Talk:Classical unified field theories

WikiProject Physics ratings

Since somebody added the {{physics}} box, I have tried to get ratings established for it. The "importance" assessment was tricky, since when one looks up the criteria this article fits between "High" and "Mid"; however, since it does provide a considerable amount of information not found elsewhere in the Wikipedia, I opted for a "High" assessment. (Note that is not supposed to mean that physicists find the topic essential.) I also nominated the article as a "Good Article", but somebody who hasn't contributed to the article needs to rate it against the GA criteria (which I think are well met, except for the optional pictures which we don't really have any use for). — DAGwyn 21:58, 4 December 2006 (UTC)

Cleanup done by DAGwyn 22:48, 15 August 2006 (UTC)

My Master's thesis was in this very field (no pun intended), which I had thoroughly researched since childhood. I provided missing text (concerning Eddington and Schroedinger) and general cleanup, especially in the section on Einstein's work. I added some primary references for the sections I edited. A few related pages such as the one on the cosmological constant also received minor edits as a side effect.

While I don't really agree with the addition of Whyte and a few other things, I left that text alone since it doesn't do any real harm.

I am removing the marker calling for page cleanup. If there is some reason to retain such a marker, feel free to add it back, but please use one of the specific tags rather than the generic one, so we will know what it is about the page that is of concern.

Unitary Field Theory of Lancelot Law Whyte added 24 May 2006 by R.J.Anderton

This approach to the Unified field theory added today, has been overlooked. It was based upon the idea of an organising process called the Unitary Principle. The experimental work on this theory was carried out by Leo Baranski.

I ripped this out. On reading it, it looked heavily dodgy. How did something written by someone (User:Roger Anderton) whose website is "www.einsteinconspiracy.co.uk" survive so long? William M. Connolley (talk) 10:25, 3 September 2012 (UTC)

Several years ago, removing it caused an editing war. The version that was left in the article was a compromise. As I noted in the Talk page, I don't think it needs to be included. — DAGwyn (talk) 19:22, 7 June 2014 (UTC)

Origin of reference to "generalized theory of gravitation"

Some people might wonder where our anon got:

The Generalized theory of gravitation's exact details are unavailable, as it was never fully published, and there is no evidence that Einstein ever worked them out. Because of this, Einstein's theory has never been accepted by physicists.

from. Its a bizarre sentence. The answer is... over at dynamic theory of gravity, where he has copied in a portion of the header there [1].

Also: as far as I can tell (from reading Pais) there is no one theory. There were many different attempts.

User:William M. Connolley

New version

I'm going to take a hand at rewriting some of this. Salsb 7 July 2005 00:29 (UTC)

Hi, Salsb, I agree and in fact I'd go further. It seems to me that this article really should be retitled "History of attempts to unify gravitation and electromagnetism". This is because there are no satisfactory theories which achieve this goal, just more or less intriguing attempts, sometimes repeated attempts by the same person, including Einstein. So, this has been an important theme in physics in the past 100 years, but certainly there are not successful theories, much less a "generalized theory of gravity", much less an unpublished theory due to Einstein. Pais is certainly the best place to start for AE's contributions in this area.---CH (talk) 09:56, 10 July 2005 (UTC)

I (dedwards@math.uga.edu) added :

Recent work by Komech ( A.I.Komech, Lectures on Quantum Mechanics (nonlinear PDE point of view), http://arxiv.org/PS_cache/math-ph/pdf/0505/0505059v4.pdf ) puts Einstein's earlier work in a more favorable light. This book realizes Einstein's Unified Field Theory Program and shows that almost all the empirical results known until the 1980's were derivable from it. From the quantum mechanical point of view, it is a local hidden variables theory and hence cannot derive EPR type results. EPR type experiments were performed in the 1980's and confirmed quantum theory; leaving viable only Bohmian style non-local hidden variable theories which are not Lorentz invariant. Such applications as quantum cryptography and quantum computing require EPR type situations. The Maxwell-Dirac system is the super-classical limit of (the not mathematically well-defined) QED.

The Einstein-Maxwell-Dirac system is a satisfactory classical unification of gravity with matter and electromagnetism. By going further to the Einstein-standard model one should be able to derive much of the predictions of the Big Bang Theory. 8:40, Oct.6, 2009. —Preceding unsigned comment added by David edwards (talk • contribs) 12:42, 6 October 2009 (UTC)

Hey, I didn't start the title, but I kept it as a reasonable title, as the early work were attempts to generalize the theory of gravity to include electromagnetism. I've been working from a review article to avoid overemphasizing Einstein's contributions. Please make contributions. I'm mostly vaguely familar with the earlier, pre-WWII work. Salsb 13:37, 10 July 2005 (UTC)

Hi, Salsb, here's why I don't feel the title is adequate:

• incorrectly suggests one establised/coherent theory, rather than a bunch of more or less intriguing (but more or less outdated) papers by various people, including but hardly limited to Einstein.
• "generalized" is misleading; the article appears to mostly concern early attempts to unify electromagnetism and gravitation, especially in the first few decades after 1915; I think "unify" is more apt than "generalize".

Assuming you agree with my take on what the article is about, I do think there is a need for such an article and I hope you will write it!---CH (talk) 08:13, 27 July 2005 (UTC)

I more or less agree with you. I don't agree with your remark on 'generalized'. At least the early work seems to be a set of attempts to generalize the differential geometry of gravity in such a way that electromagnetism came out as well, so they really were attempts to generalize gravity. Having written that, I am okay with you moving the page and putting a redirect from "Generalize theory of gravitation". The page is here because I was, and hopefully will come back to, cleaning up a messy article. Salsb 14:21, 27 July 2005 (UTC)

Hi, Salsb, good, sounds like we all agree on the main points. One quibble: we are talking about attempts to unify electromagnetism and gravitation, the two fundamental interactions which were well established in the early part of the twentieth century. It customary to speak of "unification" in this context, not "generalization". Using nonstandard terminology will just confuse students (and annoy experts). See for example the recent review by Gönner (cited below the article), where "unification" not "generalization" is used.---CH (talk) 04:08, 18 August 2005 (UTC)

Material copied from Albert Einstein by User:Harald88

CH wrote on my Talk page: What are you doing to this article? Any expansion should use the Hubert Goenner review article (see citation in previous version) as the basic source, not Albert Einstein. ---CH 21:27, 17 May 2006 (UTC) Harald88 22:18, 17 May 2006 (UTC)

Actually, no, I wrote "What are you doing to this article? Any expansion should use the Hubert Goenner review article (see citation in previous version) as the basic source, not Albert Einstein." See the difference? ---CH 07:46, 18 May 2006 (UTC)

To me it doesn't make sense to rely on a single source and to ignore what other editors already have contributed (that's POV forking). Anyway, that's (for now) not the issue; Fastfission changed a redirect of the stub Unitary field theory (which focussed on Einstein's attempts) from Albert Einstein to Classical unified field theories. Of course, that's a good idea, if indeed all the relevant info is contained under the existing header "Einstein's Geometric Approaches". However, that section was empty (!) Thus, you are invited to either: 1. expand on it (with help of all relevant sources, including the one you like), Or to: 2a. delete that section 2b. replace it with a clarification why Einstein's attempts aren't discussed in this article 2c. undo the redirect by Fastfission. You may want to discuss it with him; I don't really care. Harald88 22:18, 17 May 2006 (UTC)

I wrote "use the Hubert Goenner review article as the basic source" not "rely on a single source"! Sheesh! Have you studied the article by Goenner, Harald? If not, please read it ASAP. I think you will soon see why I feel that revised article Classical unified field theories should seek similar coverage, scope, and emphasis. This is a fine review article!---CH 07:45, 18 May 2006 (UTC)

Good that you don't insist on using a single source; I did not read that paper, and I'll be happy to read about it in Wikipedia! This here is a technical matter: we already have information from other sources as contained in Albert einstein; remains to rework it and add from that review article if you like. What matters now is that the section to which the redirect points was empty for no reason, and now again eventhough the redirect to it is still in place. If someone can improve it that will be great, but please don't simply vandalise a whole section to which a redirect was made (see editing guidelines!). See Talk:Unitary field theory and please comment there, as your actions affect that discussion. Harald88 19:21, 18 May 2006 (UTC)

Harald, what is so difficult about understanding my suggestion? I am suggesting that anyone planning major edits to Classical unified field theories, he/she/it should first study the review article by Hubert Goenner and use this as the primary source for new additions. This LRR article is available on-line and I had previously entered the citation into the article. ---CH 22:07, 18 May 2006 (UTC)

The new additions unbalance the article. And why is there a picture of Einstein's Princeton residence in this article? This article is about classical unified field theories, not about Einstein or Princeton landmarks. Please move the picture back to Albert Einstein. ---CH 22:12, 18 May 2006 (UTC)

Apparently for 1 (one) year the section remained empty, and I also won't invest time in this. But I now added a precise pointer to your info into the article space. Harald88 20:39, 23 May 2006 (UTC)

GA on hold

• Lead is too big, should be 2-3 paragraphs
• NO inline citations
• After the 1930s, fewer and fewer scientists worked on classical unification, 'fewer and fewer' ? just put fewer scientists
• However, this theory influenced Einstein's later, remove 'however'
• years alone shouldnt be wikilinked
• theory - the, do not use '-' use a comma

When these issues have been dealt with i will have another look for more problems, but you have alot of work to do. M3tal H3ad 03:00, 20 December 2006 (UTC)

I revised the article along the suggested lines, except for inline citations, which according to the official criteria are needed only for information that is likely to be challenged. Note that most of the references are not available on line, and the primary on-line reference is an extensive survey, so that linking to it is not very helpful. — DAGwyn 06:59, 21 December 2006 (UTC)

Citations don't need to be online, you can refer to books, papers and such but information about that is needed. For this article to be a GA it will require inline citations.

• Classical unified field theories should be the first thing mentioned in the article, not in the second sentence
• Any kind of pictures of anything related to the article that can be added?
• See also Gönner, 2005, external link in the middle of the text.

It's looking better but still needs a lot of work, i suggest a scientific Peer review which will give you automated suggestions on how to improve and readers will also suggest ideas. M3tal H3ad 07:17, 21 December 2006 (UTC)

The intro paragraph has to distinguish the subclass from the wider class, which is best done by mentioning the wider class first, as is typical for definitions in general. — DAGwyn 06:57, 27 December 2006 (UTC)

Pictures? Of abstruse fundamental theory? Is the goal to entertain or to inform? — DAGwyn 06:57, 27 December 2006 (UTC)

Failed. It needs in-line references. M3tal H3ad 05:23, 26 December 2006 (UTC)

As I pointed out before, the GA criteria do not require inline citations. They are called for only where points are likely to be disputed, which should not apply here since the material is a historical report. Is there an identifiable point of contention? We certainly cannot insert a reference for every single statement. — DAGwyn 06:57, 27 December 2006 (UTC)

Mendel Sachs

DAGwyn: Why do you remove the information on Mendel Sachs? - SJRubenstein —Preceding unsigned comment added by SJRubenstein (talk • contribs) 01:25, 17 August 2010 (UTC)

The reasons were given in the edit description. The cited reference didn't support the text that had been added, and disrupted the nice closing of the previous text. Sachs evidently did not publish a complete theory like the others(*) in the article, and certainly did not "complete" Einstein's work.. If we were to start mentioning relatively minor contributions, there are numerous candidates from more recent times, Penrose's twistor theory for example. Since later work of this sort borrowed ideas more heavily from quantum theory, it doesn't really fit the theme of the article.

(*) The existing text concerning Whyte could also be challenged as referring to an incomplete theory, but attempts to remove the associated text turned into an "editing war", ending in a compromise in which the text remained but was adjusted to more accurately reflect the status of Whyte's work. The article would be improved by excising the section on Whyte, but I don't want to instigate that at this time. — DAGwyn (talk) 01:45, 6 September 2010 (UTC)

Since the preceding comment, some other editor removed the section on Whyte, and no editing war ensued (unlike a previous attempt to excise it). I think that was an improvement. — DAGwyn (talk) 08:28, 7 August 2015 (UTC)

Einstein's geometric approaches (On Why Electromagnetism curves spacetime)

The first sentence in this section describes mass-energy equivalence as being pivotal to understand why the electromagnetic field energy has a corresponding stress-energy tensor. This actually threw me off a bit while trying to understand Einstein's approach to a classical unified field theory. If mass-energy equivalence was the reason the electromagnetic field energy had a stress-energy tensor, then wouldn't every form of energy curve spacetime? Heat energy should curve spacetime. Sound should curve spacetime. All via mass-energy equivalence.

I feel a more valid explanation has to do with the fact that the electromagnetic field energy creates attractive and repulsive forces via electrical charges. And given that general relativity describes the attractive forces of gravity with stress energy tensors/spacetime curvature, one would expect that a field theory unifying gravity and electromagnetism would also represent the attractive/repulsive forces of electromagnetism with stress-energy tensors/spacetime curvature. Tamedu quaternion (talk) 22:24, 13 May 2022 (UTC).