Alcubierre drive

Definition: The Alcubierre drive was proposed in 1994 by Mexican physicist Miguel Alcubierre, to create a physically-feasible method of creating a "warp drive" like those shown on the television (and film) series Star Trek.

How the Alcubierre Drive Works

Normally, Einstein's theory of relativity doesn't permit any object to travel faster than the speed of light, because accelerating up to that speed requires an infinite amount of energy. The Alcubierre drive gets around this by proposing that the drive would actually manipulate spacetime itself, causing the space in front of it to contract while the space behind it expands. This "warp bubble" allows the ship to reach a destination faster than a light beam traveling through "normal" spacetime.

According to relativity, space is malleable, which is how the Alcubierre drive achieves this feat. (The early universe, for example, expanded faster than the speed of light because spacetime itself can expand faster, even though objects within spacetime cannot accelerate faster.) In this scenario, the ship containing the Alcubierre drive actually sits still and is carried along the warp bubble, kind of like a surfboard riding on an expanding wave. This means that time dilation and other relativistic effects aren't significant, despite the intense speed.

How to Build an Alcubierre Drive

The Alcubierre drive is purely theoretical. Some proposals have been put forth about how it might be possible to construct such a drive. One example involves placing masses of exotic material, such as tachyons, along a route before the trip is made. In this case, the ship can only travel along the designated route, sort of like how trains can only travel on train tracks. Of course, this means that the set-up can only be performed at speeds under the speed of light, so it would be a massive interstellar construction project.

Also Known As: warp drive,Alcubierre metric