User talk:Footlessmouse/sandbox

Comments by Ponor
2020-09-11 Hey, I've seen your call for comments. Generally, I think you need to do a lot more pruning. The lead is too long (trying to say everything), the article is too long (trying to say everything). The first thing you see on the mobile site (that's ~50% of users) is that huge, two-screen long infobox. I don't think that people who come to read about the magnetic field need anything from it. If they want to know the units, they'll search for units. Alternative names for the field(s?) - who in 2020 calls B the magnetic induction?

In the lead, you're dealing with something "perpendicular to the field" before you say the field has a direction. Note that all materials are diamagnetic, then some of those are also paramagnetic (paramagnetism is much stronger though), and some ferromagnetic. The whole lead needs more focus. The history para is a distraction, thus unnecessary. I still don't see why there needs to be any mention of B and H here. The field is there no matter how we describe it, so just say how it's generated, what it can do, and where it's used in technology.

Then the same in the rest of the article. The article is still full of many little details that have or should have their own articles. There are quite of few jumps from what the field does to how it's generated and back.

The two right-hand rule illustrations are the first images in the article, and seem so out of place (in addition to being a punch in the eye, IMO). Bending bubble chamber particle tracks or electron beam bending by a magnet in a gas-filled tube would be a much better choice.

Lorentz force definition section starts with a known B-field and defines the force caused by it, not the other way round. I like how Feynman introduces it, sort of builds-up the idea of the field; all in words, no formulas.

There are way too many digressions, going back and forth, examples of this and that. Is the Magnetic dipole moment (L's and S's) section really needed here? Force on a magnetic dipole? - that can be a single sentence pointing to a separate article. Energy of a dipole in a magnetic field is much more important, is it there?

Does magnetostatic (?!) dipole image imply there are N and S monopoles?

Magnetic field lines - way too long, and probably too late in the article because you're already using them to represent the field. (little magnetic needles scattered around might be a better representation of the field)

Magnetic field shape descriptions - some of these are really hard to imagine if you already don't know what thay're like. Again, trying to say too much.

Units and measurements - units for H before H is defined. This can be the last section in the article, IMO. The field is independent of our measures.

Magnetic pole model has zero (if I'm not mistaken) references. This tells me how important the subject is. A tree that bears no fruit. Looks like someone's little turf that no one dares to remove.

Vector potential is defined out of the blue, before Maxwell's eqs. Note, I have linked to vector potential in curl section and deleted vector potential section.Footlessmouse (talk) 12:55, 11 September 2020 (UTC)

Maxwell's eqs in that table look scary. Not sure the integral eqs are ever used in this full form. I'd list the differential eqs, not in a table, but leave the integral eqs for other articles. Remember, this article is for high-school kids and desperate housemen and housewives.

I don't think

I could go on and on. Prune. By 50%, please.

Good luck, Ponor (talk) 08:50, 11 September 2020 (UTC)

Version of the page @Ponor reviewed: updated 07:54, 11 September 2020


 * , thanks! Okay, as this is a talk page on a user page, I am going to be informal and strike-through items which I believe I have addressed. I would LOVE to delete the magnetic field shape descriptions section - I was, up to now, not deleting sections outright, but just trying to reword them. Also, both Amperian loop and Magnetic pole models can be deleted and a single line statement with a link to the magnetic moment article will suffice (as it discusses both models). I will have to think about the other changes, I already realized that I can't use the gallery like that, but haven't changed it yet mostly as I need to look up the proper way to reference figures from the text. The main reason I had magnetic field lines and units and measurements where they are is for the TOC organisation, but I suppose that is not a very high priority. Thanks for the Feynman tip for the Lorentz force section, I understand, that would be better. I spent a lot of time thinking about how to explain vector calculus concepts and forgot to focus on the physics. I will continue on! If you are ever bored, feel free to casually look everything over and let me know if you have any other suggestions. Footlessmouse (talk) 09:37, 11 September 2020 (UTC)

Sorry for the pause in editing, I needed a break, to come back with fresh eyes. I will resume soon. Footlessmouse (talk) 04:32, 14 September 2020 (UTC)