I don’t think quantum immortality changes anything. You can rephrame this in terms of standard probability theory and condition on them continuing to have subjective experience, and still get to the same calculus.
I agree that quantum mechanics is not really central for this on a philosophical level. You get a pretty similar dynamic just from having a universe that is large enough to contain many almost-identical copies of you. It’s just that it seems at present very unclear and arguable whether the physical universe is in fact anywhere near that large, whereas I would claim that a universal wavefunction which constantly decoheres into different branches containing different versions of us is pretty strongly implied to be a thing by the laws of physics as we currently understand them.
However, only considering the branches in which you survive, or conditioning on having subjective experience after the suicide attempt, ignores the counterfactual suffering prevented in all the branches (or probability mass) in which you did die, which may be less unpleasant than the branches in which you survived, but are many many more in number! Ignoring those branches biases the reasoning toward rare survival tails that don’t dominate the actual expected utility.
It is very late here and I should really sleep instead of discussing this, so I won’t be able to reply as in-depth as this probably merits. But, basically, I would claim that this is not the right way to do expected utility calculations when it comes to ensembles of identical or almost-identical minds.
A series of thought experiments might maybe help illustrate part of where my position comes from:
Imagine someone tells you that they will put you to sleep and then make two copies of you, identical down to the molecular level. They will place you in a room with blue walls. They will place one copy of you in a room with red walls, and the other copy in another room with blue walls. Then they will wake all three of you up.
What color do you anticipate seeing after you wake up, and with what probability?
I’d say 2⁄3 blue, 1⁄3 red. Because there will now be three versions of me, and until I look at the walls I won’t know which one I am.
Imagine someone tells you that they will put you to sleep and then make two copies of you. One copy will not include a brain. It’s just a dead body with an empty skull. Another copy will be identical to you down to the molecular level. Then they will place you in a room with blue walls, and the living copy in a room with red walls. Then they will wake you and the living copy up.
What color do you anticipate seeing after you wake up, and with what probability? Is there a 1⁄3 probability that you ‘die’ and don’t experience waking up because you might end up ‘being’ the corpse-copy?
I’d say 1⁄2 blue, 1⁄2 red, and there is clearly no probability of me ‘dying’ and not experiencing waking up. It’s just a bunch of biomass that happens to be shaped like me.
As 2, but instead of creating the corpse-copy without a brain, it is created fully intact, then its brain is destroyed while it is still unconscious. Should that change our anticipated experience? Do we now have a 1⁄3 chance of dying in the sense that we might not experience waking up? Is there some other relevant sense in which we die, even if it does not affect our anticipated experience?
I’d say no and no. This scenario is identical to 2 in terms of the relevant information processing that is actually occurring. The corpse-copy will have a brain, but it will never get to use it, so it won’t affect my expected anticipated experience in any way. Adding more dead copies doesn’t change my anticipated experience either. My best scoring prediction will be that I have 1⁄2 chance of waking up to see red walls, and 1⁄2 chance of waking up to see blue walls.
In real life, if you die in the vast majority of branches caused by some event, i.e. that’s where the majority of the amplitude is, but you survive in some, the calculation for your anticipated experience would seem to not include the branches where you die for the same reason it doesn’t include the dead copies in thought experiments 2 and 3.
(I think Eliezer may have written about this somewhere as well using pretty similar arguments, maybe in the quantum physics sequence, but I can’t find it right now.)
You get a pretty similar dynamic just from having a universe that is large enough to contain many almost-identical copies of you.
Again, not sure why a large universe is needed. The expected utility ends up the same either way, whether you have some fraction of branches in which you remain alive or some probability of remaining alive.
Regarding the expected utility calculus. I agree with everything you said but i don’t see how any of it allows you to disregard the counterfactual suffering from not committing suicide in your expected value calculation.
Maybe the crux is whether we consider the utility of each “you” (i.e. you in each branch) individually, and add it up for the total utility, or wether we consider all “you”s to have just one shared utility.
Let’s say that not committing suicide gives you −1 utility in n branches but commiting suicide gives you −100 utility in n/m branches and 0 utility in n−n/m branches
If we treat all copies of you as having separate utilities and add them all up for a total expected utility calculation, not committing suicide gives −n utility while committing suicide leads to −100n/m utility. Therefore, as long as m>100, it is better to commit suicide.
If, on the other hand you treat them as having one shared utility, you get either −1 or −100 utility, and −100 is of course worse.
Do you agree that this is the crux? If so, why do you think that all the copies share one utility rather than their utilities adding up?
In a large universe, you do not end. Like, not in expectation see some branch versus other; you just continue, the computation that is you continues. When you open your eyes, you’re not likely to find yourself as a person in a branch computed only relatively rarely; still, that person continues, and does not die.
Attemted suicide reduces your reality-fluid- how much you’re computed and how likely you are to find yourself there- but you will continue to experience the world. If you die in a nuclear explosion, the continuation of you will be somewhere else, sort-of isekaied; and mostly you will find yourself not in a strange world that recovers the dead but in a world where the nuclear explosion did not appear; still, in a large world, even after a nuclear explosion, you continue.
You might care about having a lot of reality-fluid, because this makes your actions more impactful, because you can spend your lightcone better, and improve the average experience in the large universe. You might also assign negative utility to others seeing you die; they’ll have a lot of reality-fluid in worlds where you’re dead and they can’t talk to you, even as you continue. But I don’t think it works out to assigning the same negative utility to dying as in branches of small worlds.
Yes, but the number of copies of you still reduces (or the probability that you are alive in standard probability theory, or the number of branches in many worlds). Why are these not equivalent in terms of the expected utility calculus?
Imagine they you’re an agent in the game of life. Your world, your laws of physics are computed on a very large independent computers; all performing the same computation.
You exist within the laws of causality of your world, computed as long as at least one server computes your world. If some of them stop performing the computation, it won’t be a death of a copy; you’ll just have one fewer instance of yourself.
You are of course right that there’s no difference between reality-fluid and normal probabilities in a small world: it’s just how much you care about various branches relative to each other, regardless of whether all of them will exist or only some.
I claim that the negative utility due to stopping to exist is just not there, because you don’t actually stop to exist in a way you reflectively care about, when you have fewer instances. For normal things (e.g., how much do you care about paperclips), the expected utility is the same; but here, it’s the kind of terminal value that i expect for most people would be different; guaranteed continuation in 5% of instances is much better than 5% chance of continuing in all instances; in the first case, you don’t die!
I claim that the negative utility due to stopping to exist is just not there
But we are not talking about negative utility due to stopping to exist. We are talking about avoiding counterfactual negative utility by committing suicide, which still exists!
guaranteed continuation in 5% of instances is much better than 5% chance of continuing in all instances; in the first case, you don’t die!
I think this is an artifact of thinking of all of the copies having a shared utility (i.e. you) rather than separate utilities that add up (i.e. so many yous will suffer if you don’t commit suicide). If they have separate utilities, we should think of them as separate instances of yourself.
it’s the kind of terminal value that i expect for most people would be different; guaranteed continuation in 5% of instances is much better than 5% chance of continuing in all instances; in the first case, you don’t die!
And even in the case where we are assigning negative utility to death, most people are really considering counterfactual utility from being alive, and 95% of that (expected) counterfactual utility is lost whether 95% of the “instances of you” die or whether there is a 95% chance that “you” die.
I agree that quantum mechanics is not really central for this on a philosophical level. You get a pretty similar dynamic just from having a universe that is large enough to contain many almost-identical copies of you. It’s just that it seems at present very unclear and arguable whether the physical universe is in fact anywhere near that large, whereas I would claim that a universal wavefunction which constantly decoheres into different branches containing different versions of us is pretty strongly implied to be a thing by the laws of physics as we currently understand them.
It is very late here and I should really sleep instead of discussing this, so I won’t be able to reply as in-depth as this probably merits. But, basically, I would claim that this is not the right way to do expected utility calculations when it comes to ensembles of identical or almost-identical minds.
A series of thought experiments might maybe help illustrate part of where my position comes from:
Imagine someone tells you that they will put you to sleep and then make two copies of you, identical down to the molecular level. They will place you in a room with blue walls. They will place one copy of you in a room with red walls, and the other copy in another room with blue walls. Then they will wake all three of you up.
What color do you anticipate seeing after you wake up, and with what probability?
I’d say 2⁄3 blue, 1⁄3 red. Because there will now be three versions of me, and until I look at the walls I won’t know which one I am.
Imagine someone tells you that they will put you to sleep and then make two copies of you. One copy will not include a brain. It’s just a dead body with an empty skull. Another copy will be identical to you down to the molecular level. Then they will place you in a room with blue walls, and the living copy in a room with red walls. Then they will wake you and the living copy up.
What color do you anticipate seeing after you wake up, and with what probability? Is there a 1⁄3 probability that you ‘die’ and don’t experience waking up because you might end up ‘being’ the corpse-copy?
I’d say 1⁄2 blue, 1⁄2 red, and there is clearly no probability of me ‘dying’ and not experiencing waking up. It’s just a bunch of biomass that happens to be shaped like me.
As 2, but instead of creating the corpse-copy without a brain, it is created fully intact, then its brain is destroyed while it is still unconscious. Should that change our anticipated experience? Do we now have a 1⁄3 chance of dying in the sense that we might not experience waking up? Is there some other relevant sense in which we die, even if it does not affect our anticipated experience?
I’d say no and no. This scenario is identical to 2 in terms of the relevant information processing that is actually occurring. The corpse-copy will have a brain, but it will never get to use it, so it won’t affect my expected anticipated experience in any way. Adding more dead copies doesn’t change my anticipated experience either. My best scoring prediction will be that I have 1⁄2 chance of waking up to see red walls, and 1⁄2 chance of waking up to see blue walls.
In real life, if you die in the vast majority of branches caused by some event, i.e. that’s where the majority of the amplitude is, but you survive in some, the calculation for your anticipated experience would seem to not include the branches where you die for the same reason it doesn’t include the dead copies in thought experiments 2 and 3.
(I think Eliezer may have written about this somewhere as well using pretty similar arguments, maybe in the quantum physics sequence, but I can’t find it right now.)
Again, not sure why a large universe is needed. The expected utility ends up the same either way, whether you have some fraction of branches in which you remain alive or some probability of remaining alive.
Regarding the expected utility calculus. I agree with everything you said but i don’t see how any of it allows you to disregard the counterfactual suffering from not committing suicide in your expected value calculation.
Maybe the crux is whether we consider the utility of each “you” (i.e. you in each branch) individually, and add it up for the total utility, or wether we consider all “you”s to have just one shared utility.
Let’s say that not committing suicide gives you −1 utility in n branches but commiting suicide gives you −100 utility in n/m branches and 0 utility in n−n/m branches
If we treat all copies of you as having separate utilities and add them all up for a total expected utility calculation, not committing suicide gives −n utility while committing suicide leads to −100n/m utility. Therefore, as long as m>100, it is better to commit suicide.
If, on the other hand you treat them as having one shared utility, you get either −1 or −100 utility, and −100 is of course worse.
Do you agree that this is the crux? If so, why do you think that all the copies share one utility rather than their utilities adding up?
In a large universe, you do not end. Like, not in expectation see some branch versus other; you just continue, the computation that is you continues. When you open your eyes, you’re not likely to find yourself as a person in a branch computed only relatively rarely; still, that person continues, and does not die.
Attemted suicide reduces your reality-fluid- how much you’re computed and how likely you are to find yourself there- but you will continue to experience the world. If you die in a nuclear explosion, the continuation of you will be somewhere else, sort-of isekaied; and mostly you will find yourself not in a strange world that recovers the dead but in a world where the nuclear explosion did not appear; still, in a large world, even after a nuclear explosion, you continue.
You might care about having a lot of reality-fluid, because this makes your actions more impactful, because you can spend your lightcone better, and improve the average experience in the large universe. You might also assign negative utility to others seeing you die; they’ll have a lot of reality-fluid in worlds where you’re dead and they can’t talk to you, even as you continue. But I don’t think it works out to assigning the same negative utility to dying as in branches of small worlds.
Yes, but the number of copies of you still reduces (or the probability that you are alive in standard probability theory, or the number of branches in many worlds). Why are these not equivalent in terms of the expected utility calculus?
Imagine they you’re an agent in the game of life. Your world, your laws of physics are computed on a very large independent computers; all performing the same computation.
You exist within the laws of causality of your world, computed as long as at least one server computes your world. If some of them stop performing the computation, it won’t be a death of a copy; you’ll just have one fewer instance of yourself.
Whats the difference between fewer instances and fewer copies, and why is that load bearing for the expected utility calculation?
You are of course right that there’s no difference between reality-fluid and normal probabilities in a small world: it’s just how much you care about various branches relative to each other, regardless of whether all of them will exist or only some.
I claim that the negative utility due to stopping to exist is just not there, because you don’t actually stop to exist in a way you reflectively care about, when you have fewer instances. For normal things (e.g., how much do you care about paperclips), the expected utility is the same; but here, it’s the kind of terminal value that i expect for most people would be different; guaranteed continuation in 5% of instances is much better than 5% chance of continuing in all instances; in the first case, you don’t die!
But we are not talking about negative utility due to stopping to exist. We are talking about avoiding counterfactual negative utility by committing suicide, which still exists!
I think this is an artifact of thinking of all of the copies having a shared utility (i.e. you) rather than separate utilities that add up (i.e. so many yous will suffer if you don’t commit suicide). If they have separate utilities, we should think of them as separate instances of yourself.
And even in the case where we are assigning negative utility to death, most people are really considering counterfactual utility from being alive, and 95% of that (expected) counterfactual utility is lost whether 95% of the “instances of you” die or whether there is a 95% chance that “you” die.