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During this meeting, we will focus on nonlocality and Bell’s theorem. The meeting on 10/24 will continue our discussion of nonlocality, and take a deeper look at contextuality and the KS Theorem, as well as the possible implications for interpreting QM.

Reading Assignment:

  • "What is Real?," Adam Becker, Chapter 7

Optional Readings:

  • Becker’s chapter includes a simplified proof of Bell’s theorem, based on the work of David Mermin. For our discussion it’s not necessary to follow all the details of this proof, but those who are interested may find it helpful to look at the same proof in Mermin’s papers “Quantum Mysteries for Anyone” and/or “Is there Moon There When Nobody Looks”, which are available in Rhett's Google drive and on Discord.
  • An excellent and accessible discussion of nonlocality and Bell’s Theorem can be found in chapter 12 of Nick Herbert’s "Quantum Reality," available in ⁠Rhett's Google drive. Herbert provides a good discussion of nonlocality, and his version of Bell’s theorem is much closer Bell’s 1964 version.,
  • Bell offered his own simplified discussion of his theorem and its consequences in his amusing and largely accessible paper “Bertlemann’s Socks and the Nature of Reality”, available in ⁠Rhett's Google drive and on Discord.

During the next two or three meetings we are going to explore the “nonlocality” and “contextuality” of quantum mechanics, each of which challenges the possibility of ‘completing’ QM with “hidden variables” as hoped by Einstein. (The precise meaning of “nonlocality” and “contextuality” will be explained in our readings and during our meetings.)

The apparent nonlocality of QM was shown in a famous theorem by John Bell in 1964, as described in Chapter 7 of "What is Real?"

Two years earlier, Bell had noticed that Von Neumann’s infamously flawed “proof” against the possibility of hidden variables had depended on the false assumption that quantum properties (and any associated hidden variables) were not “contextual." The contextuality of QM was also proven in 1967 by another famous theorem, that of Kochen and Specker.

The upshot of both Bells Theorem and the KS Theorem is that hidden variables in the sense Einstein favored are impossible; if there is another "hidden layer" of QM, then it must be both nonlocal and contextual.

Meeting information:

Our live meeting will take place on Zoom.

Text-based discussions during and between live meetings will be hosted on the Blinding Cyclops Discord server. You can also find resources related to this seminar and reading assignments there. Join link: https://discord.gg/urPBsNTWuK. Channels related to this seminar can be found under the "Quantum Physics" category.

Syllabus:

We meet alternating Fridays at 4pm PT to discuss interpretations of quantum physics and the philosophy of Niels Bohr.

This seminar has begun with a close reading of a book critical of Niels Bohr, “What is Real?” by Adam Becker, so that we can become grounded in an opposing and critical viewpoint. It's also likely that we'll semi-regularly read source materials as a supplement.

Suggested secondary readings (which we’ll not cover directly but which may be referenced):

  • “Quantum Reality,” by Nick Herbert
  • “Beyond Weird,” by Philip Ball
  • “Elegance and Enigma,” edited by Maximilian Schlosshauer

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