in experience/moral patient deduplication and ethics, i explore the question of whether running the same computation of a moral patient twice counts as double, ethically. in all claw, no world i draw up a view of the cosmos based on time steps in the universal machine which suggests that duplicated computations do count as double, because they occupy twice the amount of time-steps in the universal program.
when coming across the concept of many-worlds, i think people most generally assume the view on the left, where new timelines are being created. i think the view on the right, where a constant amount of "reality fluid" or "reality juice" is being split into different timelines, is more correct and makes more sense: we wouldn't expect the amount of "stuff existing" to keep exponentially growing over time. i believe it also maps to the notion of quantum amplitude.
(where at a given time,
A is the amplitude of a particular timeline and
ΣA is the sum of amplitudes across all timelines)
i think the way to view this that makes sense, if one is thinking in terms of discrete computation, is that the universe starts out "computing" the same thing in all of many "threads", and then as timelines branch fractions of these threads start diverging.
this also explains what goes on inside a quantum computer: in the quantum circuit it, rather than saying that a bunch of "new" universes are being temporarily created and then re-merged, instead it's merely the case that different computation threads are temporarily computing something different instead of the same thing.
if P=BQP or the universal program is quantum, then it makes sense to live in a quantum universe, but:
(one view that completely circumvents all of this is if P≠BQP and the cosmos is, ultimately, implemented classically, but we still only inhabit quantum worlds — perhaps classical worlds simply don't exist, or the cosmos is really just our big bang and nothing else. in that case, it could be that the classical program taking exponentially long to compute us exponentially far approximately compensates for the time step distribution favoring earlier us's, possibly exponentially much. that'd be really strange, and it feels like we'd be too far, but i guess it's possible.)
anyways, what this suggests is that, in the simplest model, the universe is running many computation threads which are originally computing the same thing, and then some fraction of them diverge sometimes — either to re-merge in local situations like quantum computers or the double-slit experiment, or to decohere the rest of the world and more "permanently" split it.
but more importantly, this suggests that: