Images: What 'Star Wars' tech is real?

Star Wars, Star Trek, Babylon 5 and innumerable other fictional universes employ hyperspace as a technological mainstay. How else to transport our heroes to distant star systems in less than a few millennia?

The only problem is that Einstein's theory of special relativity seems to prohibit motion (and the transmission of information) faster than the speed of light. As matter approaches the speed of light, the theory goes, the energy needed approaches infinity. That seems to bar acceleration to or beyond light speeds through traditional means.

Still, physicists have, as thought experiments, postulated work-arounds consistent with Einstein's theories. Wormholes, for instance, could effectively create shortcuts by altering the topology of space-time. Tachyons are theoretical particles that travel faster than light. And Mexican physicist Miguel Alcubierre has speculated how a "warp drive" would work.

NASA is funding a project called Breakthrough Propulsion Physics, whose Web page says, in the understatement of the century, "no breakthroughs appear imminent." There's even a book called Faster Than Light: Superluminal Loopholes in Physics. But there's still no Millennium Falcon.