Enlarge Image Star power. Saul Perlmutter (left), Brian Schmidt (center), and Adam Riess share this year's Nobel Prize in physics. Credit: LBNL, ANU, JHU Thirteen years ago, two teams of astronomers and physicists independently made the same stark discovery: Not only is the universe expanding like a vast inflating balloon, but its expansion is speeding up. At the time, many scientists expected that the gravitational pull of the galaxies ought to slow down the expansion. Today, researchers from both teams shared the Nobel Prize in physics for that dramatic observation, which has changed the conceptual landscape in cosmology, astronomy,...