[Spaceships] Real Life Non-Super Science Reactionless Engines

[malloyd]

Originally Posted by Anthony

'Our FTL drive seems to always move forward on the time axis in this particular reference frame, which I have called the Subspace Reference Frame'.

Doesn't help. Relativity is about the relationship between reference frames, there is no special "frame you are traveling in", you are traveling in all of them.

Simplifying some (because I don't want to hunt it out and the math got pretty ugly with sub and superscripts I probably can't do in ASCII anyway when we actually worked through this) it's roughly if there exists some frame in which you have your ship at point A at time T0, and at point B at time T1, such that T1>T0 then *either* (B-A)/(T1-T0) <= c *or* there exists some equally valid frame in which T1' < T0', and in which (B'-A')/(T0'-T1') is less than c, allowing you at B'T1' to fire your laser back at yourself at A' and blow yourself up before T0' happens and you start the trip.

It does not actually matter how you moved between A and B, all the coordinate transformations say is that if you did in some frame, then there's another frame you travelled backward in time. No you didn't in the first frame, but so what? The contradiction *is* the causality problem. Stuff happened when you look at the universe one way that didn't if you look at it another, is what doesn't make sense about violating causality.