Recently I've been studying a lot of history, and I've often thought about how, according to special relativity, you can translate time into space and vice versa, and therefore how from a different perspective we can think of the past as distant in space rather than time: my childhood being 40 light years away, rather than 40 years for instance. I can visualise my own body as a sort of long, four dimensional tendril through spacetime, of which I only ever see a three-dimensional cross-section. This is the block universe idea of course. What occurred to me recently was that the past, in any physical theory I know of, is "locked down". There is only a single history consistent with the present (ignoring the microscopic ambiguities of quantum interference effects), but the present is consistent with multiple futures. However, we know that "now" - and therefore the division into past and future - is an artifact of mind with no physical reality, a "quale". So therefore, if the past is singular, so is the future, and seen from "outside", every quantum event, whether "future" or "past" from any particular fame of reference, is in fact completely determined in its outcome, even though it is also random in the sense there is no way of explaining why it is the way it is, beyond the description provided by Born rule probabilities. Is that not weird, if not downright absurd? What is this "necessity" that dictates that this particular subset of all the possible quantum events was selected as the way things are? Somehow the idea of the future being indeterminate but the past fixed seems palatable because it accords with our subjective experience, but really it is incoherent as soon as we acknowledge that the past-future distinction is not physically meaningful.
Would this mean that if we could run the big bang over again from the same initial conditions, it would always go exactly the same way? That is absurd, as it would mean there is something prebuilt as it were into the laws of physics that dictates that only this particular world history is permitted, for no reason at all. But if it could go a different way, that is equally absurd because it implies that variance is allowed at the level of entire universes, but not at the level of individual quantum events within those universes. What can resolve this paradox? Perhaps I'm cheating by imagining different possible universes in a universe where only one is real and allowed, but who can seriously countenance such a cosmology of absurdity where everything "just is"? Of course if MWI is correct, then the paradox is resolved, because there is only a single past in the sense that there is only a single shortest path from any limb of a tree to its base, and there is no need for some principle of arbitrary necessity to dictate that all quantum events only have one possible outcome. For me this is a powerful argument in favour of many worlds, yet it's not one I've heard before. Any comments? -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
