Hey, how predictable is a frame of reference going faster than c?

[KillaMarcilla]

Yo, d00dz, I'm just starting an introductory quantum physics class, so this'll probably be childishly foolish to some of you, but the risk of sounding childish has yet to stop me from saying something on the internet

It seems like the transformations of special relativity just break down at speeds greater than or equal to c, so that maybe if you somehow happened to get to a speed faster than light without needing to go through the energetic asymptote in your way, you might be all set to go around faster than light as long as you want, until it comes time to skip down back below c

Or is there some way of verifying the impossibility without relying on empirical observations from down here, of the method of faster than light travel wherein one skips past c?

For some reason, any Physics book I've had so far has said that there's no way I could understand tensor analysis, and therefore couldn't possibly even begin to have any grasp of general relativity..

 

[selfAdjoint]

Objects that would move faster than c would have imaginary masses (that is multiples of the square root of minus one). They have a name, tachyons. They are not forbidden in relativity itself, but experts on quantum field theory say the existence of tachyons would cause our quantum vacuum to decay, and we're all going to die! I don't know, some string and brane theories have tachyons in them so maybe they aren't the end of the world after all.

 

[KillaMarcilla]

Well, the equations we've come up with so far would say they'd have imaginary masses and whatnot, but how likely do you think that really is? Would stuff like that really have to be the case?