Category talk:Physics

cut-off
Ah - there is a cut-off occurring because you can only have 200 links on a page.

So the quantum mechanics category and page aren't linked from here!

Serious need to categorise some pages, here.

Charles Matthews 19:43, 19 Feb 2005 (UTC)

I agree. I came looking for a link to Particle Physics, but it seems to be cut off. This page needs to be cleaned up, particularly the individual articles in the category. StuTheSheep 20:29, Mar 17, 2005 (UTC)
 * See note below:
 * You are free to restore the notice if you believe the issue is not yet properly addressed. I merely commented out the notice. Ancheta Wis 08:56, 23 Mar 2005 (UTC)

How to add categories to the physics articles
You can add relevant categories to help populate the subcategory lists. To do this, at the foot of a Physics article (see section below for Physics subcategory), add the text

By saving your edit, you will produce a link to the physics subcategory. To test out the view, you can hit the Preview button to check whether your chosen subcategory is working. A colon (":") before the "category tag", e.g., Category:Add physics subcategory here, will allow you to include the link to a  physics subcategory in an article, without placing the article in that physics subcategory. By convention, the category tags are placed before the interwiki links, which are usually the very last tags on the article.

Note: To navigate the category lists, you can use the Category TOC links. Just click on the letter corresponding to the first letter of the article or subcategory which you seek. Alternatively, click on the next 200 or previous 200 links on the category page.

For more information, see also: Category -- See the source text (click Edit this page above) for an example of the pipe trick, which forces an alphabetization in the category sequence for an item.

How to assign physics subcategories to the physics category
Read Help:Category, where there is a clear description on how to add subcategories to an existing category.

Here is another example related to the Physics category. On Sun, 9 Dec 2007, there was no Statistical Mechanics subcategory in the Physics category. Now, Statistical Mechanics was already a category by itself. To add the Statistical Mechanics category as a subcategory to the Physics category, point your browser to the Statistical Mechanics category, edit this page, add the following line



at the end of the Statistical Mechanics category page, but above the interwiki links, and then save the page. Voila`. You could now go back to the Physics category page, to check that Statistical Mechanics was now listed as a subcategory to the Physics category.

The above was an example for an existing category page, such as the Statistical Mechanics category page. If a category page did not exist yet, you need to first create this new category page, before making it a subcategory to the physics category. To create a new category page for a new article that you wrote, you just need to add at the end of your article the line



where "New_category" is the appropriate name for the new category, save the article, and click to go to the new category page to create it. Read Help:Category for more details on how to create a new category page.

After the new-category page had been created, repeat the steps described further above to make the now-existing new-category page a subcategory to the Physics category.

(The category software currently allocates 200 links per category page, whether they are subcategory or article links.)

Vql (talk) 16:09, 10 December 2007 (UTC)

Cleanup still needed
There are too many articles in this category. They need to be sorted into subcategories so that they are arranged by topic, not by alphabet. (If you don't already know the name of the article you're looking for, and you don't already know what each article is about, it can be really hard to find things on a very long alphabetical list like this.) -- Beland 23:19, 30 Mar 2005 (UTC)

Cleanup almost done
OK, I think I just whacked about 150 articles or so. I'm getting sleepy, time to go to bed, can someone review the remaining 70 or so, and see if they can prune another 20-40 away? Please leave a core of 10-40 articles covering general topics. linas 09:18, 1 May 2005 (UTC)

Never mind. I am done. linas 18:23, 1 May 2005 (UTC)

General Physics Topics subcategory
Should we create a General Physics Topics subcategory for things like Thought Experiments and Fermi Problems? I'll wait for responses before I make that change. StuTheSheep 18:25, May 5, 2005 (UTC)

This is a good idea – I was just looking for this category! I'll create it. &mdash; Sebastian (talk) 16:55, 2005 May 18 (UTC)

So i did it now, and it worked very well for the categories, but now that i'm starting to categorize the articles, it becomes fuzzy. E.g. would someone who just read Physical law rather want to see the subdisciplines listed in category:physics or rather the concepts on category:General physics topics? &mdash; Sebastian (talk) 10:47, 2005 May 20 (UTC)


 * In my opinion, Category:General physics topics is a little pointless, because everything that isn't specific for any other category should just stay in Category:Physics, which is general by virtue of it's name. Also, General physics topics is a bit too synonymous with Introductory physics for my taste. The category's been around for almost a month and not much has been palced in it - so do we need it? I propose to delete this category. Karol 06:41, Jun 16, 2005 (UTC)


 * I'm actually inclined to agree. It didn't quite work out the way I thought it would. The categories in Category:General physics topics can be their own subcategories in Category:Physics, and the other articles can be moved there, too, now that it's mostly depopulated. StuTheSheep 04:44, Jun 18, 2005 (UTC)


 * OK, I have emptied this category. According to wiki policy, we can make it a candidate for deletion 24h after the last change. Karol 08:56, Jun 18, 2005 (UTC)


 * Having recategorized hundreds of physics articles, I agree overall. linas 16:25, 18 Jun 2005 (UTC)

Deletion
I'm not happy about the way this went, although everybody complied with existing policies.

What happened was a waste of time: Stu's request has been sitting here uncontested for two weeks until I acted on it. Then again no protest for 4 weeks. Then all of a sudden, within 2 days, everything is changed. I don't really see a need for this haste. Both Karol and I spent some time categorizing and recategorizing. If a majority were to vote against the change we would have to spend the same time for a third time.

I see the following problems in this process:
 * Categories have no history.
 * By the time a category reaches CfD, it has been emptied. There is an a priori bias for deleting because there is no apparent reason to keep it.
 * The existing discussion is devalued.

I'm not sure what to do about this. I'd hate to further complicate our policies. But all I can think of at the moment is an amendment. Maybe we can work it out together so that it isn't a complication. How about something like this:
 * 1) The intention to delete a category (with more than n entries) should be announced on CfD before the category is emptied.
 * 2) If there is already a discussion on the pertinent talk page then it should be kept there and the timing will be governed by that discussion.
 * 3) Else, CfD's 1-week deadline applies.
 * 4) Once consensus is reached the category will be emptied and deleted immediately.  &mdash; Sebastian (talk) 05:42, 2005 Jun 19 (UTC)

---


 * After having emptied Category:General physics topics, I have to admit it was hasty action. Although in this case there is little ground for disagreement, I understand how this situation potentially leads to doubling or tripling work.Karol 09:35, Jun 19, 2005 (UTC)
 * Thank you! You're obviously a sensible contributor. I gotta go now, but I'm looking forward to working on this with you in the future. &mdash; Sebastian (talk) 16:12, 2005 Jun 19 (UTC)

Motivation for the general category
One reason for creating the category was to make it easier to separate the articles that belonged into subcategories from those that genuinely pertain to physics in general. This made some sense because there were over 100 articles in physics, but I agree that it isn't necessary now that there are only 35 articles. However, this changes rapidly. (I think I left only a dozen articles, which means it grew at about 1 article/day; apparently many of which are not genuine general articles but just roughly categorized as "physics".) Does anyone see a way to segregate the articles that are more equal than others without adding an extra category? &mdash; Sebastian (talk) 05:42, 2005 Jun 19 (UTC)


 * As much as I think Category:General physics topics has lost its purpose, I actually think it would be good to have a category named something like Category:Basic physics concepts (just a proposal), which could encompass the fundamental concepts such as time, energy, matter, interaction, vector, tensor, relativity, and so forth, which as of now are simply dispersed among various specific categories. Would this be a good idea? Karol 10:22, Jun 19, 2005 (UTC)


 * I'd be fine with the name "Basic physics concepts". I assume you mean this as a name for the merge of "general" and "introductory"?
 * We might also consider a category like category:mathematical tools in physics, which could hold tensors and the like. &mdash; Sebastian (talk) 07:40, 2005 Jun 20 (UTC)


 * Hi all, just wanted to mention that in honor of the World Year of Physics 2005, I have embarked upon a project of improving the General relativity pages, including articles on tensors and whatever other background also needs improvement. I just finished a lengthy rewrite of the article on Lorentz group where I encountered the problem of how to divide up math/physics content between two closely related articles, namely Lorentz group and Möbius transformation.  (So far I haven't done much with the second article, but might eventually move some of the more mathematical content from the first to the second article.)  I am too inexperienced to have any general comments, but I am interested in the question you are discussing here.  See also the talk pages of the articles on exact solutions of  Einstein's field equations and pp wave spacetimes.---CH  (talk) 3 July 2005 06:41 (UTC)

Individual changes
It seems to me some of the changes were a bit hasty. E.g. many people will have trouble finding Waves. Which layperson would think of Dynamical systems or Differential equations? Also, narrowing the connection between tensors and physics to theoretical physics doesn't do justice to their wide practical application. &mdash; Sebastian (talk) 05:42, 2005 Jun 19 (UTC)


 * A propos Category:Waves. If we were to put every article a layman might look for into Category:Physics, we would be back to square one. It is probably a good idea to include Category:Waves in Category:Introductory physics since it is such a 'basic' concept. I also mentioned before before that Category:General physics topics and Category:Introductory physics very much overlap in their intentions, and this is one of the reasons why the latter is not needed any more. Karol 09:48, Jun 19, 2005 (UTC)
 * I agree about square 1; that "introductory" is a good category for waves; and about the overlap. It doesn't mean that the distinction is completely unnecessary, though. But a merge to "basic concepts" seems to make sense. &mdash; Sebastian (talk) 07:40, 2005 Jun 20 (UTC)


 * A propos Category:Tensors. Just as many other theoretical concepts - such as function, derivative, or simply vector - tensors are often used in physics practice, but again I don't think we can have all of these in the upermost Category:Physics. Since it is a basic physics concept, it should probably also be included in Category:Introductory physics, I think.
 * Yes, that or category:mathematical tools in physics. &mdash; Sebastian (talk) 07:40, 2005 Jun 20 (UTC)

Discussion on WikiProject Physics
I have started a WikiProject Physics. It has only this discussion now (so maybe we continure there), but maybe it will develop into something more useful afterwards. Karol

WikiProject Mathematics
Since we do not have a WikiProject Physics at this time, please consider taking conversations such as the above to WikiProject Mathematics A number of seasoned physicists hang out there. linas 16:25, 18 Jun 2005 (UTC)
 * Thanks for the hint. Since the conversation is already taking place here, I'll go there and invite people. &mdash; Sebastian (talk) 07:40, 2005 Jun 20 (UTC)
 * I had noticed myself a while ago that WikiProject Physics is missing. You do have WikiProject Fluid dynamics and WikiProject Particles, but as it follows from this discussion you guys better make your own physics wikiproject then start stealing participants from the other ones. :) Oleg Alexandrov 08:47, 20 Jun 2005 (UTC)
 * There is now a WikiProject Physics :) Karol 11:18, Jun 20, 2005 (UTC)

Definition of Physics
I utterly disagree with the given definition of physics.

Energy does not interact with matter but particles, people, animals interact with each other. It is a bit like saying pears interact with apples.

When energy interacts with a bicycle, does this mean that the bicycle is beginning to move? No. When a person interacts with a bicycle (pushs the pedals) the bicycle begins to move. Energy is an abstract concept that does not interact with anything!

I would switch to the etymological definition :


 * Physics is the science of nature

but I would add


 * In practice, Physics is the science performed within the scientific method as applied by the physics community and defined by the works of physicists like Gallilei, Descartes, Planck, Einstein, Dirac or Feynman.

because I believe a science is not only defined by its object but also by its methods and the community of people doing it.

Alike we could have


 * Chemistry is the science of chemical compounds

and


 * In practice, Chemistry is the science performed within the scientific method as applied by the chemistry community and defined by the works of chemists like Lavoisier, Proust, Dalton, Gay-Lussac, etc...

And


 * Biology is the science of life

and


 * In practice, Biology is the science performed within the scientific method as applied by the biology community and defined by the works of chemists like Pasteur, etc...

The definition I propose allows the subsequent defintion of Physical Biology, Biophysics, Physical Chemistry, Chemical Physics, Physical Biochemistry and so on. For example Physical Chemistry is the science of chemical compounds performed with the methods of Physics in the Chemistry community and Chemical Physics is the science of chemical compounds performed in the Physics Community (have a look at the journal Journal of Chemical Physics and Journal of Physical Chemistry to understand this subtle nuance).

Of course I understand not everybody agree with that. I let this topic open for discussion. And if nobody disagree or if a concensus is found I shall change the definition of physics accordingly.


 * I think you're trying to change the wrong page, because this intro is to a category and shouldn't really be too elaborate. I think no one has changed it since like a year, becuase it jsut isn't important, so I reduced it to a minimum. A complete definition and anything else about physics should be found simply in the article about physics. Cheers. Karol 12:07, July 14, 2005 (UTC)


 * I agree to the given definition. --Meno25 02:25, 23 November 2006 (UTC)