Say we synchronize two clocks in a space ship each at the opposite ends of the ship a length of x'. Now we accelerate the ship to a velocity v with respect the the initial rest frame. So now according to the rest frame. The clocks are out-of-sync by vx'/c^2. What exactly happened to the clocks when they were accelerating to make one of them ahead of the other in the rest frame? Or is this all wrong?