Why is quantum mechanics non-local? (I wish someone had told me this 20 years ago.)
1,018,841
Published 2023-07-08
Last year, the Nobel Prize in physics was awarded to three physicists who allegedly found that the universe is not locally real. But what does this mean? What are the two types of non-locality? And what did Einstein's have to do with it? That's what we'll talk about today.
Some examples for models that violate measurement independence are here:
C. H. Brans, International Journal of Theoretical Physics 27, 219 (1988)
link.springer.com/article/10.1007/BF00670750
T. N. Palmer, Proc. Roy. Soc. A, 451, 585-608 (1995)
arxiv.org/abs/quant-ph/9505025
J. Degorre, S. Laplante, J. Roland, PRA 72, 062314 (2005)
arxiv.org/abs/quant-ph/0507120
M. J. W. Hall, Phys. Rev. Lett. 105, 250404 (2010)
arxiv.org/abs/1007.5518
G. S. Ciepielewski, E. Okon, D. Sudarsky
arxiv.org/abs/2008.00631
S. Donadi, S. Hossenfelder, PRA 106, 2 (2022)
arxiv.org/abs/2010.01327
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00:00 Introduction
00:39 Two types of Non-Locality
05:32 Quantum Mechanics
12:32 Local Causality
16:34 Measurement Independence
19:55 Bell's Theorem
22:39 Summary
23:32 Brilliant Sponsorship
#science #physics #quantum
All Comments (21)
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The guys who proved the violation of Bell‘s inequality won the No-Bell Prize 😂
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When Sabine said, “You’ve already watched 20 videos on Bell’s theorem and they didn’t help,” I felt that.
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I usually only understand about 50% of deep physics, but I like that your videos help nudge that percentage up to 50.1% with a 0.1% error margin either way.
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Quantum mechanics and Artificial Intelligence is being taught to the general public by journalists. It's no wonder it seems like no one understands either.
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I never thought i could be capable of both understanding something and completely not understanding that very thing at the same time.
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For all the math people out there, locality is sort of the physics version of the Intermediate Value Theorem, which states that for a continuous graph, if it passes through point A and B with coordinates (x1, y1) and (x2, y2), respectively, the graph has to go through every point in between. So locality is if the the graph is continuous and non-locality is if the graph is non-continuous, meaning it doesn’t have to pass through any of the points in between
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I've a Ph.D. in physics, and this is the best explanation of Bell's Inequality I've seen.
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Listening to Sabine I wish I could forget all the incorrect information I have listened to in my 70 years. Conditioning is a real problem as your brain keeps going back to the old patterns. Thanks for the videos. I am slowly getting a better picture…. from a person with an Arts degree. Love the dry humour as well🇨🇦
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This makes me feel more intelligent because it convinced me that if I only put a little more effort into it I would be able to understand it all. Obviously I’m not going to put that theory to the test
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The ideas of explaining non-locality with portals, the lightcone, the graphics and the entry and exit arrows are magnificient.
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This is the BEST thing I've learned in years. Thank you! Finally, someone who understands and can explain the problem with Bell's Theorem. Bless you!
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Thank you Sabine. I didn’t manage to follow the whole video, but your explanations of wave functions, collapse of wave functions, and entanglement were the most accessible that I have seen or read. They really improved my understanding. 🙏
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This was some of your best work Sabine! Apparently making peoples brains hurt and making them laugh at the same time is just what science education needs. Why the Profs thought they could be dry as an old biscuit and expect people to listen has always been beyond me?? I would've gone to your lectures instead of reading the book. That's a big statement as the book has all the knowledge you need and doesn't expect you to get out of bed or even wear pants!
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I was recently attending a course where the professor stressed that if you let go of the assumption of measurement independence, all problems go away (and you are a super determinist). So there's at least some physicists acknowledging this to their students.
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Precisely when you said "wow, you are still with me, so glad you haven't left," I was thinking that this video should win sort of educational award. It's shockingly informative.
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This taught me more about quantum mechanics than any video I’ve seen. You are truly talented to make such complex topics understandable for the layman
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Sabine’s dry humor is hilarious and makes learning complicated physics much more fun. Existential Physics is an awesome book for the same reason.
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If I had seen this video in 1981, I'd have an MS in physics today. A beautiful, clear explanation. The papers with +1and -1 are Feynman-esque. Just brilliant.
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Very nice video, even though I feel it goes over my head at some points. But trying to explain something complicated to us watchers is very much appreciated Sabine!
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This was great for me thanks. I studied physics at uni, so was already familiar with the topic. Love your witty, to the point explanations, cheers!
