Re 1.: Yeah, if you consider “determined but unknown” in place of the “non-quantum randomness”, this is indeed different. Let me sketch a (toy) example scenario for that:
We have fixed two million-bit numbers A and B (not assuming quantum random, just fixed arbitrary; e.g. some prefix of pi and e would do). Let P2(x) mean “x is a product of exactly 2 primes”. We commit to flipping a quantum coin and on heads, we we destroy humanity iff P2(A), on tails, we destroy humanity iff P2(B). At the time of coin-flip, we don’t know P2(A) or P2(B) (and assume they are not obvious) and can only find out (much) later.
Is that a good model of what you would “deterministic but uncertain/unknown”? In this model (and a world with no other branchings—which I want to note is hard to conceive as realistic), I would lean towards agreeing that “doing the above” has higher chance of some branch surviving than e.g. just doing “we destroy humanity iff P2(A)”.
(FWIW, I would assume the real world to be highly underdetermined in outcome just through quantum randomness on sufficient time-scales, even including some intuitions about attractor trajectories; see just below.)
Re 2.: The rate of accumulation of (ubiquitous, micro-state level) quantum effects on the macro-state of the world are indeed uncertain. While I would expect the cumulative effects on the weather to be small (over a year, say?), the effects on humanity may already be large: all our biochemistry (e.g. protein interactions, protein expression, …) is propelled by Brownian motion of the molecules, where the quantum effects are very strong, and on the cellular scale, I would expect the quantum effects to contribute a substantial amount of noise e.g. in the delays and sometimes outcomes. Since this also applies to the neurons in the brain (delays, sometimes spike flipped to non-spike), I would assume the noise would have effects observable by other humans (who observed the counterfactual timeline) within weeks (very weak sense of the proper range, but I would expect it to be e.g. less than years).
This would already mean that some crucial human decisions and interactions would change over the course of years (again, scale uncertain but I would expect less rather than more).
(Note that the above “quantum randomness effect” on the brain has nothing to do with questions whether any function of the brain depends on quantum effects—it merely talks about nature of certain noise in the process.)
An ingenious friend just pointed out a likely much larger point of influence of quantum particle-level noise on humanity: the randomness in DNA recombination during meiosis (gamete formation) is effectively driven by single molecular machine and the individual crossovers etc likely strongly depends on the Brownian-level noise. This would mean that some substantial part of people would have slightly different genetic makeup, from which I would expect substantial timeline divergence over 100s of years at most (measuring differences on the level of human society).
My impression is that you’re arguing that quantum randomness creates very large differences between branches. However, couldn’t it still be the case that even more differences would be preferable? I’m not sure how much that first argument would impact the expected value of trying to create even more divergences.
Re 1.: Yeah, if you consider “determined but unknown” in place of the “non-quantum randomness”, this is indeed different. Let me sketch a (toy) example scenario for that:
We have fixed two million-bit numbers A and B (not assuming quantum random, just fixed arbitrary; e.g. some prefix of pi and e would do). Let P2(x) mean “x is a product of exactly 2 primes”. We commit to flipping a quantum coin and on heads, we we destroy humanity iff P2(A), on tails, we destroy humanity iff P2(B). At the time of coin-flip, we don’t know P2(A) or P2(B) (and assume they are not obvious) and can only find out (much) later.
Is that a good model of what you would “deterministic but uncertain/unknown”?
In this model (and a world with no other branchings—which I want to note is hard to conceive as realistic), I would lean towards agreeing that “doing the above” has higher chance of some branch surviving than e.g. just doing “we destroy humanity iff P2(A)”.
(FWIW, I would assume the real world to be highly underdetermined in outcome just through quantum randomness on sufficient time-scales, even including some intuitions about attractor trajectories; see just below.)
Re 2.: The rate of accumulation of (ubiquitous, micro-state level) quantum effects on the macro-state of the world are indeed uncertain. While I would expect the cumulative effects on the weather to be small (over a year, say?), the effects on humanity may already be large: all our biochemistry (e.g. protein interactions, protein expression, …) is propelled by Brownian motion of the molecules, where the quantum effects are very strong, and on the cellular scale, I would expect the quantum effects to contribute a substantial amount of noise e.g. in the delays and sometimes outcomes. Since this also applies to the neurons in the brain (delays, sometimes spike flipped to non-spike), I would assume the noise would have effects observable by other humans (who observed the counterfactual timeline) within weeks (very weak sense of the proper range, but I would expect it to be e.g. less than years).
This would already mean that some crucial human decisions and interactions would change over the course of years (again, scale uncertain but I would expect less rather than more).
(Note that the above “quantum randomness effect” on the brain has nothing to do with questions whether any function of the brain depends on quantum effects—it merely talks about nature of certain noise in the process.)
An ingenious friend just pointed out a likely much larger point of influence of quantum particle-level noise on humanity: the randomness in DNA recombination during meiosis (gamete formation) is effectively driven by single molecular machine and the individual crossovers etc likely strongly depends on the Brownian-level noise. This would mean that some substantial part of people would have slightly different genetic makeup, from which I would expect substantial timeline divergence over 100s of years at most (measuring differences on the level of human society).
My impression is that you’re arguing that quantum randomness creates very large differences between branches. However, couldn’t it still be the case that even more differences would be preferable? I’m not sure how much that first argument would impact the expected value of trying to create even more divergences.
Yeah, this makes sense, thanks.