Talk:Retarded potential

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--Griffiths--

I wrote these equations in to paste them into a paper I was writing, which is due in a little over 24 hours. I will fix up the page later. I used Griffiths' Introduction to Electrodynamics (1999), and followed his notation for the most part.

Mgummess 02:24, 15 May 2007 (UTC)Reply

It would help, if the person who wrote this item, would return and give a general, plain language explanation of the meaning of this term. I first ran across it in a two-volume work by Alfred O'Rahilly on "Electromagnetic Theory" which was first published in 1938 by Univ. of Cork Press and republished in 1965 by Dover. What I got out of it (very crudely and perhaps wrongly) was that the mathematics of EM fields should take into account the finite speed of light, so e.g. forces exerted by one object on another distant object (EM or gravity I suppose) are not instantaneously exerted between the objects where they are "now" but where they "were" at some time in the past, roughly d/c where d is the distance between them and c is the speed of light. Taylour (talk) 20:05, 18 November 2007 (UTC)Reply

I am not the person, you thought of, but I have read your remarks and took reason from them to improve (I hope so!) the introduction essentially.

- 87.160.60.134 (talk) 08:21, 29 October 2008 (UTC)Reply

Dude, isn't retarded potential an all famous concept that is used throughout physics? I'm surprised (disappointed) at this small section on the topic. I, unfortunately, don't know enough to add anything yet. —Preceding unsigned comment added by 131.211.109.69 (talk) 14:44, 7 May 2009 (UTC)Reply

The use of retarded potentials is better understood in the framework of relativity. I've added a hyperlink to the Liénard–Wiechert potential which is a relativistically invariant retarded potential. That should help increase the understanding of the concept.99.37.226.68 (talk) 04:54, 1 January 2010 (UTC)Reply

I would really appreciate if wiki would consider wording this in a more socio-sensitive way. I have a niece who's neuro-atypical and I really think this article is thoroughly offensive for its heavy use of The R word. 64.123.99.139 (talk) 01:54, 4 March 2012 (UTC)Reply

You took the words right out of my mind, I agree that this article is in an absolutely sorry and appalling state... I have rewritten it, although "retarded" in this context is actually used in the literature unfortunately. I tried to reduce the amount its used... F = q(E+v×B) ⇄ ∑_ic_i 12:16, 26 May 2012 (UTC)Reply

It could be noted that retarded potentials (and presumably advanced potentials as well) occur in the vector potential part of the Coulomb gauge potentials. Xxanthippe (talk) 22:46, 26 May 2012 (UTC).Reply

I thought the retarded potentials occur for any gauge, am I wrong? At the time of rewriting I happened to have Griffiths' book to hand and was typing from it, the Lorenz gauge seems to be the easiest to talk about... F = q(E+v×B) ⇄ ∑_ic_i 23:02, 26 May 2012 (UTC)Reply

In the Coulomb gauge the scalar potential is formally instantaneous. The vector potential is partially retarded (or advanced as the case may be). Also, explicit expressions should appear for the retarded and advanced times. Xxanthippe (talk) 23:06, 26 May 2012 (UTC).Reply

Sorry about the delay (I'm "retarded"!?), I was distracted and had to do something else. How is the new section? I couldn't find a source for the solution of the coulomb gauge potential for A so had to copy the form in coulomb gauge, if that's ok (that was cited from Jackson)... F = q(E+v×B) ⇄ ∑_ic_i 23:43, 26 May 2012 (UTC)Reply

Added the retarded/advanced time formulae. F = q(E+v×B) ⇄ ∑_ic_i 23:49, 26 May 2012 (UTC)Reply

Do you really think people who are "neuro-atypical" are going to be spending much time looking at articles on electromagnetic physics? --Genya Avocado (talk) 06:02, 30 November 2012 (UTC)Reply

I suspect you don't know a lot of neurodiverse people if you think geeky physics articles aren't an attractor. TricksterWolf (talk) 23:27, 2 May 2023 (UTC)Reply

I think you are being overly sensitive. In the context of the article it is a technical term that has absolutely nothing to do with mental or physical handicap. Its naming also had nothing to do with mental handicaps.Traditionally the word means slowed or hindered. It only acquired the modern connotation when people started using it as a Bowdlerization of the word "idiot". I can respect and understand that some people dislike the word, but it happens to be the correct term to use in this article.--2003:69:CD06:A801:2E81:58FF:FEFF:8F4B (talk) 11:34, 3 August 2013 (UTC)Reply

NUH UH 192.230.254.254 (talk) 18:11, 10 October 2023 (UTC)Reply

Another person thought this article had to conform to socio-sensitive ways.. Huge huge misnomer. If retarded is too sacred it can't be used in any context, god-willing someone chooses to identify as "retard" and then complain someone is using their time, then what is its application if at all? Stigmatizing the term will only get people away from it, and let the most ignorant peddle and redefine it.

It surely is quite very odd that something that could universally mean 'slowed', and be used by countless people casually without a second thought, and now people's entire trains of thought and rooms stop because of the huge amount of misinformation and reactionaryism around the word. Borifjiufchu (talk) 01:00, 9 January 2024 (UTC)Reply

The formula given in Retarded potential#In_the_Lorenz_gauge uses the symbol ${\displaystyle {\varphi }}$, while the description afterwards only introduces φ (${\displaystyle \Phi }$) as the electric potential. In math notation the only difference is a "var" prefix. Which symbol should be used? Depending on the font, both may render the same.

The divergence was introduced in this old rewrite https://en.wikipedia.org/w/index.php?title=Retarded_potential&diff=prev&oldid=494454697 that added section headers, updated the formulas, bot not the descriptions for the variables.

The article describing the Liénard–Wiechert potential uses ${\displaystyle {\varphi }}$.

The section Scalar potential#Scalar potential in Euclidean space uses ${\displaystyle \Phi }$. Roxblau (talk) 17:27, 29 September 2025 (UTC)Reply