Why Don’t We Have Faster-Than-Light Travel?

Faster-than-light travel is one of those little necessities of sci-fi. Space is so vast that without such ludicrous speed our heroes would never interact with anyone. So Star Trek’s Enterprise, Star Wars’s Millennium Falcon, and the Battlestar Galactica all travel faster than the speed of light.

With modern propulsion technology, humans can't even begin to approach a speed that would make interstellar travel feasible. But the biggest obstacle for FTL is the one kids learn in school: light speed is the galactic speed limit. Writing about the issue on NASA’s website, David Allen Batchelor says that FTL travel "violates known physics (Einstein’s Special Theory of Relativity) to an extent that can’t be defended."