2011 Nobel Prize in Physics

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

Perlmutter is at The Supernova Cosmology Project, Lawrence Berkeley National Laboratory and University of California, Berkeley, CA, USA. Schmidt is at The High-z Supernova Search Team, Australian National University, Weston Creek, Australia and Riess at The High-z Supernova Search Team, Johns Hopkins University and Space Telescope Science Institute, Baltimore, MD, USA.

Basically, this is for the supernovae evidence for “dark energy” (the 2008 sciencebase feature on dark energy).

In 1998, cosmology was shaken at its foundations as two research teams presented their findings. Headed by Perlmutter, one of the teams had set to work in 1988. Schmidt headed another team, launched at the end of 1994, where Riess was to play a crucial role. The research teams raced to map the Universe by locating the most distant supernovae. More sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors (CCD, Nobel Prize in Physics in 2009), opened the possibility in the 1990s to add more pieces to the cosmological puzzle.

The teams used a particular kind of supernova, called type Ia supernova. It is an explosion of an old compact star that is as heavy as the Sun but as small as the Earth. A single such supernova can 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. The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion.

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 will continue to speed up the Universe will end in ice.

The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma – perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore 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.

Full announcement – The 2011 Nobel Prize in Physics.

UPDATE: 11:03 BST: Schmidt compares winning the Nobel to the birth of his children, in interview with Nobel committee broadcast live. Says he feels weak at the knees. Even though he was one of the favourites to win the 2011 Prize, it was unexpected. Looking forward to teaching his cosmology class on Wednesday on this very subject. Grew up in Alaska so looking forward to the medals in December in the Swedish winter.

Thought Perlmutter’s team were getting an answer that the universe is slowing down not speeding up, was with trepidation that revealed to the world that the expansion of the universe is speeding up. A little scared by their findings. Always looks to Einstein for explanation, the energy of space itself, the simplest reason for the acceleration of the expansion of the universe. So despite, recent allegedly superluminal neutrinos, Einstein’s 1915 theory does predict the acceleration the supernovae data provide evidence for. Confirm Einstein’s cosmological constant published 1917.