This guy must've been paying attention when Neil deGrasse Tyson explained how lightsabers work. Allen Pan, the California-based electrical engineer who brought us a real version of Thor's hammer, has invented the first ever working lightsaber, and he got together with a bunch of guys at Node to demonstrate its capabilities.
Pan's lightsaber uses a nichrome ignition to ignite a stream of methanol and acetone fuel. Pan can control the flame (or the blade, if you will) with a valve control in the handle, which also conveniently makes cool lighsaber noises. He put the entire contraption inside of a model lightsaber he bought, and he used a 3D printer to create his own mini fuel container.
The lightsaber doesn't do as much damage as one of George Lucas' creations, but it's fun to set things on fire with a mythical weapon straight out of a movie. (As Pan demonstrates, it's also good for lighting cigarettes.) Now that Pan has the weapon, three questions remain: Will he destroy the Sith or join them? Will he bring balance to the force or leave it in darkness? And when will these things hit the mass market?