. The
family moved to Gordon, Nebraska, a town about 25 miles away, where my
father entered the insurance business. All of my formal schooling through
high school was in the public schools of Gordon. During this period my
parents retained ownership of the ranch but the operation was largely left
to others. E. B. White has defined farming as 10% agriculture and 90%
fixing something that has gotten broken. My memories of ranching are
primarily not the romantic ones of rounding up and branding cattle but
rather of oiling windmills and fixing fences.
Probably the most significant occurrence in my education came when, as a
soldier in the U.S. Army in WWII, I was sent to Los Alamos, New Mexico, to
work on the
Manhattan Project. The work I did there under the direction of Ernest
Titterton, a member of the British Mission, was highly stimulating. The
laboratory was small and even as a technician garbed in a military fatigue
uniform I had the opportunity to meet and see at work many of the great
figures in physics:
Fermi,
Bohr,
Chadwick,
Rabi,
Tolman. I have recorded some of the experiences from those days in a
chapter in All in Our Time, a book edited by Jane Wilson and
published by the Bulletin of Atomic Scientists. I spent 3 years at Los
Alamos and in that period learned well the techniques of experimental
physics. I observed that the most accomplished experimentalists were also
the ones who knew most about electronics and electronic techniques were
the first I learned. But mainly I learned, in approaching the measurement
of new phenomena, not just to consider using existing apparatus but to
allow the mind to wander freely and invent new ways of doing the job.
Robert Bacher, the leader of the physics division in which I worked,
offered me a graduate assistantship at
Cornell after the war but I still had to finish the work for an
undergraduate degree. This I did at McGill
University. And then another opportunity for graduate work came from
Columbia and I ended up there working with
Jim
Rainwater for my Ph. D. thesis. One day in his of fice, which he
shared at the time with Aage Bohr, he handed me a preprint of a paper by
John Wheeler devoted to µ-mesic atoms. This paper emphasized, in the case
of the heavier nuclei, the extreme sensitivity of the Is level to the size
of the nucleus. Even though the radiation from these atoms had never been
observed, these atomic systems might be a good thesis topic. At this same
time a convergence of technical developments took place. The Columbia
Nevis cyclotron was just coming into operation. The beams of (pi)-measons
from the cyclotron contained an admixture of µ-measons which came frome
the decay of the (pi)'s and which could be separated by range. Sodium
iodide with thallium activation had just been shown by
Hofstadter
to be an excellent scintillation counter and energy spectrometer for gamma
rays. And there were new phototubes just being produced by RCA which were
suitable matches to sodium iodide crystals to convert the scintillations
to electrical signals. The other essential ingredient to make a gamma-ray
spectrometer was a multichannel pulse height analyzer which, utilizing my
Los Alamos experience, I designed and built with the aid of a technician.
The net result of all the effort for my thesis was the pioneering work on
µ-mesic atoms. It is of interest to note that we came very close to
missing the observation of the gamma-rays completely. Wheeler had
calculated the 2p-1s transition energy in Pb, using the then accepted
nuclear radius 1.4 A1/3 fermi, to be around 4.5 MeV.
Correspondingly, we had set our spectrometer to look in that energy
region. After several frustrating days, Rainwater suggested we broaden the
range and then the peak appeared - not at 4.5 MeV but at 6 MeV! The
nucleus was substantially smaller than had been deduced from other
effects. Shortly afterwards Hofstadter got the same results from his
electron scattering experiments. While the µ-mesic atom measurements give
the rms radius of the nucleus with extreme accuracy the electron
scattering results have the advantage of yielding many moments to the
charge distribution. Now the best information is obtained by combining the
results from both µ-mesic atoms and electron scattering.
Subsequently, in making precise gamma-ray measurements to obtain a better
mass value for the µ-meson, we found that substantial corrections for the
vacuum polarization were required to get agreement with independent mass
determinations. While the vacuum polarization is about 2% of the Lamb
shift in hydrogen it is the very dominant electrodynamic correction in µ-mesic
atoms.
My interest then shifted to the strange particles and K mesons but I had
learned from my work at Columbia the
delights of unexpected results and the challenge they present in
understanding nature. I took a position at Princeton where, most often
working with a few graduate students, I spent the next 20 years studying
K-mesons. The ultimate in unexpected results was that which was recognized
by the Nobel Foundation in 1980, the discovery of CP-violation.
At any one time there is a natural tendency among physicists to believe
that we already know the essential ingredients of a comprehensive theory.
But each time a new frontier of observation is broached we inevitably
discover new phenomena which force us to modify substantially our previous
conceptions. I believe this process to be unending, that the delights and
challenges of unexpected discovery will continue always.
It is highly improbable, a priori, to begin life on a cattle ranch and
then appear in Stockholm to receive the Nobel Prize in physics. But it is
much less improbable to me when I reflect on the good fortune I have had
in the ambiance provided by my parents, my family, my teachers, colleagues
and students. I have two sons from my marriage to Elise Cunningham who
died in 1972. In 1976 I married Daisy Harper who brought with her three
stepchildren into my life.
Honors and Distinctions:
I am a fellow of the American Physical Society and the
American Association for the Advancement of Science, a member of the
American Academy of Arts and Sciences
and the National Academy of Sciences. I
hold the Cyrus Fogg Brackett Professorship of Physics at
Princeton University and since
1976 have served as chairman of the Physics Department. I received the
E. O. Lawrence award in 1968. In 1967 Jim Cronin and I received the
Research Corporation award for our work on CP violation and in 1976
theJohn Price Witherill medal of the
Franklin Institute.
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