Talk:Magnetic moment

message: This article uses both \mathbf{\mu} and \mathbf{m} for the magnetic moment.  In cgs it probably makes more sense to use \mathbf{\mu}, but Jackson uses \mathbf{m} (in SI).  My vote would be for \mathbf{m} on the basis that the magnetic moment is rarely used as a scalar quantity, so there shouldn't be ambiguity (with mass). Turtle47 (talk) 12:24, 29 April 2014 (UTC)
replies: text: Most of the article already uses \mathbf{m}, so I lean towards that. RockMagnetist (talk) 13:43, 29 April 2014 (UTC)

text: ackk! I have been working on this article starting more or less from the top which uses mu. I will try to follow RockMagnetist's suggestion to use m which is the symbol used by the physics textbooks that I use. Unfortunately both symbols have conflicts with other quantities that use their symbols. In the case of m there are two conflicts (with mass and with the quantum number for lz). TStein (talk) 06:12, 17 April 2018 (UTC)

text: I converted the article to just use m for the magnetic moment. I left the bohr magneton as \mu_B for now. Along the way I had to change the symbol used for mass from m --> \mu in order to avoid using m for two different things. TStein (talk) 15:31, 18 April 2018 (UTC)
thread_title:  Notation consistency 

message: The article does not specify how this quantity is measured.--79.119.209.81 (talk) 15:59, 30 March 2015 (UTC)
replies: text: Good point. We should have a summary of Magnetometer#Laboratory magnetometers in this article. RockMagnetist(talk) 18:18, 30 March 2015 (UTC)
thread_title:  Measurement 

message: In the units section of the main article, it states that units for magnetic dipole are N.m/T = A.m^2 = J/T.
I shrieked when I saw a torque of N.m converted to J.  I'm a mechanical engineer, and for me, that is a huge no-no.  You never convert torque to energy.  Torque, of course, is meters cross-product newtons, whereas work is meters dotted with newtons.  Our unit system does not carry along this vector operation aspect, so we have to know that we cannot interchange them.  We represent torque as a vector, whereas work is a scalar.  To my mind, it is fundamentally incorrect to convert newton-meters of torque to joules.  In the end, units can be manipulated and the answer will come out the same, so if you guys tell me that in the magnetics world, you cover your eyes and commit this atrocity all the time for some reason, then fine.  I'll simply not like it.  But if you agree, then I'd like to delete the bit where it shows J/T.  
Kimaaron (talk) 15:19, 19 February 2016 (UTC)
replies: text: Kimaaron, your argument makes sense, but IEEE Magnetics and NIST accept J/T (I have added a citation). Surprisingly, I can't find any sources that suppose N.m/T, so I'm going to tag that. RockMagnetist(talk) 16:58, 19 February 2016 (UTC)

text: Kimaaron,the distinction between Nm and J is important to me as well. In this case though both makes sense for different reasons: the former comes from the equation N =mxB and the latter because U = -mdotB. That being said from a limited search I usually see J/T. TStein (talk) 06:13, 17 April 2018 (UTC)
thread_title:  Units Problem 

message: Here "m" is taken as "mj", whereas in the Wikipedia page "Magnetic quantum number" m is taken as "ml", with different meanings. Please reach an agreement between the two pages, or use the unambiguous notation mj, ml respectively.Grausvictor (talk) 16:51, 24 May 2016 (UTC)
replies: text: The complaint here appears to be an issue of notation rather than of substance.  Not using the same notation as another Wikipedia page does not make the information wrong.  I am therefore going to remove the  tag that has been sat there for over four years without action.  If the claims in the article are actually wrong, that is a another matter, but can't you WP:JUSTFIXIT rather than leave it sitting there for years? SpinningSpark 11:41, 22 July 2020 (UTC)
thread_title:  Magnetic moment of an atom 

message: funny talk: "If one had started from a differential definition" ... how about deleting these confusing lines with contradicting equations? Ra-raisch (talk) 16:08, 15 April 2018 (UTC)
replies: text: I did not understand that section either. I redid that section, but much more work needs to be done. Please check to make sure that the section makes sense. Thanks. TStein (talk) 06:15, 17 April 2018 (UTC)
thread_title:  factor {{sfrac|1|2}} 

message: It occurs to me that the dipole moment is used for 3 very different cases corresponding roughly to 3 different size regimes:
:# atomic size magnetic moments depend heavily on the relationship with the quantized angular momentum
:# engineering devices such as electromagnets, permanent magnets, quadrupole magnets, etc use the concept of magnetic moments differently. Here the currents are well controlled and known. Magnetic moments may use Amp turns instead of Amps, etc.
:# planetary sized (and larger) where the dipole moment is inferred from the measured magnetic fields and is used to get a better understanding of what layer produces the magnetic field and how.
Each of these regimes overlap but each also treat the magnetic dipole differently.
I don't want to reorganize this article willy-nilly, especially when I am uncertain both what the proper way to reorganize it and how much time I will be able to dedicate to this. Any thoughts on this will be greatly appreciated. TStein (talk) 06:33, 17 April 2018 (UTC)
thread_title:  I need thoughts on organizing parts of the article into 3 size regimes 

message: I have no problem with your shortening of the section titles. The middle edit (Two models of ...) may be an issue, though. There are a large number of links to that particular section. I wouldn't mind fixing all of these links (I have fixed many of those links from an earlier change before) myself, except that I have the most generic settings for my editor. I am fairly certain there are tools to fix this but I have no clues where to look to find them or which tool to use. The what links here is useless as far as I can tell. TStein (talk) 15:58, 4 May 2018 (UTC)
replies: text: Oh, sorry, my bad. Didn't think it was important, you may revert that particular title. I'm having the same issue with another article. Maybe we need expert help with that. --MaoGo (talk) 16:05, 4 May 2018 (UTC)
replies: text:  he, he. I was hoping that you had better tools for fixing links. I like your title for the subsection. I will chase down fixing the broken links later. TStein (talk) 19:14, 4 May 2018 (UTC)
replies: text:  I tried asking in the help desk but it doesn't seem to exist a standard way of fixing this issue. Check out the discussion Wikipedia:Help_desk#Is_there_a_Whatlinkshere_for_sections --MaoGo (talk) 16:00, 5 May 2018 (UTC)
replies: text: I don't see any sign that there were links to this section title, except for one inside Momentum. If there were an issue, I think  would solve it. RockMagnetist(talk) 16:27, 5 May 2018 (UTC)
thread_title:  [[User:MaoGo]] one of your section edits is probably breaking links 

message: I've just discovered that magnetic pole strength redirects here to a heading that no longer exists.  I've corrected that, but I have to say that I think the redirect into this article was a terrible idea.  Look at it from the point of view of someone who has typed the term into the search box.  They want to know about pole strength, not magnetic moment.  So yes, now they are redirected to the right place they can learn that m=pl, but now they still have to go back to the top of the article and read the whole thing because now you have forced them to understand magnetic moment before they can understand pole strength. SpinningSpark 07:14, 19 May 2018 (UTC)
replies: text: You have a point, but I don't think the answer is to restore the article, which only had one link leading to it. Instead, we could import more of the material from the article into that section - most importantly, the definition of an oersted in terms of magnetic poles. RockMagnetist(talk) 21:18, 20 May 2018 (UTC)
replies: text: I think there is an error in how you describe m as the volume integral of remanence Br.  In fact it is the volume integral of the internal magnetization M, which is not the same except in special/unusual cases.  See this link  https://farside.ph.utexas.edu/teaching/jk1/Electromagnetism/node61.html 98.159.210.62 (talk) 15:36, 4 April 2022 (UTC)
thread_title:  Magnetic pole strength 

message: I need to know how a magnetic dipole behaves in an electric, not a magnetic, field.  I suppose it precesses in some way, but not in identically the way that a magnetic dipole behaves in a magnetic field.  Can anybody direct me to information on this?     Slyfox4908 (talk) 22:01, 29 May 2019 (UTC)
replies: text: This WP:NOTFORUM. Anyway, I think you are looking for Spin–orbit interaction (in the case of an atom the electron spin is a magnetic dipole, and the electric field comes from the nuclei).--MaoGo (talk) 22:07, 29 May 2019 (UTC)

text: Traveling magnetic dipole is affected by electric field through Lorentz force. To see it, change for a moment coordinates such that magnetic dipole is resting  - now the source of electric field is traveling in magnetic field, and the resultant Lorentz force also acts on the magnetic dipole through third Newton's law. Here is such simple Lagrangian with magnetic dipole \mu from https://en.wikipedia.org/wiki/Free-fall_atomic_model:  \mathbf{L} =  \frac{1}{2}m\mathbf{v}^2+\frac{Ze^2}{r}+\frac{Ze}{c}\left[ \mathbf{v}\cdot\left( \frac{\mu\times \mathbf{r}}{r^3}\right)\right]  — Preceding unsigned comment added by 89.64.54.158 (talk) 04:59, 14 October 2019 (UTC)
thread_title:  Behavior of magnetic dipole in an electric, NOT magnetic, field. 

message: Theres a phrase in the introduction ;- "..and all other fractal expressions of electromagnetic energy". What in the dickens can that possibly mean? Theres no other reference to fractals in there. Looking on the net, this isn't a wingnut special, its a real thing, but the article doesn't expand what exactly is meant by that turn of phrase. As a non physicist, that phrase has thrown me on a loop, could someone please add something to explain what that means? Duckmonster (talk) 08:02, 16 February 2021 (UTC)
replies: text: It was some random IP that added that without proper justification. I reverted it to the previous stable version. Thanks for pointing it out. Also, remember that new sections should go at the bottom of the page.--ReyHahn (talk) 08:41, 16 February 2021 (UTC)
thread_title:  Fractal what? 

message: "Intrinsic magnetic moments and spins
of some elementary particles"
Is it a fake? Where You got such values from? 79.204.137.204 (talk) 11:43, 22 March 2024 (UTC)
replies: text: The table is referenced in the caption as CODATA Johnjbarton (talk) 16:01, 22 March 2024 (UTC)
thread_title:  what's that?