Sidney Coleman Is My Interpretation-of-Quantum-Mechanics Guru; Plus BRIEFLY NOTED: for 2021-12-17 We
The talk that made me a many-worlds Everettian; plus things that went whizzing by that I want to remember...
I have long loved Sidney Coleman’s 1994 Quantum Mechanics in Your Facelecture. Now it has been published, for real, with well-drawn versions of the slides:
Sidney Coleman: Quantum Mechanics in Your Face: Transcript and slides edited by Martin Greiter: ’This is a write-up of Sidney Coleman’s classic lecture first given as a Dirac Lecture at Cambridge University and later recorded when repeated at the New England sectional meeting of the American Physical Society (April 9, 1994). My sources have been this recording and a copy of the slides Sidney send to me after he gave the lecture as a Physics Colloquium at Stanford University some time between 1995 and 1998. To preserve both the scientific content and most of the charm, I have kept the editing to a minimum, but did add a bibliography containing the references Sidney mentioned.—MG…
And, of course, there still is the video: Sidney Coleman (1994): Quantum Mechanics in Your Face <https://www.youtube.com/watch?v=EtyNMlXN-sw>:
Plus there is the essential reading:
N. David Mermin: What’s Wrong with These Elements of Reality?<https://pdfs.semanticscholar.org/3d27/ad8d1cee3a12b35b4e424b9c36ec424ecc6e.pdf>
N. David Mermin: Is the Moon There When Nobody Looks?: Reality & the Quantum Theory <https://physics.csuchico.edu/kagan/435B/problems/Mermin.pdf>
N. David Mermin (1990): Quantum Mysteries Revisited <http://www.physics.smu.edu/scalise/P5382fa15/Mermin1990a.pdf>
Daniel M. Greenberger, Michael A. Horne, & Anton Zeilinger: Going Beyond Bell’s Theorem <https://arxiv.org/pdf/0712.0921.pdf>
Wojciech H. Zurek: Decoherence & the Transition from Quantum to Classical—Revisited <https://arxiv.org/pdf/quant-ph/0306072.pdf>
You know, i used to think that I would—someday—understand electron spin.
I used to think that I would—someday—understand why Stern-Gerlach magnets arranged along the x-axis would knock an electron that was in the <↑| state in the z-basis into the z-basis <↓| . And I used to think I would—someday—understand why if we rotated the magnets into the y-direction the little square-root-of-minus-one i’s would start appearing in the math…
Now I know that it is hopeless.
And, similarly, it is hopeless to ask why the triple measurement σ(1x)σ(2y)σ(3z) applied to the three electrons 1, 2, and 3 that are in Coleman’s entangled (<↑↑↑| - <↓↓↓|) state always produce the answer +1.
It is the Pauli matrices that are the underlying reality—or, at least, are our only through-a-glass-darkly shadowy and illusory simulacrum of understanding. They are not the things that can be explained in terms of more fundamental principles. They are, rather, our feeble monkey-brain grasp of what the fundamental data are.
All of which is to say that Sydney Coleman’s Quantum Mechanics in Your Facelecture—the title of which, I am told in good authority, is incomprehensible to Britishers, save that they suspect and fear that it is in some way obscene—is the best thing on the interpretation of quantum mechanics I have seen.
And if it does not convince you to be a root-and-branch Everettian many-worlder—well, then I think that, back in The Day, there would have been nothing to convince you to be a non-Ptolemaic Copernican either. The Copernican points would have whizzed by: In the Copernican model there is no unmotivated sharp division between the behavior of the inferior and the superior planets as there is in the Ptolemaic model? You would have shrugged. The peculiar coincidence in the Ptolemaic model that all of the planets have at least one epicycle that is the same as the main cycle of the sun, which lacks an epicycle? You would have stared blank-eyed.
If Coleman doesn’t convince you now. Copernicus would not have convinced you then…
Very Briefly Noted:
Arun Venkatesan: The Iconic Watches That Inspired Apple Watch Faces <https://www.arun.is/blog/apple-watch-faces/>
Econ 135: 4.3.3., 4.4.3., & 4.5.3. Zoom Session: Globalization, Convergence, & Underdevelopment :: Slides <https://www.bradford-delong.com/2021/03/econ-135-433-443-453-zoom-session-globalization-convergence-underdevelopment-slides.html>
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