> Your last point doesn't explain why or how time dilation occurs, just that we know that the speed of light is a constant to all reference frames. But that's

> Your last point doesn't explain why or how time dilation occurs, just that we know that the speed of light is a constant to all reference frames. But that's what the light clock experiment [1] is all about. The two observers see the light moving at the same speed, but one observer thinks the light takes a longer path than the other observer does. If both observations are equally valid, the inevitable conclusion is time dilation. [1] http://www.emc2-explained.info/The-Light-Clock/#.WBxO8vnLdPA http://www.emc2-explained.info/The-Light-Clock/#.WBxO8vnLdPA