University of California, Berkeley
George Smoot, a University of California, Berkeley scientist, led an effort to measure cosmic temperature variations.
The Nobel Prize in Physics will be awarded to two Americans whose findings lend support to the big-bang scenario of the universe's origins.
The winners are John Mather, 60, who works at NASA's Goddard Space Flight Center, and George Smoot, 61, who works at the Lawrence Berkeley National Laboratory in Berkeley, Calif.
"They have not proven the big-bang theory but they give it very strong support," said Per Carlson, chairman of the Nobel committee for physics.
The pair led an effort to measure ancient radiation left-over from the big bang. Their satellite experiment, called COBE and launched in 1989, made a very precise measurement of faint radiation produced after the big bang. When the data was finally shown at a conference, scientists gave a standing ovation.
COBE's measurements gave strong support for the big bang, which was the only theory that could explain the precise pattern of radiation. The experiment also showed that the radiation had small variations in temperature in different directions. Scientists think these small irregularities explain why matter began to clump in the universe, leading to the formation of galaxies, instead of spreading out evenly.