4 ms·

Why do you think this disproves pilot wave theory? > Physicists also compulsorily reject Bohm’s construction because it explicitly builds nonlocality into its

Why do you think this disproves pilot wave theory? > Physicists also compulsorily reject Bohm’s construction because it explicitly builds nonlocality into its framework—even though violations of Bell’s inequality have conclusively shown that the stage of our universe is nonlocal. This is perplexing. Nonlocality is unavoidable in any theory that recovers the predictions of quantum theory. Therefore, any criticism of a theory that displays Nature’s nonlocal feature in an obvious way is both unfounded and counterproductive. Despite this, Bohm’s inherent explication of nonlocality continues to be obnoxiously mistaken as a strike against it instead of for it.

codethief 8y ago
> even though violations of Bell’s inequality have conclusively shown that the stage of our universe is nonlocal They have not. What they have shown is that the universe cannot be local and deterministic at the same time.
- tezthenerd 8y ago
  Bell's theorem rules out locality even for non-deterministic theories as well. Don't get determinism and realism confused...
  - codethief 8y ago
    I might not be using the same definitions as you are or maybe I'm getting something mixed up, so I'd be glad if you could elaborate on what exactly you mean by "determinism", "realism" and especially "locality". (In my book, the Copenhagen interpretation is a non-realistic(∆), non-deterministic and local theory, which would contradict your statement.) (∆) Assuming, of course, that the wave function is not an object of reality, as I think is standard.
    - tezthenerd 8y ago
      Many would argue that Copenhagen is not local, but its very hard to even define locality if you are genuinely non-realist about everything. Regardless, if it was possible to be "local + non-deterministic" many of us would be fine with that. But its not - Bell rules out "locality + realism", regardless of whether the realistic theory is deterministic or non-deterministic.
      - codethief 8y ago
        > Many would argue that Copenhagen is not local Who? I believe the point of view that the Copenhagen interpretation is local is the standard one.[1] > but its very hard to even define locality How so? There are various definitions of locality—in terms of no faster-than-light transmission of information, in terms of commutators of field operators at spacelike distances vanishing as well as in terms of C* algebras—and the Copenhagen interpretation fulfills them all. > if you are genuinely non-realist about everything I'm being non-realist only about things whose existence we can't prove, e.g. the wave function. > Regardless, if it was possible to be "local + non-deterministic" many of us would be fine with that. But its not - Bell rules out "locality + realism" I don't see how this disproves anything of what I said. While I think you're right[2] about the fact that the violation of Bell's inequality rules out local realism—irrespective of determinism—, I already said that, in my book, Copenhagen is not a realistic theory because the wave function is not an object of reality. [1]: https://en.wikipedia.org/wiki/Principle_of_locality#Copenhagen_interpretation https://en.wikipedia.org/wiki/Principle_of_locality#Copenhag... [2]: "However, Fine's theorem shows that, this deterministic assignment of properties is not required to prove Bell's theorem. This is because the set of statistical distributions for measurements on two parties, once locality has been assumed, are independent of whether or not determinism is also assumed." (https://en.wikipedia.org/wiki/Principle_of_locality#Local_realism https://en.wikipedia.org/wiki/Principle_of_locality#Local_re...)
        codethief 8y ago
        s/realistic/realist, sorry for the typo.
    - testvox 8y ago
      Don't throw out realism so easily. Ending the quest for answers by invoking mysticism is very easy for people to do but its never the right answer. https://www.lesswrong.com/s/5uZQHpecjn7955faL/p/6i3zToomS86oj9bS6 https://www.lesswrong.com/s/5uZQHpecjn7955faL/p/6i3zToomS86o...
      - codethief 8y ago
        Where did I invoke mysticism? And where did I end the quest for answers? I said "in my book" for a reason. You might of course argue that the wave function is real, which would make the Copenhagen interpretation a realistic, albeit non-local theory (as the collapse of the wave function would happen instantaneously everywhere). I'd be very happy to discuss this but please bear in mind that this was not what the discussion was about.
jmcmichael 8y ago
Because pilot wave theory assumes realism and determinism[1], and the authors of the first paper I listed conclude that their result "suggests that giving up the concept of locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are abandoned." Their conclusions could be wrong, of course, but if they are not, according to the authors' interpretation physicists should abandon realist theories like pilot-wave theory. [1] https://en.wikipedia.org/wiki/Pilot_wave_theory#Principles https://en.wikipedia.org/wiki/Pilot_wave_theory#Principles

codethief 8y ago

> even though violations of Bell’s inequality have conclusively shown that the stage of our universe is nonlocal They have not. What they have shown is that the universe cannot be local and deterministic at the same time.

tezthenerd 8y ago
Bell's theorem rules out locality even for non-deterministic theories as well. Don't get determinism and realism confused...
- codethief 8y ago
  I might not be using the same definitions as you are or maybe I'm getting something mixed up, so I'd be glad if you could elaborate on what exactly you mean by "determinism", "realism" and especially "locality". (In my book, the Copenhagen interpretation is a non-realistic(∆), non-deterministic and local theory, which would contradict your statement.) (∆) Assuming, of course, that the wave function is not an object of reality, as I think is standard.
  - tezthenerd 8y ago
    Many would argue that Copenhagen is not local, but its very hard to even define locality if you are genuinely non-realist about everything. Regardless, if it was possible to be "local + non-deterministic" many of us would be fine with that. But its not - Bell rules out "locality + realism", regardless of whether the realistic theory is deterministic or non-deterministic.
    - codethief 8y ago
      > Many would argue that Copenhagen is not local Who? I believe the point of view that the Copenhagen interpretation is local is the standard one.[1] > but its very hard to even define locality How so? There are various definitions of locality—in terms of no faster-than-light transmission of information, in terms of commutators of field operators at spacelike distances vanishing as well as in terms of C* algebras—and the Copenhagen interpretation fulfills them all. > if you are genuinely non-realist about everything I'm being non-realist only about things whose existence we can't prove, e.g. the wave function. > Regardless, if it was possible to be "local + non-deterministic" many of us would be fine with that. But its not - Bell rules out "locality + realism" I don't see how this disproves anything of what I said. While I think you're right[2] about the fact that the violation of Bell's inequality rules out local realism—irrespective of determinism—, I already said that, in my book, Copenhagen is not a realistic theory because the wave function is not an object of reality. [1]: https://en.wikipedia.org/wiki/Principle_of_locality#Copenhagen_interpretation https://en.wikipedia.org/wiki/Principle_of_locality#Copenhag... [2]: "However, Fine's theorem shows that, this deterministic assignment of properties is not required to prove Bell's theorem. This is because the set of statistical distributions for measurements on two parties, once locality has been assumed, are independent of whether or not determinism is also assumed." (https://en.wikipedia.org/wiki/Principle_of_locality#Local_realism https://en.wikipedia.org/wiki/Principle_of_locality#Local_re...)
      - codethief 8y ago
        s/realistic/realist, sorry for the typo.
  - testvox 8y ago
    Don't throw out realism so easily. Ending the quest for answers by invoking mysticism is very easy for people to do but its never the right answer. https://www.lesswrong.com/s/5uZQHpecjn7955faL/p/6i3zToomS86oj9bS6 https://www.lesswrong.com/s/5uZQHpecjn7955faL/p/6i3zToomS86o...
    - codethief 8y ago
      Where did I invoke mysticism? And where did I end the quest for answers? I said "in my book" for a reason. You might of course argue that the wave function is real, which would make the Copenhagen interpretation a realistic, albeit non-local theory (as the collapse of the wave function would happen instantaneously everywhere). I'd be very happy to discuss this but please bear in mind that this was not what the discussion was about.

jmcmichael 8y ago

Because pilot wave theory assumes realism and determinism[1], and the authors of the first paper I listed conclude that their result "suggests that giving up the concept of locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are abandoned." Their conclusions could be wrong, of course, but if they are not, according to the authors' interpretation physicists should abandon realist theories like pilot-wave theory. [1] https://en.wikipedia.org/wiki/Pilot_wave_theory#Principles https://en.wikipedia.org/wiki/Pilot_wave_theory#Principles