Perhaps: the field of physics, in its discussions, allows for local observation and within local observation, the observation of local causal effects. The lack

Perhaps: the field of physics, in its discussions, allows for local observation and within local observation, the observation of local causal effects. The lack of causal effects in your observable context when a distant event occurs means that the time of the event to your local context is the time of the effects of that arrival (when you actually have evidence of it). One might suggest this is a correlate of the "no" answer to the "if a treefalls in the woods but no one is around to observe it, does it make a sound?" question but... On the more practical side you can consider CPU clocks and time synchronization. One can only synchronize two clocks to agree up to a time span but within that span the relative ordering of events at each is undefined. The physics reason is that only causality establishes order, the cause precedes the consequence and beyond causal entanglements, ordering is undefined. I'm not a physicist but I've been pondering this sometime...