Hey there, I am not a physics student, nor have I ever studied physics. I have this question though (read thread title). I have googled for an answer but couldn't find any. According to Einstein, we are always traveling through the universe at the speed of light. When we are still, A (speed traveling) = 0 and B (rate we are traveling through time time) = c (speed of light). Thus when we move, A increases and B decreases by the same amount. Since the speed of light is propagating at c, isn't it stationary in the 4th dimension? Is light not aging and thus never dies until it hits something and the energy is transferred? Is that how photons can propagate through a vacuum and never go out... There might be a real simple answer that physics guys learn I dunno.