Today.Az » Weird / Interesting » Nobel Prize in physics: Expanding Universe
05 October 2011 [20:30] - Today.Az
The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2011 with one half to Saul Perlmutter, of the Supernova Cosmology Project at Lawrence Berkeley National Laboratory and the University of California, Berkeley; and the other half jointly to Brian P. Schmidt, of the High-z Supernova Search Team at Australian National University, Weston Creek, Australia, and Adam G. Riess, of the High-z Supernova Search Team at Johns Hopkins University and the Space Telescope Science Institute, Baltimore for the discovery of the accelerating expansion of the Universe through observations of distant supernovae.
Written in the stars
"Some say the world will end in fire, some say in ice,"
Robert Frost wrote. What will be the final destiny of the Universe?
Probably it will end in ice, if we are to believe this year's Nobel
Laureates in Physics. They have studied several dozen exploding stars,
called supernovae, and discovered that the Universe is expanding at an
ever-accelerating rate. The discovery came as a complete surprise even
to the Laureates themselves.
In 1998, cosmology was shaken at its foundations as two research
teams presented their findings. Headed by Saul Perlmutter, one of the
teams had set to work in 1988. Brian Schmidt headed another team,
launched at the end of 1994, where Adam 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 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.
/Science Daily/
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