The Alcubierre drive is a speculative idea based on a valid solution of the Einstein field equations as proposed by Miguel Alcubierre by which a spacecraft might achieve faster-than-light travel, making travel to other stars a possibility. Rather than exceeding the speed of light within its local frame of reference, the ship would traverse distances by contracting space in front of it and expanding space behind it.
In 1994 Alcubierre proposed a way of changing the geometry of space by creating a wave which would cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship would then ride this wave inside a region of flat space known as a warp bubble, and would not move within this bubble, but instead be carried along as the region itself moves as a consequence of the actions of the drive. If this is so, conventional relativistic effects such as time dilation would not apply in the way they would in the case of a ship moving at a very great velocity through flat spacetime, relative to other objects.
This method of propulsion would not involve objects in motion at speeds faster than light with respect to the contents of the warp-bubble; that is, a light beam within the warp-bubble would still always move faster than the ship. Thus the mathematical formulation of the Alcubierre metric does not contradict the conventional claim that the laws of relativity do not allow a slower-than-light object to accelerate to faster-than-light speeds.
The Alcubierre drive, however, remains a hypothetical concept with seemingly insuperable problems: The amount of energy required is unobtainably large, there is no method to create a warp bubble in a region that does not already contain one, and there is no method to move from the warp-bubble once having arrived at an intended destination.
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In 1994 Alcubierre proposed a way of changing the geometry of space by creating a wave which would cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship would then ride this wave inside a region of flat space known as a warp bubble, and would not move within this bubble, but instead be carried along as the region itself moves as a consequence of the actions of the drive. If this is so, conventional relativistic effects such as time dilation would not apply in the way they would in the case of a ship moving at a very great velocity through flat spacetime, relative to other objects.
This method of propulsion would not involve objects in motion at speeds faster than light with respect to the contents of the warp-bubble; that is, a light beam within the warp-bubble would still always move faster than the ship. Thus the mathematical formulation of the Alcubierre metric does not contradict the conventional claim that the laws of relativity do not allow a slower-than-light object to accelerate to faster-than-light speeds.
The Alcubierre drive, however, remains a hypothetical concept with seemingly insuperable problems: The amount of energy required is unobtainably large, there is no method to create a warp bubble in a region that does not already contain one, and there is no method to move from the warp-bubble once having arrived at an intended destination.
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