Saul Perlmutter. Portrait of the American cosmol- ogist Saul Perlmutter holding a candle against a starfield showing a supernova. Perlmutter is head of the Supernova Cosmology Project (SCP) at the Lawrence Berkeley Laboratory, University of California, USA. The SCP uses type Ia supernovae as standard candles" for distance measurement in the universe. These are explosive star deaths which have characteristic spectra, allowing their distances and recessional velocities to be measured accurately. SCP researchers found the universe to be expanding at an increasing rate, implying it will expand forever rather than being slowed by gravity. Photographed in 1999."