Physical Society Colloquium

Michael S. Turner is the Bruce V. and Diana M. Rauner Distinguished Service Professor and Chair of the Department of Astronomy & Astrophysics at The University of Chicago. He also holds appointments in the Department of Physics and Enrico Fermi Institute at Chicago and is member of the scientific staff at the Fermi National Accelerator Laboratory. Turner received his B.S. in Physics from the California Institute of Technology (1971) and his Ph.D. in Physics from Stanford University (1978). His association with The University of Chicago began in 1978 as an Enrico Fermi Fellow and in 1980 he joined the faculty. Turner is a Fellow of the APS and of the American Academy of Arts and Sciences and is a member of the National Academy of Sciences. He has been honored with the Helen B. Warner Prize of the American Astronomical Society, the Julius Edgar Lilienfeld Prize of the American Physical Society, the Halley Lectureship at Oxford University, the Klopsteg Lecture Award of the American Association of Physics Teachers, and the Quantrell Award for Excellence in Undergraduate Teaching at Chicago. Turner has served on or chaired many advisory committees for the NRC, DoE, NSF and NASA, and since 1984 he has been involved in the governance of the Aspen Center for Physics, serving as President from 1989 to 1993. He currently serves on the Board of Trustees of the Illinois Math and Science Academy. Turner's transparencies were featured in a one-man show at the CfPA Gallery.

Turner is a cosmologist whose research focuses on the earliest moments of the Universe. He has made important contributions to inflationary Universe theory, understanding of dark matter and the origin of structure. Turner and Edward Kolb helped to establish the Theoretical Astrophysics Group at Fermilab and wrote the monograph, The Early Universe.

Today the Universe consists of galaxies moving away from one another in a pattern of motion that indicates a big-bang beginning. Using telescopes, computers and particle accelerators we can trace the Universe back to the hot quark soup that existed a fraction of a second after the beginning. Armed with bold ideas that are rooted in the deep connections between the inner space of elementary particles and the outer space of the cosmos, we are trying to extend our understanding back to an even earlier time when galaxies existed only as quantum fluctuations in the fuzzy subatomic world. If these ideas are correct, then our big bang was a burst of expansion called inflation, galaxies are held together by the gravity of elementary particles left over from the big bang, and the expansion of the Universe is speeding up because of an odd form of energy that pervades the Universe. A flood of observations made possible by recent technological advances are putting these ideas to the test. These are very exciting times in cosmology.

While images of the distant Universe reveal millions of colorful galaxies in every square degree of the sky, the Universe is actually held together by dark matter as it is being pushed apart by the gravitational effects of dark energy. According to our first, complete accounting of matter and energy, the recipe for our Universe is: 0.5% bright stars; 5% ordinary matter; 30% slowly moving elementary particles left over the earliest moments; and 65% dark energy, totaling to the critical density. The elementary particles are thought to be either neutralinos or axions, and their gravity holds together all structures in the Universe -- from galaxies to the great walls of galaxies. (Neutrinos left over from the big bang account for as much mass as do bright stars.) The dark energy, whose fundamental character is still a mystery, is causing the expansion of the Universe to accelerate rather than slow. Now, the big question is, ``Who ordered all that?"