Then again, that is a problem with any rocket propellant/fuel... you take a lot of fuel and then propel it away, giving you some acceleration... you know what, never mind... that was a little stupid of me... the fact that you threw away the whole asteroid at the end, means that you gained that much momentum for yourself, regardless of how fast you threw the powdered substance away. I'll still post this, just in case someone else who, like me, has forgotten all physics might start wondering the same thing.
I wonder though, how much nuclear fuel would one have to carry to generate that much thrust? because, essentially the asteroid only gives you enormous amount of propellant to use, not fuel... to carry the amount of nuclear fuel that can propel essentially the whole asteroid away can't be a trivial problem!
Oh damn, forgot to include the relativistic jet. Idioth. Anyhoo... black hole spins, drags stellar gas / dust / occasional star towards it (accretion disk, om nom nom), things spin around faster than the speed of light (yes, FTL. Objects can't move faster than speed of light, but regions of spacetime can move FTL relative to other regions),
Now this doesn't make sense to me. what do you mean by "regions of spacetime can move FTL relative to other regions"? does it make any sense to talk about an object being stationary wrt a region of spacetime? if yes, then what is the relative velocity of an object that is stationary in one of these spacetime reference frames with respect to another object that is stationary in the other spacetime reference frame? FTL?