Nobel Prize for Physics 2011 announced
4 October 2011 | Source: nobelprize.org
This year’s Nobel Prize for Physics has been awarded to US and Australian pioneers of astrophysics for the discovery of the accelerating expansion of the Universe through observations of distant supernovae
Saul Perlmutter from the Lawrence Berkeley National Laboratory and University of California, Berkeley, has been awarded half of this year’s prize for his work on the Supernova Cosmology Project, with the other half awarded to Brian P. Schmidt from the Australian National University and Adam G. Riess from the Johns Hopkins University and Space Telescope Science Institute, Baltimore, for their work on the High-z Supernova Search Team.
In response to the announcement, Professor Sir Peter Knight, President of the Institute of Physics, said, “The recipients of today’s award are at the frontier of modern astrophysics and have triggered an enormous amount of research on dark energy.
“These researchers have opened our eyes to the true nature of our Universe. They are very well-deserved recipients.”
Roger Davies, President of the Royal Astronomical Society and Philip Wetton Professor of Astrophysics, Department of Physics, University of Oxford, “It is wonderful to see the award of the Nobel Prize in Physics to the supernova cosmology teams. This recognises a transformative discovery in astrophysics that was a huge surprise at the time. The discovery set the direction for work over the last decade or so and stimulated some of the most ambitious proposals for future space missions and ground based surveys.
“The surprise is perhaps best illustrated by the fact that before the discovery of the accelerating universe astronomers had been attempting to measure its deceleration hypothesised to be caused by the mass of galaxy halos slowing the universal expansion. The discovery led to the realisation that empty space exerts a pressure that pushes the galaxies apart – something that demands new physics and a new understanding of space-time.”
Michael Rowan-Robinson, Professor of Astrophysics at Imperial College London, said, "The two astrophysics teams, one led by Saul Perlmutter, the other by Brian Schmidt and Adam Riess, found evidence of the accelerated expansion of the Universe at approximately the same time using data from exploding white dwarf stars in distant galaxies.
"The signals were somewhat fainter than expected, suggesting the galaxies were further away than originally predicted. This suggested that galaxies are being pushed apart by some mysterious repulsive force, the so-called dark energy. A repulsive force acting on large scales in the universe was first proposed by Einstein in 1916, when he was trying to construct a static model of the universe. There is still no consensus among physicists on the nature of this dark energy.
"The impact of this finding on cosmology has been huge. The dominant role of dark energy in the universe has been confirmed by the WMAP mission, analysing fluctuations in the microwave background radiation left over from the earliest stages of the Big Bang.
"I have a particular interest as I was part of a group that looked for other reasons to explain how the Universe can appear to be expanding at an ever-faster rate. We were unable to undermine the findings of the two teams and it's now momentous to see the research which indicated the existence of dark energy being rewarded so prestigiously.
"These astrophysicists' research revolutionised our common perception of the Universe and unveiled an array of mysteries that we are still trying to fathom."