Gene, the easiest way to understand Special Relativity, which covers the realm of your questions, is to think of space-time as four dimensions, of which one is time. In this four dimensional space-time, everything. And I do mean everything moves at the speed of light in four dimensions. What? Bear with me.
You and I, we are right now moving pretty close to the speed of light in the direction of the time dimension (t). If we now start to accelerate to high velocities in one of the spacial dimensions (x, y, z) we start to reduce our velocity in the time dimension, because the total velocity which is the square root of vx^2+vy^2+vz^2+vt^2 must always equal c. If we put all our velocity in the spacial direction so that sqrt(vx^2+vy^2+vz^2) is nearly equal to c, then there will be almost no velocity at all in the time dimension.
The other thing to realize is that there is no place in the universe you can say "this is the center, and this is completely at rest in a given dimension(s)." The only way you can measure how fast something is moving is space-time is to have an observer. It's the relative motion between the two, the object and the observer, that allow us to make these measurements. And it doesn't matter if it's the object observing the observer, they will see the same things. If an observer sees something moving very close to the speed of light, say a ship, they will also see that the clocks on the ship are pretty much frozen in time. And that same ship, looking back to that observer, would see the observer's clocks frozen in time too.
|