Bad news I’m afraid — it looks as if faster-than-light travel isn’t possible after all. That’s the conclusion of a new study into how warp drives would behave when quantum mechanics is taken into account. “Warp drives would become rapidly unstable once superluminal speeds are reached,” say Stefano Finazzi at the International School for Advanced Studies in Trieste, Italy, and a couple of friends.
[Mexican physicist Michael] Alcubierre imagined a small volume of flat spacetime in which a spacecraft might sit, surrounded by a highly distorted bubble of spacetime which shrinks in the direction of travel, bringing your destination nearer, and stretches behind you. He showed that this shrinking and stretching could enable the bubble–and the spaceship it contained–to move at superluminal speeds.
Now Finazzi and pals have worked it. For a start, they say that the inside of the bubble would be filled with Hawking radiation, making life rather uncomfortable for any spacecraft within it. […] in the front wall of Alcubierre’s bubble travelling at superluminal speeds, the renormalised stress-energy tensor grows exponentially.
Darn it… that renormalised stress-energy tensor gets you every time. Oh well. Back to the drawing board, guys.