Josh Frieman is a past President, past Vice-President, and former Trustee of the Aspen Center for Physics. He is Professor and currently Chair of the Department of Astronomy & Astrophysics at the University of Chicago and Distinguished Scientist at the Fermi National Accelerator Laboratory (Fermilab). Frieman’s research spans observational and theoretical cosmology, including studies of the early universe, large-scale structure, gravitational lensing, supernovae, dark matter and dark energy. The co-author of over 600 publications, he was a co-founder and later Director of the Dark Energy Survey (DES), an international collaboration of 500 scientists from 25 institutions in 7 countries that carried out a six-year survey to map the Universe using a 570-megapixel camera it built for the Blanco 4-meter telescope in Chile. DES has cataloged several hundred million galaxies and discovered several thousand supernovae, yielding state-of-the-art measurements of cosmological parameters. Frieman completed his Ph.D. in physics at the University of Chicago (UChicago)  and was a postdoc in the Particle Theory Group at SLAC National Accelerator Laboratory before joining the Fermilab scientific staff and UChicago faculty. He is an elected member of the National Academy of Sciences and a Fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the American Astronomical Society, and the American Physical Society and an Honorary Fellow of the Royal Astronomical Society. His awards include the Department of Energy (DOE) Office of Science Distinguished Scientists’ Fellow Award, the Pappalardo Lectureship at the Massachusetts Institute of Technology (MIT), and the Bethe Lectureship at Cornell.