P. R. Wallace

When the Montreal effort moved to the Chalk River site in 1946, Wallace joined the Mathematics Department at McGill University and began to build a group of young theoretical physicists there. The anomaly, at least in North America, of theoretical physicists in the Math department, not in Physics, had historic roots at McGill, dating from Ernest Rutherford's time. More generally, Canadian universities followed the British model of separation of mathematics from physics, perhaps deigning to have a small separate department of applied mathematics. Rutherford's strongly expressed views solidified things at McGill for 50 years. But by the early 1960s circumstances had changed; Wallace and his group moved into the Physics Department. He has documented the post-war story of the growth of a tiny number of isolated theoretical physicists in Canada, basically "outsiders," into a viable community of "insiders," not only at McGill.[5]

Initially working in nuclear physics and properties of graphite, in the mid-1950s Wallace turned his attention to the newly discovered positron annihilation in solids and liquids. In 1960 he published what became a standard reference in the field.[6] His later research focused on semiconductors and semimetals, particularly their behaviour under intense magnetic fields, with regular returns to properties of graphite. In addition to summer school proceedings, in 1969 he edited two volumes on superconductivity [7] and in 1973 he co-edited a volume on new developments in semiconductors.[8]

Wallace was a superb lecturer and mentor of students. His undergraduate course in methods of mathematical physics was inspirational. It allowed many students to see what a disciplined and well-trained mind could accomplish by applying mathematics to physical problems. More than a few careers were encouraged on their paths by Wallace's course. A text based on his notes was finally published in 1973.[9] Over his career at McGill Wallace supervised over 30 graduate students to M.Sc. and Ph.D. degrees, more than one third of them Ph.D.s. After his retirement he continued to teach in France at the Paul Sabatier University in Toulouse.

Wallace was active in professional affairs, a co-founder of the Canadian Association of Physicists and founder and first chair of its Theoretical Physics Division, 1957–58. He served as Editor of the Canadian Journal of Physics, 1973–80, and on numerous advisory and planning committees for conferences. At McGill he was Director of the Institute of Theoretical Physics, 1966–70, and active in faculty and university affairs.