In its award citation, the Royal Swedish Academy of Sciences wrote that “the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the universe will end in ice.”
In the 1990s, two teams raced to measure the expansion of the universe by observing dozens of stars exploding in distant galaxies.
By measuring how fast the stars, called Type 1a supernovae, were racing away from Earth, the teams reached the same astonishing conclusion: The universe was flying apart with ever-quickening speed.
One of the teams was led by Saul Perlmutter, 52, who heads the Supernova Cosmology Project at the Lawrence Berkeley National Laboratory and the University of California at Berkeley. He will receive half of the $1.4 million prize.
The other half will go to two members of the second team, Brian Schmidt and Adam Riess.
Schmidt, 44, heads the High-z Supernova Search Team at Australian National University in Weston Creek, Australia. He holds dual U.S.-Australian citizenship.
Riess, 41, is an astronomy professor at Johns Hopkins University and a scientist at the Space Telescope Science Institute in Baltimore.
Riess said intense competition “lent a sense of urgency” to the hunt for distant supernovae. By the time he and Schmidt entered the race, Perlmutter’s team had a five-year head start.
“There was some friction between the two groups. They felt like we were usurpers,” said Robert Kirshner, a Harvard University astrophysicist and graduate adviser to Riess and Schmidt when the High-z team began its hunt. “But young people like Brian [Schmidt] with supple minds could catch up very quickly. So we did catch up.”
By late 1997, the team had enough data from a telescope in Chile and the Hubble Space Telescope to calculate the mass of the universe — and how fast, or slow, it was expanding.
The answer confused Riess. “I remember thinking, ‘Ugh, I’ve made a terrible mistake. And I have to find this mistake.’ And then spent weeks looking for it.”
Riess soon heard that Perlmutter’s team members — some of whom Riess knew from games of “mud football” on the Berkeley campus — had come to the same astounding conclusion.
“And when I did find out that they were seeing the same thing, it went from ‘Oh, this must be a terrible mistake’ to ‘Oh, this must be the right answer,’ ” Riess said.
At a news conference Tuesday, Perlmutter said: “I thought it was the kind of project any scientist would love. You’re getting to ask a very philosophical question about the fate of the universe.”