Talk:Charge (physics)

Radio waves
"Moving electric charges generate radio waves." ??? What is this about? Virtual photons? Surely only acclerating electric charges radiate real photons (which in some situations may be considered to be radio waves). I've removed the offending sentence. If it is justified then it needs clarification. JimChampion 16:39, 3 November 2006 (UTC)

'Gilbert defined charge as some thing which when possessed by a body (object) enables it to respond to the electric field and exert electric force' Is this really true? Did Gilbert already have a concept of electric force and field?

Are wikipedia's science articles getting too complicated and technical?
I think some of Wikipedia’s science articles are too complicated. Articles need to be written with the intended audience in mind. Hence, this article about “charge” (in physics) would presumably be for people wanting to learn what a “charge” is. Particle physics gurus would therefore not be the intended audience of this article, as they would already know what a “charge” is. But if you read the opening few paragraphs of the article below, I believe it would take a particle physics guru to understand it. Why aren’t we writing science articles with the intended audience in mind?

Opening paragraphs from Wikipedia’s article on “charge” (physics):

"In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges are associated with conserved quantum numbers.

More abstractly, a charge is any generator of a continuous symmetry of the physical system under study. When a physical system has a symmetry of some sort, Noether's theorem implies the existence of a conserved current. The thing that "flows" in the current is the "charge", the charge is the generator of the (local) symmetry group. This charge is sometimes called the Noether charge.

Thus, for example, the electric charge is the generator of the U(1) symmetry of electromagnetism. The conserved current is the electric current."

Do we honestly think there are people out there that don't know what a charge is, but do understand "Color charge in quantum chromodynamics", "conserved quantum numbers", "Noether's theorem", "local symmetry group", "the U(1) symmetry of electromagnetism"? —Preceding unsigned comment added by 59.101.161.126 (talk) 05:33, 1 March 2008 (UTC)


 * Would it help with this issue to have a "For electric charge, see Electric charge" type of hatnote? I can see the argument for doing this, but (on the other hand), the first sentence does make it obvious where to go if you were looking for electric charge.  Djr32 (talk) 00:52, 31 December 2008 (UTC)


 * I struggled with the concept of a charge all through grad school, even though I knew exactly what "Color charge in quantum chromodynamics", "conserved quantum numbers", "Noether's theorem", "local symmetry group", "the U(1) symmetry of electromagnetism" are. The problem was that these last five topics get hammered into you in multiple classes, multiple exams, but the word "charge" is used so loosely and casually, and in such bizarre situations, that its hard to grasp what is meant by it. 67.198.37.16 (talk) 07:46, 3 September 2015 (UTC)
 * i agree that this article needs to be changed. It is far too technical. There is nothing wrong with a technical definition, but there should also be a definition of this page that is more accessible to the general public. I have a pretty extensive scientific background. I am a chemistry PhD student and I read in my free time about all sorts of scientific subjects including quantum physics. That being said, I'm not a physicist and have only a chemistry focused education on quantum mechanics. If this article is incomprehensible to me, which it mostly is, then it is absolutely useless to the general public. If only the people who wrote it can understand it, then it has no use whatsoever. Science Is My Life (talk) 04:57, 14 October 2023 (UTC)

Translated to FR
Just to advise the contributors to this article has just been translated into french, and to thank all of you. Hop ! Kikuyu3 (talk) 14:13, 19 June 2010 (UTC)

'Magnetricity'
Under the hypothetical bullet point, the page states that "Magnetic charges are not seen experimentally in laboratory experiments, but would be present for theories including magnetic monopoles". Now, there has been a recent discovery in the field of condensed matter physics of magnetic monopoles that can carry magnetic charge and acts in a similar way to electric charges. Before changing the article however; I'm unsure if it is referring to the monopoles of condensed matter physics or topological defect version of a monopole.
 * Also, might Gravitoelectromagnetism relate to this page? It has kinetic analogies to charge and current, although I'm not sure if it is just an analogy and not an actual charge in the same sense decribed in the article.  --Wormulon (talk) 02:11, 9 September 2012 (UTC)


 * Yeah, the condensed-matter magnetic charge is probably a topological charge, i.e. describable by a holonomy on the U(1) bundle (which should redirect to circle bundle. Which in turn should mention/describe the Bohm-Aharonov effect. But whatever.) But I haven't looked at the condensed-matter result. Sentences would have to be added to distinguish condensed matter from vacuum physics.


 * Gravitoelectromagnetism is ... a dicey beast. It is the linearized form of Einsetin's eqns, (i.e. valid only in weak fields) and re-written so that it resembles ordinary electromagnetism. This means that, as a mathematical set of equations, it would indeed have many/most of the same kinds of mathematical phenomena. But as a theory of physics, its really not quite right; one would not have, for example, gravito-magnetic monopoles, since these require having the aforementioned U(1) bundle, which is provided by Schroedinger's equation, but does not have an analog in the Einstein eqn's, linearized or not.  Now the gravito-electric charge is just mass, but it would also be incorrect to suggest that mass arises as a conserved quantity, e.g. from some gravito-Noether's theorem. That would be wrong. So I'd say gravito-anything doesn't really belong in this article. 67.198.37.16 (talk) 04:24, 31 August 2016 (UTC)

Merge proposal
Someone tagged this article for merge with conserved quantity, but did not explain the reason for this proposal. My knee-jerk reaction is "don't merge", as it seems that there is a bit of a mis-understanding that leads to the merge proposal. That is this: this article is about quantum operators and their eigenvalues, while the other article is about dynamical systems and differential equations. Yes, there is conceptual overlap -- but you'd have to get deep into the theory of Fredholm operators to understand how a differential equation or a dynamical system is a lot like a quantum-mechanical operator. That kind of theory is kind-of wayyy beyond both this article, and the other one, and so the raw basis for the merge seems to be invalidated. This is does not seem to be the right place for covering such deep and broad topics. (although I guess they could be mentioned.) Clearly, my opinion is don't merge. 67.198.37.16 (talk) 04:11, 31 August 2016 (UTC)