| 1969 | BA, Physics, Brandeis University |
| 1976 | Ph.D., Physics, Harvard University |
| 1977-1978 | Instructor, Astronomy Department, Harvard University |
| 1978-1983 | Assistant Professor of Astronomy, Harvard University |
| 1983 | Visiting Professor, Dept. of Astronomy, UC Berkeley (Spring) |
| 1983-1986 | Associate Professor of Astronomy, Harvard University |
| 1986-1987 | Lecturer in Astronomy, Harvard University |
| 1986-1990 | Astrophysicist, Smithsonian Astrophysical Observatory |
| since 1987 | Professor, Dept. of Astronomy & Astrophysics, Enrico Fermi Institute and the College, The University of Chicago |
| 1991-1997 | Chairman, Dept. of Astronomy & Astrophysics, The University of Chicago |
| 1997-2002 | Director, Ctr. for Astrophysical Thermonuclear Flashes, The University of Chicago |
| since 1998 | William E. Wrather Distinguished Service Professor, The University of Chicago |
| since 1999 | Senior Fellow, Computations Institute, The University of Chicago |
| since 2000 | Professor, Dept. of Physics, The University of Chicago |
| 2002-2005 | Chief Scientist, Argonne National Laboratory (ANL) |
| Associate Laboratory Director for Physical, Biological, & Computing Sciences, ANL |
| 2004 | Rothschild Visiting Professor, Newton Institute for Mathematical Sciences, University of Cambridge, UK |
| Visiting Fellow, Clare Hall, Cambridge University, UK |
| since 2005 | Life Member, Clare Hall, Cambridge University, UK |
| 2005-2009 | Director, Argonne National Laboratory |
| 2006-2009 | President, UChicago/Argonne LLC |
| 2007-2009 | Chairman, DoE National Laboratory Directors' Council |
| 2009-2010 | Visiting Professor, Stanford University |
