It's the kind of call you want to get in the middle of the night if you are a scientist.
When the phone rang at U.C. Berkeley professor Saul Perlmutter's house overnight it was to give him the news that he had won the 2011 Nobel Prize in physics. He said at first he thought it was a spoof, but then the phone kept ringing with reporters looking for a comment about his win.
Perlmutter said the actual call from the Nobel Prize people came an hour after the wake up call.
Perlmutter won it for discovering the accelerating expansion of the universe through observations of distant supernovae.
For that he will get half of the $1.5 million award. The other half goes to scientists Brian Schmidt and Adam Riess.
The three worked in the 1990s to map the universe’s expansion by analyzing a particular type of supernovas, or exploding stars.
Perlmutter is also an astrophysicist at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and heads the international Supernova Cosmology Project. The lab characterized the discovery as a groundbreaking study to determine the nature of dark energy.
Because he is a Cal professor, Perlmutter will now be allowed to park in a special lot on campus that is reserved for people who have been award Nobel Prizes.
He told a gathering at Lawrence Berkeley National Laboratory that before his research he thought that the universe was in fact speeding up. But he said he proved that wrong when he found it was slowing down and "could come to a halt someday."
He said the acceleration of the universe is thought to be driven by dark energy, but there is still much that remains to be discovered. "Science is a method, not a finished product," Perlmutter said Tuesday.
Perlmutter lives in Berkeley with his wife and young daughter. His little girl came to the Tuesday news conference and told reporters that she was very proud of her dad.