4 ms·

Here's the article in short. 1. "Roland Omnès says the idea that every little quantum “measurement” spawns a world “gives an undue importance to the little dif

Here's the article in short. 1. "Roland Omnès says the idea that every little quantum “measurement” spawns a world “gives an undue importance to the little differences generated by quantum events, as if each of them were vital to the universe.” This, he says, is contrary to what we generally learn from physics: that most of the fine details make no difference at all to what happens at larger scales." 2. "What can it mean to say that splittings generate copies of me? In what sense are those other copies “me?”" / "Consciousness relies on experience, and experience is not an instantaneous property: It takes time, not least because the brain’s neurons themselves take a few milliseconds to fire. You can’t “locate” consciousness in a universe that is frantically splitting countless times every nanosecond" 3. "You could become a billionaire by playing quantum Russian roulette. Your quantum splitter is activated while you sleep, and if the dial says Up then you’re given a billion dollars when you wake. If it shows Down then you are put to death painlessly in your sleep." / "But a committed Everettian should have no hesitation about doing so using the quantum splitter. For you can be certain, in this view, that you’ll wake up to be presented with the cash. Of course, only one of “you” wakes up at all; the others have been killed. But those other yous knew nothing of their demise. Sure, you might worry about the grief afflicted on family and friends in those other worlds. But that aside, the rational choice is to play the game." 4. "Alice is put to sleep before the measurement is made, knowing she will be wheeled into one of two identical rooms depending on the outcome. Both rooms contain a chest. Inside one is twice her stake, while the other is empty." / "But what if Alice were to say, “The experience I will have is that I will wake up in a room containing a chest that has a 100-percent chance of being empty”? The Everettian must accept this statement as a true and rational belief too, for the initial “I” here must apply to both Alices in the future." / "In other words, Alice Before can’t use quantum mechanics to predict what will happen to her in a way that can be articulated — because there is no logical way to talk about “her” at any moment except the conscious present (which, in a frantically splitting universe, doesn’t exist)." Sengachi's reply in the comments below basically summarises my reaction.

EGreg 8y ago
People ridicule the nonlocality of Pilot Wave theory. But I’d rather question locality than embrace Everett’s many-worlds theory. If you need to postulate such amazing complexity just to say basically nothing in terms of realism, then you’ve already lost. Meanwhile as one good physics professor pointed out, none of these alternatives to PWT even rule out nonlocality. So why not just assume it and be done with the weirdness?
- ZhuanXia 8y ago
  > If you need to postulate such amazing complexity just to say basically nothing in terms of realism, then you’ve already lost. What about many worlds is complex? The Schrodinger equation predicts macroscopic decoherence. Macroscopic decoherence implies many worlds. Many worlds can hardly be called an interpretation. Rather, it is a prediction. It is just taking the Schrodinger equation literally. Every other "interpretation" is more complex, as they bolt things onto the Schrodinger equation, and often very ugly things, too.
  - kgwgk 8y ago
    Macroscopic decoherence is about the interaction of a quantum system with its environment, resulting in a mixture state for the subsystem of interest. But if you describe the whole universe as a quantum system there is no environment, no decoherence, no many worlds, the universe will remain in a pure state if it was originally in a pure state.
- JProthero 8y ago
  >If you need to postulate such amazing complexity just to say basically nothing in terms of realism, then you’ve already lost. Defenders of the Many-Worlds Interpretation, and some other types of multiverse theory such as Eternal Inflation, would actually say that the multiverse idea is the simpler alternative, not the more complex one. Multiverse theories produce an abundance of universes, but the underlying description of those universes is typically simpler than alternatives that suppose a single, unique universe. Concepts such as wave function collapse or hidden variables, which actually add complexity to the theory, have to be introduced in order to get the theory to produce a unique observed reality. One could have argued with Aristarchus or Hubble that the idea that there were other solar systems, or other galaxies, added more complexity than was necessary to explain reality. From a broader perspective though, our reality would actually be stranger and more difficult to explain if the properties we observed of our solar system, or our galaxy, were the only ones that could exist. Ditto our universe, say the Everettians. Kepler desperately struggled to explain the properties of our solar system as the product of a unique and divine geometry before he discovered the more general truth [1], which allowed the existence of the infinity of alternative configurations which are now known to exist around other stars. [1] https://en.wikipedia.org/wiki/Mysterium_Cosmographicum https://en.wikipedia.org/wiki/Mysterium_Cosmographicum
int_19h 8y ago
It occurs to me that a lot of these arguments revolve around the author's preferred definition of consciousness, which is essentially arbitrary. There's no physical phenomenon that is consciousness - it's a term that we came up with for the subjective feeling that we experience as we function. You don't really know if someone is conscious or not unless you ask, and you don't really know if the answer is true or not anyway (because they might be conscious but unable to communicate, or because it might be an unconscious automaton that's programmed to answer that it is conscious) - so there's no way to define it experimentally. I can't help but think that "consciousness" is really just a modern atheistic version of the "soul" concept, nothing more. Basically, we just gave up on immortality, and accepted that there are some physical processes underneath that cause it to start and stop - but we're still clinging to that self-perception of ourselves as a singular entity that drives self, as something that meaningfully exists in the physical world. But it is recursive - we think that we're conscious as a function of conscious, basically. You can't really distinguish consciousness from unconsciousness per se, because when you're unconscious, you do not observe or reason. In others, you can only observe the lack of prerequisites of consciousness (e.g. brain activity), or the lack of its side effects (communication etc), but you can't observe unconsciousness as such. From that perspective, the idea of consciousness has no more place in science (or criticism of science) than soul does.

EGreg 8y ago

People ridicule the nonlocality of Pilot Wave theory. But I’d rather question locality than embrace Everett’s many-worlds theory. If you need to postulate such amazing complexity just to say basically nothing in terms of realism, then you’ve already lost. Meanwhile as one good physics professor pointed out, none of these alternatives to PWT even rule out nonlocality. So why not just assume it and be done with the weirdness?

ZhuanXia 8y ago
> If you need to postulate such amazing complexity just to say basically nothing in terms of realism, then you’ve already lost. What about many worlds is complex? The Schrodinger equation predicts macroscopic decoherence. Macroscopic decoherence implies many worlds. Many worlds can hardly be called an interpretation. Rather, it is a prediction. It is just taking the Schrodinger equation literally. Every other "interpretation" is more complex, as they bolt things onto the Schrodinger equation, and often very ugly things, too.
- kgwgk 8y ago
  Macroscopic decoherence is about the interaction of a quantum system with its environment, resulting in a mixture state for the subsystem of interest. But if you describe the whole universe as a quantum system there is no environment, no decoherence, no many worlds, the universe will remain in a pure state if it was originally in a pure state.
JProthero 8y ago
>If you need to postulate such amazing complexity just to say basically nothing in terms of realism, then you’ve already lost. Defenders of the Many-Worlds Interpretation, and some other types of multiverse theory such as Eternal Inflation, would actually say that the multiverse idea is the simpler alternative, not the more complex one. Multiverse theories produce an abundance of universes, but the underlying description of those universes is typically simpler than alternatives that suppose a single, unique universe. Concepts such as wave function collapse or hidden variables, which actually add complexity to the theory, have to be introduced in order to get the theory to produce a unique observed reality. One could have argued with Aristarchus or Hubble that the idea that there were other solar systems, or other galaxies, added more complexity than was necessary to explain reality. From a broader perspective though, our reality would actually be stranger and more difficult to explain if the properties we observed of our solar system, or our galaxy, were the only ones that could exist. Ditto our universe, say the Everettians. Kepler desperately struggled to explain the properties of our solar system as the product of a unique and divine geometry before he discovered the more general truth [1], which allowed the existence of the infinity of alternative configurations which are now known to exist around other stars. [1] https://en.wikipedia.org/wiki/Mysterium_Cosmographicum https://en.wikipedia.org/wiki/Mysterium_Cosmographicum

int_19h 8y ago

It occurs to me that a lot of these arguments revolve around the author's preferred definition of consciousness, which is essentially arbitrary. There's no physical phenomenon that is consciousness - it's a term that we came up with for the subjective feeling that we experience as we function. You don't really know if someone is conscious or not unless you ask, and you don't really know if the answer is true or not anyway (because they might be conscious but unable to communicate, or because it might be an unconscious automaton that's programmed to answer that it is conscious) - so there's no way to define it experimentally. I can't help but think that "consciousness" is really just a modern atheistic version of the "soul" concept, nothing more. Basically, we just gave up on immortality, and accepted that there are some physical processes underneath that cause it to start and stop - but we're still clinging to that self-perception of ourselves as a singular entity that drives self, as something that meaningfully exists in the physical world. But it is recursive - we think that we're conscious as a function of conscious, basically. You can't really distinguish consciousness from unconsciousness per se, because when you're unconscious, you do not observe or reason. In others, you can only observe the lack of prerequisites of consciousness (e.g. brain activity), or the lack of its side effects (communication etc), but you can't observe unconsciousness as such. From that perspective, the idea of consciousness has no more place in science (or criticism of science) than soul does.