Professor Sir Brian Pippard; Physicist who proved the existence of the Fermi surface (Independent)
Hyfler/Rosner
existence of the Fermi surface and was the first President
of Clare Hall, Cambridge
Tuesday, 7 October 2008
Brian Pippard was a distinguished physicist and university
teacher, a talented classical pianist, a historian of
science and an able administrator. He enjoyed discussion and
debate and he had an impressive knowledge and understanding
of classical physics, quantum physics and statistical
thermodynamics. He was the Cavendish Professor of Physics at
Cambridge University from 1971 to 1982 and the first
President of Clare Hall, a newly founded graduate college,
from 1966 to 1973.
Pippard was a leader in the field of low temperature physics
and semiconductors. The Fermi surface is an abstract
boundary derived in part from the nature of the crystalline
lattice, helping to predict the thermal, electrical,
magnetic and optical properties of metals, semi-metals, and
semiconductors. It had been recognised in theory, but in the
1950s Pippard demonstrated its existence in reality by
establishing the shape of the surface in copper through
measuring the reflection and absorption of microwave
radiation.
Alfred Brian Pippard was born, one of two sons, in Earls
Court, London in 1920. His father was an aeronautical
engineer and when Brian was eight the family moved to
Bristol, where his father took up the post of Professor of
Engineering at the university. Brian attended Clifton
College, where he was brilliant at classics and science and
was a talented pianist. He considered a career as a
professional musician but chose science instead.
He went to Clare College in 1938 and took physics in part II
of the natural sciences tripos in 1941. He then went to the
radar research establishment at Great Malvern, becoming
proficient in microwave techniques. One of his projects
included the design of an aerial for equipment to follow the
trajectory of mortar shells. Coincidentally, I attended a
meeting at the War Office in January 1945 where we approved
the trial use of this equipment by troops in the Sixth
Airborne Division in the Rhine Crossing.
After the Second World War, Pippard returned to Cambridge
with a Stokes Studentship at Pembroke and embarked on a
doctorate in low temperature physics under the supervision
of David Shoenberg. After four terms at Pembroke, he became
a demonstrator in physics and returned to Clare as a fellow,
director of studies in physics and college librarian.
After completing his doctorate, he moved on to the behaviour
of electrons in ordinary metals, which led to his work on
the Fermi surface. He then worked on magnetic resistance and
magnetic breakdown, a quantum mechanical effect for
electrons in high magnetic fields, which kept him occupied
for the next two decades. He became a lecturer in physics in
1950, and after his marriage in 1955 he went with his wife
Charlotte to the University of Chicago for a year. He became
a reader in 1959 and professor in 1960.
Though his early career was dominated by his scientific
research, he also proved himself to be an inspiring teacher
and an able administrator. His approach to teaching was
embedded in the experimental traditions of the Cavendish
Laboratory, but he instituted a number of changes towards
more challenging projects. I was surprised at his ready
acceptance of changes in the 1960s that allowed final-year
students the option of taking a theoretical physics tripos,
with lectures in mathematics and quantum theory replacing
the extensive laboratory classes.
He surprised me again with the support he gave when I set up
an interdisciplinary research group on energy studies
shortly before the price of oil quadrupled in 1973. By then
he was Cavendish Professor and his support was crucially
important, both for the recruitment of research students and
for the allocation of space in the laboratory.
In 1964 at Clare College he fully supported the plans for a
college for advanced study, with special emphasis on
visiting fellows living in college with their families, and
he was invited to become its first president. The invitation
was just in time for the drawings by the architect, Ralph
Erskine, to be modified so that the President's House could
accommodate Pippard's grand piano.
In the summer of 1969, Pippard moved into Clare Hall with
Charlotte and their three daughters, and from then until the
end of his seven-year tenure in 1973 they made a
long-lasting contribution to its success. After the end of
his presidency, he became a Professorial Fellow of Clare
Hall and continued to contribute to music in the college. He
became an Emeritus Fellow of Clare Hall in 1987 and an
Honorary Fellow in 1998.
In 1971, he succeeded Neville Mott as Cavendish Professor at
Cambridge and automatically became head of the physics
department. He took early retirement in 1982, but he
remained productive in writing about physics and in
supporting research in the Cavendish Laboratory. His
contribution to the social and musical scene in Clare Hall
continued until a few months before his death. As Cavendish
Professor, Pippard continued the tradition of allowing heads
of research groups the freedom to develop their own
fiefdoms, with open competition to attract the best research
students.
After his early retirement in 1982 he developed a Foucault
pendulum, apparatus that demonstrates the rotation of the
earth. It provided an interesting greeting to visitors to
the Cavendish, where it swung from near the ceiling of the
main entrance hall. It was moved later to the Science Museum
in London.
Pippard was the author of several important textbooks,
notably Elements of Classical Thermodynamics for Advanced
Students of Physics (1957), Dynamics of Conduction Electrons
(1962), Forces and Particles (1972), The Physics of
Vibration (published in two volumes, 1978 and 1983),
Response and Stability (1985) and Magnetoresistance (1989).
He was co-author of the three-volume encyclopaedia Twentieth
Century Physics, served as editor of the European Journal of
Physics, and in 1962 he published Cavendish Problems in
Classical Physics, a collection of 200 problems suitable for
the first two years of undergraduate study. A second edition
followed in 1971.
Pippard had no strong religious views, but he believed
science had its limits: "it cannot cope with human feelings
or belief at all; the strength of science lies in the fact
that it does not try to do [these] things". He won several
prizes, including the Hughes Medal of the Royal Society, of
which he was elected Fellow in 1956.
Richard Eden
In March 1965, Professor Sir Nevill Mott, then Cavendish
Professor of Physics in Cambridge, exasperated by CP Snow as
Minister for Science in Harold Wilson's first government,
invited four young Labour back-benchers, including myself,
for a weekend at the Master's Lodge in Gonville and Caius
College for in-depth discussions on science policy, writes
Tam Dalyell.
From Cambridge came two Fellows of Caius, Dr David
Shoenberg, Director of the Mond Low Temperature Laboratory,
and Sir Vincent Wigglesworth, the Quick Professor of
Biology, along with the astronomers Fred Hoyle and Martin
Ryle, the Professor of Organic Chemistry and Master of
Christ's, Lord Todd, and "my young colleague, Plummer
Professor of Physics, the younger Pippard," as Mott
described him to us.
The politicians were agreed, later, that in this august,
heavyweight company, it was "young Pippard" who made the
most lasting impact on us, by his vehement espousal of the
importance of giving financial backing to the best
researchers and allowing them to proceed wherever their
research took them. However, Pippard also understood that
there was no infinite pot of gold with which to finance
research, and therefore proposed a "mechanism of shrinkage"
by which money could be saved on research and teaching of
obsolescent science.
I shall never forget a delicious moment when the
intellectually powerful Edmund Dell interjected, "But,
Brian, you are intolerably autocratic and elitist". Pippard
retorted, "Of course I'm elitist - and it's often kind to be
autocratic, and kill off not very good researchers; they
might be better as school teachers for sixth forms". Even
our host, Mott, a Nobel prize-winner, shifted uncomfortably
in his chair, at his protégé Pippard's panache.
Over the next 40 years, first as weekly columnist for the
New Scientist, and, latterly, as an obituarist for The
Independent, I phoned Pippard frequently for opinions or
quotations, at Clare, and then at home. He was generous, not
only with his time, but about people with whom he had huge
disagreements, such as Edward Teller, father of the H-bomb,
and Victor Weisskopf, Director of Cern, who " gobbled up
money which could be better spent on solid-state physics."
Having been enormously impressed as a graduate student by
Brian Pippard's magnificent monograph Elements of Classical
Thermodynamics, which I used with relish at the University
College of Wales to stretch the minds of top-quality
undergraduates, I looked forward in anticipation to a
lecture that he was to give at the Royal Society in the
early 1970s when the university grants committee organised a
symposium on the future of higher education in the UK,
writes Sir John Meurig Thomas.
I was not disappointed: the depth of his analysis, the
lucidity of his exposition and the brilliantly fluent
arguments that he deployed in favour of setting up two-year,
rather than three-year courses (with the brighter students
going on to four-year courses) elicited lively discussion.
Although he did not convince everyone present, they all knew
that they were listening to one of the most pyrotechnically
gifted scientists of the day.
It was a joy for me, as Director of the Royal Institution in
London, to recommend his appointment as Visiting Professor
in Physics there from 1988 onwards. Two particular lectures
Pippard gave in my day at the RI stand out vividly: his
demonstration of the principles and operation of Foucault's
pendulum to an enthralled audience at a Friday evening
discourse, and a lunch-time talk entitled "The Invincible
Ignorance of Science", which, inter alia, repudiated the
argument, praised by many ardent scientists, that
ultimately, when science runs its full course, all the
mysteries and enigmas of the natural world will be
understood. He took the example of simple phase transitions
within solids and between a solid and a liquid to
demonstrate his case and showed that even this phenomenon
was deeply enigmatic.
His love of music was profound, and his skills as a pianist
were remarkable. While he was at Clifton, some of the
masters there urged him to read music rather than physics or
chemistry. "But," he said later, "I saw David [the
conductor, organist and composer Sir David Willcocks, a
fellow Cliftonian] in action and when I saw him I knew that
he was so far ahead of me, I ruled out contemplating a
career in music there and then."
His service to music in Cambridge and its environs was
considerable. He was once president of the Cambridgeshire
Youth Orchestra, and at the time of his death he was the
president of the Cambridge University Musical Society, of
which Sir David Willcocks is vice-president.
Alfred Brian Pippard, physicist and university
administrator: born London 7 September 1920; Scientific
Officer, Radar Research and Development Establishment, Great
Malvern 1941-45; Stokes Student, Pembroke College, Cambridge
1945-46; Demonstrator in Physics, Cambridge University
1946-50, Lecturer 1950-59, Reader 1959-60, John Humphrey
Plummer Professor of Physics 1960-71, Cavendish Professor of
Physics 1971-82 (Emeritus); Fellow, Clare College, Cambridge
1947-66; FRS 1956; President, Clare Hall, Cambridge 1966-73
(Honorary Fellow 1993); President, Institute of Physics
1974-76; Kt 1975; married 1955 Charlotte Dyer (three
daughters); died Cambridge 21 September 2008.