This is a big if. It may be true (though it also implies that events as unlikely as Boltzmann Brains are true as well), but it’s not true in a way that has causal impact on my current predicted experiences. If so, then the VAST VAST MAJORITY of universes don’t contain me in the first place, and the also-extreme majority of those that do will have me die.
Assume quantum uncertainty affects how the coins land. I survive the night only if I correctly guess the 10th digit of π and/or all seven coins land heads, otherwise I will be killed in my sleep.
In a literal experiment, where a human researcher kills you based on their observations of coins and calculation of pi, I don’t think you should be confident of surviving the night. If you DO survive, you don’t learn much about uncorrelated probabilities—there’s a near-infinite number of worlds, and fewer and fewer of them will contain you.
I guess this is a variant of option (1) - Deny that QI is meaningful. You don’t give up on probability—you can estimate a (1/2)^7 * 1⁄10 = 0.00078 chance of surviving.
Universe is finite (or only countably infinite), and MWI is irrelevant (makes it larger, but doesn’t change the cardinality). When you die, you die. There may or may not exist near-but-not-exact duplicates outside of current-you’s lightcone.
is not one of your considerations. This seems most likely to me.
A more interesting counterargument is “distribution shift.” My next observer-moments have some probability distribution P of properties—representing what I am most likely to do in the next moment. If I die, and MWI is false, but chaotic inflation is true, then there are many minds similar to me and to my next observer-moments everywhere in the multiverse. However, they have a distribution of properties P2 - representing what they are more likely to observe. And maybe P ≠ P2. Or may be we can prove that P=P2 based on typicality.
If there is no identity substance, then copies even outside the light cone matter. And even non-exact copies matter if the difference is almost unobservable. So I think that countable infinity is enough.
I suspect we don’t agree on what it means for something to matter. If outside the causal/observable cone (add dimensions to cover MWI if you like), the difference or similarity is by definition not observable.
And the distinction between “imaginary” and “real, but fully causally disconnected” is itself imaginary.
There is no identity substance, and only experience-reachable things matter. All agency and observation is embedded, there is no viewpoint from outside.
The problem with observables here is that there is another copy of me in another light cone, which has the same observables. So we can’t say that another light cone is unobservable—I am already there and observing it. This is a paradoxical property of big world immortality: it requires actually existing but causally disconnected copies, which contradicts some definitions of actuality.
BTW, can you comment below to Vladinir Nesov, who seems to think that first-person perspective is illusion and only third-person perspective is real?
This is a big if. It may be true (though it also implies that events as unlikely as Boltzmann Brains are true as well), but it’s not true in a way that has causal impact on my current predicted experiences. If so, then the VAST VAST MAJORITY of universes don’t contain me in the first place, and the also-extreme majority of those that do will have me die.
In a literal experiment, where a human researcher kills you based on their observations of coins and calculation of pi, I don’t think you should be confident of surviving the night. If you DO survive, you don’t learn much about uncorrelated probabilities—there’s a near-infinite number of worlds, and fewer and fewer of them will contain you.
I guess this is a variant of option (1) - Deny that QI is meaningful. You don’t give up on probability—you can estimate a (1/2)^7 * 1⁄10 = 0.00078 chance of surviving.
If QI is false, it must have theoretical cost:
Either:
Universe is finite and no MWI
Personal identity is based on some kind of destructible soul and my copy is not me
We use some variant of updateless decision theory, especially designed to prevent this type of problems (which is rather circular counterargument)
I’m not sure why
Universe is finite (or only countably infinite), and MWI is irrelevant (makes it larger, but doesn’t change the cardinality). When you die, you die. There may or may not exist near-but-not-exact duplicates outside of current-you’s lightcone.
is not one of your considerations. This seems most likely to me.
A more interesting counterargument is “distribution shift.” My next observer-moments have some probability distribution P of properties—representing what I am most likely to do in the next moment. If I die, and MWI is false, but chaotic inflation is true, then there are many minds similar to me and to my next observer-moments everywhere in the multiverse. However, they have a distribution of properties P2 - representing what they are more likely to observe. And maybe P ≠ P2. Or may be we can prove that P=P2 based on typicality.
If there is no identity substance, then copies even outside the light cone matter. And even non-exact copies matter if the difference is almost unobservable. So I think that countable infinity is enough.
I suspect we don’t agree on what it means for something to matter. If outside the causal/observable cone (add dimensions to cover MWI if you like), the difference or similarity is by definition not observable.
And the distinction between “imaginary” and “real, but fully causally disconnected” is itself imaginary.
There is no identity substance, and only experience-reachable things matter. All agency and observation is embedded, there is no viewpoint from outside.
The problem with observables here is that there is another copy of me in another light cone, which has the same observables. So we can’t say that another light cone is unobservable—I am already there and observing it. This is a paradoxical property of big world immortality: it requires actually existing but causally disconnected copies, which contradicts some definitions of actuality.
BTW, can you comment below to Vladinir Nesov, who seems to think that first-person perspective is illusion and only third-person perspective is real?