U.S. physicists nab Nobel for discovery fueled by 'dark energy'
Three American physicists were awarded the Nobel Prize in physics early Tuesday morning for their discovery that the expansion of the universe is accelerating.
Brian Schmidt of Australian National University in Weston Creek, Australia; Adam Riess of Johns Hopkins University and the Space Telescope Science Institute in Baltimore; and Saul Perlmutter of UC Berkeley and Lawrence Berkeley National Laboratory are sharing this year's prize for discovering that the universe is moving faster and faster outward -- movement likely powered by the mysterious "dark energy" that fills about 70% of the universe.
Riess got the call in the wee hours as he was listening to his 10-month-old son "crying and sleeping," according to an interview with Adam Smith, editorial director of Nobel Media.
Riess and Schmidt were on a team that had been taking measurements of supernovae billions of light years from Earth to measure the acceleration of the universe. Perlmutter, on a competing team, had been working on the same problem. The competition, Riess said, "lent a sense of urgency" to the work.
That competition had further benefit when the results of the scientists' work began to come in. The researchers had thought that the universe's rate of expansion would have slowed by now -- but their data seemed to show the opposite, causing Riess to briefly doubt his work.
"When I did find out that" Perlmutter and his team "were seeing the same thing, it went from 'Oh, this is a terrible mistake' to 'Oh, my God, this might be the right answer!' So, it was very exciting," Riess told Smith.
The dark energy thought to propel this expansion remains an unexplained force in physics -- one that could potentially help reconcile inconsistencies between two important theories in physics, quantum mechanics and Einstein's general theory of relativity.
Half of the $1.5-million awarded with the Nobel will go to Perlmutter; the other half will be shared by Riess and Schmidt.
The three scientists also shared the 2006 Shaw Prize in Astronomy for showing that the universe's expansion was accelerating. The Nobel award ceremony will be held in December in Stockholm.
-- Amina Khan
Photo: UC Berkeley's Saul Perlmutter will receive half of the $1.5-million award that goes with the Nobel Prize. He won along with Brian Schmidt and Adam Riess. Credit: Roy Kaltschmidt / Lawrence Berekely National Laboratory