Division of Physics, Mathematics and Astronomy (PMA)
Ph.D., University of Leiden, 1956; Sc.D., Yale University, 1966. Associate Professor, Caltech, 1959-64; Professor, 1964-81; Institute Professor, 1981-87; Moseley Professor, 1987-96; Moseley Professor Emeritus, 1996-. Executive Officer for Astronomy, 1972-75; Chairman, Division of Physics, Mathematics and Astronomy, 1976-78; Director, Hale Observatories, 1978-80.