Talk:Wheeler–Feynman absorber theory

Discussion on section "Modern interpretation" and Causality

The matter of causality was resolved some time ago. I have added material and references to reflect that. The Wheeler-Feynman time-symmetric theory is more important than people realize. It was a precursor to Feynman's quantum electrodynamics. It vindicated the Breit equation which has been used with success in relativistic quantum chemistry. However, the Lamb shift necessitated a self-energy term as demonstrated by Hans Bethe. Feynman and Bethe had many an intense discussion over that issue but there is still no other way to explain it. —Preceding unsigned comment added by 171.71.55.135 (talk) 23:41, 16 January 2009 (UTC)

I think there actually is. Lamb-like shift of resonance frequency can be explained as due to interaction with other bodies. One simple model is to calculate motion of an oscillator coupled directly with many other oscillators. Jaynes has shown that it is easy to get both spontaneous emission and Lamb shift behaviour in classical mechanics. See http://bayes.wustl.edu/etj/articles/prob.in.qm.pdf — Preceding unsigned comment added by 195.113.33.28 (talk) 12:04, 3 September 2012 (UTC)

The new material has been moved under the section "Modern interpretation". Also I tryed to simplify this section. I'm not up to date with the more recent developments. Are the works of Moore and Scott the only existent/relevat recent works? Davide Sangalli 00:05, 5 March 2013 (UTC)

Other change. I've moved the section "Modern interpretation" from the main page to the talk. I beleive that the references are not clear enough to put the material in the page on Wheeler-Feynman absorber theory. There are also other subsequent works on the subject which are not cited here. However none of them is commonly accepted by the scientific community. Davide Sangalli 23:01, 17 March 2013 (UTC)

It's a mistake to defer the section of "Modern Interpretation" to the talk page in my view. The resolution of causality is very important. The work of Moore and Scott is one of the very few results worthy of Physical Review Letters. Clearly it is more accepted by the community than, for example, Cramer's transactional interpretation, and certainly far better backed up mathematically and computationally. I would return it, even in a condensed form. There has been many citations to the absorber theory but largely discussion and interpretation, not actual results or proofs. We must not forget that the absorber theory remains controversial and the scientific community largely discarded it in favor of quantum field theory. Because of quantum "non-locality", many have a renewed interest in the absorber theory but they misuse it and there is so much nonsense about retro-causality. The modern interpretation is conservative and avoids that nonsense. I think it is salutary to return it. — Preceding unsigned comment added by Tonymath (talk • contribs) 08:08, 21 March 2013

Dear Tony math, Indeed I'm not sure about the "Modern interpretation". I think that "one of the few results worthy of Physical Review Letters" is, by far, a too strong statment. Two observations: (i) there are many other works on the absorber theory. Why should we accept the work of Scott and Moore as the modern interpretation? If we want a section modern interpretation we need an overview of all reasonable works. (ii) Reasonable means published on good peer-reviewd journals, as PRL which is the reference peer-revied journal for physics, but also with a good "follow up". However I see only 15 citations, less than 1 per year on average and 8 of which by Scott and Moore themselves, for the PRL in question. I'm not saying that the work is wrong, but, this is not enough to consider it as the Modern interpretation of Wheeler-Feynam Absorber theory. The work of Feynman and Wheeler has 492 citations. Why should we consider only the work of Scoot and Moore? I would be glad to have the comments of other experts in the field. Regards. Davide Sangalli 11:25, 21 March 2013 (UTC)

Actually "Modern Interpretation" is what you apparently called it in a previous version if I am not mistaken. That is why I put that in quotes! Yes, there is other work but you scrapped all mention of the work since the Wheeler-Feynman theory including the work of Hoyle and Narliker in gravity theory. I am not saying the work of Scott and Moore is the only body of work we should consider but at least it should be included in a list. I would put Scott and Moore, mention John Cramer (there is a wikipedia site for his transactional interpretation) and whatever others from the list of citations you mentioned. There are also some VERY interesting experiments in quantum entanglement related to this and by now I am sure you are aware of the work of Ed Jaynes. By completely removing even mention of this work, you have caused a severe devolution of this wikipedia article. If 15 citations is not enough for you, then by all means, add more but don't scrap mention of ALL of them! At least mention some. Mention the highlights at least. The work of Scott and Moore and Cramer and Hoyle and Narliker are amongst those significant highlights. By all means, add more if you want. BTW, I should mention few of those 492 citations reached PRL and PRL is considered the top Theoretical Physics Letter journal in the world. We're suppose to inform. Wikipedia articles are suppose to grow and cross-link to each other - not devolve! I propose the work of Moore and Scott be returned to this wikipedia site but not under the banner "Modern Interpretation" (that was never my call) but under the banner "Work since Wheeler and Feynman". Not to mention even a few highlights is a fantastic ignorance of history! I hope you will agree. — Preceding unsigned comment added by TonyMath (talk • contribs) 15:31, 21 March 2013 (UTC)

Dear TonyMath, clearly I've just expressed my opinion, i.e. why I'm not going to restore the section "modern interpretation". However, if you feel that it should be there, I do not see any reason why you cannot restore it. I just ask you, in doing so, to try to take in consideration the ideas emerged from this discussion. Likely other users will read either the article or the conversation, they will express their opinion and do their changes. A consensus could eventually emerge. This is how wikipedia and also how the scientific community work. For me this is an occasion to lear something new. Davide Sangalli 20:39, 21 March 2013 (UTC)

Rest assured, this discussion has been useful. I just wanted agreement so as to achieve the consensus you mention. I can add restore the material. By all means, you are welcome to add anything from those 492 citations you deem worthwhile to add. — Preceding unsigned comment added by TonyMath (talk • contribs) 22:46, 21 March 2013 (UTC)

My half-pennyworth: it would clearly be useful to say something (what I'm not sure) about work that has been done on absorber theory after Feynman and Wheeler. The study didn't end with them and it would be a pity not to take things further. 82.68.102.190 (talk) 10:26, 23 March 2013 (UTC)

Ok I have restored the material of Scott and Moore and also added a more fleshed-out mention of the work of Fred Hoyle, Jayant Narliker, John G. Cramer, and especially Edwin Thompson Jaynes on the Lamb shift. I hope this addresses the matter of restoration of the material (the material of Scott and Moore can be taken out out of the talk section now since it has been restored to the article itself :-) ). I am sure there are further additions other editors would like to add but I think the current ones address the highlights. There is also the work of Guang-Jiong_Ni concerning neutrinos whose work was apparently partly inspired by the absorber theory but I did not mention it unless someone can find me a strong connection. I am sure there will be connections and (hopefully) additions and other links but this is a start. At least, many of the links to other wikipedia articles (and more) have been restored.TonyMath (talk) 23:01, 24 March 2013 (UTC)

Please explain

why should we accept

E tot = the average ( and not the sum) of the retarded and advanced waves

and what is meant by "your" universe where E free = 0 and why should I accept that the difference between the sums of advanced and retarded waves are equal.

regarding: the "phenomenon of the absorption from all the particles of the universe of the radiation emitted by each single particle."

can we be sure that all radiation is absorbed by particles? at this moment not all the radiation from the big bang has been absorbed ( because it continues to be detected ). can we be sure that there will ever be a time in which all radiation has been absorbed. What about radiation absorbed by black holes. There is no symmetry there. — Preceding unsigned comment added by Davidseed (talk • contribs) 21:21, 2 June 2011 (UTC)

It's the average of retarded and advanced potentials to ensure that when the charge does not move, the potentials reduced to the standard static Coulomb potential. That's why you need the factor of 1/2. BTW, if you don't like the complications and assumptions of the absorber theory, Moore and Scott " showed that the radiation reaction can be alternatively derived using the notion that on average the net dipole moment is zero for a collection of charged particles, thereby avoiding the complications of the absorber theory." If you read the cited article in PRL, they were able to recover the radiation reaction term merely by assuming that the local net charge and the local net dipole moment to be zero on average, a condition which often exists for sufficiently large spaces. This avoids large cosmological issues but you do raise a valid point: if these conditions are not met, what are the consequences? Hope this helps. TonyMath (talk) 17:00, 29 July 2011 (UTC)

"A retarded solution"

This line in the article: "electromagnetic waves have, in general, two possible solutions: a retarded solution and an advanced one." Yeah, retarded is the appropriate word, but to someone new to the subject, it will seem like it's saying "a stupid one and a correct one." Is there another word we can use instead of retarded? --Goodbye Galaxy (talk) 14:55, 15 December 2011 (UTC)

You could perhaps add "(delayed)" in parens to clarify, but I wouldn't make up a new terminology. Dicklyon (talk) 16:10, 15 December 2011 (UTC)

Good call. I'll make the change. Goodbye Galaxy (talk) 18:14, 16 December 2011 (UTC)

Minor correction?

Should "Then, if you consider that in your universe holds the relation" actually read "Then, if you consider that if your universe holds the relation" -- the word "if" instead of "in?" The sentence is stating that when you consider the supposition that the quantitative results are zero, the following holds true, so the word "if" may be what the OP desired. — Preceding unsigned comment added by Damotclese (talk • contribs) 01:02, 15 March 2012 (UTC)

I don't see anyone suggesting a correction is expected, I assume that the article is not watched very much. Damotclese (talk) 21:19, 8 August 2013 (UTC)

Hubble Constant damping

Feynman and Wheeler, in considering the whole Universe as both emitter and absorber, certainly considered the Hubble Constant expansion of the Universe, yet I don't see Hubble in their proposed solutions. For some reason -- probably because I'm a dimwit -- I expected to see expansion terms in the equations. So I have to ask, are equations that include Hubble missing from the article?

If we were in a static, non-expanding Universe, the retarded and advanced wave would have the same distances to traverse to encompass the volume of space/time, yet in an expanding Universe, the accummulative absorber universally is undergoing an expansion, the distances that the advanced wave must travel to reach every absorber is increasing. The retarded wave could encompas the Universe in less time than the advanced wave because the volume of the Universe is less for the retarded wave, hence T-symmetry is broken for electromagnetic wave propagation and causality exists as humans perceive it.

Just seems to me that expansion solutions are missing from the article some how, yet that's probably because I don't understand what it is that Feynman-Wheeler atr proposing. Damotclese (talk) 22:08, 8 August 2013 (UTC)

The Wheeler-Feynman theory really applies to microscopic processes which are expressed in quantum electrodynamics in terms of retarded and advanced propagators, originally formulated for electromagnetic processes only. The Hubble constant is more germane to the gravitational theory of Hoyle and Narliker. Feynman explains thermodynamics beautifully in his lectures of physics (some of which you can actually find on YouTube) as the increase of disorder which I gather is the most effective explanation for the arrow of time. On a cosmological scale, the ball game is very different. TonyMath (talk) 21:34, 11 September 2013 (UTC)

If this is at all helpful Hubble's law is probably best explained by the Friedmann equations resulting from the Friedmann–Lemaître–Robertson–Walker metric which is a General Relativity model.TonyMath (talk) 11:37, 1 May 2015 (UTC)

Unreferenced

the section on Hoyle–Narlikar theory of gravity says it has been challenged by observation but gives no example so I tagged it as needing a reference. RJFJR (talk) 00:26, 19 October 2015 (UTC)

References can be found in the main article on the Hoyle-Narlikar theory i.e. Edward L. Wright. "Errors in the Steady State and Quasi-SS Models". Retrieved 7 August 2010. I would not bother adding the reference - just point towards the main article,TonyMath (talk) 11:51, 21 October 2015 (UTC)

All right, the missing reference was added.TonyMath (talk) 04:56, 23 February 2016 (UTC)

The mention of a revised Hoyle-Narliker theory of gravity called "Gravitational absorber theory" as pointed out in the article on the Woodward effect has been added. Some lines were added here as to show how the original HN theory was challenged and how the revised theory better handles recent astronomical observations. It also ties in nicely with the Woodward effect.TonyMath (talk) 08:51, 10 July 2017 (UTC)

Lede w/o condescension?

When reading this I freely admit that I am absolutely in over my head. Having said this, I genuinely believe that EVERY lede should be phrased as directly and clearly and humbly as possible. Though I do not expect to grasp the fullness of this theory, I propose (hope) that the language of the below two sentences, from the first paragraph, can be rephrased in a way that is less jarring and ego-crushing.

Indeed, there is no apparent reason for the time-reversal symmetry breaking, which singles out a preferential time direction and thus makes a distinction between past and future. A time-reversal invariant theory is more logical and elegant.

I particularly dislike being scolded by a sentence that begins: "Indeed, there is no apparent reason ...".

With a year between question and answer, I realize that I am not exactly in the most dynamic part of WP. I shall attempt to wait patiently.

In case you care how I have been so sidetracked: -- No original research -- led to -- Identifying reliable sources -- to -- Surely You're Joking Mr Feynman! -- to -- .

Gracias GeeBee60 (talk) 03:24, 16 July 2018 (UTC)

Eleven years ago someone switched from this Old revision of Wheeler–Feynman absorber theory which has language that seems much more encyclopedic. Suggest rewriters build on it. GeeBee60 (talk) 15:17, 9 September 2018 (UTC)

Sources

A good description of the motivations behind this theory can be found from Mehra (1994) The beat of a different drum : the life and science of Richard Feynman. Chapter 5: Action-at-a-distance in electrodynamics: the Wheeler-Feynman theory (archive.org) Jähmefyysikko (talk) 05:23, 27 September 2023 (UTC)

I made some headway on the first part of this article, esp. moving the motivation content away from some make-believe about time symmetry towards the physics of electromagnetism.

The biggest flaw in my mind is the confusion between micro and macro causality. The theory is derived with arguments about advanced/retarded fields; using the word causality in that part sets up a confusion with the macro argument. (Unfortunately I'm not too clear on the micro argument TBH).

I used 'arrow of time' for the macro part, but the latter part of that section is still not correct. Globally the Wheeler-Feynman theory can run either way, and the reverse-time way ultimately is discarded by various arguments independent of the micro theory.

I think the article would be better if "causal" appear only later and only in the context of explaining how it is related, rather than being part of two different unrelated aspects of the explanation. Johnjbarton (talk) 18:25, 1 November 2023 (UTC)

Misquoted reference

"Feynman and Bethe had an intense discussion over that issue, and eventually Feynman himself stated that self-interaction is needed to correctly account for this effect" cites Gleick's biography. There is no such 'stated', but more important the section in the book is about Feynmann's QED not Wheeler-Feynman absorber theory. Johnjbarton (talk) 02:12, 28 October 2023 (UTC)

I deleted the entire section. I guess this content was copied from elsewhere, it criticizes Abraham-Lorentz theory and points out the absorber theory does not have these problems. Great but there is no ref and the section was bizarrely called "Criticism".

I have found refs for absorber theory + radiation reaction and on Abraham-Lorentz + radiation reaction but none on Abraham-Lorentz + absorber. Johnjbarton (talk) 18:24, 28 October 2023 (UTC)

Big equation in the intro.

@Mgolden96 I appreciate that you are trying to improve this article. However adding the action formula without explanatory text or references to the introduction is not an improvement.

Please move the content in to the article with enough context and reference so someone can understand how it is related to the theory. Then a short summary can go in the intro.

Thanks Johnjbarton (talk) 18:38, 24 February 2024 (UTC)