"The negation of the concept of simultaneity doesn't necessarily mean that there exists many different realities, the events whic happen doesn't happen simultaneously because the signal reaches different observers at different times.
But the thing is that, the event has already taken place...
Special Relativity predicts that moving clocks run slow, mass and length are variable and simultaneity is relative. These are 'real' phenomena and leads me to think that the reality of one observer (the passing of time, all physical properties and space-time events) can be regarded as 'his...
If I shine a torch at the moon the light will after a time be seen on the surface. If I then swing the torch so as to move across the moon does the spot of light on the surface travel faster than c?
Reality
If I was Homer Simpson I'd say what about orange juice but that is the best explanation I've had yet. The use of a third observer really attaches 'reality' to the effect of time dilation. Thanks a million!
Say 2 observers are moving with a constant non-zero velocity with respect to one another. Each sees the others clock running slow but since they both know about relativity they know that the other is infact aging at the same rate as they are. They just observe otherwise. To the layman this begs...