[Spaceships] Real Life Non-Super Science Reactionless Engines

[scc]

Originally Posted by Agemegos

Agreed. I'm just saying that if you do (abandon the Postulate of Relativity) you can end up with a case in which travel occurs along a space-like interval (FTL in some inertial frames of reference, backward-in-time in others, instantaneous in boundary cases) but it is not possible for any signal from the arrival event to get back within the past-ward light-cone of the departure event.

Isn't there some law or rule in physics that says the amount of mass an energy in the universe is constant? Or has it been over turned?

And I'm pretty sure that if we never managed to detect tachyons the FTL debate will start back up again