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QM interpretation is a subtle thing and QBism makes a lot of sense. Yet (IMHO) it trades practical interpretation for some (nomen omen) purity. In QM you can d

by stared 11y ago

QM interpretation is a subtle thing and QBism makes a lot of sense. Yet (IMHO) it trades practical interpretation for some (nomen omen) purity. In QM you can describe a quantum state with a wavefunction (to incorporate quantum ignorance) or a density matrix (to incorporate both quantum and classical ignorance). (A for classical ignorance only, one would just use probability vector). States than can be described with just a wavefuctions are called pure states. And many-world interpretation revolves around having _only_ pure states (so, while being unsettling, does not add other assumptions and is, well... more pure). In QBsim pure states are not singled out. Having said that, if you are coming to QM, QBism will protect you against a lot of BS. :) And BTW: I remember my meeting with Chris Fuchs. It was a very illuminating story how did he turned from a (sinful) frequentist to an (enlightened) bayesianist. And how we should focus on knowing and not knowing things, rather that consider reality as an abstract thing. A --bit-- lot of shameless self-advertisement: - Hydrogen ion and classical vs quantum not-knowing: https://johncarlosbaez.wordpress.com/2015/03/13/quantum-superposition/ https://johncarlosbaez.wordpress.com/2015/03/13/quantum-supe... - My quantum game - I want _show_ how does quantum mechanics work http://quantumgame.io/ http://quantumgame.io/ (just a sign-up list; I will release alpha this Sept) - in my PhD thesis I coined qubism (for a plotting scheme for quantum states), only to realize later that a similar word is already taken; chapter 3 of http://arxiv.org/abs/1412.6796 http://arxiv.org/abs/1412.6796: "The name qubism (inspired by Cubism, the art movement) should not be confused with QBsim (quantum Bayesianism)"

platz 11y ago
QB still seems like Berkely to me, but just with a dose of math.
- stared 11y ago
  In QM math is essential. Most of things I had learnt about QM before learning its basic, well, mechanics were actually building false intuitions. Without math, many-world interpretation is a ridiculous absurd, and an Ockham's nightmare. With - well, it's pure QM _without_ adding additional assumptions.
  - amelius 11y ago
    > ...and an Ockham's nightmare... Just never forget that Ockham's razor has absolutely no basis in science. Also, what one person finds a simpler or more elegant theory, another person might not; in that sense it is quite arbitrary.
    - pdonis 11y ago
      > what one person finds a simpler or more elegant theory, another person might not; in that sense it is quite arbitrary But one can quantify the complexity of a theory as the number of bits required to compute all of its predictions. In that sense, the MWI is the least complex version of QM, because, as stared pointed out, it's just the basic math of QM with nothing added on. All of the other interpretations add something on, which means requiring more bits for computation.
    - jasonwatkinspdx 11y ago
      > what one person finds a simpler or more elegant theory, another person might not; in that sense it is quite arbitrary There are ways of making it formal and precise. See section 3 in this chapter from Judea Pearl's book: http://bayes.cs.ucla.edu/BOOK-99/ch2.pdf http://bayes.cs.ucla.edu/BOOK-99/ch2.pdf or for a more lightweight discussion that happens to be in my tab stack atm, see https://probmods.org/occam's-razor.html https://probmods.org/occam's-razor.html I understand people think they're being helpful with the knee jerk "that's not science" response to someone asserting Occam, since the principle is often abused/overused, but the academic perspective on this has been much richer for decades now. It's not fair to just sweep that away with a ba-humbug.
    - nazgulnarsil 11y ago
      Has a basis in information theory. But it's funny how you would assert that so confidently. What lead you to being that confident? https://en.wikipedia.org/wiki/Kolmogorov_complexity https://en.wikipedia.org/wiki/Kolmogorov_complexity
      - amelius 11y ago

by stared 11y ago

platz 11y ago

QB still seems like Berkely to me, but just with a dose of math.

stared 11y ago
In QM math is essential. Most of things I had learnt about QM before learning its basic, well, mechanics were actually building false intuitions. Without math, many-world interpretation is a ridiculous absurd, and an Ockham's nightmare. With - well, it's pure QM _without_ adding additional assumptions.
- amelius 11y ago
  > ...and an Ockham's nightmare... Just never forget that Ockham's razor has absolutely no basis in science. Also, what one person finds a simpler or more elegant theory, another person might not; in that sense it is quite arbitrary.
  - pdonis 11y ago
    > what one person finds a simpler or more elegant theory, another person might not; in that sense it is quite arbitrary But one can quantify the complexity of a theory as the number of bits required to compute all of its predictions. In that sense, the MWI is the least complex version of QM, because, as stared pointed out, it's just the basic math of QM with nothing added on. All of the other interpretations add something on, which means requiring more bits for computation.
  - jasonwatkinspdx 11y ago
    > what one person finds a simpler or more elegant theory, another person might not; in that sense it is quite arbitrary There are ways of making it formal and precise. See section 3 in this chapter from Judea Pearl's book: http://bayes.cs.ucla.edu/BOOK-99/ch2.pdf http://bayes.cs.ucla.edu/BOOK-99/ch2.pdf or for a more lightweight discussion that happens to be in my tab stack atm, see https://probmods.org/occam's-razor.html https://probmods.org/occam's-razor.html I understand people think they're being helpful with the knee jerk "that's not science" response to someone asserting Occam, since the principle is often abused/overused, but the academic perspective on this has been much richer for decades now. It's not fair to just sweep that away with a ba-humbug.
  - nazgulnarsil 11y ago
    Has a basis in information theory. But it's funny how you would assert that so confidently. What lead you to being that confident? https://en.wikipedia.org/wiki/Kolmogorov_complexity https://en.wikipedia.org/wiki/Kolmogorov_complexity
    - amelius 11y ago