The Nobel Prize in Physics 2011 was awarded for the discovery of the accelerating expansion of the Universe through observations of distant supernovae with one half to Saul Perlmutter and the other half jointly to Brian Schmidt and Adam Riess.

For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion continues to speed up, the Universe will end frozen, the prize committee said.

Here are some details about the winners:

* SAUL PERLMUTTER:

-- Born in 1959 in the United States, Perlmutter is professor of Physics at the University of California, Berkeley, and senior scientist at the Lawrence Berkeley National Laboratory.

-- Perlmutter graduated from Harvard magna cum laude in 1981, and received his PhD from the University of California, Berkeley, in 1986. He was elected a member of the U.S. National Academy of Sciences in 2002.

-- He joined the University of California, Berkeley, Physics Department in 2004. He is also an astrophysicist at Lawrence Berkeley National Laboratory and leader of the international Supernova Cosmology Project, which first announced the results in 1998 indicating that the universe will last forever, with its expansion ever accelerating.

-- The Supernova Cosmology Project (SCP) studies type Ia supernovae to map out the expansion history of the universe and measure cosmological parameters and the dark energy's equation of state.

* BRIAN SCHMIDT:

-- Schmidt, born in February 1967 in Montana, is a Federation Fellow at the Australian National University's Mount Stromlo Observatory, Canberra.

-- He received undergraduate degrees in Physics and Astronomy from the University of Arizona in 1989, and his Master's degree (1992) and PhD (1993) in Astronomy from Harvard University.

-- In 1994 he formed the HighZ SN Search team, a group of 20 astronomers on five continents who used distant exploding stars to trace the expansion of the Universe back in time.

-- This group's discovery of an accelerating Universe was named Science Magazine's Breakthrough of the Year for 1998.

-- Schmidt joined the staff of the Australian National University in 1995, and was awarded the Australian Government's inaugural Malcolm McIntosh award for achievement in the Physical Sciences in 2000.

-- Schmidt has continued to work on using exploding stars to study the Universe, and is leading Mount Stromlo's effort to build the SkyMapper telescope, a new facility that will provide a comprehensive digital map of the southern sky from ultraviolet through near infrared wavelengths.

* ADAM RIESS:

-- Riess, born in December 1969 in Washington, D.C., is an astronomer at the Space Telescope Science Institute and a professor at Johns Hopkins University in Baltimore.

-- From 1996-1999, Riess was a Miller Fellow at the University of California, Berkeley. Riess qualified in Physics from the Massachusetts Institute of Technology in 1992 where he was inducted into the Phi Beta Kappa Society.

-- He received his PhD from Harvard University in 1996.

-- In 1998 Riess led a study for the High-z Team which provided the first direct and published evidence that the expansion of the Universe was accelerating.

-- He followed this work with a number of studies to test the susceptibility of this measurement to contamination by unexpected types of dust or evolution. To this aim, Riess led the Hubble Higher-z Team beginning in 2002 to find 25 of the most distant supernovae known with the Hubble Space Telescope.

-- In 2006 Riess, together with Perlmutter and Schmidt, were awarded the $1 million Shaw Prize in astronomy, for their discovery of the mysterious dark energy that is causing the universe to expand at an ever-faster rate.

Sources: Reuters/www.nobel.org/www.cfa.harvard.edu/http://msowww.anu.edu.au/www.stsci.edu/http://hubb

Sources: Reuters/www.nobel.org/www.cfa.harvard.edu/http://msowww.anu.edu.au/www.stsci.edu/http://hubb lesite.org

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