The linked article is very unpersuasive; he says ‘we can get probabilities out of QM, by using Expected Value from decision theory’ and seems to think that justifies MWI in some way, but he ignores the fact that Expected Value depends on the probability of various payoffs. All his algebra is just making things one step more complex by hiding probability in the definition of V(x). So he doesn’t even do what he sets out to do, much less explain how it justifies MWI.
But maybe I completely misunderstand MWI: what testable predictions does the MWI make? Are there some technical issues that , if resolved, would allow for testable predictions? If not, how is MWI science, and not just bong-hit speculation?
The inductive step fails because you can not guarantee step 2 works for all time increments. One can conceive of a position in which every version of you still living will die within the next ten seconds, giving a 0% chance of survival. As the proportion of universes that you inhabit decreases, this becomes more likely.
That said, this does not disprove the essentials of this argument. Only if one can prove that there is such a time period is the argument disproved.
There’s definitely a discontinuity there. I don’t experience going from being in bed the night before to <blink> instantly being in bed the next morning.
Also, it should be noted, it’s debatable whether you’re unconscious when you sleep in the philosophical sense.
There’s always brain activity during sleep, and even if you wake someone in the deepest, non-REM sleep, they’ll often have some recollection of (scattered) thoughts immediately prior to waking.
So sleep is a time of altered consciousness and poor memory creation, but not brain off.
MWI is an interpretation of QM, not a theory, which is why it doesn’t need to make testable predictions. All of the testable predictions are in QM itself – MWI is just a speculative (although probably not bong-hit speculative) interpretation of what they mean.
The main benefit of MWI over the Copenhagen interpretation is the absence of “wavefunction collapse”. Wavefunction collapse makes people uncomfortable because nothing in QM really tells us why this should happen and it opens up a whole can of worms about what constitutes an observer and observation. MWI is essentially, “what if wavefunction collapse doesn’t happen, but our identity is just one branch of our wavefunction ourselves? Then QM can happen just like it looks like it happens and we’d never know the difference, and the apparent collapse of the wavefunction is covered under standard physics.”
I’d say that implies there is no discontinuity–it’s a little fuzzy on the boundaries, but your brain was obviously doing something in the intervening time since it wasn’t an instantaneous jump.
Contrast to general anesthesia, which in my experience *does *involve a perceptually instantaneous jump from one spacetime location to another. The anesthesiologist is injecting the drugs–and bang, you’re somewhere else. It is like the time was actually missing, instead of simply having forgotten what you did at the time.
The argument is clear enough to me, thank you. The problem is not with the structure of the argument but with the fact that it makes so many huge and highly questionable assumptions in its premises.
Huge, highly questionable assumption (but at least one that is out in the open).
Well yes, but the claim being made is not one about someone surviving a Schrödinger’s cat type experiment, where life or death is engineered to depend on single, isolable quantum events, it is about surviving in the real world where death is almost caused by macroscopic events of enormous complexity at the quantum level, and which would generally not be rendered non-lethal by any single difference at that level. Maybe it can be shown that the same considerations will apply, but I do not think it can be taken for granted.
That appears to be false to me, as it stands, although its meaning is unclear and perhaps equivocal because of the weird use of tense. Here are two possible true interpretations:
4a. I don’t currently experience any world in which I have been killed.
4b. I am currently experiencing a world in which I will be killed.
I do not think either by itself will support any of the relevant inferences, though.
Well, yes, presumably, but why is that the I that counts, as opposed to all the zillions of Is that got or get killed? Many worlds also implies that the I of any particular moment is also going to die and suffer in all of the most gruesome and painful ways possible. How did Everett get his complacency out of that? The only way I can see is by somehow taking it that the real Everett out of all the zillions, the one who is the true continuation of Everett now is the one who survives, and all the others somehow do not count. What is the basis for that. (At a guess, the basis comes from the sort of equivocal use of tense exemplified in your number 4.)
[I see you have now realized the relevance of this issue in your post #20. As it seems you now realize, all sorts of hairy issues about personal identity over time are being elided here.]
Bullshit. Save that crap for your first-year logic students. No reasonable person should be expected to waste their life going over the details of every complex argument looking for its flaws when the self-interested motivation for the conclusion is staring them in the face. We - even philosophers - make pragmatic heuristic judgements about which arguments are worth the effort of picking apart and which are obviously silly all the time. Frankly I have already wasted far more time on this one than it deserves.
Yeah, because that is how wish fulfillment fantasies work. People always consider the bad consequences of their wishes coming true.:rolleyes:
Anyway, if the original argument works, so does one in which it is inevitable that, on some timeline, Everett not only survives but survives in good health, in paradisaical conditions, and all his loved ones survive too. And no doubt that is the one Everett he thinks will be the real him, as opposed to those who live on in agony, and all those many more still who die.
iamnotbatman
You mistake me. I have no particular objection to the many worlds interpretation as a piece of philosophy of physics. I do not have the technical knowledge to judge it in that respect, and if you are saying that it has real advantages, in terms of clarity, conceptual simplicity, or whatever, over other interpretations of QM I am prepared to take your word for it. That said, my gut (which, admittedly, may not be a reliable guide to modern physics) tells me that it is silly, especially as it so obviously lends itself to supporting fantasies of the type under discussion.
It may also be (I don’t know, but you may) that it is ontologically parsimonious in terms of the numbers of types of entities it needs to posit, relative to other interpretations of QM (no hidden variables, no collapse of the wave function - is that right?). However, if you are saying that a theory that posits a near infinity of new universes coming into existence at every moment is not grotesquely ontologically extravagant, then you must have a different understanding of the words “ontological”, “extravagant”, and perhaps also “grotesque” from mine.
With every near-death event, or seemingly lucky strike, or even some random decision there’s an entire world I’m leaving behind in which I died.
Then again, you and everyone you’ve known (or didn’t), alive or dead, will also experience life down a path of consciousness leading to some ultimate state or version your body can live to. Then, nothing…
The linked article is not meant to persuade one of the MWI, nor “justify it” (whatever that means). It is simply addressing one of the technical “issues” with it. Part of the reason I linked to it is to merely provide an example of how the MWI is regarded soberly by mainstream physicists. Informally I would say it is possibly the preferred interpretation among the majority of theoretical physicists (less so of experimental physicists).
Yes, it sounds like you completely misunderstand it. It makes no testable predictions. It is not science (although it is very much part of a long tradition of science making inroads through the adoption of alternate but equivalent mathematical descriptions). It is not bong-hit speculation. It the simplest and least ontologically bloated theoretical model. Anyone who says it is “bong-hit speculation” makes it absolutely clear that they do not understand it at all.
I felt the same way when I first gathered my opinion of the MWI from it’s popular descriptions, which do it a great disservice by hyping and framing it in a way which is very misleading. But like almost everything in physics, sadly, the popular description cannot be trusted. If you actually learn what the theory is I expect you will feel differently. But what more can I say if you are not able or willing to learn what the theory actually is? I guess you may have to trust that physicists are not stupid, that they have the same “gut” that you do, and that nonetheless they don’t feel the theory is so obviously flawed as you. At the very least this should give you pause, you should slow down and throw them a bone, and look for what, possibly, they see which you do not.
This is where is becomes clear that you just don’t understand the MWI. The MWI doesn’t “posit a near infinity of new universes.” At least not in the way you think it is. Physicists did not just smoke some weed and say “you know what? Let’s add a bunch of crazy shit to our equations that make them branch off into infinite universes, man!” No, they looked at the exact same equations physicists had been using for years, namely those specifying the evolution of the quantum wave function, and realized that they, alone, are mathematically equivalent to an infinite sea of universes. This distinction may sound subtle, but I do not think it actually is. It is an enormous difference.
You see, apart from wave function collapse, quantum mechanics is simple and beautiful. You have a wave, and it evolves according to a simple differential equation (the schrodinger equation). But wave function collapse was never understood. The Copenhagen interpretation is an ad hoc pragmatic formalism which is explicitly approximate (some would say wrong) in that it leaves out the effect of the measurement apparatus. It says “we don’t know what the hell is going on, but if we measure something, the schrodinger equation stops working and some crazy nonlinear process occurs which we do not understand, but whatever, here is how we find the probability for our measurement to be X.” The central premise of the MWI is not many universes, but simply that there is no such thing as wave function collapse. There is just the schrodinger evolution of the wave function. In this sense the MWI is the simplest, most natural, and most straightforward interpretation. The only difficulty is in seeing how wave function collapse appears to occur for conscious observers within a wave function that is evolving according to the schrodinger equation. The way you see that is by breaking down the wave function into pieces, and noting that, for example, a wave function that is spread all around space has all along been mathematically equivalent to a an infinite spectrum of classical particles, each at a slightly different location. In other words if you take the wave function, and break it into pieces like you are going to integrate it numerically, and each little piece can be thought of as a separate “universe.” Since the schrodinger equation is linear, these “universes” do not interact. They act like they are separate. You can think of it however you want; this is just a statement of mathematical equivalence, rather than a bullshit brain-dead stoner idea.
Another thing is that many of the mathematical formalisms in QM make this infinite spectrum explicit. We don’t have another way of modeling light propagation than to assume that photons take all possible paths, and ultimately interfere to produce certain high probability trajectories. There is no other theory here because that’s how stuff actually behaves.
Infinite universes are no more ontologically extravagant than assuming every particle actually behaves as an infinite collection of particles. It is really the same thing, but with slightly different mental categorization.
As has been pointed out, sleep isn’t a cessation of consciousness (although perhaps “awareness” or “observerness” is a more appropriate word). Your mind is still aware of its surroundings, it’s just that your senses are, well, dulled. Sufficient pain will wake you up, for example.
The closest I’ve personally experienced of non-being was when I was under anesthesia for my wisdom teeth removal. One second I was awake and aware of my surroundings, then the next it was about thirty minutes later. I wasn’t aware during that time at all. It was very different from sleep. The time interval is just gone.
But even that doesn’t disprove QI- because I came back. The only thing QI guarantees is that your string of internal causality, your “awareness”, continues. For example, a plausible solution for a situation in which you are 100% likely to die is that you *do *die… but are then resuscitated. This resuscitation could be immediate, or thirty minutes later, or billions of years in the future due to advanced future technology. From your point of view, your awareness continues uninterrupted. You might know, intellectually, that there was a discontinuity, but you didn’t experience it- because you can’t experience anything when you’re dead.
So anesthesia, even death, doesn’t disprove QI. QI can’t be considered science, because it’s completely untestable and unfalsifiable. It’s really more of a philosophical conclusion which can be drawn from the MWI. I’d like to *think *it’s true- it makes a lot of sense to me- but I’m sure as hell not going to rely on it.
As an aside, I independently came up with the idea for QI. I’m not a scientist; everything I know about quantum physics and the MWI is information I’ve gotten from casual reading. It was years before I found out that I wasn’t the first person (by far) to come up with the concept. I just didn’t know what the concept was called. I think it’s kinda neat that I drew the same conclusion that people who know much more about such things than I do.