American physicist. Ph.D. PhD physics, University of Chicago (1948). Professional experience includes: member, Institute for Advanced Study (19481949); research assistant, University of California, Berkeley (1949-1950); assistant professor of physics, associate professor of physics, professor of physics, Columbia University (1950-1971); physicist, director of experimental physics, European Organization for Nuclear Research (CERN) (1968-1986); visiting professor, Scuola Normale Superiore (1986-).