You Will Never Die

If I ever decided to abandon any pretense of integrity or credibility, and just shoot for making a bazillion dollars peddling quantum hokum, the particular brand of quantum philosophy I would peddle has already been laid out, in Robert Charles Wilson’s Divided by Infinity. In the story, the narrator is given a copy of a “crank book” by Carl G. Soziere, titled You will Never Die, which makes an argument that is essentially a variant of the Many-Worlds Interpretation of quantum mechanics:

And the argument was seductive. Shorn of the babble about Planck radii and Prigogine complexity and the Dancing Wu-Li Masters, it came down to this:

Consciousness, like matter, like energy, is preserved.

You are born, not an individual, but an infinity of individuals, in an infinity of identical worlds. “Consciousness,” your individual awareness, is shared by this infinity of beings.

At birth (or at conception; Soziere wasn’t explicit), this span of selves begins to divide, as alternate possibilities are indulged or rejected. The infant turns his head not to the left or to the right, but both. One infinity of worlds becomes two; then four; then eight, and so on, exponentially.

But the underlying essence of consciousness continues to connect all these disparate possibilities.

The upshot? Soziere says it all in his title.

You cannot die.

The “shared consciousness” stuff is twaddle, of course, but at its core, there’s actually a fairly coherent idea, which is no sillier than things that get published in reputable journals. For that reason, this is my favorite fictional treatment of Many-Worlds.

The sensible argument is this: in the Many-Worlds interpretation, the wavefunction of the universe contains elements corresponding to all of the possible outcomes of any particular action. This gives an exponentially expanding wavefunction– it doubles in size with every coin-flip– but we only see one outcome occurring because each of those pieces also contains a version of every observer of the event, and so on. When you flip a coin, there’s one piece of the wavefunction in which it comes up heads, and in that piece of the wavefunction, you see it come up heads, and act accordingly. Meanwhile, there’s another piece of the wavefunction in which the coin comes up tails, containing a you that sees it come up tails, and so on.

To the extent that “consciousness” is a meaningful thing, it consists of a perceived coherent history of events making up your backstory, as it were. And if that’s the case, it’s sort of by definition impossible to experience your own death– once you die, you stop experiencing anything, and that perceived history comes to a close.

If you take Many-Worlds seriously, though, there is always a piece of the wavefunction in which you don’t die. Failing to die may be ridiculously improbable, but the theory says that all possible outcomes, even ridiculously improbable ones, must take place. In a certain sense, our very existence depends on this fact– as I say in my public lecture, the only reason the Sun shines is that quantum tunneling allows fusion to occur in the core of the Sun, despite the temperature being 1,500 times lower than it would need to be for protons to come into direct contact. Every photon reaching us from the Sun is the result of a ridiculously improbable occurrence.

By that logic, then, you will never experience your own death. Death ends experience, by definition, so as time goes by your consciousness gets whittled down to only those parts of the wavefunction in which you have survived. Except “whittled down” isn’t the right term, because as Wilson rightly notes, there are an effectively infinite number of branches of the wavefunction in which you survive; granted, the number of branches in which you die is also infinite, and in some sense a “bigger” infinity than the ones in which you live (scare quotes because it’s “bigger” in a sort of fuzzy everyday-language sense, not a rigorously mathematical Cantorian sense), but infinite all the same.

Of course, Wilson takes a lot of liberties with the idea for the sake of his story. There’s no reason, after all, why the surrounding universe should become any more improbable as you go on. The most likely outcome for you to experience is a universe in which the only obvious anomaly is your own survival. There’s no particular reason why you not dying should in any way be correlated with the fate of anybody else, after all, so it’s not like you’ll be tripping over copies of Shakespeare banged out by monkeys with typewriters on your way to your three hundredth birthday party. And you certainly won’t see unwritten Heinlein novels drifting in from alternate universes. The universe around you will continue to look more or less like it “should” look, but you just won’t die.

(Of course, this totally undermines the idea’s potential as a basis for a bazillion-dollar guru empire. Following this logic out to its natural conclusion leads inevitably to the idea that everyone and everything you know and love will age and die in the usual manner. This is, after all, the creepy core of Wilson’s story, which fairly explicitly takes the side of the character who declares the whole business to be a horror story, not a fairy tale.)

This has, of course, been considered by people like Max Tegmark, who make a living thinking Deep Thoughts about quantum mechanics. I don’t really buy Tegmark’s attempt to explain this away, though– he suggests that aging and death represent a gradual degradation of “consciousness,” such that you’re not really conscious any more when the end comes. But then, that’s exactly what I would expect the Max Tegmark in my immortal branch of the wavefunction to say and experience. In the branch where I’m immortal, everybody else sees their consciousness degrade with time, but I keep on going, through a remarkable chain of quantum coincidences.

It’s true that biological processes aren’t simple binary quantum choices, but at some level, everything is the result of an accumulation of infinitely many simple binary quantum choices. If you’re going to run with the whole crazy multiverse thing, I don’t see any reason to back off the notion of immortality, other than the face-saving desire not to sound like a New Age loon. But remember, the jumping-off point for this whole thing is the idea that I’m casting aside personal integrity and scientific credibility to chase that sweet, sweet Deepak Chopra money, so, you know, bring on the craziness.

(Of course, if you really want to have a universe that avoids the seeming absurdity of everyone individually living forever, there’s a simple way out: life after death and immortal souls. Then you get to experience your own death, but that presents its own problems…)

In the end, of course, I don’t really take this that seriously. It’s fun in a late-night-dorm-room-conversation sort of way, but that doesn’t make it remotely scientific. There’s no way to test this to the satisfaction of anybody other than yourself; or, rather, there’s no way to test it that leads to all observers getting the same answer– silly business like quantum suicide let you “prove” it, but only to yourself. Granted, to an infinite number of yourselves, but you “prove” it wrong to a larger infinitude of other people.

Late-night-dorm-room-conversation sorts of idea are great bases for science fiction stories, though. And Wilson’s story does far less violence to the Many-Worlds idea than most stories in the genre. Which is why I recommend it to people as my favorite fictional treatment of the subject.

Sadly, the story also sort of undermines my ability to exploit this idea for some filthy New Age lucre– constructing a loopy philosophy directly from science fiction is probably a little too obvious (insert your own Scientology joke). But in some universe, I’m living the high life on this basis…

Comments

  1. #1 Derek R
    May 25, 2011

    What about things like sleeping, or fainting, or going under anaesthetic, shouldn’t quantum immortality prevent those from happening? If there’s always a thread where consciousness continues, then your awareness should never cease… even if you’re really really tired.

    Anyways, I’m going to rig up a quantum suicide device that will kill me if, tomorrow, pi is not equal to 3. Then tomorrow, my own private universe will mutate so that pi becomes vastly simpler. I hope I don’t break any laws of logic in the process!

  2. #2 Paul
    May 25, 2011

    Many-Worlds interpretation is pure garbage. I can’t believe there are people who take it seriously. The notion of “splitting of worlds” is completely ill-defined and makes no sense whatsoever.

    Besides if the world were really splitting there would be no interference – one copy of particle took path A in one universe the other took another path B in another universe, they are now in two separate universes with no way to influence each other whatsoever – interference between them is impossible in this picture yet it is experimentally confirmed.

    Many worlds interpretation is the most egregious violation of Occam razor one can possibly imagine. To invent an infinite collection of unobservable imaginary universes just to avoid accepting that we simply don’t know what exactly happens is the most arrogant and absurd idea ever seriously considered in the whole of science.

    Only in physics can such nonsense survive. Imagine for example what would be the reaction if some doctor tried to seriously explain the cause of alzheimer disease by inventing unobservable germs living in a parallel universe.

  3. #3 Mary
    May 25, 2011

    I more or less agree with Paul, above, right until his last line. But then it occurs to me that postulating trillions tiny invisible creatures floating in the air and water, and inhabiting our bodies, as an explanation for disease, is *also* a pretty egregious violation of Occam’s razor. The conventional germ theory, that is, parallel universes aside. And yet…

  4. #4 A Different Paul
    May 25, 2011

    While not my preferred explanation either, the Many-Worlds interpretation is a mathematically defensible hypothesis.

    The notion of “splitting of worlds” is completely ill-defined and makes no sense whatsoever.

    Arguably, it’s the “collapsing of worlds” that is ill-defined. At the quantum level there do appear to be multiple worlds for some sense of the word. Schroedinger’s cat is dead and alive. But of course, the macro-world appears to be unitary. The standard interpretation is a “collapse”, where all the quantum possibilities reduce to one. But we don’t have any good sense of what exactly causes the collapse, where it occurs, or what the math of this process is. The Many-Worlds interpretation was motivated by the idea that if we can’t explain a process for this collapse, can’t conclusively observe it occurring, maybe it doesn’t exist?

    Besides if the world were really splitting there would be no interference

    The hypothesis is that universes can cancel each other out. Two universes a half step out of phase intersecting would vanish the pair of them. If the universes are waves in a shared medium, this would be mathematically consistent.

    Many worlds interpretation is the most egregious violation of Occam razor one can possibly imagine. To invent an infinite collection of unobservable imaginary universes just to avoid accepting that we simply don’t know what exactly happens is the most arrogant and absurd idea ever seriously considered in the whole of science.

    I don’t think you get to use Occam’s razor to choose “we don’t know”. The point is to narrow down the realm of hypotheses. Which is closest to correct? I mean, is an integrated 4D spacetime really less complex than “we don’t know why there’s gravity?” Is evolution less complex than “we don’t know why life exists like it does?” If there was a really good quantum mechanics interpretation, sure, pull out the razor. But is nondeterminism less complex than a multiverse? What about very high dimensional configuration spaces?

    As the original article points out, there are some very bunk hypotheses rising out of the many worlds theorem. And it’s certainly reasonable to prefer something like De Broglie-Bohm. But it’s unscientific to dismiss the theory outright, especially if you take the infinities to be approximations (which incidentally solves the immortality problem). It does legitimately address issues in other interpretations, and reality doesn’t particularly care whether we think a multitude of universes would be too baroque or not.

  5. #5 Alex Besogonov
    May 25, 2011

    “What about things like sleeping, or fainting, or going under anaesthetic, shouldn’t quantum immortality prevent those from happening? If there’s always a thread where consciousness continues, then your awareness should never cease… even if you’re really really tired.”

    Sure, but this outcome it’s as unlikely as in quantum suicide. And in the case of ‘quantum fainting’ you are not a privileged observer, so most of ‘you’ will still experience sleep.

    MWI is internally consistent as interpretations of QM go. Even though it sounds ridiculous.

  6. #6 Alex Besogonov
    May 25, 2011

    Paul:

    The root problem in the QM is that nobody knows why the wavefunction collapse happens at all.

    MWI sounds queer, but ideas of Multiverse are now not so wild. String theory seems to be predicting them with the anthropic principle explaining our current Universe (which is not that philosophically different from MWI).

    Then there’s Transactional interpretation of the QM where each collapse happens along extreme lines in interference of the present and past lightcones of events.

    Ultimately, it’s all just an empty talk until somebody explains how QM really works. With experiments.

  7. #7 James
    May 25, 2011

    “The most likely outcome for you to experience is a universe in which the only obvious anomaly is your own survival”

    Wrong, fate conspires that the universe which you experience evolves toward a state where immortality is NOT an anomaly, ergo science will develop life extending technology.

    Everything observed already confirms technology is advancing in this direction. Only the fine details seem uncertain.

    It`s the final logical conclusion of the Anthropic Principle and Many Worlds Interpretation. You will not observe a universe in which you are dead, neither will you observe one where your immortality is exceptional.

    The idea will sound as absurd to a human as the Cambrian explosion would to a bacteria, thanks to our peer influenced conservatism.

  8. #8 A Different Paul
    May 25, 2011

    @James

    You can of course have an Anthropic Principle and MWI without immortality: there’s no reason I can’t observe just a fraction of the universe, indeed I’ve already missed the first ~13 billion years.

    But if you are right, that we are inherently part of an eternal subjective experience, I think there’s one logical conclusion past your final one. Let’s take your argument that this immortality would manifest itself among the most likely forms, not a never-ending series of biological coin flips coming up heads, but in the more likely application of life-preserving technology.

    What are the odds the observer will eternally refrain from a voluntary end of life? That they’d never, in any span of time, grow bored or depressed? The most likely outcome seems to be one where the option of suicide is not present.

    I see three possibilities there. The first is an intentional limiting of the cognitive facilities: Eternity is a long time, a dynamic thinking system will eventually land on the choice of self-destruction. So consciousness could be reprogrammed into a loop, or an otherwise constrained state-space of allowable thoughts.

    The second is that consciousness is uploaded to a simulated reality without the possibility of self-erasure. But that raises the question of why you would not give a sentinence the option to end its experiences.

    The final possibility, the one that strikes me as most likely, is that even immortals would eventually die, would eventually want to die. Then the reason for a genuine endless life would be punishment. Place a criminal in an enclosed space, nanobots providing nourishment directly, and leave him adrift in space. Or worse.

    Personally, I see zero reason to believe an individuality can’t end. But if I’m wrong, I think the implications are a bit darker than we’d like.

  9. #9 Hercules Grytpype-Thynne
    May 25, 2011

    Many years ago I read a sci-fi story with essentially this premise. In the story, the realization that many-worlds is true (I forget how they know) sets off a wave of suicidal behavior, as the characters realize they can take absolutely any insane risk at all, and in the only set of outcomes that matters, they always survive.

  10. #10 Alex Besogonov
    May 25, 2011

    “Let’s take your argument that this immortality would manifest itself among the most likely forms, not a never-ending series of biological coin flips coming up heads, but in the more likely application of life-preserving technology.”

    If MWI is true then BOTH ways are happening (right now, in different Universes).

  11. #11 James
    May 25, 2011

    “indeed I’ve already missed the first ~13 billion years”

    Yes :(

    The biggest weakness, why doesn’t it work in both directions?

    The Dystopia/Utopia was one of the `details`. The only way I can comprehend it is that as long as you have power over your own life and death, and if perpetual unhappiness were to lead to our own death, in the Many Worlds interpretation suicide becomes a powerful bargaining chip.

    But Hercules has already got there. Constantly taking suicidal risks can never be an outcome, because it is highly improbable. The universe must conspire somehow to keep us fulfilled in less dramatic way.

  12. #12 Robert
    May 25, 2011

    Could an idea similar to quantum tunneling be behind the improbability drive in HHGTTG?

  13. #13 likely true
    May 25, 2011

    The argument need not depend on MWI. It suffices to imagine an infinite cosmos, in time or space or whatever.

  14. #14 Copernic
    May 25, 2011

    @Hercules That story was “All the Myriad Ways” by Larry Niven I believe. One of my top five short stories. Worth checking out for ose who aren’t famiiar with it.

  15. #15 Copernic
    May 25, 2011

    @Hercules That story was “All the Myriad Ways” by Larry Niven I believe. One of my top five short stories. Worth checking out for ose who aren’t famiiar with it.

  16. #16 Hercules Grytpype-Thynne
    May 25, 2011

    @Copernic:

    Thanks. I couldn’t remember the author or title when I posted that comment, but now that you mention it I do remember that it was Niven.

  17. #17 Kaleberg
    May 25, 2011

    We already live in a universe full of people who have experienced life threatening situations, infections, near miss accidents, dangerous injuries, biological senescence. and so on. All of those currently alive are on a lucky branch of their universe. All of of those dead are on a less lucky branch.

    Like most of us, I come from a long line of dead people, probably thousands, even more depending on exactly when you start calling them people. Does bad luck run in my family?

    Sure, there may be luckier and less lucky universes, and it is possible that our familiar universe is much less lucky than universes in general, but that seems to require a lot of fine tuning. There are an awful lot of universes out there, and theological arguments aside, there doesn’t seem to be much basis for arguing that we, at this instant, are sharing a, let us suppose, one sigma unlucky one.

    The multiple theory can’t be ruled out, but when you consider how frequently the mesh of being would need to be split, you wind up with an incredible number of universes to consider, especially since most of them are going to look just like ours, save in certain detail.

  18. #18 Bee
    May 25, 2011

    Apart from the above mentioned question where was my consciousness before birth, that doesn’t really explain why ‘consciousness’ seems to happen pretty much in one particular branch.

  19. #19 Frank Merton
    May 26, 2011

    The fact that the wave form “multiplies” exponentially does not mean it becomes infinite: only very, very large.

  20. #20 Paul
    May 26, 2011

    @A Different Paul

    Maybe I should have put it better but by “we don’t know what exactly happens” I was referring not to complete ignorance but to competing interpretations like ensemble or Copenhagen interpretations which don’t explain where collapse comes from. I didn’t name them to avoid being drawn into arguing about them.

  21. #21 supratall
    May 26, 2011

    OK, I’ll come clean: this reminds me of an embarrassingly recent conversation with my materials science-trained boyfriend.

  22. #22 James
    May 26, 2011

    People don`t like to entertain ideas that they think would alienate them from other people. Especially other worldly philosophy that seems to have no bearing on their lives.

    Just stitch together chaos theory, quantum mechanics and many worlds interpretation, it all scales up easily. Civilization is determined to evolve in one direction. One tiny quantum event can determine the fate of a nation.

    The more I think about this idea, the more zealous I become.

  23. #23 Chad Orzel
    May 26, 2011

    James @11: The biggest weakness, why doesn’t it work in both directions?

    Why should it?
    I’ll admit there’s an implicit theory of consciousness here, namely that what we perceive as consciousness is our history of thoughts and experiences. By that logic, you can’t experience the end of your own conscious existence, because when you cease to experience things, everything stops.

    Nothing in that rules out a start to “consciousness,” though. This isn’t some mystical Extreme Copenhagenism requiring an observer to be present for every instant of the history of the universe.

    Bee: Apart from the above mentioned question where was my consciousness before birth, that doesn’t really explain why ‘consciousness’ seems to happen pretty much in one particular branch.

    Yeah, I don’t have a great answer for that one. I think the answer is decoherence– specifically that the process of entangling the “state” of your brain with the state of the universe that you are perceiving involves complicated interactions with a large environment, which introduces decoherence between the different branches, and prevents you from perceiving more than one branch. And given the above argument about consciousness as a perceived history of experience and mental states, that suggests that you only perceive your consciousness as existing in one branch.

    But that really isn’t a whole lot better than “because I said that’s how consciousness works.” I could probably come up with something better if I were willing to put a great deal of thought into the subject. I don’t have the mental processor cycles to spare right now, though.

    (And really, if I put enough thought into it to make it sound really convincing, I’d probably write it up as a book, because there’s apparently no end to the market for chin-stroking musings about the nature of consciousness…)

    Regarding the general hate for Many-Worlds, as is usually the case, a lot of the vehement reactions against it seem to me to be vehement reactions against dodgy popularizations of the subject. There’s a reason why I carefully avoided talking about “universes” in the original post, sticking to “branches of the wavefunction,” and that sort of thing.

    From what I can tell, the central idea is surprisingly inoffensive as giant cosmic theories go. It’s simple and mathematically elegant, too. It’s completely untestable, as far as we can tell, granted, but there really doesn’t seem to be anything there that should generate the extreme disdain that is so often expressed.

    The fact that the wave form “multiplies” exponentially does not mean it becomes infinite: only very, very large.

    True enough.
    It’s effectively infinite as far as human comprehension goes, though, and as noted above, I wasn’t really trying for rigorously mathematical Cantorian discussions of infinity.

    Feel free to mentally replace “infinite” with “effectively infinite” wherever it appears, though.

  24. #24 Neil B
    May 26, 2011

    Quantum absolute immortality is indeed a stretch, but “quantum suicide” (a better way to formulate the problem, see Wi-pe) is a hole that MWI dug itself into. That’s the core fault, not the stretchers. For example, if you try to kill yourself in a Cat style setup, say there’s only 1:1,000,000 chance of surviving. Well, there will be that “version” of you in the MWI that survives, and the others dead. That version is aware of its survival, and the dead ones effectively don’t count, so it seems to me “you” would experience continuing in/as one of those branches. Yes, there are weird issues about semi-conscious states, I have a piece about that too.

    QS is of course aside from “shared consciousness”, but even with that there are sever issues of “identity” in philosophy of mind. (Should you care about what would happen to a duplicate made of you, etc.) Really, if there’s no centralized self or “soul”, then survival of body death is the least of your problems, what about whether it’s really “still you” next week – considering that your brain has changed since then. What indeed is “the same thing” anymore?

    The MWI idea is silly anyway, For one issue, just consider the sticky problem of how to get unequal probabilities (unequal amplitudes in starting superposition) from a split into two worlds (always covered up in popular treatments.) Then there’s why we don’t observe them (and no, statistical arguments don’t tell me why the left over “hit” in the other detector isn’t something I can find from e.g. its deposited energy, etc.)

    Alex B: check my link for a proposed experiment to test just that.

  25. #25 James
    May 26, 2011

    No one would ever run the cat self test and would never experience the weirdness. You can`t prune off branches of you own reality because people don`t have free will. Anyone that attempted the experiment would themselves experience a last minute moment of indecision, if they could even get that far.

  26. #26 James
    May 26, 2011

    The proof of MWI would be not dying of old age, and I`m guessing the rules that govern our universe will make that seem deterministic via technology.

  27. #27 neil b
    May 26, 2011

    James, your claim is quite unreasonable. First, people really do outright kill themselves rather often. If someone was a bit suicidal but ambivalent, and believe in MWI, they might easily try the setup (eminently doable in practice!) just to see if they experience getting through. You don’t need free will, if that’s what the person set up then the consequences should be: always being able to say “oh look, I had only 1:10^100 chance of surviving but here I am” etc. Those branches have to exist if the experiment goes through.

    Now the real treat is the look on *other* people’s faces, in the branch where you survived. (Note, the chance that I as an onlooker would see this person survive is indeed only 1:10^100 because there is no effective pruning of unconscious versions of the onlookers.

  28. #28 hf
    May 26, 2011

    There’s no reason, after all, why the surrounding universe should become any more improbable as you go on. The most likely outcome for you to experience is a universe in which the only obvious anomaly is your own survival.

    Sort of. As I think Neil B tried to say, we haven’t yet found a way to derive the observed probabilities from the premises of Many Worlds. The rule involved still has to do with the wave-function or amplitude, so it doesn’t look like a separate cause, but we don’t know yet where that particular rule comes from in MWI. One proposal says that outcomes with (very loosely speaking) less than average amplitude either contain no observers or tell no coherent ‘story’, because trace amounts of amplitude from elsewhere interfere with the natural development that the OP talks about.

    This proposal seems unlikely even to the person who suggested it, but does have the advantage of blaming our confusion on the known complexity of “observers”. (Ever tried to write out in detail the rules by which you recognize consciousness in others, without circularity?) Complexity seems like a plausible source of confusion.

  29. #29 whatmeworry
    May 26, 2011

    It’s frustrating, yet satisfying, to contemplate that on an infinite number of worlds, I apparently understand this stuff. In fact, I’ve written best-sellers about it whilst being married to both Scarlette Johansson and Katy Perry.

  30. #30 hf
    May 26, 2011

    @Paul: The notion of “splitting of worlds” is completely ill-defined and makes no sense whatsoever.

    As Chad wrote, the actual notion involved goes by the name “decoherence” and follows directly from the premise of the wave-function (or of “path integrals” that assume amplitude takes all possible paths). Some areas of the wave-function interact, others don’t. This part of MWI doesn’t require any talk of consciousness (until you get to the general rule I just mentioned). From what I understand, we know decoherence can happen with certain kinds of rocks replacing the observer.

    Or to quote a character in the (very) short story, “If Many-Worlds had come first”:

    That’s because worlds aren’t fundamental, Huve! We have massive experimental evidence underpinning the fundamental law, the Wheeler-DeWitt equation, that we use to describe the evolution of the wavefunction. We just apply exactly the same equation to get our description of macroscopic decoherence. But for difficulties of calculation, the equation would, in principle, tell us exactly when macroscopic decoherence occurred.

    As for the alternative of Broglie-Bohm:

    “..there’s got to be a billion more explanations that are more plausible than violating Special Relativity,” says Nohr. “Do you realize that if this really happened, there would only be a single outcome when you measured a photon’s polarization? Measuring one photon in an entangled pair would influence the other photon a light-year away. Einstein would have a heart attack.”

  31. #31 Neil B
    May 26, 2011

    Hf, no it is not appropriate to refer to “the actual notion” as decoherence. Decoherence (now that it’s been brought up, call it D for short) is not the concept itself, but a claimed (and IMHO faulty idea) of how and why there should be multiple “worlds” in any sense of the term, and why there should be a definite outcome found by any given observer (apart from what else there might be.) D itself is a real process. The pretense of what it explains and what it makes happen is a faulty and, pun fully intended, incoherent theoretical claim. All D does and can do, in the absence of some other intervention or unknown aspect, is make the wave function distribution a messy one. In order to have more we need something we don’t understand (as Paul rightly and honestly noted) to step in and collapse that into a specific location and result.

    The common, crudest D argument is a circular one and therefore logically unfit: if you already take as given something that creates “statistics”, then sure the statistics generated by incoherent waves are like that of classical outcomes. But that begs the question, that the whole argument was originally about, of why and how something generates any statistics at all in the first place.

    Look at it this way: suppose the wave stayed coherent instead. Supposedly this wave would remain a superposition and not resolve into specific outcomes. But if the statistical tendency is real at all, why wouldn’t the coherent superposition become a statistical result, just of the sort that does show coherence? (That is, statistical showing of interference fringes instead of them remaining wave amplitudes.) D. logically has nothing to do with collapses to specifics versus continued amplitudes as such. Without collapse or some unknown extra action or aspect, either coherent waves or incoherent wave functions should stay such (that is, both present, and distributed in space according to Schroedinger.)

    Something converts coherent WFs into the kind of statistics indicative of interference, and incoherent WFs into statistics that *simulate* there having been a classical mixture all along – but that’s a misleading outcome. It’s just the coincidental way the statistical process affects disorderly waves. Without the additional process, they would just be “disordered waves” like classical incoherent EM radiation. So decoherence is a red herring, check my article at the link.

  32. #32 Neil B
    May 26, 2011

    Furthermore: the concept of “interaction” used by D theory advocates is a misleading. Waves of any level of coherence do add their amplitudes together to make a new net amplitude. That is certainly a form of “interaction.” Again, the *statistics* generated by whatever “collapse” is all about will resemble classical statistics by coincidence, but that doesn’t explain the reduction to statistics per se which is the actual problem. And if these WFs were spread around space, “interaction” itself has nothing to do with coherence. If nothing removed the other outcomes, there would just be a messy jumble of combined results. Why couldn’t it literally be superposed in my mind? It’s just a messier wave instead of an orderly one, still containing both or more outcomes, unless something does more to the wave. There is nothing intrinsic in the wave mechanics to separate them. The DT enthusiasts have fallen for a sort of post-modernist fallacy about comparing end-result statistics to the problem of what happens up to that point.

  33. #33 hf
    May 26, 2011

    if you already take as given something that creates “statistics”, then sure the statistics generated by incoherent waves are like that of classical outcomes. But that begs the question, that the whole argument was originally about, of why and how something generates any statistics at all in the first place.

    I don’t understand what you think this means.

    Probability ordinarily represents our state of knowledge. (If you disagree with that, feel free to replace “probability” with some other word throughout this paragraph.) So let’s say you happen to know that you live inside a cloud of ‘amplitude’ or mathematical arrows. For the moment please think of these as real objects existing outside of your mind, and not probabilities at all. Now let’s say you happen to know that more than one such cloud exists, and different clouds contain different outcomes of some experiment or process on what we falsely call the physical level. (That last link answers at least one of the questions you asked, NB.) If you know everything except which cloud you live in, then you immediately have a probability for the outcome you can observe. Before the split takes place you can never have full information about what “you” will observe, because versions of you will exist in more than one cloud and nothing but their locations distinguishes one “you” from another. To give the question meaning beforehand you’d have to rephrase it in terms of picking a copy randomly (i.e, without full information) according to some suitable rules.

    As I mentioned, this doesn’t yet give us the correct probability. But it does explain why we’d find ourselves dealing with statistics at all. (And the rule we observe looks like one we might eventually figure out how to derive from this starting point.)

    As for the proposed test, at first glance it doesn’t seem to test MWI. But if it actually does this we should perform the experiment and prove Neil B wrong.

  34. #34 hf
    May 26, 2011

    At second glance: do other people understand Neil B’s “Confuser” box? Does it produce quantum uncertainty, where according to Many-Worlds all outcomes actually happen, or does it produce the sort of uncertainty you might have about the Nth digit of pi? And if the former, do its ‘different outcomes’ cancel out at BS2 or not?

  35. #35 Neil B
    May 26, 2011

    Hf, I’m on my way out but tx for looking at my paper. The “confuser” is the same as e.g. used by Chad to illustrate decoherence in the first place. I’ll say more about “knowledge” but that’s a sort of hash, we still have to wonder what is “actually moving through space” etc. in these problems, if we’re going to be realists at all. And if we’re not, then why even bother to solve it.

  36. #36 hf
    May 26, 2011

    we still have to wonder what is “actually moving through space” etc.

    Something that acts like arrows. But it moves among large sets of numbers, not just sets of x,y,z coordinates. And while you can often think of the other numbers as descriptions of what exists at that location, you’ll get into trouble if you think they refer to real individual particles. Numbers in each column seem fungible.

  37. #37 hf
    May 26, 2011

    The “confuser” is the same as e.g. used by Chad to illustrate decoherence in the first place.

    My source uses a third detector (or “sensitive thingy”) placed along one of the two paths. It goes ‘bing’ if it detects a particle. By doing so, it necessarily changes the world around it (classically speaking) in a way that a particle taking one path or the other apparently does not.

    In reality, this means that the arrow which triggers the ‘bing’ arrives at different sets of numbers than the arrow which does not. So the arrows don’t add together or cancel out. Each version of each of the original two detectors receives an arrow from one path or the other, but not both. And this applies to the brain of the observer as well.

  38. #38 Neil B
    May 26, 2011

    Hf, I scan some interesting ways to look at things, and not enough time to really dig in. We can come up with all kind of representations, but “at the end of the day” the big deal is that we know that “something” is spreading out and taking both paths – really is, not just that we don’t know which – because it can cause “interference” later. The “interference” is the structure of the distribution per se, a priori of whether it stays spread out, or turns somehow into blips at specific places. So somehow, something has to go from manifesting all those directions, potentials, possible outcomes etc, to something which is pruned down.

    Just rearranging the content shouldn’t be able to do it, but nothing wrong with you trying as long as there aren’t contradictions, semantic Monty, fallacies etc. My own proposal would at least show that the “pruning” can’t happen at a certain point that some people might think it does – because we can get interference later.

  39. #39 ZenKook
    May 26, 2011

    Personally, I like the “self-aware universe” theory. The idea is that the universe is conscious and aware, to the extent that said consciousness is the observer that allows quantum mechanics to occur.

    This idea (which is fairly congruent with traditional Buddhism) says that consciousness is in fact immortal, to the extent that it’s a fundamental property of the universe. The mistake we make is assuming our conscious awareness is a emergent property of our brains. It’s not. Presumably, Buddhist teaching is designed to help us understand the nature of consciousness, in an attempt to minimize the suffering we otherwise experience from the impermanent nature of everything we care about.

    Under this formulation, our awareness never dies, but then again, it was never belonged specifically to us to begin with.

  40. #40 Gopiballava
    May 27, 2011

    Unless I’m missing something, most people seem to be missing what I think is an even more terrifying conclusion of many-worlds: There is a parallel universe where every logical operation yields the wrong answer. Where every time you add 1+1 you get 3. Presumably, there is a world where OJ’s knife quantum tunneled into your hand.

    In such a universe, it is impossible to know anything. In fact, is that hypothesis falsifiable in any way? Surely, for every test, one universe fork gives a pass, one gives a fail…

  41. #41 Ian Kemmish
    May 27, 2011

    I think my favourite fictional treatment is the Infinite Improbability Drive, largely because of the bit about physicists disapproving of the frivolous use of serious physics, “but mostly because they didn’t get invited to that sort of party.”

    I’m not sure, though, how you can have an anomalous immortal Chad Orzel in an otherwise humdrum universe – either the universe itself would have to forever harbour places hospitable to consciousness, or else it would have to offer an escape hatch. Neither of these looks much like the universe I’m in as I type this….

  42. #42 Gopiballava
    May 27, 2011

    @Ian:

    Chad is floating in a vacuum in deep space. Suddenly, one breath’s worth of oxygen atoms quantum tunnel in front of him as he tries to breathe in. Of course, in many other universes there are insufficient atoms tunneling, or it’s half chlorine half oxygen, etc.

    What is the set of possibilities at each point? Any particle tunneling anywhere else in the universe? Or is the set much smaller?

  43. #43 Frank
    May 30, 2011

    Eternal life for dummies!
    1 E^2=p^2c^2+m^2c^4 is required by Conservation of energy -mass
    2 Human body biological -physical properties are determined only by valence electrons of our atoms and molecules( C,N,O,H SI,…)I.E CARBON BASED CHEMISTRY
    4THERE IS ABSOLUTELY NO EVIDENCE THAT CONSCIOUSNESS SURVIVES THE DEATH OF THE BRAIN
    5The soul/spirit is a creation of them mind;ergo brain death means soul/spirit death
    6 Until energy conservation is proved wrong; new star(suns) will be born creating new earths and new humans will evolve which can be biologically but not of necessity identical .Is not that the fundamental defintion of being reborn .We get a “clean slate” on which to start over with no memory of the past “good or bad”
    Einstein says “God does not play dice “which is why he gave us conservation of energy “and not Schroedingers Cat”
    Frank Lipsky Scottsdale AZ

  44. #44 CCPhysicist
    May 30, 2011

    Paul @4 and Alex @6:

    Why do you think there has to be a “process”, some sort of trajectory, when what you are talking about is a complex probability amplitude? Are you thinking that God is actually playing dice, and you want to see how they tumble when an x-ray encounters a crystal?

  45. #45 I M Weezil
    June 1, 2011

    @45 lolwut

    So, wait. If each individual only ever experiences the universe in which they are immortal, does that mean thaat past a given age (say, 150) you can be sure that you’re the only consicous being in the universe?

  46. #46 larry cole h
    June 1, 2011

    uncertain principles, uncertain lifes !!!!!!!

  47. #47 Josh Mitteldorf
    June 1, 2011

    The question can be asked in a broader context: what are the different views of QM, and how might each of them affect our thinking about mind/body duality?

    I’m eager for feedback and discussion of this essay: http://mathforum.org/~josh/articles/Dualism.htm

  48. #48 John Laurie
    July 24, 2011

    I think the key word we have to bear in mind is ‘probability’. After all, the Schrodinger equation gives a list of probabilities….and as Julian Barbour argues, ‘that is the end of it’!

    So, in thought experiments, what we have to do is, once we have eliminated death/non existance from our first person experience stack, as it were, then we have to figure out the least improbable (relatively speaking) ways of survival.

    Therefore, I would agree that it is far more likely that what we will experience are universes where our survival is due to advances in technology, rather than just arbitrarily finding ourselves individually alive alone, decrepit and lonely at a ridiculously advanced age.

    Indeed as has been pointed out that is where we already find ourselves.

    I would further argue that a more probable outcome is that some of those we know and love will also have to benefit from these advances. For the simple reason that it is far more probable that we find ourselves in scenarios where not only do we continue to live, but we WANT to live (as opposed to NOT wanting to live but surviving numerous suicide attempts)

    An earlier poster said that he had missed the first 13 billion years of the universe so what is to stop him missing the next? But another way of looking at this is to say I am ‘missing’ being, say, the first person experience of being, say, President Obama, as I am instead having the experience of being John Laurie in 2011.

    While I may never experience being alive in the Stone Age or being President Obama, I’m not sure how this negates personal first person immortality under MWI.

    Another point raised was can a first person immortal sleep? I would say, yes of course, again simply due to probability. An immortal would be far more likely to experience sleep than to be trapped in a subjective hell where sleep was impossible, becoming evermore tired and then driven to (attempted)suicide.

    As a believer in MWI, like I say, I think our most probable experiences will be to be contentedly alive. Technology will keep us alive and make us happy to be so.

    My guess is that this will happen through a combination of medicine/biotechnology, and perhaps a development of virtual realities so real and so fun that we want to keep going.

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