Talk:Wave–particle duality

Consequences section is marginal
Most of it is a repeat, plus it overstates the role of Scroedinger's equation -- there is more to QM. Ldm1954 (talk) 08:35, 4 September 2023 (UTC)


 * Agreed. Perhaps remove the redundant parts and combine the rest with Classical waves and particles? The last paragraph of that section is supposed to discuss quantum dynamics and how it differs from classical dynamics. Jähmefyysikko (talk) 08:41, 4 September 2023 (UTC)
 * I put in some consequences in terms of where probability leads to charge density and DFT. Thoughts? Ldm1954 (talk) 11:37, 4 September 2023 (UTC)
 * I agree that the use of the Schrödinger wave equation is not fundamental, but just one of the ways to do QM calculations. I assume that dicussion about DFT is an attempt to balance this? From the current text, the motivation is not obvious. Jähmefyysikko (talk) 12:36, 4 September 2023 (UTC)
 * I agree. It was an attempt which was lame. I cannot justify it, there are no consequences to the concept IMHO.
 * Also, some horrible errors in the history had crept in. Electron diffraction is NOT de Broglie, even he said that. It is Schroedinger's equation and (better) Bethe's work. Even the first papers did not match the de Broglie wavelength.
 * Also, why have photons vanished? This is a key part of duality, at least as big as matter waves.
 * Delete if you don't like. Ldm1954 (talk) 13:37, 4 September 2023 (UTC)
 * N.B., feel free to take anything from User:Ldm1954/Sandbox/Duality. That was jointly developed with User:Johnjbarton and he appears to have already included parts of it. Ldm1954 (talk) 13:48, 4 September 2023 (UTC)
 * @Ldm1954 I'm traveling and not editing, but I believe my version of our work was moved into the article, then a bunch of cruft from the old one added. Johnjbarton (talk) 14:13, 4 September 2023 (UTC)

Proposed deletion and replace by redirect to Double-slit>
I am repeating User:XOR'easter suggestion with a more specific suggestion that we replace it by a redirect to Double-slit experiment. That is a well-written older article with much, much more detail and many more citations and images. There is nothing in this current version that is not already better in that article. Votes please:

* Option 1: Redirect

* Option 2: Keep Ldm1954 (talk) 20:55, 4 September 2023 (UTC)


 * @Ldm1954 if I understand correctly you propose to replace the wave-particle duality article with a redirect to double slit? Johnjbarton (talk) 21:32, 4 September 2023 (UTC)
 * Yes Ldm1954 (talk) 21:41, 4 September 2023 (UTC)
 * @Ldm1954 Redirect Johnjbarton (talk) 22:32, 4 September 2023 (UTC)
 * Comment. Wave-particle duality has a large historical component, a part of which would be out of place on Double-slit experiment (e.g. photoelectric effect). An alternative could be to retain the history here, and make the rest into a brief summary of the Double-slit article with hatnote . Jähmefyysikko (talk) 04:18, 5 September 2023 (UTC)
 * @Jähmefyysikko Tomorrow I can check that the History article contains similar material and that they connect to the duality phrase (which isn't however historical).
 * I don't see a practical way to keep this article fixed on history. Everyone has an opinion on this topic. Johnjbarton (talk) 20:08, 5 September 2023 (UTC)
 * Comment I have yet to formulate a strong opinion about what should be done. Redirecting to double-slit experiment isn't a bad idea. We might need to add a short paragraph over there saying something like, "In the early years of quantum physics, the term wave-particle duality was introduced to express the idea that quantum phenomena exhibit both wave-like and particle-like behavior. The photoelectric effect and Compton scattering show that light has a particulate aspect, while interference experiments display its wave aspect. Likewise, [something about electrons]. Quantum mechanics resolves the seeming contradictions by saying that the probability for detecting a particle in one place or another is calculated from the solution to a wave equation. Moreover, [something about how detecting trajectories makes interference fringes vanish]. While some authors have criticized the "duality" terminology as being imprecise or only of historical interest, it remains in use..." I can also see the merit of Jähmefyysikko's suggestion to retain the history and give a synopsis of the double-slit experiment. However, that might be redundant with History of quantum mechanics. XOR&#39;easter (talk) 16:31, 5 September 2023 (UTC)
 * While another article may very well be 'older', please note that this one has existed for over 22 years. (see original article text from October 2001)
 * As re-directed links can drastically reduce usability of Wikipedia for casual users, any proposals to redirect long-established article titles should be very carefully considered.
 * -- Jim Grisham (talk) 21:48, 14 January 2024 (UTC)
 * @Jim Grisham Back in Sept 2023 we completely re-wrote this article. The merge discussion never progressed beyond these few comments and mainly served help us make a decision to rewrite. Johnjbarton (talk) 17:15, 15 January 2024 (UTC)

Particle-wave reverted.
I want to explain my revert for a long section I believe was added in good faith.

I reverted a new section called "Particle waves". The name comes from a Feynman lecture: This term is not common. The added text says: but Feynman does not say this nor is the a reference for this claim.
 * The quantum behavior of atomic objects (electrons, protons, neutrons, photons, and so on) is the same for all, they are all “particle waves,” or whatever you want to call them.
 * (the term is used to reflect the property of wave-particle duality)

Wave-particle duality is sometimes considered a "property" but this is not the historic nor mainstream point of view. Rather duality is an observed phenomenon. In my opinion non-mainstream terms like "particle wave" and "wavicle" perpetuate this confusing concept. Nothing is both a particle and a wave: these are different classical macroscopic concepts jammed together.

The rest of the text consisted of a paragraph on Copenhagen and one on anti-Copenhagen. These are not about wave-particle duality. They introduce an off-topic controversy that does not pertain to the article. These subjects are well covered in other articles. Johnjbarton (talk) 15:37, 22 March 2024 (UTC)

@Johnjbarton Thank you for the detailed explanation of why you removed the section on the explanation of the particle wave.

For the use of word “particle wave”, when I was weighing which phrase to use, I had a similar concern just like you have that “particle wave” may not be popularly enough. Interestingly, when I entered “particle wave”, Wiki automatically redirected me to the “Wave-particle duality” article. That’s why I decided to go with the “particle wave”. I think “particle wave” is a nice representation of the quantum behavior of a particle (i.e., wave-particle duality). Of course, to make it more clear to most readers, other suggested terms are welcome.

Wave-particle duality of quantum particle/wave is a known quantum phenomenon. To enrich the article, the explanation for this quantum behavior is needed. Copenhagen interpretation is an important explanation to wave-particle duality. The discussion of the statistical interpretation of the wave-particle duality well fit into the content of this article. I tried to briefly summarize the mainstream explanation and the criticism to it.

One more thing, I found the peer review page of the wave-particle duality article pretty useful. The discussions there give me good inspirations on how to improve the article. Spinecho001 (talk) 10:26, 23 March 2024 (UTC)


 * @Spinecho001 Thanks for your clear reply.
 * 'I think “particle wave” is a nice representation of the quantum behavior of a particle'
 * At least as I understand it, I completely disagree. What is the "representation" equal to 'particle wave'? Here we have to nouns with diametrically opposed meanings and centuries of lengthy arguments by one side against another. Presenting them in conjunction creates an illusion of harmony clouding the nature of the historical debates and the physics of quantum mechanics.
 * "explanation for this quantum behavior is needed."
 * I agree.
 * "Copenhagen interpretation is an important explanation"
 * I completely disagree. We should briefly summarize the quantum mechanical description as it might appear in textbooks. We could include a sentence in the history section connecting duality and QM theory as well. I oppose any discussion of "interpretations" unless we have specific references connecting interpretations to duality and sufficient balance across major interpretations.
 * "I found the peer review page"
 * That page of course discusses the article before the TNT event. In replacing the old page we had a lot of discussion. We completely avoided math and generally avoided theory to be consistent with the nature of the topic. Duality is an experimental observation, a crystallization of the idea that we cannot use 'particle' models or 'wave' models for quanta. Duality is not a consequence of theory as I believe was implied by the mathematical approach of the old article. Johnjbarton (talk) 16:37, 23 March 2024 (UTC)
 * That page of course discusses the article before the TNT event. In replacing the old page we had a lot of discussion. We completely avoided math and generally avoided theory to be consistent with the nature of the topic. Duality is an experimental observation, a crystallization of the idea that we cannot use 'particle' models or 'wave' models for quanta. Duality is not a consequence of theory as I believe was implied by the mathematical approach of the old article. Johnjbarton (talk) 16:37, 23 March 2024 (UTC)

"Particle wave" listed at Redirects for discussion
The redirect [//en.wikipedia.org/w/index.php?title=Particle_wave&redirect=no Particle wave] has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at  until a consensus is reached. Johnjbarton (talk) 15:33, 23 March 2024 (UTC)

Proposal for section on quantum mechanics description of duality.
@Spinecho001 suggests that this article needs a QM explanation. I agree but believe our ideas of such a section may be far apart. I wrote my version here User:Johnjbarton/sandbox/duality. We can discuss User talk:Johnjbarton/sandbox/duality or here. In any case I will add refs before moving into article. Johnjbarton (talk) 18:20, 23 March 2024 (UTC)