Re: starship-design: FTL

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

Steve VanDevender wrote:

>As for Timothy's question about whether someone can affect their own
>past using FTL, I believe you need a conspirator to do so, but if FTL is
>possible then so is affecting your own past via the conspirator.  All
>the conspirator has to do is move fast enough (but still less than c) so
>that in his frame your FTL message appears to go backward in time, then
>send another FTL message to you in your past.

You can be your own "conspirator" if you have FTL travel capability.
If all you have is FTL communication, you can at least make your
own conspirator in the form of some robotic drone which moves fast
away relative to you.

Note that none of this requires "continuous" travel/communication.
If the travel/communication is by some sort of teleportation or
manufactured wormhole or whatever, it can be done.  All that's
needed is some mechanism to send a message or an object to some
place a certain amount faster than light would have gotten there
in a way which works the same in all (sublight) reference frames.

And also space has to be flat or convex (currently, we believe
space to be convex).
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
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