· Harry E. Gruber Professor, UC San Diego2000–2020
· Director, Calit2, University of California at San Diego2000–2020
· Director, NCSA, University of Illinois at Urbana-Champaign1985–2000
· Professor, University of Illinois at Urbana-Champaign1979–2000
· Junior Fellow, Physics/Astrophysics, Harvard University1977–1979
· Postdoc, Astrophysics, Princeton University1975–1977
· Ph.D., Physics, The University of Texas at Austin1972–1975