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## Warp Drive Speed

OK. I am very relieved. But it shows the power of 'the icon' in our personal view of the world. I should have known better, when so many reputable PF contribs were taking it all so seriously.

So, let's say I am on Earth and I have a ship going away from Earth at a significant fraction of c. What happens if I try to send the lottery numbers to it using the miniature warp drive and have it send them back to me as soon as it receives them, again using a miniature warp drive? Is it not possible to receive the numbers before the lottery draw this way? If not, what exactly would prevent this scenario?

 Quote by K^2 Of course, GR also allows time travel
Hi can you direct me to a reference for this? wiki page mentions "certain unusual scenarios" under which it might be allowed.

I think I found the answer to my question in the paper "Warp drive and causality" by "Allen E. Everett": http://adsabs.harvard.edu/abs/1996PhRvD..53.7365E (http://exvacuo.free.fr/div/Sciences/...0prd950914.pdf)

 In the space described by Eq.10 there is a region within one of the bubbles, both in the primed and unprimed coordi- nates, in which the ‘‘forward’’ light cone runs backward in time, and CTC’s occur. Suppose a passenger leaves S1 on a spaceship traveling in the unprimed bubble, starting at t=t'=0, moving along the line y=y0, and arriving at S2 at t~=0, t'=T'~=-yBD, at which point the spaceship has come to rest and the bubble has disappeared. He now travels the short distance to y=-y0 at subluminal speed through flat space, and accelerates to sublight velocity B, so as to be at rest in the primed coordinates. [We assume that this pro- cess requires negligible time since y<
So, it seems that if these "warp drives" are at all possible and if you can freely use them to travel between arbitrary points then you *can* use them to create real paradoxes just like any other FTL method and so this relies on contrived "consistency maintaining" methods existing in the universe, just like any other FTL method. Am I missing something?

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 Quote by cuberoot I think I found the answer to my question in the paper "Warp drive and causality" by "Allen E. Everett": http://adsabs.harvard.edu/abs/1996PhRvD..53.7365E (http://exvacuo.free.fr/div/Sciences/...0prd950914.pdf) So, it seems that if these "warp drives" are at all possible and if you can freely use them to travel between arbitrary points then you *can* use them to create real paradoxes just like any other FTL method and so this relies on contrived "consistency maintaining" methods existing in the universe, just like any other FTL method. Am I missing something?
Somebody out there must be 'checking' every potential FTL machine as it operates. The logic behind this sort of thing is very difficult to get to grips with. Perhaps future, real warp experiments will resolve it.

 Quote by cuberoot Am I missing something?
No, you are right. As any other FTL travel warp drives would violate causality. But I never understood how they should exceed the speed of light. A warp bubble is a special kind of gravitational wave and therefore should propagate with c at the most. Exceeding the speed of light might be possible by forcing the formation of the warp bubble from outside but not from the ship inside.