I mean, whether it’s deterministic is really hard. We’re talking about extensions of quantum field theory and there have existed both deterministic and nondeterministic accounts of quantum mechanics, the deterministic ones generally lagging the nondeterministic ones substantially.

But whether it’s _exactly the same_, I think Penrose would say that they are _almost never_ the same. The question would be whether the Big Bang of this universe is perfectly mirrored in its final state and I think Penrose would say “well all the stuff that happened in the middle probably had some sort of effect on how the thing ended up.” So if we are seeing the black holes of some other universe’s death writ large on our cosmic microwave background, then I can’t imagine our black holes will eventually look exactly the same, will they? (Keep in mind, I’ve only met Penrose once and I embarrassed myself thoroughly at the time, so my guesses about what he would say are terribly terribly weak predictions.)

But maybe they will be the same. I talk a lot on HN about the impact of fixed-point theorems on US politics, but they would also apply here. If the universe has an infinite number of sequences one might expect that it starts to converge on a situation where the black-hole-patterns in are the same as the black-hole-patterns out. Now if that happened one might imagine that, if that fixed point supports life, then there is an infinite replay of nearly-identical life experiences across the many many eons of universe, and then if we treat our existence as “choose a conscious person across the eons to be” we would almost surely randomly choose someone in the oft-repeated universe. And so yes, we would be very likely to say that our universe's end would lead to another universe wherein the exact same people living out the exact same lives having the exact same discussion on Hacker News, haha.

I am a Christian and so these sorts of things are a sort of idle speculation, a joke to laugh at rather than something to inform today’s experience, a slacking-off between meetings rather than a contribution of deep value. But it’s certainly fun and funny to think about.

Maybe the previous universe's black hole evaporation ripples cause enough chaos effect for the new universe to be different so even though the whole system is deterministic, it could always be different because of that effect. We live in a PRNG.

Edit: OOh I have an idea. What if the quantum effect is deterministic but appears random we experience are in fact ripple effects from the previous universes? Has anyone ever tried to measure quantum behavior in multiple simultaneous experiments in a kind of geometrical matrix system to see if there are shapes of correlation?