# Talk:Electromagnetism

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## Animation of lightning at top of page

Is having a distracting animation of lightning at the top of this page appropriate for electromagnetism? that animation would be better on the lighting article and certainly not at the top of any page. — Preceding unsigned comment added by 124.176.51.109 (talk) 07:06, 13 December 2012 (UTC)

Agreed. I've cut the two images entirely; I don't think the reader really benefits in their understanding of electromagnetism by being shown what a magnet and some lightning look like. --McGeddon (talk) 17:58, 20 February 2013 (UTC)

---

This article, being a gateway, should have some illustrations. I agree that the lightning bolt animation is very distracting, and a image of a bar magnet doing notiong is of no value whatever. I kind of liked the idea of a static lightning bolt, but I'm not sure what its point is relative to electromagnetism. Given that, are there illustrations that would be useful, e.g. a photo of "lines of force" around both a bar magnet and an electromagnet made with iron filings (the point being that electric current makes "magnetism", and this is the same "stuff" as a bar-magnet's "magnetism"), and an equivalent electrostatics photo-image? (Good luck creating that one!) An electromagnet hanging by thin wires in a gravitational field (like a pendulum) and being pulled sideways by another electromagnet? (Easy to do). Ditto for a tinfoil-covered styrofoam ball being repelled by a charged plate? (Not so easy; this one I found as a problem in a physics text in a chapter on the electric field -- to calculate the angle from vertical; cf Sears and Zemanski 1964:564 problem 25-11, also p. 538 problem 24-4). As a kid I learned about "magnetism" from iron-filing making lines of force, and the experience that two magnets either repel or attract. Electrostatics I learned from charged balloons repelling or attracting, and scuffing my feet to make sparks (and to light up a neon light). That they are equivalent "stuff" in different forms is not a trivial factoid -- what you'd need to illustrate the idea is a triboelectrically-charged leaf-electroscope hooked to a Leyden jar that, when discharged through a coil of wire, moves a compass-needle. Thoughts? BillWvbailey (talk) 15:39, 21 February 2013 (UTC)

## 0 / 10

Intro fails to clearly describe what the relationship between electricity and magnetism is.

Article fails to clearly describe how much magnetic force is generated from a known quantity of electricity. — Preceding unsigned comment added by 49.181.91.233 (talk) 11:39, 27 September 2013 (UTC)

## Inventors

I was wondering since people like Tesla and troy reed made electro-magnetic vehicles, and I did recently to add a small section on its historical accuracy. TBh, there are a few dozen inventers. Electro-magnetic car inventors are actually in yildiz, troy reed, wasif kahloon, tesla are a few of them. They work with plasma or a highly advanced form of hho (a battery system) with electromagnetic induction motors even. — Preceding unsigned comment added by 69.255.25.193 (talk) 20:55, 6 July 2014 (UTC)

## Unraveling a design problem

One of the design's problems has been antennas in the circuits. However, a team of researchers in university of Cambridge have invented a new way and is to integrate the antenna on the chip. last frontier of semiconductor design would be a massive leap forward for wireless communications.

MansourJE (talk) 12:40, 10 April 2015 (UTC)

Is zero negative or positive? Sandeepsiddu01 (talk) 06:06, 12 April 2016 (UTC)

Your question is not relevant to electromagnetism. Try asking at Talk:Zero. — Cheers, Steelpillow (Talk) 07:00, 12 April 2016 (UTC)
Better still, since this question is not about improving an article, you could try Wikipedia:Reference_desk/Mathematics. 15:57, 12 April 2016 (UTC)

## Chaotic and emergent phenomena

This section seems to be fringe or speculative science. Should it be part of the article?

Thanks @Constant314 :-) if you had to single out specific points about the section, what aspects in particular do you find to be too speculative or fringe? Previous edits claimed that QED could explain all aspects of electromagnetic phenomena, which I would be concerned about. How do we show readers that there are many electromagnetic phenomena which cannot be explained by (even by the quantum) linear electromagnetic equations i.e. Aharonov–Bohm effect, Beltrami plasma vortices, phase changes associated with superconductivity etc.Sparkyscience (talk) 21:30, 4 November 2016 (UTC)
I don’t know, so I am flagging the section for others to examine. But my concerns are two. In any article there is always the tension between not enough information and too much. An article about electromagnetism, reasonably could go into the QED under-pinning. A “something is wrong with QED” section is two steps removed from the subject of the article. It rightly goes into an article on QED. That’s my opinion. Secondly, a “QED doesn’t work” statement is extraordinary. I would want to see solid secondary references such as main line university physics text books. Let’s examine the statement that Aharonov–Bohm effect cannot be explained by QED. Scientific theories never explain anything; they make predictions. From my admittedly dated readings about the Aharonov–Bohm effect was that it was predicted by QED and that is what led to the experiment. Are you suggesting that AB is not predictable from QED? Constant314 (talk) 22:06, 4 November 2016 (UTC)
Hi Constant314, thanks for going through your valid points and sorry its been a while to get back to you. I completely understand the concerns raised. I suppose the real point that I'm trying to get across is not that "QED is wrong" or a point which is two steps removed from electromagnetism. I agree such things would be too far down the rabbit hole for this article; if this is how the current revision appears to the reader then current version must be changed. What i'm trying to do (...rather badly?) is emphasise an aspect about electromagnetism that is orthogonal to both classical and quantum electrodynamics, the aspect of nonlinearity.
The thing that is of note about the AB effect is not that it it is a quantum phenomena... but that it is non-local. i.e. the effects occur when there is a nontrivial field potential leading to forces which are not local in nature and therefore we sometimes require non-Abelian commutation relations, where potentials can be used to create local-to-global effects, to make accurate predictions. Beltrami plasma vortices can be understood on purely on classical terms (i.e not a two steps removed quantum phenomena), but again cannot be understood through your typical linear equations, same thing with superconductivity phase transitions and the Tesla circuit example... There's more to electromagnetism then Maxwell's equations (or quantized versions) would have you believe, and these effects should be highlighted, because they make electromagnetism interesting!
As an aside, I did not make a "QED is wrong" statement, but i can see why you might have interpreted the above remark as such, QED works great if you can apply perturbation theory, i.e. nonlinearity converges to a simplified linear problem, but this isn't always the case. In my edit on the page, I corrected the article from "All electromagnetic phenomena can be explained in terms of quantum mechanics, specifically by quantum electrodynamics" to "[QED gives] extremely accurate predictions of quantities like the Lamb shift and measurement of the magnetic moment of the electron...[and] is one of the most accurate theories known to physics in situations where perturbation theory can be applied.
I would recommend skimming over Barret & Grimes (1995)[1] to get a clearer picture of what I'm trying to get across with respect to nonlinearity. The forward by Roger Penrose seems prescient to our current conversation:
"There can be little doubt that Maxwell's equations constitute one of the great landmarks in physical theory. Their basic accuracy has been confirmed innumerable times, in many different types of experiment. Their invariance properties led Einstein to his special theory of relativity. Moreover, their gauge-theoretic interpretations led to non-Abelian generalizations, fundamental to modern particle physics. Their elegant mathematical form has provided several important influences on the development of mathematics itself.
These facts should not, however, deter theoretical or experimental physicists from seeking alternative descriptions, unconventional formulations, surprising electromagnetic effects, or radical generalizations. The various articles in this book provide the reader with a great variety of different kinds of approach to developments of this nature. We have historically motivated accounts, suggestions for new experiments, unconventional viewpoints and attempts at generalizations. We also see novel and ingenious formulations of electromagnetic theory of various different kinds.
I am sure that this book will make it clear that electromagnetism is a subject that is in no way closed to simulating new developments. It is very much alive as a source of fruitful new ideas."
Perhaps some rewording to this effect would be useful in highlighting to the reader that what we know about electromagnetism has had a huge impact but that it is not a closed subject? I'm not sure I've done that by any means. As for what i've already written, I certainly don't mind re-edits if not complete revision. The electromagnetism article does need a lot of work. I would be wary of wholesale deletion of the section. So long as we make it clear in the article what is well established within electromagnetism (which of course should be the majority of the article) and what is not well established i feel this subject matter which you have termed "fringe" or "speculative" (...I can't see any overtly dodgy references?) is in fact the "cutting edge" and does have a place on the article. Science, after all, is not a set of facts in textbooks but a method and process of discovery. Sparkyscience (talk) 11:42, 7 November 2016 (UTC)
I'm not suggesting that theoretical or experimental physicists should be deterred from seeking alternative descriptions, unconventional formulations but that rather that alternative descriptions don't belong in this article until they become main stream.
But lets look at Aharonov–Bohm effect. What about this is not local?Constant314 (talk) 18:12, 7 November 2016 (UTC)
Aharonov et al. (2016) "We have shown that the Aharonov-Bohm effect has two distinct aspects, one continuous and one instantaneous. The latter is manifestly nonlocal; it underlines the necessity of describing quantum systems via gauge-dependent quantities rather than local forces, which cannot account for abrupt changes in modular velocity."[2]
You seem to be offering very little in the way of references to back up your (currently subjective) opinion that this is fringe, speculative or not mainstream. If it is a peer reviewed journal, or it is a published article by a univeristy professor in a textbook, I think most would agree that you can not just dismiss the scientific points raised in the edit with the hand-waving you have thus far done; it needs to debated with countering peer reviewed argument of equal merit. To my mind gauge theories, non-abelian groups, nonlinearity are very well developed scientific concepts and have a place in electromagnetic theory and have many interesting and surprising results that a reader may be interested in... If you have any references to back up your opinion that they have no place in electromagnetic theory... that's great... but so far you've said you "don't know" what parts in particular you want to flag...I fear you are merely operating on a hunch...or because you are not familiar with this aspect of the subject matter that must mean it is somehow wrong...
I apologize if I sound like I'm cross examining you. I'm just asking you what the references say since I don't have access to them.Constant314 (talk) 17:10, 8 November 2016 (UTC)

References

1. ^ Barrett, Terence William; Grimes, Dale M. (1995). Advanced Electromagnetism: Foundations, Theory and Applications. World Scientific. ISBN 9789810220952.
2. ^ Aharonov, Yakir; Cohen, Eliahu; Rohrlich, Daniel (2016). "Nonlocality of the Aharonov-Bohm" (PDF). Phys. Rev. A. 93 (4): 042110. arXiv:1502.05716. doi:10.1103/PhysRevA.93.042110.

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## Nearly all physical and chemical things are explained by electromagnetism & gravity?

Wikipedia says: "The electromagnetic force is responsible for practically all phenomena one encounters in daily life above the nuclear scale, with the exception of gravity. The electromagnetic force is also involved in all forms of chemical phenomena".

If I sit in a phycics or chemistry class, and watch my teacher do some physics and chemistry demonstrations, are 100% of them explained by electomagnetic force & gravity? (At high school or university).

You can assume my teacher does not own a nuclear reactor or a particle accelerator.

If there are important exceptions, please tell.

--ee1518 (talk) 15:37, 19 May 2019 (UTC)

Feynman in his book QED says that the electromagnetic force is responsible for all everyday phenomena except gravity and radioactivity. Radioactivity is caused by nuclear forces, so the Wikipedia statement is correct, but I would have stated it as Feynman stated it. If you have and old watch with radium coated numerals, the glowing in the dark would be due to radioactivity. Also, the sun is powered by radioactive processes. Constant314 (talk) 15:55, 19 May 2019 (UTC)
Does your chemistry teacher have a set of radioactive Fiestaware? Mine did! XOR'easter (talk) 18:44, 19 May 2019 (UTC)

Since I can edit: the text of the Pauli exclusion principle in the section on fundamental forces is linked to the article about the Heisenberg uncertainty principle, not to the article about the Pauli exclusion principle. As I assume this is wrong maybe some of the priviledged editors can correct this link.2601:280:4B00:590D:49DD:4267:E71:58E6 (talk) 19:41, 26 June 2019 (UTC)

Not sure what you are asking, but if you want to suggest an edit to Pauli exclusion principle then you need to make the suggestion on the talk page of that article. If you want to suggest an edit on this article, then you need to be more explicit. It is not helpful to just say that some part of the article needs to be edited.Constant314 (talk) 20:13, 26 June 2019 (UTC)
It's done. --Ritchie92 (talk) 22:08, 26 June 2019 (UTC)

## Merge with Classical electromagnetism?

I've noticed that we have two articles with very similar title and content: electromagnetism and classical electromagnetism. Neither is in a good state, even though they are rather important articles: electromagnetism has about 30k views per month! I wonder if merging the articles could help concentrating effort into improving them? I assume electromagnetism is supposed to cover more than just classical electromagnetism, but it doesn't do it. Quantum electrodynamics is not even mentioned! Tercer (talk) 14:49, 11 January 2021 (UTC)

## "Myth" put in page as fact

Sorry I'm new so I don't know how to format very well.

In the page it says: "While preparing for an evening lecture on 21 April 1820, Hans Christian Ørsted made a surprising observation. As he was setting up his materials, he noticed a compass needle deflected away from magnetic north when the electric current from the battery he was using was switched on and off. This deflection convinced him that magnetic fields radiate from all sides of a wire carrying an electric current, just as light and heat do, and that it confirmed a direct relationship between electricity and magnetism."

If you look at Hans Christian Ørsted, it says that this is a myth, and that Hans discovered it on purpose. — Preceding unsigned comment added by Cal8205 (talkcontribs)

Thanks for calling attention to that. XOR'easter (talk) 16:41, 20 April 2021 (UTC)

## edit request

At high energy the weak force and electromagnetic force are unified as a single electroweak force. to At high energy, the weak force and electromagnetic force are unified as a single electroweak force. (missing a comma)108.46.173.109 (talk) 18:54, 11 May 2021 (UTC)

## Edit Request

An inline citation for At high energy the weak force and electromagnetic force are unified as a single electroweak force. Is this a sentence that needs an inline citation? If so, I am requesting an inline citation for this sentence. ScientistBuilder (talk) — Preceding undated comment added 17:39, 29 January 2022 (UTC)

## Electromagentism Template Message

I have added several sources with inline citations. I am working on removing the template message. ScientistBuilder (talk) 19:32, 8 February 2022 (UTC)

## Remove or Move MagnetoHydrodynamics and Nonlinear Phenomenon Section

I want to remove or merge and move the section on magnetohydrodynamics section. The section should be expanded or become a subsection in another section for better organization. ScientistBuilder (talk) 23:05, 18 February 2022 (UTC)

## Proposed merge of Electricity and Magnetism (College Level) into Electromagnetism

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.
The source page has been draftified, so despite consensus to merge this discussion is redundant. Toadspike (talk) 00:00, 18 December 2022 (UTC)

Electricity and Magnetism (College Level) pretty clearly duplicates the scope of Electromagnetism and should be selectively merged to the latter. signed, Rosguill talk 21:13, 29 November 2022 (UTC)

• Support multiple merges: the body of the article spans multiple existing articles: Electrostatics, Magnetic field, Electrical network, and this one. The sections are detailed to the level of formulas and equations, not high-level explanations, so should be selectively merged to their corresponding articles. Schazjmd (talk) 21:53, 29 November 2022 (UTC)
• Support It seems reasonable to do a selective merge. 11:01, 2 December 2022 (UTC)
• Just so you know, I am working on a GA overhaul of this page, during which I am eventually going to add a "Theory" section that will include all the material on that page. After that, the page can be deleted. Mover of molehillsmove me 02:05, 7 December 2022 (UTC)
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

## Semi-protected edit request on 27 January 2023

please change "exert accelerate other charged particles" to "exert acceleration on other charged particles" Abnormalful (talk) 01:48, 27 January 2023 (UTC)

• Done, although not exactly. Constant314 (talk) 02:33, 27 January 2023 (UTC)