Unlikely as those scenarios may be, Star Trek's writers may have been on to something legitimate. NASA researchers have conceptualized a matter/antimatter propulsion system for a Mars vehicle. Meanwhile, physicists routinely produce antimatter in giant particle accelerators, and recently, at the European laboratory CERN, they succeeded in creating the first anti-atom. At this point, the main problem with such projects isn't so much feasibility as cost. "It's just unbelievable how expensive antimatter is to produce," says Lawrence Krauss, author of The Physics of Star Trek. "To produce enough antimatter to power a light bulb would take 1,000 times the gross national product today."