I've just started learning about special and general relativity and came up with a couple of questions that look like paradoxes to me. I just need a break from reading, thought I'd discuss this with someone to see the application of what I've read so far. Here are my examples: 1. Say you leave earth on a spaceship capable of instantly accelerating to very near c and you're travelling to a garage that is 1 light-hour away. The second you leave earth, your butler activates a signal to close the garage door. It takes 1 hour for the signal to get there and he times it so it gets there 1 second after you. From his point of reference, looking into his telescope he would see light getting to the garage door 2 hours after he sent it out, a second after you flew through the open door. But from your reference point what do you see? If you look out of the ship, the signal would still be c in relation to you, not stationary, so it should pass you at c speed in relation to you, get to the door when you're half way (intuitively) and you will observe the door closing when you're 3/4ths of the way to the garage door, thereby causing you to crash. So which thing actually happens? Do you make it through the door or do you crash into it? 2. You decided to build a death star, you build it on earth and then accelerate it to travel at 0.8c towards a planet on the other side of the galaxy that is stationary in relation to earth. Once you're on the death star, you are at rest in relation to it. And while on it, you decide to built a space station, which you then launch from the death star towards the target planet at 0.8c in relation to your death star. Then later, while on the space station, you launch a space ship from it towards the target planet, again at 0.8c. What speed are you traveling at in relation to the target planet? Also light from earth is still technically supposed to arrive at the target planet before you, since it's travelling at c in relation to you, right? Am I missing something? 3. Say you were going to test out the twin paradox, but instead of travelling out an back, you got into a massive torus, where you got magnetically accelerated to near c. Does it still count that you are in motion at the speed of c in relation to an observer outside the tube, or does the fact that it's angular momentum completely change everything? If it doesn't, and you decide to synch clocks, and say, you were moving at 86% c, then would 2x time have passed outside the tube than inside, or because there is no "return journey" the effect would cancel out? At what interval would you receive the clock synch signals and how would they change while inside the tube if they were sent every second based on the outside frame?