Running a Galactic Empire requires a lot of energy. Actually, that's true for every faction in Star Wars: legions of electronic droids need some sort of power supply, and even the Rebel Alliance has to worry about sustaining secret bases and fighters, too. We don't, in this universe, know exactly how the population of Star Wars did it. We do have the next-best thing: a round table of scientists from the Department of Energy, speculating about how, exactly, energy works in a universe long ago and far, far away.

Conducted last summer, an hour-long Google Hangout featured Cathy Plesko, an applied physicist from Los Alamos National Laboratory; Peter Thelin, a master optician from Lawrence Livermore National Laboratory; Chris Ebbers, a physicist at Lawrence Livermore; and Vishal Patel, a researcher from Idaho National Laboratory's Center for Space Nuclear Research (Vishal's particular area of research is new forms of nuclear power that could fuel tomorrow's spacecraft).