Say you're in a spaceship, or someplace where there is no gravity, friction or resistance, and you have a rocket engine with a LOT fuel. You power up the rocket engine and it delivers consistant thrust for near enough infinite time. What exactly happens? As far as i understand you would go faster and faster, until you reach close to the speed of light... but that's where things get confusing for me. I know you can't go faster or really approach the speed of light, because it requires infinite energy to accelerate mass right? So what happens in the above? Is there some sort of extra resistance that's created at those speeds? From what i can tell, the increase in speed from the constant rocket engine would be linear, so it'd only be a matter of time before you reached light speed. Or is there some trickery with time at those speeds?