Banana Phone said:
OT, my favorite one ever: what would happen if a spaceship was traveling at close to the speed of light, and also spinning with a rotational velocity of close to the speed of light? One side of the ship would be exceeding the speed of light, would it not?
Nope, it would not.
What you need to remember is that Relativity doesn't only give us the rule that things can't travel faster than light, it also tells us what effects happen to those objects that get very close to that speed.
In this case, the important thing is time-dilation. At very fast speeds, time slows down, and if you get very close to the speed of light, it almost stops altogether. The object may be rotating very quickly from it's own perspective but, to an onlooker, the object itself is moving forward through time much slower than it ought to be, as such, the rotation is also slowed down hugely. Avoiding the contradiction.
A simpler example is if you stand on Earth and two ships fly off at 99% light speed in opposite directions. Now, to you on Earth, neither ship is travelling faster than light, 1% slower in fact but, surely, from each other's perspective the other ship must be travelling as 198% of the speed of light. Violating two fundamental laws of Relativity, first that you can't travel faster than light and second that every inertial reference frame is equally valid.
The answer is that, thanks to the dilation effects that take place, the ships will in fact only appear to be travelling at approximately 99.99% of light speed to each other. Avoiding the violation again.