Warp drive, a staple of science-fiction, has just been deemed "plausible and worth further investigation" by the smart and apparently not crazy people over at NASA. And by way of further investigation, they've gone and started trying to create warp bubbles in the lab.
The principle of warp drive is really fairly simple. Nothing that exists in space is supposed to be able to go faster than the speed of light, right? Right. So, the only way to go faster than the speed of light is to not do it in space. One way of going about this is to use something like a wormhole to punch a shortcut straight through one part of space to another, but a more common method (in Star Trek, at least) is to avoid the whole speed limit problem by warping space itself.
All you have to do to travel faster than light is to create a warp field with a ring of exotic matter, encasing your ship in a separate bubble of space, and then get the space to move faster than the speed of light. Technically, since it's the fabric of space that's moving, nothing in space itself is breaking the light speed limit. It's a loophole, yes, but it works. Or at least, we're not sure that it doesn't not work. In terms of powering a spacecraft this way, you'd just shrink the bubble of space in front of you and expand the bubble of space behind you, pushing your bubble along lickety-split.
While the thought experiment might be simple, making this actually work in practice isn't so much. It requires things like negative energy or some other exotic material that may or may not exist, and physicists had estimated that the amount of energy required to move a few atoms this way would be on the scale of the total amount of energy contained in our sun three times over. For an entire spaceship, we'd be talking several orders of magnitude more energy than could be produced by the entire universe. In other words, probably not practical.
Last week at the 100 Year Starship Symposium, NASA researcher Harold White presented some new research suggesting that this whole warp drive thing might not be entirely nuts. You might be able to do it with a football-shaped spacecraft surrounded by a ring of exotic matter, and you might even be able to make it work with much, much less energy. Like, just a couple thousand pounds worth of mass.
"The math would allow you to go to Alpha Centauri in two weeks as measured by clocks here on Earth," White said. "So somebody's clock onboard the spacecraft has the same rate of time as somebody in mission control here in Houston might have. There are no tidal forces, no undue issues, and the proper acceleration is zero. When you turn the field on, everybody doesn't go slamming against the bulkhead, (which) would be a very short and sad trip."
White has already started trying to generate a (very very small) warp bubble using something called a White-Juday Warp Field Interferometer, which should be able to perturb spacetime itself by one part in 10 million or so. That's not enough to take us to the stars, but perhaps enough to prove that it's realistically possible.