By Devin Powell
The shocking discovery that the universe is expanding at a faster and faster rate has taken the 2011 Nobel Prize in physics. Three American-born astrophysicists will divide the $1.5 million prize, announced October 4 in Stockholm.
“This is tremendous news, in recognition of a fundamental discovery that has changed our picture of the universe,” says Robert Caldwell, a theoretical physicist who specializes in cosmology at Dartmouth College.
Half the prize goes to Saul Perlmutter of Lawrence Berkeley National Laboratory in California. In 1988, he started the Supernova Cosmology Project to measure the brightness of a certain type of distant supernovas. Because these exploded white dwarf stars tend to put out the same amount of light, they offer a cosmic yardstick for measuring how fast distant objects are moving. Perlmutter expected to find evidence that the fabric of spacetime has been expanding at an ever slower rate as a consequence of gravity putting the brakes on the universe’s growth.