I'm sure this has been asked a million times but a quick search didn't give me quite definitive answers so here it goes: Imagine a spaceship travelling away from the Earth at 0.99c. For argument's sake, lets ignore the acceleration and deceleration stages of the ship (is that valid?). Simply the ship starts travelling at 0.99c. Now the ship stops and according to the ship's clock, they have travelled for a day which on Earth is a year or so (or whatever the difference works out to be). How far is the ship from the Earth? Surely if it has been a year, then it has travelled almost a lightyear within a day (according to ship's clock) which can't be true. So where and why is it? P.S. This is not homework, merely a question that came to mind when watching this.