I understand t.b.'s reasoning on why we should keep both the and tags, but I notice that their wikis, and more specifically their excerpts, are sufficiently similar that it would be hard to tell which to use.

(physics): Questions related to mathematical physics which include application of mathematics to problems in physics and the development of mathematical methods suitable for such applications and for the formulation of physical theories

(mathematical-physics): "Mathematical physics consists of the application of mathematics to problems in physics and the development of mathematical methods suitable for such applications and for the formulation of physical theories." (from Journal of Mathematical Physics) This tag is intended for questions on methods used e.g. in quantum mechanics or general relativity at an advanced undergraduate or graduate level.

Both seem to be about mathematical physics and thus neither captures the most common type of physics question that is asked on math.SE. Most of physics problems that get posted here (rightly or not) are about finding the solution to a physics exercise. Example: Spring Calculation - find mass is about solving an ODE from a classical mechanics problem.

"Mathematical physics", on the other hand, doesn't just mean a physics problem with math in it. It has a (somewhat) specific meaning to physicists -- it refers to a branch of physics about making mathematical models of the real world or finding new mathematical methods and techniques for evaluating current models. An example of a mathematical physics problem that one might post here is "I've determined that [some equation] models [some physical system]. But I'm having trouble finding the spectrum of [this associated operator]".

In light of this, I think the (physics) tag excerpt should be changed to better distinguish it from the (mathematical-physics) tag and make it more applicable to these types of questions. I'd just do it myself, but having never edited a tag wiki, I don't want to screw it up. Plus I'd like your input.

P.S. Do we really need the (retagging) tag on this site?

Edit: I went ahead and suggested an edit for the (physics) tag wiki as well as the (classical mechanics) and (electromagnetism) wikis. I admit my edits are not ideal, but I think they're an improvement, nonetheless. Feel free to review it if you have 20K+ rep. Any feedback would be appreciated.

  • $\begingroup$ I was not sure whether understand your post correctly: You want to change the tag-info (tag-excerpt and tag-wiki) of the (physics) tag, right? Not the name of this tag. (Additionally, I think (tag-wikis) would be more suitable for your questions than (retagging), at least if what I wrote is correct interpretation of your question.) $\endgroup$ Nov 25, 2016 at 5:56
  • $\begingroup$ If that's what the information is called when you scroll over a tag, then yes. The name of the (physics) tag is fine with me. $\endgroup$
    – user137731
    Nov 25, 2016 at 15:06
  • $\begingroup$ If you read the tag-info for tag-wikis here on meta, you can see that tag-excerpt is the part which is displayed to users when adding the tag, when hovering over a tag, and maybe in some other places. $\endgroup$ Nov 25, 2016 at 15:08

1 Answer 1


As the OP wrote in their question, they have suggested edit to the tag-info for tag. The edit of the tag-wiki was approved while the edit of tag-excerpt was rejected. The reason given was: "Tag excerpts amounting to, "[tag] is for questions about [tag]" are pointless and usually rejected. Excerpts should describe why and when a tag would be used."

I agree that the main purpose of the tag-excerpt is to give some guidance of usage of the tags. (And the tag-wiki is more suitable place for a more detailed description of the subject of the tag.) I still think that the suggested edit was an improvement, since the previous version sounded more like a tag-excerpt for . So I went ahead and edited the excerpt to the version suggested by the OP and adding one more sentence: For question from the field of mathematical physics use (mathematical-physics) tags instead. I have also added mention of (physics) tag to the (mathematical-physics) tag-excerpt.

Of course, further improvements of the tag-info both for physics and mathematical-physics are more than welcome.

  • $\begingroup$ I would imagine that in stuff tagged physics, the poster expects answers where symbols are manipulated and equations are derived in the ways that are used by physicists and expected in answers to problems handed out in physics courses in college. For stuff tagged mathematical physics, symbols are manipulated and theorems are proved in the ways used in "rigorous mathematics." There is a physics way to to quantum mechanics, as in Cohen-Tannoudji et al., and there's a mathematical physics way to do quantum mechanics, as in Reed and Simon. $\endgroup$
    – ForgotALot
    Dec 3, 2016 at 19:50

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