His interest had already turned to physics, and through the kindness of Professor K. Lark-Horovitz he was enabled, while an undergraduate, to take part in experimental research in electron diffraction. As an Exchange Student of the Institute of International Education, he spent one year at the Technische Hochschule, Karlsruhe, Germany, where he studied under Professor W. Weizel. He returned to the United States in 1934 to enter Harvard University, where he received the Ph.D. degree in 1938. After serving two years as instructor in physics at Harvard, he joined the Radiation Laboratory, Massachusetts Institute of Technology, which was organized in 1940 for military research and development of microwave radar. He became Head of the Fundamental Developments Group in the Radiation Laboratory, which was concerned with the exploration of new frequency bands and the development of new microwave techniques. This experience turned out to be very valuable. Perhaps equally influential in his subsequent scientific work was the association at this time with a number of physicists, among them I.I. Rabi, with a continuing interest in the study of molecular and nuclear properties by radio methods.

The discovery of nuclear magnetic resonance absorption was made just after the end of the War, and at about that time Purcell returned to Harvard as Associate Professor of Physics. He became Professor of Physics in 1949; his present title is Gerhard Gade University Professor. He has continued to work in the field of nuclear magnetism, with particular interest in relaxation phenomena, related problems of molecular structure, measurement of atomic constants, and nuclear magnetic behaviour at low temperatures. He has made some contribution to the subject of radioastronomy.

He is a Fellow of the American Physical Society, a member of the National Academy of Sciences, of the American Academy of Arts and Sciences, and of the President’s Science Advisory Committee under President Eisenhower from 1957-1960 and under President Kennedy as from 1960.