Objects cannot accelerate to the speed of light within normal spacetime; instead, the Alcubierre drive shifts space around an object so that the object would arrive at its destination faster than light would in normal space. Although the metric proposed by Alcubierre is mathematically valid in that it is consistent with the Einstein field equations, it may not be physically meaningful or indicate that such a drive could be constructed. The proposed mechanism of the Alcubierre drive implies a negative energy density and therefore requires exotic matter, so if exotic matter with the correct properties does not exist then it could not be constructed.
|How the proposed warp dive would work|
|Alcubierre Warp Drive Time Control and Time Travel|