What notation and symbols are commonly used here?

I just noticed that we have a new section on our FAQ about notation and symbols. What should go in this section? Obviously we can't explain all the mathematical notation that physics uses, but are there any conventions peculiar to this site that we should include?

We could try to settle for one convention where ambiguity exists, e.g. always using arrows for R³ vectors, * for complex conjugation etc. I don't know if editing posts with different conventions (e.g. bold vectors) should be encouraged though.

• I agree in principle, but there tend to be sub-discipline driven differences in the defacto standard. We wouldn't want to start a fight on the matter. Consider the issue of mean values; both \langle x \rangle and \bar{x} are popular depending on field. – dmckee --- ex-moderator kitten Jun 22 '11 at 1:29
• @dmckee you're right, it's the same as trying to enforce SI units vs natural units... So we should not encourage editing that, but at least we could state something like "if you don't know which notation to use, \vec x is common for vectors but x is ok as well" etc in the faq – Tobias Kienzler Jun 22 '11 at 6:09
• Yes, this would be helpful. And the comparison with the units issue is insightful. – dmckee --- ex-moderator kitten Jun 22 '11 at 6:11

(I was going to ask this as a separate meta-question, but the helpful title box told me that someone had already done half the work for me)

It would be nice to have a standard (not compulsory) set of notations to follow. One of the main benefits would be that instead of writing a whole paragraph explaining which standard symbols are which, we can link to an extensive list of them.

Since symbols vary between fields, I'd say that we have a question with a separate CW answer for each field. I guess the question would be better placed on the main site as meta doesn't support mathjax.

• Something like this would definitely not be appropriate for the main site. It's one of those list questions we try so hard to avoid, and besides it'd be about this site specifically, not about physics in general. We could campaign to have MathJax enabled on meta, though. – David Z Mar 12 '12 at 2:45
• @DavidZaslavsky If it wouldn't be too hard to campaign, then we should certainly do so! Do we post the question on meta.meta.physics.SE? =P – Manishearth Mar 12 '12 at 2:51
• lol... check and see if there is an existing feature-request to enable MathJax on meta, and if not, you can make one. But first I'd suggest checking on Mathematics's meta to see what arguments they had for enabling it there. The SE team will need to see a very strong case that we really need it enabled in order to do it. – David Z Mar 12 '12 at 3:21
• @DavidZaslavsky I can't seem to find the math-meta-enable-mathjax-meta-meta-request meta.math.stackexchange.com/…. I guess they got the full package when they requested mathjax. We don't have a strong case, I think we'd need it pretty rarely. – Manishearth Mar 12 '12 at 3:33
• I could write a script that enables mathjax whenever there is something of the sort : $turn_mathjax_on$ on the page. That would get rid of the main issue of SE+mathjax--slow loading times for every page. – Manishearth Mar 12 '12 at 3:34
• If you feel inclined to do it, sure! There's a ChatJax script that uses a bookmarklet to enable MathJax in chat (it's linked on Math meta somewhere), which you might be able to cannibalize some code from if it saves you any time. That would help us get a sense of how much we would actually use it on meta if it were properly available. – David Z Mar 12 '12 at 3:37
• @DavidZaslavsky No need to cannibalise code; Mathjax has an option for dynamic loading. It's a bit cobbled-together, but here it is: jsfiddle.net/2tccA/1 Remove the $%I_want_Mathjax$ in the body to disable it. Yes, I didn't separate the js and HTML though jsFiddle allows you to, because I tested it first as a local file. – Manishearth Mar 12 '12 at 4:11
• Note that SE already uses jQuery, so we aren't loading anything new. Also, this script is will not enable mathjax if one uses the signal in a comment. That can be easily fixed (run the first line for .comment-text, and add the lengths of the two results). But I doubt we need the ability to enable mathjax on a whole page just for one comment; so I'm leaving it out. – Manishearth Mar 12 '12 at 4:14
• Anyways, comment support added here: jsfiddle.net/2tccA/2 . Remember that the configuration there may be different from the SE config, but I guess the SE people could handle that. – Manishearth Mar 12 '12 at 4:30