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Wormholes, if they exist, would allow faster-than-light travel and communication. However, there is currently no observational evidence for wormholes, only theoretical. The Alcubierre drive is a speculated device that would allow a spaceship to seemingly travel faster than light (from, say, the Earth's reference frame) by actually contracting and expanding ...

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Sending messages faster than the speed of light would also send them back in time, thus opening the door for all sorts of violations of causality - just google "Tachyonic Antitelephone". The use of such a device also requires the existence of tachyons, particles which have imaginary mass, and probably wouldn't interact with ordinary matter in normal ways. ...

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All the treatments of the Alcubierre drive I've seen have not dealt with the acceleration and deceleration. The nearest I've seen is the paper The Alcubierre Warp Drive: On the Matter of Matter, but this is mainly interested in the interactions of matter with the drive and it doesn't deal with the mechanism of acceleration. You'd have to specify how the ...

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Because of the way that an Alcubierre drive alters space to get a ship to exceed $c$, unwarping that space (in order to stop/travel at sublight speeds) would undo the fancy compression/expansion of space that allows the ship to travel above $c$. In short, the act of destroying the "warp bubble" would bring the ship's velocity down below $c$. The ship would ...

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This is a question that is asked the world over and the answer seems obvious to me, yet everyone deems it to be from perception which for me seems to be the issue apply some 1st grade logic to the situation and the answers reveal themselves quite simply. For instance, travelling faster than light from a single point of perception this is absolutely possible ...

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Anything you want can happen. The Alcubierre bubble isn't a thing that appears through ordinary physical cause and effect. It's a spacetime geometry that Alcubierre wrote down by fiat, computed the stress-energy tensor field of (which you can do for any geometry), noticed that it didn't match any known physics, and published anyway. So pick whatever you want ...

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No, there is nothing like an "underdensity of space" and there is no medium that could power the "warp drive". The cosmological constant may perhaps be considered an example of a "perfect fluid" because $p,\rho$ fully specify its state. But they actually overdetermine it. For an environment to be called the cosmological constant, $w=p/\rho$ has to be equal ...

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Warp drives are not allowed by the basic laws of physics, in particular the theory of relativity prohibits any superluminal motion or superluminal propagation of usable information. So whatever "exotic matter" or other wordings are proposed to justify the superluminal warp drives is banned, too. The typical "exotic matter" needed for warp drives would need ...

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