Corbinon Lobsters • Recommends
Bell's Theorem: The Quantum Venn Diagram Paradox (2017)
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#bell'stheorem#quantummechanics#polarizingfilters
Bell's Theorem: The Quantum Venn Diagram Paradox
minutephysics
5.9M subscribers • 5 videos on Hallway
- Recommended by 9 people: 8 on Hacker News and 1 on Lobsters.
- A classic. People kept recommending it from 2019 to 2024.
- Linked in the descriptionarXiv 1408.1826arXiv 1508.05949Paper on dx.doi.org
Beginner. No background in the topic needed.
8M views9 years ago9 recommendations
Computer scienceQuantum computingMath for programmersComputation and complexity
MinutePhysics and 3Blue1Brown explain Bell's theorem and quantum entanglement using polarizing filters and a Venn diagram paradox.
Featuring 3Blue1Brown Watch the 2nd video on 3Blue1Brown here: youtube.com/watch?v=MzRCDLre1b4 Support MinutePhysics on Patreon! patreon.com/minutephysics Link to Patreon Supporters: minutephysics.com/supporters/ This video is about Bell's Theorem, one of the most fascinating results in 20th century physics. Even though Albert Einstein (together with collaborators in the EPR Paradox paper) wanted to show that quantum mechanics must be incomplete because it was nonlocal (he didn't like "spooky action at a distance"), John Bell managed to prove that any local real hidden variable theory would have to satisfy certain simple statistical properties that quantum mechanical experiments (and the theory that describes them) violate. Since then, GHZ and others have managed to extend the theoretical work, and Alain Aspect performed the first Bell test experiment in the late 1980s. Thanks to Vince Rubinetti for the music: soundcloud.com/vincerubinetti/one-two-zeta And thanks to Evan Miyazono, Aatish Bhatia, and Jasper Palfree for discussions and camaraderie during some of the inception of this video. REFERENCES: John Bell's Original Paper: inspirehep.net/record/31657/files/vol1p195-200_001.pdf Quantum Theory and Reality: scientificamerican.com/media/pdf/197911_0158.pdf "What Bell Did" By Tim Maudlin: arxiv.org/pdf/1408.1826 Bell's Theorem on Wikipedia: en.wikipedia.org/wiki/Bell%27s_theorem 2015 experimental confirmation that QM violates Bell's theorem: arxiv.org/pdf/1508.05949.pdf journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.250402 Bell's Theorem without Inequalities (GHZ): dx.doi.org/10.1119/1.16243 Kochen-Specker Theorem: en.wikipedia.org/wiki/Kochen–Specker_theorem MinutePhysics is on twitter - @minutephysics And facebook - facebook.com/minutephysics And Google+ (does anyone use this any more?) - bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry ReichWhy it's here
9 people recommend this, 3 dispute itWhat people say. Recommended as an exceptionally clear, accessible explanation of Bell's theorem and the non-classical nature of quantum mechanics.
justinpombrioon Hacker News • Recommends
On “How random can you be?”
> Are you saying an omniscient being is impossible, because something about quantum mechanics implies that it is impossible to possess all possible knowledge? > Or are you saying that even if an omniscient being possesses all possible knowledge, they would nevertheless be unable to accurately predict all sequences because of some knowledge we have about quantum mechanics? That's an extremely astute question. I'm impressed that you managed to realize that that's an important distinction and that you don't know which it is. It's actually the latter, and incredibly we can prove it. And the proof of this is surprisingly accessible: link to this video
cdumleron Hacker News • Recommends
On “Quantum supremacy: the gloves are off”
My goal wasn't to explain a "correct" view quantum physics, only to demonstrate at a cursory level that a binary computer's bits differs from a quantum computer's qbits. Quantum physics is not intuitive and attempting to use a classical understanding of probability will get you in trouble. I highly suggest looking at videos on YouTube, which have a far better explanations on the actual behavior of quantum computation. This is a very good video on Bell's Inequality: link to this video
arson Hacker News • Recommends
On “Ask HN: What scientific phenomenon do you wish someone would explain better?”
Why Quantum Mechanics I have no idea. Why interpretations: There is an experiment you can do that is hard to explain: Either particles are able to somehow influence each other faster than light (non-local), or the particle somehow doesn't exist except when interacting with some other particle (non-real). Try this video: link to this video the AHA moment in the video comes when you realize you can entangle the light and that adding a filter by one stream of light somehow causes the other stream of light to also be influenced.
monocasaon Hacker News • Recommends
On “Ask HN: What scientific phenomenon do you wish someone would explain better?”
Minute Physics and 3brown1blue did a two part collab that simplifies some of it down to a counting problem that'd be suitable for grade school. link to this video link
vulcan01on Hacker News • Recommends
On “Ask HN: What scientific phenomenon do you wish someone would explain better?”
I found these two videos very helpful in understanding the quantum nature of light after being stuck in the same spot: link to this video link (Watch those in order, because they're a collaboration between two YouTubers)
simcop2387on Hacker News • Recommends
On “What did Einstein mean by “spooky action at a distance”?”
Part of this is because of tests like the ones involved with Bells theorem. Minute physics does a better job explaining it then I can. link to this video
tsimionescuon Hacker News • Recommends
On “What did Einstein mean by “spooky action at a distance”?”
I can also suggest a video that seemed to me to explain Bell's theorem and what it means that the correlations are stronger than classically possible here: 0 link to this video
demurgoson Hacker News • Recommends
On “Inside the proton, the ‘most complicated thing you could possibly imagine’”
I really enjoyed this Minute Physics and 3Blue1Brown video describing hidden variables and Bell's theorem: link to this video As you said, it's implies that we're not failing to measure some "hidden variable" that would explain probabilities away, but that the vary nature of these objects is probabilistic.
astrangeon Hacker News • Disputes
On “My mental model of how alpha opacity works is wrong (2020)”
It's claimed that polarization is due to quantum effects. link to this video …I think it actually isn't and the people explaining it have just forgotten it's supposed to be a metaphor though.
avodonosovon Hacker News • Disputes
On “Third-polarizing-filter experiment demystified (2004)”
…filter, the first photon will be affected - it will get a chance to pass though the pair of filters. That they say is "spooky action at distance" - the second photon will influence behaviour of the first photon at the remote site of the experiment and the "influence" is faster then the speed of light. Example here by MinutePhysics and 3Blue1Brown: link to this video Explanation about entanglement starts at around 8:50. But even with that addressed, to me personally this video is not satisfying. If the spooky action at distance can be observed so trivially - choosing a filter at one site site affects what happens at the remote site - we don't need a mathematical inequality (the Bell's inequality), it's…
bowsamicon Hacker News • Disputes
On “Third-polarizing-filter experiment demystified (2004)”
Yeah it is a common misconception. There is also a minutephysics video on it ( link to this video ) that portrays the effect of polarising filters in a misleading/wrong way, leading to further confusion. Polarisation is used in many books and courses as a familiar classical system, which we then use to springboard into Stern-Gerlach, which actually is an inherently quantum effect. Polarisation already appears when writing down the full solution to the classical EM wave equation. On the other hand, the similar effect seen in the Stern-Gerlach experiment with the angular momentum measurements is not: the non-commutivity of the angular momentum operator for different measurement axes is a purely quantum p…
zwkrton Hacker News • Mentions
On “Imaging Bell-type nonlocal behavior”
…that either quantum objects experience instantaneous action-at-a-distance (locality), or they do not have actualized measurement values when they aren’t being actively measured (realism). This paper is showing a way to produce a visual image of a bell inequality and explores ways that these inequalities can be used for other visual techniques. 1 link to this video…
ahelweron Hacker News • Mentions
On “Build a toy quantum computer at home”
This is incorrect edit: it isn't - see the standard "three polarizing filter" experiment 0 which is impossible to explain with classical mechanics edit: it can actually be explained, see coolgod's comment below. Polarizing filters don't just zero out the perpendicular component of an electric wave, they measure each individual photon that passes through and either blocks it or permits it to pass with some probability proportional to the angle between the photon's polarization and the filter's polarization. 0 link to this video
Kednicmaon Hacker News • Mentions
On “The Knowledge Machine: How Irrationality Created Modern Science”
0 is a 20min video which you can replicate for $20 at a convenience store. 1 has Conway explaining in detail, although it's not excruciating. I don't see why the burden of proof is on me; Bell's inequalities are not new. 0 link to this video 1 link
ksajon Hacker News • Mentions
On “OPhysics: Interactive Physics Simulations”
…t the same as the double-slit example, but is related to it. Either way, this site is really good. Unfortunately the first thing I tried to replicate didn't work because they haven't taken quantum effects into account. Here is a video about the effect with 3 polarized lenses - it sounds crazy enough I want to add a bit of proof to avoid downvotes: link to this video And here is Action Labs demonstrating something related, where light seemingly shines through a solid ball for a slightly different, but not unrelated reason: link…