UC Berkeley Professor Wins 2011 Nobel Prize for Physics

UC Berkeley will need another Nobel Prize parking spot, this time for Saul Perlmutter — a physics professor who helped discover that the universe is expanding at an increasing rate because "something" is pushing it apart.

That "something", as this Economist article explains, has been labelled "dark energy", but is really physicists' short-hand for "we haven't got a clue". What is known is that dark energy constitutes about three quarters of the Universe.

The Nobel Assembly announced that three winners will share the prize —Perlmutter, Brian P. Schmidt and Adam G. Riess () — stating that the discovery that the universe is expanding at an ever-accelerating rate "came as a complete surprise even to the Laureates themselves." 

It was 1998 when the discovery was made. Two research teams had set to work in 1988, one headed by Perlmutter and the other by Schmidt. 

"The research teams raced to map the Universe by locating the most distant supernovae," explained the Nobel Assembly during the awards ceremony. The teams studied a particular kind of supernova, called type Ia supernova — an explosion of a compact star as heavy as the sun but as small as the Earth. A single such supernova can emit as much light as a whole galaxy.

The two research teams found over 50 distant supernovae whose light was weaker than expected, which proved to be a sign that the expansion of the Universe was accelerating. "The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion," explained the Nobel Assembly.

Until then, for almost a century, the universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. "The discovery that this expansion is accelerating is astounding," concluded the Nobel Assembly. "If the expansion will continue to speed up the universe will end in ice."

Perlmutter will receive half of the 10 million-Swedish-kronor ($1.5 million) prize, with Schmidt and Riess splitting the remainder.

“It was fun to explain something that was just so basic,” said Perlmutter in a telephone interview with Bloomberg. “When we started this project we thought we were measuring how much the universe was slowing down, but it’s just getting faster and faster.”

The Guardian did a comprehensive live blog of the announcement of the 2011 Nobel Prize in Physics, and NPR's Adam Frank has penned a heartfelt explanation of the significance of the discovery to scientists. The UC Berkeley News Center has an in-depth profile of Permutter's career, as well as the details about the scientific process behind the discovery.

Also see the video (to the right of the page) of Perlmutter and fellow Berkeley astrophysicists discussing the secrets of the universe. 

And here's that Robert Frost poem, Fire and Ice, to mark the occasion:

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice.