Physics Nobel for 3 for discovery of accelerating expansion of universe

Three scientists share the 2011 Nobel Prize for physics, for the discovery of the accelerating expansion of the universe, through observations of exploding stars, the Nobel Prize Committee said today.

Saul Perlmutter of the US will share half of the prize amount of 10 million Swedish crown ($1.45 million) while another US citizen Adam G Riess and US-Australian Brian P Schmidt will share the remaining half equally between them.

"They have studied several dozen exploding stars, called supernovae, and discovered that the universe is expanding at an ever-accelerating rate," the Nobel Committee for Physics at the Royal Swedish Academy of Sciences said.

"The discovery came as a complete surprise, even to the laureates themselves," the committee noted.

"Some say the world will end in fire, some say in ice... What will be the final destiny of the Universe? Probably it will end in ice, if we are to believe this year's Nobel Laureates in Physics," the committee said in a statement.

Working in two research teams the three presented their findings in 1998. Headed by Saul Perlmutter, one of the teams had set to work in 1988. Brian Schmidt headed another team, launched at the end of 1994, where Adam Riess was to play a crucial role.

The research teams mapped the universe by locating the most distant supernovae using sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors.

Observing a particular kind of supernova, called type Ia supernova - an old compact star that is as heavy as the Sun but as small as the Earth - they found a supernova could emit as much light as a whole galaxy.

All in all, the two research teams found over 50 distant supernovae whose light was weaker than expected - this was a sign that the expansion of the universe was accelerating. While there had been pitfalls, the two teams had reached the same conclusion.

While the Universe was already known to be expanding as a consequence of the Big Bang about 14 billion years ago, the discovery that this expansion is accelerating has been astounding, the committee said.

If the expansion will continue to speed up the Universe will end in ice, it added.

While the acceleration of expansion of the universe is thought to be driven by dark energy, what is dark energy remains an enigma. Dark energy constitutes about three quarters of the universe.

"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," the Nobel Prize Committee said.

Saul Perlmutter is a US citizen, born in 1959 in Champaign-Urbana, Illinois. A Ph.D from the University of California, Berkeley, he was professor of astrophysics, Lawrence Berkeley National Laboratory and University of California, Berkeley, California and head of the Supernova Cosmology Project.
 
Brian P Schmidt, born in 1967 in Missoula, MT, USA, is both a US and Australian citizen. A Ph.D from Harvard University, Cambridge, Massachusetts, he is the distinguished professor at Australian National University, Weston Creek, Australia and head of the High-z Supernova Search Team.

Adam G Riess, is a US citizen, born in 1969 in Washington DC. A Ph.D from Harvard University, Cambridge, Massachusetts, he is professor of astronomy and physics, Johns Hopkins University and Space Telescope Science Institute, Baltimore.