Illustration of the US astrophysicist Saul Perlmutter (born 1959). Perlmutter is best known for his work on the rate of acceleration of the universe. He heads the Supernova Cosmology Project (SCP) at the Lawrence Berkeley Laboratory, University of California, USA. The SCP studies type Ia supernovae, whose distance can be determined by the amount of light that can be detected from them. Small shifts in this light give the speed at which they are moving away from the observer. Unexpectedly Perlmutter observed the supernovae, and therefore the universe, accelerating outwards. Perlmutter was awarded the 2011 Nobel Prize in Physics for this discovery along with Adam Riess and his colleague Brian Schmidt who made the same discovery independently.