[Spaceships] Real Life Non-Super Science Reactionless Engines

[malloyd]

[QUOTE=Agemegos;1795379]Well, they can be if the other frames of reference use the special frame to synchronise their clocks, but then the Principle of Simultaneity won't hold in any frames except the privileged ones (ie. c won't be invariant, with odd implications for Maxwell's Equations).

But c is invariant (or more generally that the laws of physics, at least one of which involves c, and yeah Maxwell's Equations are that one, don't have to take into account the motion of your reference frame) *is* the principle of relativity. You don't get to keep it if you pick causality and FTL.