Re: starship-design: FTL

[kuo@bit.csc.lsu.edu (Isaac Kuo)]

Steve VanDevender wrote:
>However, I do think it's accurate to
>say that if you claim to be able to link events separated by a spacelike
>interval, then you can construct causality violation under the right
>conditions.

This is true assuming general relativity and a flat or convex universe.
If special frames of reference exist, it may be possible to avoid
causality violations while having FTL.
If the universe is hyperbolic (average energy density is negative), then
it's also possible to avoid causality violations.  Intuitively speaking,
this is the case where the universe is expanding apart so fast that
it's impossible to return to where you came from in spacetime.
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
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