[ash_scotland88]

http://www.technologyreview.com/blog/arxiv/23292/

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.

Warp drives have been the focus of science fiction writers for decades. But scientists kept them at arms length until 1994 when the idea was put on a firm (ish) theoretical footing by the Mexican physicist, Michael Alcubierre. His thinking is that while relativity prevents faster-than-light travel relative to the fabric of space time, it places no restriction on the speed at which regions of spacetime may move relative to each other.

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.

The conclusion is the result of classical thinking using the ideas of general relativity but physicists have long wondered what would happen if you threw quantum mechanics into the mix? 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.

They have also studied a property of a quantum field called the renormalised stress-energy tensor which should be well-behaved under normal circumstances. But in the front wall of Alcubierre's bubble travelling at superluminal speeds, the renormalised stress-energy tensor grows exponentially.

That strongly implies that such a bubble would be unstable. So it looks increasingly likely that, after a brief few years of excitement, Alcubierre's warp drive is impossible.

[NCC-73515]

Deflector against radiation - and the bubble is kept stable by the constant energy from the warp coils

[starbase63]

Originally Posted by ash_scotland88

http://www.technologyreview.com/blog/arxiv/23292/

The Vulcans also thought that time travel was impossible...

Maybe they've actually figured out it CAN work and so they're now putting out disinformation...

[gornski]

<Spock voice, imperative voice>MISTER SCOTT, TRY INVERSE PHASING!</Spock voice>

So disappointing. But this:

"Alcubierre's warp drive is impossible"

is not logically equivalent to this:

"Warp drives cany exist"

Dream on crazy physics dudes, we must slay the impossible.

[horatio]

What did Socrates say, something like "I know that I don't know anything".
I guess that a hundread years ago, most physicists did not believe that anything beyond Newtonian physics is possible ... and then there came this guy from the patent office.

[NCC-73515]

Comment on trekmovie.com

11.Rick Sternbach - April 3, 2009 In the TNG tech manual, we posited a -bunch- of layered moving bubbles to get around the problem, and we did it back in 1990.

[Saquist]

That is a logical assessment gornski.

The bubble doesn't have to shrink space time.
It can also expand and contract which would have a similar effect of motion while not limiting its speed.

[Beetlescott]

Of course it is impossible, Zefrim Cochran hasn't been born yet!!!

[Saquist]

Oh...boy.

[That Metal Beastie]

Heavier-than-air flight, the four minute mile for runners, lots of things have been deemed impossible over the years. And remember someone suggested around the turn of the last century that the US patent office be closed because there was nothing left to be invented. Tomorrow never knows.

Oh yeah, it was impossible for the Titanic to sink.