Hey guys, this is a question that has been bothering me since I finished my special relativity course last year. I was told that nothing can travel faster than the speed of light. Thinking relativistically, I take this to mean no one thing in the universe can travel faster than any other thing in the universe by a difference 'c'. This seems like a difficult condition to satisfy-- with so many objects moving around in different directions, some of them spinning really fast, like neutron stars, they would have to be configured just so... I guess it's just hard for me to imagine why, if I am in a space ship, I can't just keep accelerating in one direction. Will my constant thrust start producing diminishing acceleration after a while? Put another way, if some object is hurtling towards me at c/2, will it be easier for me to accelerate away from the object than towards it?