Presumably you mean a thought experiment, not an actual test.
No, I meant an actual test—putting one’s money where one’s brains are. To, as one sequence put it, treat the quantum immortality hypothesis as something which pays the rent in measured experience.
How would you know if it succeeded or failed?
Indirectly. Mostly through whatever other evidence supports MWI at all.
In extremis, if I do ever win a lottery, change my behaviour, and just barely escape the destruction of my home (or my home town), then that would be at least weak evidence favoring MWI through Everett Immortality.
Why not try to write out the actual probabilities in a rigorous way and see what comes out? It’s possible that it would be very much unlike what your intuition tells you.
Doing this ‘rigorously’ is a bit tricky, given the levels of uncertainty involved in just about every number, which even Feynman estimation can only reduce so far. What I have been consciously trying to do is estimate the decibans of probability, since logarithmic measurements help my all-too-limited intuition keep a better handle on the math involved.
The way I wrote my reply was misleading, sorry. I’m not talking about the specific numbers, I’m talking about the model itself. Remember that even in MWI, for any freak incident that allows you to avoid some disaster, there are zillions of far likelier ways of avoiding that disaster. Consider the following:
You point a gun at your head, pull the trigger, the bullet blasts through your head, but miraculously only causes damage to unimportant areas and you stay alive.
While that scenario could happen, it’s far more likely that:
You stand there with a gun to your head and your finger on the trigger, and you suddenly realize “What the hell am I doing?” and put the gun down. You remain alive.
Going back to your ‘narrowly-avoiding destruction of house’ scenario, it’s not likely that it will occur due to some freak occurence. It’s more likely that it will occur due to some mundane occurence. You’ll be out of the house buying groceries. Only half your house will be destroyed. Etc. And even if it does happen due to some freak occurrence, it will only probably be a singular event in your lifetime, giving you no meaningful way to update your beliefs.
To phrase it another way, MWI doesn’t make the improbable probable. It can’t. Otherwise we’d be seeing freak occurrences happen to us all the time. As Elezier said, it all adds up to normality. Even if Everett immortality is correct and you wind up living for a million years, you’ll look back at your life and realize that the path to your immortality was… pretty mundane, probably. You were frozen upon death and revived 100 years later into the nanotech revolution. Your consciousness merged with a computer. Etc. All stuff that we consider relatively likely here on LessWrong.
And my intuition tells me that if you actually construct a simple model this is precisely what you will find. That the probability of P(x | M), where x is the path to your immortality, and M is MWI being true, will be the same as P(x | ~M), preventing you from making any updates to your belief. I haven’t actually constructed a rigorous model here and I’d love to be proven wrong, but it’s what my intuition tells me.
if I do ever win a lottery, change my behaviour, and just barely escape the destruction of my home (or my home town), then that would be at least weak evidence favoring MWI through Everett Immortality.
If my home is ever unsurvivably destroyed, then the sequence of events lottery win → move away → previous home destroyed is more likely to be what I experienced in a universe where the laws of physics contain MWI (due to Everett Immortality) than they are to be what I’d have experienced in a universe lacking MWI (and in which I could confidently predict that I’m not going to experience winning a lottery). Thus, a simple Bayesian analysis would mean that experiencing lottery → move → destruction should increase my estimate that MWI is true. Maybe not by much, but more than nothing.
If my home is ever unsurvivably destroyed, then the sequence of events lottery win → move away → previous home destroyed is more likely to be what I experienced in a universe where the laws of physics contain MWI (due to Everett Immortality) than they are to be what I’d have experienced in a universe lacking MWI
Let me repeat myself: Huh?
You weren’t killed in the recent tornadoes in Illinois. Is this also “evidence” for MWI?
If it is evidence for MWI, it’s exteremely weak, perhaps on the order of epsilon; because in both MWI and non-MWI versions of physics, I don’t have any particular reason to have predicted that I would travel to Illinois at all.
Presumably you mean a thought experiment, not an actual test.
How would you know if it succeeded or failed?
No, I meant an actual test—putting one’s money where one’s brains are. To, as one sequence put it, treat the quantum immortality hypothesis as something which pays the rent in measured experience.
Indirectly. Mostly through whatever other evidence supports MWI at all.
In extremis, if I do ever win a lottery, change my behaviour, and just barely escape the destruction of my home (or my home town), then that would be at least weak evidence favoring MWI through Everett Immortality.
Why not try to write out the actual probabilities in a rigorous way and see what comes out? It’s possible that it would be very much unlike what your intuition tells you.
Doing this ‘rigorously’ is a bit tricky, given the levels of uncertainty involved in just about every number, which even Feynman estimation can only reduce so far. What I have been consciously trying to do is estimate the decibans of probability, since logarithmic measurements help my all-too-limited intuition keep a better handle on the math involved.
The way I wrote my reply was misleading, sorry. I’m not talking about the specific numbers, I’m talking about the model itself. Remember that even in MWI, for any freak incident that allows you to avoid some disaster, there are zillions of far likelier ways of avoiding that disaster. Consider the following:
You point a gun at your head, pull the trigger, the bullet blasts through your head, but miraculously only causes damage to unimportant areas and you stay alive.
While that scenario could happen, it’s far more likely that:
You stand there with a gun to your head and your finger on the trigger, and you suddenly realize “What the hell am I doing?” and put the gun down. You remain alive.
Going back to your ‘narrowly-avoiding destruction of house’ scenario, it’s not likely that it will occur due to some freak occurence. It’s more likely that it will occur due to some mundane occurence. You’ll be out of the house buying groceries. Only half your house will be destroyed. Etc. And even if it does happen due to some freak occurrence, it will only probably be a singular event in your lifetime, giving you no meaningful way to update your beliefs.
To phrase it another way, MWI doesn’t make the improbable probable. It can’t. Otherwise we’d be seeing freak occurrences happen to us all the time. As Elezier said, it all adds up to normality. Even if Everett immortality is correct and you wind up living for a million years, you’ll look back at your life and realize that the path to your immortality was… pretty mundane, probably. You were frozen upon death and revived 100 years later into the nanotech revolution. Your consciousness merged with a computer. Etc. All stuff that we consider relatively likely here on LessWrong.
And my intuition tells me that if you actually construct a simple model this is precisely what you will find. That the probability of P(x | M), where x is the path to your immortality, and M is MWI being true, will be the same as P(x | ~M), preventing you from making any updates to your belief. I haven’t actually constructed a rigorous model here and I’d love to be proven wrong, but it’s what my intuition tells me.
Huh? That’s not evidence at all.
If my home is ever unsurvivably destroyed, then the sequence of events lottery win → move away → previous home destroyed is more likely to be what I experienced in a universe where the laws of physics contain MWI (due to Everett Immortality) than they are to be what I’d have experienced in a universe lacking MWI (and in which I could confidently predict that I’m not going to experience winning a lottery). Thus, a simple Bayesian analysis would mean that experiencing lottery → move → destruction should increase my estimate that MWI is true. Maybe not by much, but more than nothing.
Let me repeat myself: Huh?
You weren’t killed in the recent tornadoes in Illinois. Is this also “evidence” for MWI?
If it is evidence for MWI, it’s exteremely weak, perhaps on the order of epsilon; because in both MWI and non-MWI versions of physics, I don’t have any particular reason to have predicted that I would travel to Illinois at all.
You are expressing, basically, a personal anthropic principle. It is NOT evidence for MWI.
How do you know that it isn’t?