Imagine a fictional stellar shootout between two ships .. ?

Question

lets say you have 3 ships being separated by 5 lightminutes each, forming a triangle. all three ships maintain their distances and travel same course with half the speed of light in a very light nebular (for optical reasons)
Now Ship A fires a 1 minute laserbeam on Ship B, destroying it.
Ship C takes photos.. what will these photos tell ?
What do they exactly observe, why and when ?
(This is NOT a homework question) :P

any redshift/blueshift .... ?

Answer 1

First, if all 3 are moving in the same direction at the same speed, there won't be any relative motion among them, so the fact they are moving at .5c is irrelevant. Second, why specify 'photos'? Why not a continuous video? That way, whatever there is to see, will be seen. Ship A fires at Ship B at T=0 . Ship C will see Ship A fire on Ship B at T+5'. It will take 5 more minutes for the laser beam to reach Ship B, which Ship C will see at T+10'. One minute later T+11', Ship C will see Ship B explode.

Answer 2

Since all of the ships are travelling at the same speed, Ships C will take the photos, but of images that are five minutes old. The image of the ship being destroyed will be as if all three were standing still.

Answer 3

Since they are all going at the same speed in the same direction and not accelerating, it is exactly as if they were all standing still and the nebular region was moving past them at 1/2c. It would be different if ship C was at rest, but it isn't; it is moving along with A and B. All 3 ships are at rest with respect to the other two, and the outside universe does not matter at all. That is called an inertial reference frame in physics.

Answer 4

challenging subject. seek from yahoo. this may help!