[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: starship-design: FTL
[Kyle] I have a question (don't I always?):
If you dissapear from orbit above earth, and later on reappear in orbit
of tau ceti I, is causality violated? If so, why? No one saw you.
[L. Parker] Kyle poses a rather interesting question which I am going to
expand a little for the sake of clarity:
If you can move from here to there instantaneously, or nearly instantaneously,
is causality violated? If you go from here to Tau Ceti in 1 second of real
time, you don't arrive at Tau Ceti 11 years ago you arrive at t+1 sec. There
is no FTL communication that I can see and no causality violation.
Now expanding on this theme and ignoring everything except relativity for the
moment, there would seem to also be a point or factor if you will beyond c at
which causality is violated but only if you exceed that factor. That point
would seem to be 2c - the speed which would put you at your destination at
exactly t+0. Delta t for this trip would be -1 putting your arrival at any
destination at exactly the point necessary to produce a causality violation.
Am I being to simplistic here, or does this adequately describe causality? If
so, then time travel isn't necessarily impossible, just USEFUL time travel.