Are all events in eternal memory of spacetime?

[Snip3r]

consider A and B particles synchronizing clocks. Immediately after that B flies off at high velocity at the same time A flashes light perpendicular to B's motion. It hits some target c. Now in A's frame the event happened after t$_{a}$=perpendicular distance/c. But in B's frame it happened after t$_{b}$=hypotenuse/c evidently t$_{b}$ being higher. Does this mean all events exists always and there is always a frame which is yet to witness anything ever happened?

 

[ghwellsjr]

All frames are equally valid. There is nothing that one frame will provide a witness to any observer that another frame won't. Any event that you want to consider in one inertial frame can be transformed into any other inertial frame using the Lorentz Transform. But this doesn't mean that an observer can see anything differently just because a different frame is used. Frames just provide a consistent way to establish coordinates to things that happen.