Contrasting this with Eternalism, which says that the past & future exist such that time travel is theoretically possible, still the human would require a lifespan of such length that the acceleration necessary could be gradual enough to be withstood by the human host — assuming traveling near the speed of light is the most plausible way for flesh to reach the future more quickly than the standard speed of time.
To my limited way of understanding, Presentism matches neatly with the Copenhagen interpretation of quantum mechanics, one of several attempts to explain the observable vs. non-observable aspect of quantum behavior being at odds with itself, whereby the non-existent future corresponds to a particle before it is measurably observed and the non-existent past to the same after this measurement has taken place.
(Constructing the previous sentence brought to mind something I stumble over trying to get my head around movement in time and our expressions for it, and how it puts on the tip of my tongue a notion regarding a certain semantical sameness of the future & the past.)
What then matches neatly with Eternalism? Enter Everett’s many worlds interpretation. This typically gets explained by way of the implication that any possible past exists in its own parallel universe. One might argue that this lines up more accurately with the philosophy of the Growing Block Universe, wherein only the the existence of the future is forbidden, but this is one point where I cannot let go of the future.
It seems to me that when one discusses the existence of an infinite number of parallel universes, there is one factor I have yet to encounter that makes sense, if only by misconstrued default: For every quantum split there would be an occurrence of a comparable split at some point earlier, meaning the alternate realities that result in your being a history teacher in one world and an investment banker in another would not necessarily have matching timelines. In this sense, then, the decisive turn of events in World A that resulted in your attending Brown University may have in turn been the result of your having been born a few minutes earlier than in World B.
If we extrapolate from this an infinite number of anything’s opening the door to every version imaginable and then some, then there are several simulations of World A happening at every point along the timeline of the meta-verse — if such a meta-timeline exists.
And this brings us back to the question of time travel, or if indeed it might be more feasible to hop into the parallel universe identical in every way to your own save for its having occurred minutes, months, or millennia earlier or later than the one you are living in now.