Wikipedia talk:WikiProject Physics/Archive April 2015

Equation Numbering

I received a request at Wikimedia OTRS that I thought I would share to see if any of you think it has merit:

In many (all?) Wikipedia articles the equations are not numbered. I suggest that Wikipedia's "standard" for including equations in an article require that equations be numbered. I also suggest that it be made easier for readers to find a particular equation in an article. One way would be to have the numbering of the equations NOT be included in the PNG representation of the equation, since that content can not be searched by a browser. A better way to do it would be to have a table of equation links at the top of an article, like the Contents box. Some examples of articles with unnumbered equations are the following:

• Friedmann equations#Density parameter
• Special relativity
• Schwarzschild metric
• Hubble's law#FLRW equations
• Accelerating universe#Evidence for acceleration

I'd be interested in your thoughts Flat Out let's discuss it 05:13, 1 April 2015 (UTC)

This is an interesting idea, and I will give serious thought to it, but my initial reaction is "this is going to be a pain to implement." First off, we would have to find every page that has equations on it and number them. Second, we would (probably) have to come up with an entirely new template as a numbering system, since if the equations are scattered across the entire page and one gets added/removed the entire list will need renumbering (a royal pain to do manually). Doable, but I'm wondering if the hassle of implementing it is worth the minor convenience of being able to say "see Eq. X." Primefac (talk) 10:42, 1 April 2015 (UTC)

Not every article with equations need numbering - especially those with only a few usually don't need it. Numbering would be really helpful in a few articles. However an extra Table of equations at the beginning would be more distracting than helpful. If a table, I would suggest it at the end, maybe similar to the footnotes. --Ulrich67 (talk) 19:14, 1 April 2015 (UTC)

I did think that a template - say {{eqlist}} that created a numbered list in a footnote might be an option. Instead of adding <ref></ref> tags it could be <equation>Special relativity</equation>, but this would require someone smarter than I to develop it. Flat Out let's discuss it 23:40, 1 April 2015 (UTC)

Numbering all equations would be prohibitively costly. Also it would create problems in situations where one deliberately numbers a few equations, because the two numberings would conflict. JRSpriggs (talk) 01:20, 2 April 2015 (UTC)

It would certainly be possible to number equations, and most of the work could probably be done by a bot. But just because we can doesn't mean we should. When an equation is important enough for a number, it's important enough for a name, and it can then be referred to by name. Equation numbering would add clutter, provide an added complication to editing, and is probably unnecessary because Wikipedia articles are relatively short.-Dilaton (talk) 18:26, 2 April 2015 (UTC)

News about fysics

It is about Erik Verlinde see: https://en.wikipedia.org/wiki/Talk:Erik_Verlinde Its very interesting about dark matter. (exist or not) But I am not good in English. Who can write this? http://www.fysica.nl/media/files/Verlinde_-_NTvN_maart_2015.pdf (in Dutch) about the Mordehai Milgrom empiric law in 1983 about the acceleration of gravity when !!no dark matter excist!! the same value Verlinde calculated. Sorry I am not good in english. Perhaps an Idea for english wikipedia. I wrote some on Dutch wikipedia. Jan Duimel (talk) 10:49, 16 April 2015 (UTC)

Edits about Gravity Theory Based on Mass Energy Equivalence

Fwiw, I undid a few edits (here, here and here) about this by new user GravityForce (talk · contribs). - DVdm (talk) 04:50, 17 April 2015 (UTC)

Here is the publication reference. Lipinski, S.A., Lipinski, H.M., Gravity Theory Based on Mass-Energy Equivalence, Acta Phys. Pol. B 39, 2823 (2008). I assumed that since wikipedia has a page on the physics journal and prestigious establishments associated (https://en.wikipedia.org/wiki/Acta_Physica_Polonica), a paper from this science journal is valid source to include as a reference in an article about gravity. GravityForce (talk) 10:11, 17 April 2015 (UTC)

What you need, is a few wp:secondary sources to establish the notability. - DVdm (talk) 11:08, 17 April 2015 (UTC)

To GravityForce: The main change you made was to add a subsection called "Relativistic Scalar Theories". After reading it, I fail to see how it can be considered relativistic, even as much as the other scalar theories already described in the article Alternatives to general relativity. JRSpriggs (talk) 13:39, 19 April 2015 (UTC)