Suppose that 2 particles, A and B, which are far away, are travelling towards each other at a constant equal speed. From A's point of view, will b be having uniform or uniformly accelerated motion? Wouldn't that be same from B's point of view? And what would happen if A and B are travelling at the speed of light? What would be the speed of the approaching particle then? (here, lets assume A and B are light itself) Ok. So this was a random thought I had a few days ago.. Thanks in advance guys!!