Born in Zürich, Switzerland. He was educated there and at the Eidgenössische Technische Hochschule, also in Zürich. Initially studying engineering he soon changed to physics. Graduating in 1927 he continued his physics studies at the University of Leipzig, gaining his doctorate in 1928. He remained in German academia, studying with Heisenberg, Wolfgang Pauli, Bohr and Enrico Fermi. In 1933 he left Germany, emigrating to work at Stanford University in 1934. He was naturalised in 1939. During WW II he worked on atomic energy at Los Alamos National Laboratory, before resigning to join the radar project at Harvard University. Post-war he concentrated on investigations into nuclear induction and nuclear magnetism. For his work on nuclear magnetism he shared the 1952 Nobel Prize in Physics with Edward Mills Purcell. In 1954-1955, he served for one unsatisfactory year as the first Director-General of CERN. In 1961, he was made Max Stein Professor of Physics at Stanford University.