Berkeley’s Saul Perlmutter wins Nobel Prize in Physics

Nobel laureate Saul Perlmutter with an image of supernova 1987a in the background. Photo: Lawrence Berkeley National Laboratory

Update 7:30 a.m. “It’s the only reason to win a Nobel Prize,” replied Saul Perlmutter to Berkeleyside during a teleconference early this morning. The new Nobel laureate was replying to our question about when he would receive the prized NL parking permit, reserved for laureates on the Berkeley campus. He expects to pick it up today, he said.

Perlmutter said he first heard about the prize when his phone rang at 2:45 a.m. this morning. A Swedish reporter asked him, “How do you feel?” “How do I feel about what?” Perlmutter replied. Perlmutter’s wife hurried to check the web to see if the call was a hoax. The Royal Swedish Academy of Sciences reached Perlmutter at about 3:15 a.m. with the official call.

Perlmutter said the academy had called the wrong cellphone number earlier, because one of his colleagues, a Swedish physicist, still had an old number in his contact list.

The discovery that led to the prize was described by Perlmutter as “the slowest aha moment you’ve ever heard”. He explained how he and his team spent four months sifting data from their observations of type 1a supernovae, expecting that further calibration would allow the data to plot “where we expected it to”. Instead, the data were absolutely in contradiction to “the elements of physics that we knew about”.

“This was a big shock,” Perlmutter said.

Perlmutter said that for the last 12 years, since the announcement of the joint discovery by his team and Schmidt and Reiss’s team, there had been an average of one paper per day by theoretical astrophysicists trying to explain the acceleration of the universe’s expansion. “We have no idea why it’s speeding up,” he said.

He also said that “it’s been a full-time job ever since” for him to find experimental ways to understand the discovery.

“If we can understand something new about our universe, we have no idea where it’s going to lead us,” Perlmutter said.

Original post 5:59 a.m. Saul Perlmutter, Professor of Physics at the University of California Berkeley and an astrophysicist at Berkeley National Lab, was awarded the Nobel Prize for Physics today “for the discovery of the accelerating expansion of the universe through observations of distant supernovae.”

The Royal Swedish Academy of Sciences awarded half of this year’s prize to Perlmutter and the other half jointly to Brian Schmidt from Australian National University and Adam Reiss from Johns Hopkins University and the Space Telescope Science Institute.

Perlmutter and Schmidt and Reiss separately announced their findings in 1998 that the expansion of the universe was expanding at an ever-accelerating rate, not slowing down as previously thought. Both teams had been analyzing light from type 1a supernovae: the discovery that the light was weaker than expected led them to their conclusion.

As the Royal Swedish Academy of Sciences put it in its announcement today: “The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma — perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that to a large extent is unknown to science. And everything is possible again.”

Perlmutter, 52, was born in Illinois, did his undergraduate work at Harvard and his PhD at Berkeley. In addition to teaching at the university, he runs the Supernova Cosmology Project at LBL. He has won numerous other prestigious scientific prizes for his work. Earlier this year, Perlmutter and Schmidt shared this year’s Albert Einstein Medal.

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