Talk:Point source

Old comments from pollution page
 ''This section contains older comments copied from Talk:Point source (pollution). New discussion starts below.''

It seems very strange to restrict the point source page to pollution point sources, particularly as this is one of the least common uses according to websearches and wikipedia usage (most links to "point source" on wikipedia go to wiktionary because the definition on this wikipedia page is so limited and unhelpful).

The general definition of point source (i.e. without the word "pollution") works for any type of point source (whether an optical point source, a radio point source, a chemical point source, a pollutant point source or whatever). Why can't the word "pollution" be removed from the definition so it applies to all types of point source, otherwise it's like defining a car as being a "Ford" and sending users to a disambig page for all other types of car.

I tried to make these changes, but they were immediately reverted. It would be useful if we could have a vote on this. Alternatively, we could have separate pages for pollution point source, optical point source, audio point source, radiation point source, chemical point source, etc. which would be almost identical. Rnt20 20:15, 4 September 2006 (UTC)

Perhaps the article could start with the definition given on the Wiktionary page:
 * "A source, especially of radiation, waves or pollution, that has one specific location (and usually negligible physical extent), especially an idealized source having zero extent"

Rnt20 20:33, 4 September 2006 (UTC)


 * Rnt20, with all due respect, not all of the readers and users of Wikipedia are physicists or astronomers. Every environmental pollution regulatory agency of local, state, province, and national governments in most countries of the world have air and water pollution laws and regulations which specifically reference point sources of pollution.  There are many, many thousands of publications, articles, books, conference proceedings, etc. which deal with air and water point source pollution ... and  there are many thousands of professional engineers, scientists and others who work in the field of air and water pollution.


 * Any of those thousands of people interested in point sources of air and water pollution, who come to Wikipedia for information about sources of pollution, would be looking specifically for such information about air and water pollution ... they would have no interest in radiation, optical or wave sources. So why not have an article specifically devoted to pollution sources? Is there anything wrong with that? I think this article should remain as it is, an article about pollution sources.


 * This article is tagged with an opening alert that other uses of the phrase "point source" are available at Point source (disambiguation). I may be wrong, but your above comment sounds as if you might possibly be averse to the idea of disambiguation pages. Is that the case? Regards, -mbeychok 21:23, 4 September 2006 (UTC)


 * I would also point out that this article was just created less than 24 hours ago. Before it was created, all related article were linked to the disambiguation page and had been so linked for quite some while. So all this article did was to provide a separate page that could be used by articles related only to pollution point sources. This article, in less than 24 hours, already has about 27 pollution related articles that link to it. - mbeychok 00:08, 5 September 2006 (UTC)


 * Hi Rnt20. It seems clear to me that the pollution usage of the term needs its own article, separate from other uses. They are not the same thing. From what I read here, I gather that in pollution tracking, a "point source" is just a localized source. Unlike point sources in physics, an inverse square law emission is not implied, nor is the source necessarily of negligible spatial extent. When this article was created, I actually moved it to Point source (pollution), but I moved it back shortly afterward because I wasn't sure that was the best location. If we do decide that we need an article on point sources as used in physics and other sciences, I would certainly support moving this article to a more specific title, and reserving the simpler title for the more common and more direct usage.
 * It's not clear that the physics usage needs an article, however. One of the Wikipedia's core rules is that Wikipedia is not a dictionary. If all there is to say about a word or phrase is its definition, the word or phrase belongs on Wiktionary, not here. It's not clear to me that "point source", as used in physics, is a viable topic for a Wikipedia article. As a result, I have adjusted all the links that weren't pollution-related to point to the Wiktionary entry point source. Contrary to what you assert, the links do not go to Wiktionary because this page is unhelpful. They go there because the Wiktionary article was the appropriate place to send someone who needs a definition of "point source", and there seemed little point in linking this phrase to anything more than a simple definition. I should know; I made every one of those links myself, last night.
 * It might be advisable to move this article to a more specific title, such as Point source (pollution) and allow Point source to be a redirect to the disambiguation page. Even though there are no other Point source articles, this article will invariably collect bad links from people writing physics articles who make links without checking the destinations. It might be less confusing overall to avoid that situation.--Srleffler 03:56, 5 September 2006 (UTC)


 * OK, I will create separate pages for each type of point source. Note also that in Physics & Chemistry a point source also does not imply an inverse square law -- e.g. a point source of gas or fluid in fluid dynamics. Also note that in pollution usage, a point source must have negligible spatial extent to distinguish it from an area source or volume source, just as in Physics & Chemistry. 84.220.102.68 06:16, 5 September 2006 (UTC)


 * Ooops -- just read your comment about the wiktionary links -- I had been changing them all back! Sorry. Given that "point" has multiple meanings in English, and that in physics the laws for point sources of gas, fluid or substance are quite different to those for e.g. electron waves or light, I think a wiktionary definition is insufficient. However, the laws for e.g. a gas or for noise are the same regardless of whether or not it is called "pollution".
 * I have also started dealing with some of the links to the disambiguation page. However, many of the links are to point sources in general (not one specific type of point source), and I don't know what to do with those (currently I am leaving them pointing to the disambig page) -- e.g. an optical point source is an optical point source whether it is "light pollution" or just light -- lenses image a point source whether they are microwave lenses, optical lenses or electron lenses -- so where should these links to "point source" go? There are still more links to point source (disambiguation) that need changing:


 * Diffraction
 * Double-slit experiment
 * Huygens-Fresnel principle
 * Lens (optics)
 * Microscopy
 * Mass transfer
 * Quasar
 * Wave equation
 * Electromagnetic pulse
 * Inverse-square law
 * Arago spot
 * Partial differential equation
 * Confocal laser scanning microscopy
 * Gauss's law
 * Focus
 * Interferometry
 * Spherical aberration
 * Shadow
 * Collimated light
 * Deconvolution
 * Ufology
 * Photometry (optics)
 * Kerr metric
 * Coma (optics)
 * Voltage clamp
 * Point spread function
 * Stevens' power law
 * Explorer XI
 * 2004 Indian Ocean earthquake
 * Wavefront
 * Wavicle
 * Free-fall time
 * Isotropic radiation
 * Transverse Doppler effect
 * Isotropic radiator
 * Schlieren
 * Strehl ratio
 * Circle of confusion computation

Rnt20 13:07, 5 September 2006 (UTC)


 * STOP. Before you do any more damage, please read Disambiguation and Manual of Style (disambiguation pages). You don't seem to understand disambiguation, and as a result you are making bad edits that create more work for everyone. If you have changed the wiktionary links to point to the disambiguation page, I expect you to change them all back (or change them to point to an article) before you do anything else. It is never acceptable to deliberately link to a disambiguation page. Disambiguation pages exist to catch erroneous links; cases where someone makes a link without bothering to check that they are linking to the correct article. The ultimate goal is to have zero links to each dab page (except for dablinks at the beginning of articles, etc.) Disambiguation pages are not to contain any information beyond that needed for a reader to quickly find the link to the page they are looking for.


 * Do not create articles for the different types of point source unless you are sure there is enough to say about them to make a viable encyclopedia article. If it is not possible to expand the article much beyond a simple definition, the article should not be created.--Srleffler 16:12, 5 September 2006 (UTC)

Suggested move
I suggest that Point source be moved to pollution point source, and that point source (disambiguation) be moved to point source (except for the company reference). A new disambiguation page would then be needed with two entries:


 * A point source is a single identifiable localized source of gas, fluid, heat, noise, waves, substance or pollution. A point source has negligible extent, distinguishing it from other source geometries, such as a line source.
 * Point Source (company), a company that produces lasers and fiber optic devices

What do people think? This would make the article more consistent with e.g. Line source. Rnt20 12:59, 5 September 2006 (UTC)


 * It seems clear to me that the definition of a point source is essentially the same for Environmental, Physical and many other applications. They are all based on a mathematical abstraction of a source with a fixed location and no spatial extent in any dimension (in the real physical world these sources have small spatial extent - but often mathematics dealing with an object of no physical extent can be used as an approximation). I think there should be a main definition page, which would go further than a wiktionary definition and perhaps list common applications of the mathematical abstraction - e.g. in pollution theory or radiation etc. There should also be a seperate page that is less mathematical and solely deals with the term in it's pollution context. The articles about pollution point sources should link to this page. 131.111.48.50 14:20, 5 September 2006 (UTC)

It would be useful to have some more comments on this


 * The proposed disambiguation page does not comply with WP:MOSDAB, in several respects. In particular, it is not appropriate to create a disambiguation page with only two entries. The proposed name for the pollution page is also inappropriate. A better name would be Point source (pollution). Note also that disambiguation pages are not articles. See Disambiguation.--Srleffler 16:16, 5 September 2006 (UTC)

Disambiguation page reformat and merge proposal
OK, I have reformatted this article as a proper disambiguation page, in accordance with Manual of Style (disambiguation pages). There are now many articles that link here, however. Two days ago, we had no inappropriate links to this disambiguation page. Another Wikipedian went through and changed many of them to point back here, and created many new ambiguous links as well, contrary to WP:D. He also created many little stub articles, one for each "type" of point source. It seems that we now have two options:
 * 1) Adjust the links to this page to point to the appropriate individual articles on each type of point source, or
 * 2) Merge some or all of the individual articles into a single article on point sources in general

I say "some or all" largely because of the pollution article. This topic is distinct enough from the other articles (all of which deal with physics) that it may benefit from being treated in a separate article. The kinds of things one might want to say about a "point source" of pollution are different from the things one might consider for point sources of light, sound, heat, etc. Or maybe it's not that distinct after all and could be covered in the same article. I'm a physicist, so I don't really know much about it.--Srleffler 05:02, 6 September 2006 (UTC)

To be clear: If we merge all of these articles, we would eliminate the disambiguation page and just have dablinks between the two articles Point source and Point Source (company). If we only merge some of the articles, a disambiguation page would still be required as well as the merged article. We can discuss the appropriate names for those later.

If it seems like we're going in circles, it's because we are. The intent of this discussion is to stop the thrashing around, and get a consensus on how to move forward.--Srleffler 05:26, 6 September 2006 (UTC)


 * I think it all makes sense scientifically now (it certainly didn't before). I would also be happy for all of the information to go on one point source page -- good luck in trying to do that though (I tried to do this before, but there was some of resistance from other editors). Changing the links is a little tricky, as the majority of links refer to point sources in general and not one specific type (e.g. they do not single out the case of light, radio or light pollution, but discuss waves in general which would include all of these, or e.g. they discuss the emission and tracking of a gas but do not state whether or not the gas is a pollutant). I will make these point to the general point source article. Rnt20 09:18, 6 September 2006 (UTC)
 * I think the resistance you saw was mostly from me. My main issue is that there is a difference between a disambiguation page and an article on point sources. They have different purposes, and different structure. A combined article on point sources is fine, but should not be marked as a disambiguation page.--Srleffler 16:20, 6 September 2006 (UTC)

The one about pedestrian traffic is even less about physics than the one about pollution. But all of them, including the ones on pedestrian traffic and pollution, are about things studied by mathematical methods. In some cases, the mathematics may be nearly the same even when the subject matter to which it is applied is different. Traffic flow and flow of water are physically different, but those who study them mathematically say the math is often the same. I think it is sometimes appropriate to link to a disambiguation page, and we should consider in each case whether it is such a occasion. Michael Hardy 19:31, 6 September 2006 (UTC)

Comments?
As an example of why the pollution topic may need its own article, user:Anlace just changed Point source (heat) to thermal pollution, apparently assuming that "point source" automatically meant a point source of pollution. I reverted and reorganized the list to put pollution at the top, in hopes of avoiding this confusion.--Srleffler 05:33, 6 September 2006 (UTC)


 * the merger is probably the best idea, since the creation of all these stubs is of dubious value (e.g. point source (fluid) etc.) It doesnt seem likely some of these stubs will ever amount to useful articles.  the thrust of point source should be to describe the theory of using the concept of point source and draw examples from the varous fields. i have just greatly expanded line source and feel this is a reasonable model for point and area source articles. regards Anlace 05:59, 6 September 2006 (UTC)


 * Note that the definition of a point source is not changed whether or not the gas / fluid / light / heat is considered a pollutant. I think the pollution case can be included on the same page by simply stating that the substance, waves (e.g. light, sound) or heat being emitted might be a pollutant for the case of pollution tracking (or not for the case of Physics, Chemistry, Engineering, Optics etc). The same laws and mathematics apply whether the gas or smoke is labelled a pollutant or not, so why have a separate page? Rnt20 08:43, 6 September 2006 (UTC)
 * Mbeychok can probably address this better than me, but for an article on pollutant point sources one might want to discuss regulatory definitions and other issues that don't arise in consideration of point sources in physics. Even if fundamentally they are the same thing, there may be good reason to treat point sources of a pollution in a separate article, since there may be much to say about them that does not overlap with what one would want to discuss in an article on point sources in physics and chemistry.--Srleffler 16:11, 6 September 2006 (UTC)

I strongly believe Point source (pollution) should be a separate article
Srleffler, I thought we had settled all of this in the preveious discussions yesterday. I think the re-organization edits made by Michael Hardy after those discussions were a good compromise. I also remind you that during those discussions yesterday, you were the first to suggest that Point source (pollution) be a separate article. And I remind you of what you posted on my talk page this morning:


 * You've still got Point source (pollution). That seems like a good title for your article. Why not work there?--Srleffler 02:48, 6 September 2006 (UTC)

What changed your mind since you wrote that? I think perhaps you are bothered by Michael Hardy not having followed the Manual of Style (MOS) on disambiguation pages. In my opinion, the MOS is not meant to be so rigid as to be cast in stone. It is meant to be guidance. I must say that I am disappointed that you have, in a few short hours, changed your mind and suggested a merger that is not needed.

Anlace, if you think that a few of the stubs created after Michael Hardy's reorganization yesterday may not evolve into useful articles, then why not simply suggest they be deleted? I don't believe they should be a basis for the completely reversal of his re-organization, do you? -mbeychok 07:33, 6 September 2006 (UTC)
 * their deletion is fine with me Anlace 12:23, 6 September 2006 (UTC)


 * I haven't changed my mind. I still support having the pollution article be separate, although I think more discussion on why this is useful would be good. What motivated my change in approach was that after Michael moved the disambiguation page and the pollution point source article, user:Rnt20 created a whole bunch of little stub articles, which had not been discussed previously. I initiated a discussion of merging those stubs or keeping them. I had initially planned to exclude the pollution point source article, but as I was preparing the merge proposal I realized that it was inevitably going to come up anyway, and I thought it was better to include the page in the proposal from the beginning. As I indicated above, we don't have to merge all of the articles. We can merge some of them and leave others independent. What we need, though, is to discuss the issue and come to a consensus of how best to organize this information.


 * And yes, I am concerned about the format of the disambiguation page. The MoS is flexible when necessary, but I don't see a need here to bend it. If we want a combined page that discusses all types of point sources, what we need is an article on point sources, not a disambiguation page.--Srleffler 16:07, 6 September 2006 (UTC)


 * i am really missing the question being asked by mbeychok. i didnt want to stir up an argument about anyone's past edits, so i didnt comment on Michael Hardy's "re-organization". now that you seem to belabour the matter i have tried to study his edits and dont find them to have a great impact. i m more interested in where we are going here than trying to criticise anyone's past edits. i think point source should be as unified as possible.  if the concensus is to have a separate point source (pollution) article, then so be it.  i really would like to get rid of the multiplicity of stubs. most of our readers are interested in the concept of point source and all this fragmentation doesnt help them. regards Anlace 17:12, 6 September 2006 (UTC)


 * Having a unified point source page and a separate page for point source (pollution) aren't necessarily exclusive alternatives. The second would seem to be a subtopic of the first; a summary could appear here while more detail was available on the subtopic page. The usefulness of this alternative would depend on how much information could be developed on point source (pollution). Christopher Parham (talk) 19:55, 6 September 2006 (UTC)

The following comments dated Sept. 4th and 5th
The following comments dated September 4th and 5th were co-opted by Srleffler from another (previous) discussion of this same topic. They are out of chronological order and hence confusing. In all fairness, they should be moved to the top of this page since they were made before Srleffler's merger proposal and before Michael Hardy resolved them by his re-organization. - mbeychok 17:31, 6 September 2006 (UTC)
 * I did not move them here. Until I looked at the history I thought you had copied them here. Actually, though, they were put here by user:Rnt20. I agree with you entirely, about them being confusing. I added a box around them. Hopefully that will help.--Srleffler 17:43, 6 September 2006 (UTC)


 * It does help a bit. I have now moved them to the top of this page where they belong. - mbeychok 18:20, 6 September 2006 (UTC)

RFC
I came to this article via RFC and it seems like the articles have a substantial amount of repetition. Also, it seems that by breaking up the material readers aren't able to get a full scope of the variety of applications in which this concept it used; part of the interest of the topic is the breadth of its applications and chopping it up hides that. It seems like the best solution would be a single major article on the topic at this title (dab-linked to the company) with subtopic pages broken off as needed if a large amount of information is developed on any one particular application. If there is opposition to such a merge, I am having difficulty characterizing it based on the above discussion, so help me out. If there is no opposition, let me know and I will try to carry out the merge. Christopher Parham (talk) 19:50, 6 September 2006 (UTC)

Partial consensus?
I think we have a consensus for merging all of the point source stubs except for the pollution one. I don't think I have seen anyone argue against merging those. I don't think we have consensus on the pollution article yet. Perhaps we should agree that the other articles will be merged (when we're done the discussion), and focus the discussion on the interaction with the pollution article.

I generally support keeping it separate, but I'm not an expert in this field and can't make the case for it. Some of Rnt20's recent edits attempting to harmonize the articles make me quite uncomfortable, however. While a point source of pollution is treated as "negligible in extent" for the purpose of modeling its effect on the broader environment, it is typically not in any usual sense "small". The overlap of definitions also leads to some confusing and misleading terminology. For example, contrary to what Rnt20 asserts, a streetlamp may be a point source of light pollution, but it is most certainly not an "optical point source". A power plant is a "point source" in a pollution model, but is not a great example of a "gas point source" in general.

The use of "point source" in pollution studies seems almost metaphorical, not carrying with it the connotation of smallness found in most other uses of the term.--Srleffler 03:47, 8 September 2006 (UTC)


 * I think this sounds OK, but the main point source page must have a brief summary of pollution point sources (with a link to the pollution point source article). Note that point sources in physics are often (perhaps usually?) much larger than point sources in pollution tracking. Typical point sources in physics are: stars (the typical example of a point light source, 100,000 miles to 100,000,000 miles across, but still of negligible size as far as astronomers are concerned), the Earth (typical example of a point gravity source for solar orbit discussions, 10,000 miles across), quasars (billions of miles across), etc so the argument that pollution point sources are not always small seems a bit of a lame reason for having a separate page! One of my physics textbooks gives a distant streetlamp as another classic example of an optical point source in physics (there really aren't separate definitions of point source for physics and pollution -- they really are identical definitions if you look in textbooks -- only mathematics deals with the non-physical concept of a really point-like (infinitesimal) source). The only difference is thus between the definition of a mathematical point source (an abstract concept, infinitesimally small) and a point source in pollution tracking or physics (a real object of finite size, like a street lamp, star or power plant). Note also that not all sources in pollution tracking are labelled as point sources -- only the sources of negligible size are called "point sources" (see line source, area source etc. for examples of sources which are too large to be point sources in pollution tracking). Part of the disagreement seems to stem from a misunderstanding of what a point source is in physics (basically the same thing as a point source in pollution tracking). Rnt20 09:52, 8 September 2006 (UTC)


 * As far as the merge itself is concerned, I am happy to help with merging the text, although I haven't been involved with merging any articles before so I'm not an expert in this. Rnt20 10:10, 11 September 2006 (UTC)