2011 Nobel Prize for Physics: Discovering the Accelerating Expansion of Universe

By James Riordon

The 2011 Nobel Prize for Physics has been awarded to three astrophysicists who discovered the accelerating expansion of the universe through their observations of distant supernovae.

Half the Nobel Prize goes to APS Fellow Saul Perlmutter (Lawrence Berkeley National Laboratory and University of California), and half is shared by Brian P. Schmidt (Australian National University) and APS member Adam G. Riess (Johns Hopkins University and Space Telescope Science Institute).

The accelerating expansion of the universe is believed to be driven by a mysterious source, which APS Vice President Michael Turner originally coined “dark energy” in 1998. According to Turner, “The discovery of cosmic acceleration and dark energy provided the last piece in the current cosmological model and at the same time gave us the most profound mystery in all of science – what is dark energy, the source of the repulsive gravity that is causing the universe to speed up?”

“On behalf of the American Physical Society,” said APS Executive Officer Kate Kirby, “I offer our warmest congratulations to each of the 2011 Physics Nobel Prize winners. Their work has profoundly impacted our view of the universe and has challenged us with new questions.”