I'm trying to understand why the speed of light is the same for all observers. I have found different answers on-line. This page claims that it relates to time dilation. But consider the following thought experiment: two ships flying at 98% c. Ship A is moving toward the sun, and ship B is moving away from the sun. The moment the two ships pass each other they are in the same gravitational field and are flying at the same speed. Time dilation should be the same for both. It would seem that light would be traveling at different speeds for the two ships, but is nevertheless measured to be the same speed. In this situation, it doesn't seem that differences in time dilation provide the explanation.