I was looking at this because well i wanted to. http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/Special_relativity_clocks_rods/index.html And i worked something that if it was right i would be fantastic. But i cant really believe its this easy. [Quote First, we will take the simple case of a light clock whose motion is perpendicular to the rod. The light clock will function as before. But now there is an added complication. The light signal leaves one end of the rod and moves toward the other end. But since the rod is moving rapidly, the light signal must chase after the other end as it flees. As a result, the light signal requires more time to reach the other end of the rod That means that the moving light clock ticks more slowly than one at rest. rod is moving rapidly, the light signal must chase after] But if you fire the photon from the opposite end of the light rod the other end will get there quicker causing time to be faster .how can we have 2 clocks going at same speed with different results.