Meeting Information

Cosmology from Wilkinson Microwave Anisotropy Probe

September 22, 2004
American Center for Physics
College Park, MD


A prodigious burst of high-energy radiation was generated during the Big Bang. Today, this radiation is seen as a nearly uniform faint glow across the sky, now as low-energy microwaves due to the expansion of the universe over billions of years. Tiny temperature variations of the radiation across the sky were first discovered by NASA s Cosmic Background Explorer (COBE) space mission in 1992. The Wilkinson Microwave Anisotropy Probe (WMAP) space mission, launched in 2001, has now mapped the temperature variations (anisotropy) of the cosmic microwave background radiation over the full sky with unprecedented accuracy and precision. The WMAP observations provide definitive answers to cosmological questions and open the door to new investigations. For example, the WMAP has determined that the content of the universe is dominated by dark matter and dark energy. The large-scale geometry of the universe is flat, in that the sum of the interior angles of a triangle adds up to 180 degrees even over vast distances. New limits are set on the mass of neutrinos and the nature (equation of state) of the dark energy. The WMAP results also place new limits on the physics of the very early universe, usually described in terms of Inflation theory: a rapid exponential expansion of the universe within a fraction of a second. Observations are on-going and will improve our understanding of the physics of the universe.


Dr. Charles L. Bennett is a Senior Scientist for Experimental Cosmology at the NASA Goddard Space Flight Center and a Goddard Senior Fellow. He has been an astrophysicist at Goddard since September 1984. He leads the Wilkinson Microwave Anisotropy Probe (WMAP) mission as Principal Investigator (P.I.). Previous to his work on WMAP, Dr. Bennett was the Deputy P.I. of the Differential Microwave Radiometers (DMR) instrument and a member of the Science Team of the Cosmic Background Explorer (COBE) mission.

Dr. Bennett has received several awards and honors, including NASA Scientific Achievement, Outstanding Leadership, and performance awards. He is a Fellow of the American Association for the Advancement of Science (AAAS), a member of the American Academy of Arts and Sciences, and a Fellow of the American Physical Society (APS).

Dr. Bennett received his Ph.D. in Physics from the Massachusetts Institute of Technology and a B.S. degree from the University of Maryland.