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Prof Sir Brian Pippard

October 7, 2008

Physicist who proved the existence of the Fermi surface and was the first President of Clare Hall, Cambridge

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.

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 protege 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.

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