>>12194975>>12194979Ironically, time dilation is PRECISELY a coping mechanism, so to speak. Once you take the constancy of the speed of light in all reference frames as an axiom, you can easily deduce time dilation and length contraction. Basically, these phenomena arise because you have to cope with the fact that c is the same for all observers -- something else has to give way instead.
So the real question is, why is it so important that c be the same in all reference frames? You can think about it in terms of causality. c is really the speed of causality, and dictates in what regions of spacetime it makes sense for a given observer to talk about cause-and-effect. Without some finite, consistent notion of this region (called the light cone), you run into all sorts of illogical inconsistencies of causality of events.
