Schmidt, Brian Paul (1967-…), an American astrophysicist, shared the 2011 Nobel Prize in physics for the discovery that the expansion of the universe is accelerating. Schmidt shared the prize with the American astrophysicists Saul Perlmutter and Adam Riess. Schmidt and Reiss worked on the same team. Perlmutter worked on a separate project that made the same discovery.
The discovery is based on observations of a certain kind of exploding star called a Type Ia supernova. All Type Ia supernovae are thought to be of a similar size and luminosity (brightness). These similarities enable scientists to accurately calculate the distance to a Type Ia supernova by measuring its apparent brightness as seen from Earth. See Supernova (Thermonuclear supernovae) .
Schmidt and Riess worked as members of a team formed in 1994 to search for distant supernovae. After finding and studying around 20 supernovae, the team determined that the distant Type Ia supernovae appear dimmer—and thus farther away—than expected. This evidence suggests that the expansion of the universe is speeding up. The team announced this discovery in 1998. Scientists had long known that the universe was expanding, but they expected the expansion to be slowing due to gravitational attraction among the universe’s matter. The discovery of the acceleration has led many scientists to believe that a mysterious form of energy, which they named dark energy, is driving the universe apart (see Dark energy ).
Brian Paul Schmidt was born on Feb. 24, 1967, in Missoula, Montana. He graduated from the University of Arizona with two B.S. degrees, one in physics and one in astronomy, in 1989. He received his M.A. degree in 1992 and his Ph.D. degree in 1993, both from Harvard University. Schmidt was a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics in 1993 and 1994. He began research at the Mount Stromlo Observatory near Canberra, Australia, in 1995.
See also Riess, Adam Guy ; Perlmutter, Saul .
