Studies of Universe’s Expansion Win Physics Nobel

Saul Perlmutter and Adam Riess of the US and Brian Schmidt of Australia will divide the prize.


The trio studied what are called Type 1a supernovae, determining that more distant objects seem to move faster.


Their observations suggest that not only is the Universe expanding, its expansion is relentlessly speeding up.


Prof Perlmutter of the University of California, Berkeley, has been awarded half the 10m Swedish krona (£940,000) prize,Nobel prize in physiology with Prof Schmidt of the Australian National University and Prof Riess of Johns Hopkins University's Space Telescope Science Institute sharing the other half.


'Weak knees'
Prof Schmidt spoke to the Nobel commitee from Australia during the ceremony.


"It feels like when my children were born," he said.


"I feel weak at the knees, very excited and somewhat amazed by the situation. It's been a pretty exciting last half hour."


The trio's findings form the basis of our current understanding of the Universe's origins, but raises a number of difficult questions.


In order to explain the rising expansion, cosmologists have suggested the existence of what is known as dark energy. Although its properties and nature remain mysterious, the predominant theory holds that dark energy makes up some three-quarters of the Universe.


They were hoping to measure how fast the universe, which has been expanding since its fiery birth in the Big Bang 14 billion years ago, was slowing down, and thus to find out if its ultimate fate was to fall back together in what is called a Big Crunch or not. Instead, they reported in 1998, it was inexplicably speeding up, a conclusion that nobody would have accepted if not for the fact that both groups wound up with the same answer.


At the time, “We were a little scared,” Dr. Schmidt said. Subsequent cosmological measurements have confirmed that roughly 70 percent of the universe by mass or energy consists of this antigravitational dark energy.


The most likely explanation for this bizarre behavior is a fudge factor Albert Einstein introduced into his equations in 1917 to stabilize he universe against collapse and then abandoned as his greatest blunder. “Every test we have made has come out perfectly in line with Einstein’s original cosmological constant in 1917,” Dr. Schmidt said.


Quantum theory predicts that empty space should exert a repulsive force, like dark energy, but one that is 10120 times stronger than what the astronomers have measured, leaving some physicists mumbling about multiple universes.


Lawrence M. Krauss, a cosmologist at Arizona State University said, “The discovery that the universe is dominated by the energy of empty space has changed everything in cosmology. Nothing could, literally, not be more exciting, because now we know nothing is almost everything!”


In the years since then the three astronomers have shared a number of awards.


Dr. Perlmutter, who led the Supernova Cosmology Project out of Berkeley, will get half of the 1.5 million Swedish kronor prize. The other half will go to Dr. Schmidt, leader of the rival High-Z Supernova Search Team, and Dr. Riess, who was the lead author of the 1998 paper in Science, in which the dark energy result was first published. They will get their prizes in Stockholm on Dec. 10.