[net.space] Causality and FTL

bstempleton (08/06/82)

Does anybody out there have a nice explanation of exactly why FTL travel
of information blows our ideas of causality out of the water?

I remember the explanation given to me in Relativity class years ago, but
I was never entirely satisfied with it.  Admittedly instantaneous
transmission of information destroys the lack of simultanaity in the
universe, but why can we not have something propogating at finite but
FTL speed.  I do have some idea of why this is true, but does anybody
have an explanation that is more straightforward than a couple of years
of physics courses?