My thought is that in special relativity, there is no absolute present, only the present from different reference frames. Essentially, “now” isn’t an objective

My thought is that in special relativity, there is no absolute present, only the present from different reference frames. Essentially, “now” isn’t an objective thing. “Happen simultaneously” is not an observer-independent equivalence relation, and so there is no observer-independent way of splitting things into “the present (which exists)” vs “the past” vs “the future”. If you want to refer only to that which you presently observe as “existing”, then there is only the boundary of your past light cone, but this would be a bit solipsistic imo, as any other person you observe, the boundary of their past light cone would mostly not be part of the boundary of yours (it would be in it, just not on the boundary of it), and so they would seem to see things that “don’t exist”. This doesn’t seem sensible to me. I don’t see any good alternative to treating the past and future as being fully real.