Hacker News new | past | comments | ask | show | jobs | submit login
Disprove quantum immortality without risking your life (2019) (vankessel.io)
53 points by vankessel 8 days ago | hide | past | web | favorite | 61 comments





This is a really nice argument and I hope that Kevin and others continue to pursue it. However, I think there is a subtle flaw in the presented argument that is parallel to issues illuminated by Goedel's incompleteness theorem. The problem, I believe, is with the assertion:

> 1. The many-worlds interpretation is true.

> 2. Consciousness experiences the reality in which it lives the longest.

> If all the previous assumptions are true, then at least one of these two must be false.

Both of these statements can be simultaneously true if we allow for a third possibility that is logically consistent with the entire argument:

3. Having near logical certainty and awareness that quantum immortality is true is fundamentally incompatible with living on the subjective immortal multiverse timeline.

This would actually be a robust assumption to have explicitly included at the start, as it also makes intuitive sense. Afterall, if you absolutely knew that quantum immortality was true, then you could (and likely would) walk around taking obviously foolish risks without ever experiencing any consequences. Such a universe would basically lack a coherent sense of cause-and-effect from your subjective point of view. And if it was a universe where cause-and-effect don't hold for you, then how could you have logical certainty about anything?

This means that if quantum immortality is true, you can never have logical certainty of its truth.

This is very similar to how Goedel's incompleteness requires that there be true statements that can't be proven as true because the existence of an explicit proof would negate the statement itself, breaken the consistency of the system of logic (and, hence, making it incomplete by necessity).


If quantum immortality is true, and I, knowing that, step in front of a car, how is it going to prevent my bones from breaking?

I remember a haunting fantasy short story about a boy in a small town who accidentally meets and becomes friends with the man who digs all of the graves. Eventually he notices that somehow, the gravedigger knows when a grave is needed before a person dies, but won't say how or who. Often it is possible to guess though. One day, he's told that he'll never guess who the next grave is for, and indeed, he can't. So that night he finds out his parents have been in an auto accident, and therefore one of them is presumably going to die...and so he goes back and kills the gravedigger and buries him in the grave that was intended for one of his parents.

The rest of the story is that once the gravedigger is dead, people in the town stop dying...but that is not a good thing - first his mother is paralyzed, then she has a stroke, then there is a fire... And the end is that the murderer becomes the new gravedigger to restore normality and now old, he hopes for someone to relieve him of the job.


"If quantum immortality is true, and I, knowing that, step in front of a car, how is it going to prevent my bones from breaking?"

Quantum immortality doesn't promise health. It promises consciousness.

It is in fact a horrible idea and you better damned well hope it is false, because it looks a lot less like "I'm going to live forever in at least some fraction of the multiverse and be healthy and happy!" and rather a lot more like SCP-2718 [1]. Probably without the pain in question, but certainly with your consciousness stuck in a body that is literally minimally capable of being conscious and nothing else, past the heat-death of the universe, until the point where even quantum randomness isn't enough to keep you conscious, assuming that such a point can even arrive. QI doesn't protect your mobility, your senses, your health or happiness... just your consciousness. On the plus side, "minimal consciousness" doesn't necessarily entail a great deal of awareness of time passing.

[1]: http://www.scp-wiki.net/scp-2718 , for those not familiar with the format of the site, be sure to click the "► Play" on the bottom for the text I'm referring to. On the topic of SCP, the "End of Death" canon rather resembles your story, albeit moreso: http://www.scp-wiki.net/end-of-death-hub


It also doesn't necessarily entail remembering who you are. So I think it's not that horrible: you lose more and more of your memories and your capabilities of forming thoughts and intentions, until it's just generic consciousness aware of itself doing nothing and of (what's left from) input stimuli.

So, in the limit it's not observably different from death? Then it's death.

It's all the things. QI is basically just an consciousness-centric view of the already-understood truth that in the quantum multiverse, everything that can possibly happen does. It just means that there is some way in which you may actually experience some aspect of that, because your future conscious experience excludes all the universes in which you are not conscious. You can draw a subset of future universes in which you are minimally conscious, in which you're just a wee bit more conscious than that, in which you're conscious enough to be aware of your plight indefinitely, in which as I say in another message you're healthy indefinitely. You're not causing anything to be or not to be, you're just carving various subsets of radically differing, but non-zero, size out of the near-infinity of the full quantum multiverse, which exist whether or not you choose to regard them.

So, you know, in a fraction of the universes in which you remain conscious that would require something like 1 over a number in arrow notation to describe, you'll be conscious enough to be perturbed. This is utterly, utterly dominated by the universes in which you're just sort of there. However, if you then choose to exclude those latter universes on the grounds that you consider that to be "dead", then that brings that tiny fraction back to the fore by virtue of eliminating everything else.

It's a lot of definition chopping and manipulating rather enormous exponentials in the probabilities. However, there is still an underlying truth there, if the multiverse is true. It's just more subtle than the casual human view of "survival" or a brief gloss of the argument might entail. You have to think in quantum terms about whether or not this spin goes that way or the other, not in human terms like whether or not the gun fires. The latter is made up of an incomprehensibly large number of the former sort of things, and as you start talking about the fringe cases the quantum events require staggeringly enormous exponential probabilities to describe anything even remotely human-visible.


Branching of multiverse on every measurement event is an approximation. The branches aren't fully isolated. I suspect that extremely low amplitude branches undergo merger events, which makes it impossible to have coherent timeline in them. But I'm completely out of my depth here.

I don't think that's an official part of the theory. It may be true, but I don't think anyone's proposed it.

Defining "low amplitude" branch meaningfully would be a real challenge. As I like to say sometimes, the probability of anything happening is indistinguishable from zero. 15-16 billion years after the Big Bang, we've already got a pretty low amplitude, one that would require something like arrow notation (as I reference in another comment) to describe where we are now relative to where the universe started. Heck, it takes arrow notation just to describe how much probability mass we're shedding every second.

(It actually occurs to me after a discussion of this that I can tweak an argument I've been growing over the years to prove that you can't have all three of "a universe that never ends", "the quantum multiverse", and "a coherent conscious experience".)


A world where each and every person still lives would be pretty bizarre. That's around 107 billion people.

Such a world is utterly dominated by the worlds in which you are kept conscious, but nobody else is. If QI keeps you conscious for a billion years, you'll be alone.

(I keep typing "you are kept alive", but that's not the promise. Only conscious. Being "alive" will be extraneous to that.)


Great explanation. Thank you. And, I got to look up "arrow notation." I had never heard of it.

The other view is that QI is literally true, and it literally proves the existence of an immortal soul which transcends whatever happens to the body.

So consciousness can never be killed. But it can be temporarily inconvenienced.

The problem with this argument is that the universe continues to operate when we're asleep, in a coma, etc.

It's almost as if it has an independent existence that doesn't rely on our personal experience of it.


QI is usually explained in terms of many worlds, where there is an objective reality independent of our experience.

Those concepts aren’t incompatible, if that’s what you were suggesting by your last sentence.


>If quantum immortality is true, and I, knowing that, step in front of a car, how is it going to prevent my bones from breaking?

Your body quantum-tunnels [1]through the car and emerges un scathered on the other side. IANAP, but I believe it is technically possible although the probability is astronomically close to zero. Butif QI is true, you would experience it. It is an example of the apparently logical impossilities that the parent is referring to if I understand correctly.

[1] or fails to interact, or whatever. Again, IANAP.


Yeah, but if consciousness is the invariant, then there are vastly more futures in which I don't tunnel through the car but just barely avoid brain-death.

And when I say vastly, I'm pretty sure the ratio is larger than the number of particles in the universe squared.


Under many worlds, the you who did not step in front of the car avoids broken bones.

If there is anything to quantum immortality, it is only in those circumstances where the probability of immediate death is strictly between 0 and 1. I suspect, however, that quantum immortality is merely the tautology that survivors, and only survivors, survive, and has nothing to do with interpretations of the QM formalism.


Thank you. I really like the point you are making, but I am unsure about a lack of cause and effect. When I think of cause and effect, I think of it as taking the state of the universe from state t+0 to t+1 using the laws of physics. All of it being deterministic, except for quantum mechanics. This indeterminism in QM creating the branches allowing one to escape death.

Couldn't believing in quantum immortality be compatible with this? You could do things like firing a gun to your head, and it would misfire every time. You could jump off a building and would land in a passing open-topped garbage truck full of soft material. You'd experience all sorts of crazy coincidences, but all of them plausibly deniable and within the framework of cause and effect as we know it.

With that said, I feel like what you are saying is true but can not fully formulate my thoughts on it yet. I agree completely that you can never have logical certainty of it's truth, but I'm not certain it's contingent on it being true. Perhaps we should instead say that QI is either true or false, but we can never prove which? This removes the implication but still makes sense in the context of Godel's first incompleteness theorem.


I find the whole QI following so weird... Do people really argue that QM can provide cartoon-like effects like a convenient truck under the bridge?

Do people really argue that conscience is so special that the universe refuses to end one?

The universe don't differentiate between a dead human and a living one. From a QM point of view, both body masses, correctly placed, can work as an "observer" to cause waveform collapse.


Well, yes. Those examples were chosen to be cartoonish stereotypes. Extremely statistically unlikely events would look... strange, to say the least. Sort of like the flapping of a butterfly's wings resulting in a hurricane.

Also there has been some discussion about how quantum events would only affect the microscopic and the macroscopic would remain the same. This is false, quantum events can only occur in the microscopic, but their effects can propagate to the macroscopic in ways beyond our comprehension. Take the experiment itself, the outcome of a quantum event propagates to the life or death of a human being.

Lastly there have also been remarks about how death needs to be guaranteed because QI only promises consciousness not health or a lack of suffering. I will address that here too. That is a perfectly fine way of viewing QI but there is a distinction we should formalize to make it clear.

Greedy QI and Perfect QI.

Greedy QI just branches from the present moment to whichever consciousness will persist. This can result in a local optimum where you are maimed but alive.

Perfect QI always picks the best branch point of every present moment to account for all future possibilities. I argue this in assumption #2. Once the bullet has say, pierced the brain stem, there is no greedy choice from there that will save you. Perfect QI likely won't maim you as that would limit your survival possibilities. It's the global optimum.

There is still a problem with this though. What if there is more than one timeline where you always live? How is one chosen? My guess would be either it's randomly chosen, or there is only one timeline. Let me elaborate on the latter with a mathematical analogy.

You have an infinite list of real numbers. These numbers represent different timelines, the value being how long you survive. If you order them, you can always find a larger finite number looking at the next one, but none of them are infinite in value. Since QI assumes immortality not longevity we will assume the limit of this ordered list is infinity and not a finite number. Thus there is one reality in which you live infinitely, and that's the limit of this ordered set. The only chance for approaching this limit is through a mechanism like perfect QI.


"Do people really argue that conscience is so special that the universe refuses to end one?"

QI doesn't protect consciousness. Its argument applies to any quantum state, described by any arbitrarily complicated acceptance function of that state. The QI argument implies that you can pick up a rock, and that there exists some set of universes in which that rock will survive indefinitely, exactly as it is now, to any degree of accuracy you care to specify. It's just the more precise your specification gets, the lower the probability mass is.

That's why in my other message, I say QI only promises consciousness. Technically, there are universes in which by sheer quantum chance you are in fact healthy and happy indefinitely. It's just that "a healthy and happy body" is incomprehensibly more orders of magnitude more unlikely than being stuck in whatever constitutes the minimally conscious body. And in fact, the latter isn't a unique construct either. It's actually a function of the selectivity you apply to the acceptance function; you have the universes in which you are conscious enough to realize your plight, but they're dominated by the universes in which you are too minimally conscious to even realize that, which are in turn dominated by the universes in which you are just not conscious. But those are excluded from your consciousness' future states, which means your consciousness is left over with whatever else is left.

The distinctive thing that consciousness adds to the argument is merely that if you metaphorically drew out the future universes in which your consciousness survives, there is something meaningful (to us, anyhow!) "inside" that set. You can do the same thing to the rock as I described above, but there isn't really anything "inside" that set; it's just the rock and nothing else. Excepting of course that vanishing fraction of the universes in which quantum processes drive the rock to become conscious by any definition of your choice, of course.

(Another thing I'd point out is that for this discussion, I have no concern about what your definition of "consciousness" is. The argument works regardless of your definition, it just tweaks the exact non-zero numbers that come out.)


Why should it bring more comfort than knowing, e.g. that there are alternative universes where my deceased loved ones are alive?

There seems to be a belief that our consciousness will "jump" to an alive alternative. I think that's a strong misconception of what many-worlds interpretation says.

Talking about misconceptions, without having more than superficial background in QM, I doubt that being able to consider even very unlikely outcomes allows you to discard macroscopic causality altogether, which QI basically requires.


"Why should it bring more comfort than knowing, e.g. that there are alternative universes where my deceased loved ones are alive?"

I'm not sure you're reading my posts for what they say, rather than what you expect them to say. I think QI is horrible, as in, more suited to horror stories, than something that offers comfort. Nor do I discuss any sort of "jumping".


"Couldn't believing in quantum immortality be compatible with this? You could do things like firing a gun to your head, and it would misfire every time. You could jump off a building and would land in a passing open-topped garbage truck full of soft material. You'd experience all sorts of crazy coincidences, but all of them plausibly deniable and within the framework of cause and effect as we know it."

I think one of the several issues I have with this article is that you're measuring survival in human terms, not quantum terms. One of the secret constraints in the quantum suicide thought experiment is that your method of death must be literally 100% guaranteed, and ideally for the argument, instantaneous from the point of view of your consciousness. (That is, for our consciousness's sake, I don't think Planck time is particularly relevant; more human time frames are relevant.) Sometimes this is expressed as sitting next to an atom bomb rather than just a gun.

But, even then, as a pragmatic matter, a real person trying to perform this experiment would need to be concerned about the quantum probability that the bomb does indeed go off, but leaves them maimed because it didn't exactly explode fully, but the explosives half-detonate and the uranium goes only a bit critical, spraying you with radiation and seriously injuring you but not actually killing you. As you sit there next to your quantum number generator, you are indeed systematically pruning the quantum state space of the worlds in you do actually die, but the remaining quantum state space has a great deal more than just "you get up and turn off the quantum number generator once you are satisfied".

Similarly, a gun can do a lot more than just fire and kill you, or not fire and leave you harmless. It could fire, and put what should be a fatal hole in your head, but the bare minimum quantum events occur to keep you just barely conscious.

As you prune away all the likelihoods, you're amplifying the probably of everything other than what you pruned away, not just the human-conceivable events. The harder and more successfully you prune, the weirder what's left over gets. Given that you've set up a situation in which you've got a gun aimed at your head or an atom bomb or what have you, those "weird" situations are likely to be unpleasant.

Of course, if QI and the multiple worlds hypothesis is correct, this all happens anyhow all the time, and seeing our family or friends just suddenly explode for no reason is something we are literally experiencing all the time, just with such a low probability that it hasn't happened yet. But, somewhere in the great multiverse, there's a set of people who read this message and it is immediately followed by, say, their left hand just disintegrating. Take heart... for some yet smaller fraction of you, it will also immediately fix itself.


> Afterall, if you absolutely knew that quantum immortality was true, then you could (and likely would) walk around taking obviously foolish risks without ever experiencing any consequences.

On the contrary, wouldn't it be the case that all the "yous" that did such a thing died, leaving only the "yous" that attempted only a small fraction of risky events? Just because many worlds is true, it doesn't mean all possibly infinite combinations of things also exist (e.g. PI is infinite, but it doesn't contain all possible combinations of numbers, nor itself).


> you could (and likely would) walk around taking obviously foolish risks without ever experiencing any consequences

Only things that are random on a quantum level cause world splitting.

Walking in front of a car for example is not random on a quantum level and would not cause multi-world effects.

In the popular consciousness multiple worlds means every single possibility exists. This is not true!

In fact there are very few macro effects that are caused by quantum randomness. Even if multiple worlds is true they are all identical except microscopically.


It’s my understanding that radioactive decay is a quantum random.

Radioactive decay emits particles that can interfere with dna and cause cancer.

So some number of people would have/not have cancer in these many worlds. Not all these people would have profound impacts, but the background noise would start to add up quickly.


> if you absolutely knew that quantum immortality was true, then you could (and likely would) walk around taking obviously foolish risks without ever experiencing any consequences.

What if you get put on a path where you eventually die because of your recklessness, and that was the longest you would have stayed alive? Basically you already exhausted all possible paths but this one.


Hold on, assumption 2 does not seem right. There should be lots of versions of you cheerfully experiencing timelines that involve an imminent lightning strike, gamma ray burst, etc. Those things haven't happened yet, so those worlds still have a conscious you in them. Retroactively declaring those selves unconscious seems to be a much stronger idea than quantum immortality.

Also, there is a way to test quantum immortality for everyone, not just yourself. Build a world-spanning doomsday machine. Give it to highly unstable, paranoid people, and distribute the ability to trigger it widely. Perhaps add in some geopolitical tensions, technical failures, ego, and military-industrial collusion. Make it really unlikely that it will remain untriggered. The longer we experience a world with such a device armed and ready, the more likely quantum immortality is true. There would be all sorts of bizarre close calls, and the world history would get more deranged by the year as timelines trigger the device and drop out, leaving progressively weirder timelines to survive.

But that would be crazy, nobody would ever build such a thing.


Part of the reason 2) can't be right is that there are lots of versions of you that are similar, but not quite the same. Suppose you're born with a severe life-limiting genetic disease caused by a single de novo mutation that will kill you by age 20. But in another timeline, there's a person who was born exactly the same as you were, but without the mutation, who will definitely live longer than you. Are you and them the same person, so you're not conscious? Is your consciousness proof that you're not the same person, after all? Should we consider everyone with a life-limiting disease p-zombies?

I like the idea that we're all immortal from our own perspective. I don't think this article contradicts it.

>Consciousness experiences the reality in which it lives the longest: Under this assumption we can change the circumstances from a punishment to a reward. Instead of a gun, imagine a doctor has information about your health. If he tells you about it and you act on the information, you will certainly live a longer life. The doctor will only tell you about the information based the result of the quantum event. If the current assumptions are true, then you should always experience the reality in which the doctor tells you about your unknown ailment.

No I think this misunderstands the issue. Consciousness experiences the reality in which it exists. There are two types of 'timelines', if you like: those where your consciousness ends, and those where it doesn't. The only one you can possibly be in is the one where it doesn't. You can't 'extend' your life with QI. You won't live a longer life, you'll always life forever.

It's not quantum longeivity. It's quantum immortality. If the button you were clicking killed you on a random bit being 1 and not on the bit being 0, then you would survive clicking it.

OR, you would just not click on it. Because there're worlds where you click it, and worlds where you don't.


Yes. To add to this: it seems like to avoid sharp changes in experience, like at the point of death/non-death, QI seems to have an effect on the past.

All else being equal, it should be less likely you’ll press a button giving you a 90% chance of dying then a button giving you a 50% chance of dying.

It’s anyway probabilistic and there are lots of factors at play, so hard to disprove.


> I like the idea that we're all immortal from our own perspective

I think of this everytime I'm in a situation where I just almost died. I don't really think it's the case but everytime it happens I update my my credences and add 0.00000000000000001% to the chances that it could be true :-)


I think it was the movie "The Darwin Awards" that first introduced me to the concept of "micro-morts". The idea that there are activities that carry a small increase in the probability of death... Since then, I've seen other evidence of that idea.

I read a story about a nomadic tribe that will not sleep under dead trees as it is seen as bad luck. On any given night the chance that a dead tree will fall on you is very small, but if you sleep under dead trees every night, the chance that one will fall on you starts to add up, and it's likely to be your eventual cause of death.


I got the following message:

'j/.uG}mzgP8zs_4=q|_nN'{C@EpQ}=lzSt9+'l~SmqVyusft8BGgt)K"XKcly24N1cmZg_iz\z$/pt.`P".W-CwP>w4#2%axJHATmA}xg?d%(8<W[QN&>7`wQCe3jIl^kPHQI#dp.

I think it would be just as likely for the message to say "Do the following to extend your life" as it is for the supposedly random characters above being interpreted a certain way. In this case, the characters that jump out at me immediately are JHAT, 4 consecutive uppercase ASCII letters. Googling that shows "'jhat' is a heap analysis tool that parses a Java heap dump and enables web-browsing a parsed heap dump..." which leads me to think that by switching over to being a Java programmer (I mostly code in Python/Go) that I can extend my life. So that's something worth considering.


>2. Consciousness experiences the reality in which it lives the longest.

This seems like a very strong version of the quantum immortality idea. I was under the impression that quantum immortality didn't suggest that there was only one path among the splitting universes where someone is "truly" conscious and experiencing reality.


I don't think this really disproves quantum immortality? You never experience the gun firing because in all the universes where it fires you die so quickly you can't sense it. That doesn't mean the gun never fires. It just means that you only experience it in the event it didn't. This is kind of tautologically true. By definition, if you're alive, you haven't been shot in the head at point blank range.

Particularly, assumption 2 is in no way required for the quantum immortality thought experiment to work.


First, obligatory short story (free open access on the site below) for this entire concept. It takes things to their extreme conclusion and I liked it very much with the way it experiments with QI: https://www.tor.com/2010/08/05/divided-by-infinity/

This brings me to my second point: in relation to the death of a close family member a couple years ago from cancer. The end lasted a month and largely consisted in its last days of a slow withering of conscious reasoning and awareness. How exactly would something like that square with the notion of consciousness suddenly jumping to the QI state in which it simply "persists"? An argument around this was already made by Max Tegmark, who suggested that the flaw in that reasoning is that dying is not a binary event. Instead it is very often a progressive degeneration, with a continuum of states of steadily decreasing consciousness. In other words, in most real causes of death (and this squares with my experience), one experiences such a gradual loss of self-awareness that an observer defies all odds only within the confines of a very abstract scenario.

Furthermore, the obvious: QI does not at all save us from the loss of loved ones who do die in our quantum branch. Even if it were true, and each individual continues to perceive consciousness in a sort of immortal state of constantly branching awareness, we objectively know that we see these people die forever in our perception, with no allowance that I know of for a reunion in the future. Thus, its ultimate outcome if you follow this logic is deeply tragic: We keep living, seeing those we love die to our perception, while these same loved ones go through the same process, even if in some other branch other versions of both get to see said loved ones continue to live for a certain time longer.


I agree. Under QI it's possible we end up as some disembodied conscious matter in a state of eternal agony; QI only says consciousness will persist, it says nothing about quality of life.

When we die, our consciousness just gets transferred over to the atoms that make us up. Since there is no longer a self-contained "vessel" for it, specifically a hippocampus, we don't have any short-term or long-term memory anymore, but are still experiencing. That's why we can't remember time before we were born.

This is one of my favorite stories ever.

I've been obsessed with QI ever since I first heard about it. Every time I have a small glimpse of inattention, I always like to think that my consciousness just got transposed to another reality. Sometimes it's while I'm driving my car, and it makes it all the more trippy.

However, I'm not sure I understand the logic behind their reasoning.

> Consciousness experiences the reality in which it lives the longest.

> you should always experience the reality in which the doctor tells you about your unknown ailment.

If you experience the reality in which you live the longest, wouldn't the ailment just never come about?

Going back to the gun and bullet example, your consciousness being transposed to the branch where none of that even happens, wouldn't the same thing apply to any disease that would develop within your body? You would just get transposed to the reality in which no such disease develop, extending your life even further.


>Consciousness experiences the reality in which it lives the longest.

That formulation doesn't make sense to me. I would say it as "Consciousness can only experience realities in which it exists." Therefore you won't move into futures in which you don't exist.


My reasoning behind this was that there can be multiple futures where you could exist and experience, but some of them shorter than others. E.g.

A------B

\ --------C

If you are travelling towards B, once you reach it, you die. But you can't magically jump last second to parallel reality C, you can only branch from the present. Thus you would have needed to branch down to C in advance. Thanks for pointing this out, I will make my reasoning more clear in a future edit.


Two points:

1. Delayed choice quantum eraser experiments suggest to me, unless I've misunderstood them (which is highly possible), that effects can affect causes. https://en.m.wikipedia.org/wiki/Delayed-choice_quantum_erase...

2. Getting shot in the head isn't always fatal. The bullet could deflect off your skull, or even go through your brain and just not hit you. The bullet could experience spontaneous existence failure, or simply fail to interact with the matter in your body and pass through you. My limited understanding of physics says that things like these are possible but massively unlikely at large scale. However, if some set of things are possible but rare, and the only alternative things are impossible, then something rare will happen.


That's what I understood based on the gun example. However the same would hold true for any deadly disease you develop, wouldn't it?

True, the doctor example is really just supposed to be segue into thinking about how a direct message could work. Although, perhaps facing death and recovering turns you into the kind of fellow who will live their life in a vastly different way leading to a longer life?

Oh, there's a horrifying contrapositive to that statement.

See, what that statement is really trying to do is assert uniqueness of consciousness within a many-worlds quantum interpretation.

Let's set up your standard quantum deathtrap: radioactive decay triggers the release of a deadly poison. And let's make it a really nasty poison, that is incurable but is going to inflict a good solid day or two of suffering as your organs fully liquify, so we have a nice, meaty, juicy thought experiment.

So many worlds, bam, there are now two (sets of) worlds, one where the particle decayed in the specified time period and your organs are now slowly liquifying and one where you are let out of the death trap, footloose and fancy free, to live a long and happy life, or at least, longer than the you slowly stewing in their own juices.

So what happens to your consciousness?

Well, in a boring materialistic interpretation of the world and consciousness, "you" forked at the same time as the worlds divided, being an aggregate property of the atoms involved, and one of you is blissfully unaware that the other is in horrible agony, perhaps philosophically reassured that there is a version of them not suffering in another quantum universe.

Under the proposition "Consciousness experiences the reality in which it lives the longest.", the you that is slowly liquifying doesn't live the longest, so it isn't conscious. It's a p-zombie, it acts like a conscious person without the underlying "experiencing" of it.

Now, let's carry that on through some more steps.

TV shows and movies like to make it seem like the many-worlds of quantum mechanics are caused by human decisions and the ups and downs of human life. The universe where you chose to go left instead of right, the universe where Hitler's painting career took off, etc etc. But they're caused by quantum events, and there are an uncountably large number of quantum events happening every microsecond as different particles of thorium in the Earth's radioactive core "choose" to decay, let alone what's happening in Betelgeuse.

"Many" in "many-worlds" is an unbelievably large number, and you are only going to live the "longest" in one of them, which means you are a p-zombie in every other one, because your consciousness only experiences the one in which you live the longest.

Now, what are the chances anyone else lives the longest in the same quantum world as you?

Zero. Less than zero. Zero followed by so many zeros it's meaningless.

Under this assumption, everyone you have ever known, everyone you have ever talked to -- me, even -- everyone you have ever loved was a p-zombie the entire time you knew them. Your parents? P-zombies. Your mee-maw? P-zombie. Your children? P-zombies.

Which is ultimately a good thing, I suppose, because then you don't have to feel bad if they die before you, because they're just p-zombies, and you don't have to feel bad about all those times they saw you die in other quantum worlds, because it was mostly just p-zombies watching other p-zombies die.


I think assumption 4 is in error.

>There exists a message in the encoding that can extend one's life.

If quantum immortality holds then there is no message which will extend your life because you're already immortal.


But there must be a mechanism for the immortality shouldn't there be? Let's go back to the gun example quickly. (assuming a perfect gun, no misfires, or lucky non-fatal shots)

If quantum immortality holds and the experiment is run 8 times, you should see the sequence 00000000 right? This is a message too, because it deviates from expectation to shovel you down a reality you can experience. Sort of like Zipf's law where the less likely the result the more information it contains https://en.wikipedia.org/wiki/Zipf%27s_law#Applications


> Consciousness experiences the reality in which it lives the longest.

This is a huge straw-man. The claim is that it is that it takes a probability distribution that inherits from the underlying multiversal one, but weighted by your existence. All this proves is that the none of the n-bit random messages will cause you to immediately divide into at least 2^n copies of yourself.

For more interesting discussion on ideas in this space, see

https://en.m.wikipedia.org/wiki/Anthropic_principle https://en.m.wikipedia.org/wiki/Boltzmann_brain https://en.m.wikipedia.org/wiki/Doomsday_argument


There seems to be a gap in the argument between step 2 and steps onwards from 4.

The experiment assumes that, given the opportunity, the universe will give a person the knowledge of how to extend their life. But of course that knowledge could have been given at any point in their life up to then, and at any point afterwards. Why hasn't a computer glitch emailed you the contents of an immortality potion before now?

The answer I would suggest is that this is not the optimum moment for life extension, and there's no reason the universe has to do anything if a better local minimum can occur.

My corollary for this experiment would be:

4. There exists a message in the encoding that can extend one's life... but that message will only be given if

a) Having the message actually results in the timeline that does what is needed, and

b) There is not in fact a more optimum time that the universe might use later on.

The problem is that absent points a and b, the experiment proves nothing. It could well be that you wouldn't have correctly responded to any message given here, but instead the universe will choose a moment when you're 65 to announce a life extension drug has just been released into the upper atmosphere.


I would say that this test is especially vulnerable to error, because all the auxiliary hypotheses being tested. The problem here is known as the Duhem-Quine thesis:

https://en.wikipedia.org/wiki/Duhem%E2%80%93Quine_thesis

> The Duhem–Quine thesis, also called the Duhem–Quine problem, after Pierre Duhem and Willard Van Orman Quine, is that it is impossible to test a scientific hypothesis in isolation, because an empirical test of the hypothesis requires one or more background assumptions (also called auxiliary assumptions or auxiliary hypotheses). In recent decades the set of associated assumptions supporting a thesis sometimes is called a bundle of hypotheses.

I’m not going to enumerate the auxiliary hypotheses being tested, but this is a particularly thorny problem in the philosophy of science, and it becomes less tractable as the problems you are solving become more complicated (like this one).

My personal feeling is that the philosophy of science, as a field, is still quite immature.


People have pointed out many flaws in this argument, but I haven’t seen what I believe is the simplest flaw: specifically, if QI as defined in the article is true, you can’t conclude that the universe will take every possible opportunity to extend your life, only that you will always fail to experience life-ending events. A failure to receive a message about extending your life is not a life ending event, as your life could be saved later through other means. And it doesn’t matter how unlikely those other means are, because your consciousness will simply follow the path in which it still exists, regardless of the likelihood of that path.

And if you think about that for a minute, the prospect of QI ought to horrify you. What sort of being will you be in 1000 years, if the only thing preventing you from dying is the ability to follow infinitesimal paths through the evolving wave function?


One thing to keep in mind is our understanding of physics is only approximate so it's dangerous to draw too extreme conclusions.

Approximate immortality is after all very different from actual immortality.

We may well discover that the number of worlds is enormous but ultimately finite, and that the number of worlds you're in decreases exponentially with every risk you take.


It all hinges on #2, "Consciousness experiences the reality in which it lives the longest" which is a straight-up mistaken understanding of quantum immortality. I feel embarrassed for the author. With QI, you have to actually die, there's no other way around it.

There is an assumption here that all conciousness and experience ceases at the moment of death, which doesn’t agree with many people’s beliefs. If there is an afterlife, it is entirely possible you’ll find yourself in a universe where you have died.

>Since you can’t possibly experience the timeline in which you are dead

Death is a slow process, of course you experience it from the start to the end.


As a counter, the best way to “prove” QI is true without risking your life is to live a really long time.

A-priori that’s unlikely unless QI is true.


Can you prove a negative?

1. I think I'm conscious. Therefore, under the axiom "Consciousness experiences the reality in which it lives the longest." I must be experiencing the reality in which I live the longest.

2. I am not the best version of me. I'm 40 pounds overweight, I have poor sleep habits, I wheeze going up stairs, I don't wear sunscreen when going outside in the summer. There is strong evidence that all of these things shorten my life. There's a couple of moles I occasionally worry about yet I do nothing.

3. So either the versions of me that keep perfectly fit, exercise just the right amount to maintain health without putting too much strain on the body, wear sunscreen, and keep a regular sleep cycle of an appropriate duration are inevitably doomed to die young (is there a 100% chance of a famine across all quantum worlds I exist in, where I'll need to survive off of my body fat for 3+ months?), I am not actually conscious, I just think I am(?), or the proposition "Consciousness experiences the reality in which it lives the longest." must be false.

(Now obviously, you can't take my word for me being conscious, because that's exactly what a p-zombie would say, but you can ask yourself if you are conscious and if there is any way you can be better than you are now; if the answer is "yes" to both questions and you still believe in quantum immortality, you should start trying to figure out what inevitable catastrophe your life-shortening vices make you suited to survive, more than not having those life-shortening vices.)


Deductively, yes.



Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact

Search: