Better bring a sweater when you visit Wolfgang Ketterle’s laboratories. This master of cool has managed to reduce temperatures in his vacuum chambers below those found in interstellar space. “The colder we are, the more we have the potential to make new discoveries,” says Ketterle. He won the 2001 Nobel Prize in Physics for generating Bose-Einstein condensates -- atoms that clump together briefly in a gas at frigid temperatures. Now, Ketterle is manipulating these transient events in novel ways. Using a magnetic field, he can generate Bose-Einstein condensates and transport them, potentially to microchips. He envisions supersensitive chips that will help measure rotation and gravity to aid navigation and geological exploration in the decades ahead. And in his latest triumph, Ketterle actually formed ultracold molecules after bringing two atoms together in the chilliest manmade conditions ever generated. He flouted chemists’ predictions and achieved no heat release. “We’re holding atoms in a laser beam, turn down the laser power and those atoms turn into molecules…. If nature had knocked on my door and said you have one free wish, wish for something you want in science, I wouldn’t have been bold enough to ask for that!”