Misplaced Pages

Revision as of 14:49, 7 August 2010

This redirect does not require a rating on Misplaced Pages's content assessment scale. It is of interest to the following WikiProjects:

Physics: History High‑importance This redirect is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Misplaced Pages. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics High This redirect has been rated as High-importance on the project's importance scale. This redirect is supported by History Taskforce. History of Science High‑importance This redirect is part of the History of Science WikiProject, an attempt to improve and organize the history of science content on Misplaced Pages. If you would like to participate, you can edit the redirect attached to this page, or visit the project page, where you can join the project and/or contribute to the discussion. You can also help with the History of Science Collaboration of the Month.History of ScienceWikipedia:WikiProject History of ScienceTemplate:WikiProject History of Sciencehistory of science High This redirect has been rated as High-importance on the project's importance scale. Psychology Low‑importance This redirect is within the scope of WikiProject Psychology, a collaborative effort to improve the coverage of Psychology on Misplaced Pages. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PsychologyWikipedia:WikiProject PsychologyTemplate:WikiProject Psychologypsychology Low This redirect has been rated as Low-importance on the project's importance scale.

This page is not a forum for general discussion about centrifugal force. Any such comments may be removed or refactored. Please limit discussion to improvement of this redirect. You may wish to ask factual questions about centrifugal force at the Reference desk.

Archives

Archive 1 Archive 2 Archive 3 Archive 4 Archive 5 Archive 6 Archive 7 Archive 8 Archive 9 Archive 10 Archive 11 Archive 12 Archive 13 Archive 14 Archive 15 Archive 16 Archive 17 Archive 18 Archive 19 Archive 20 Archive 21

This page has archives. Sections older than 31 days may be automatically archived by Lowercase sigmabot III when more than 4 sections are present.

Tip: #section links are case-sensitive on most browsers Links from this article with broken #section links : ] You can remove this template after fixing the problems | FAQ | Report a problem

Don't revert removal of xkcd links

You need to give a reason for putting xkcd links in an article. Misplaced Pages isn't an xkcd fan-site. WeDon'tWantAny (talk) 07:34, 5 December 2009 (UTC)

The use of cartoons like this to illustrate difficult topics has a long history in physics. As it happens whether this should be included or not, this question came up before, and the decision was that we actually want to include the cartoon in the article if at all possible. The cartoon is after all, technically accurate and penned by a professional physicist.- Wolfkeeper 13:55, 5 December 2009 (UTC)

Please find the discussion for reference. Until then the link stays out of the article. I don't buy your reasoning (the comic explains nothing to the reader, and is simply an in-joke for people to feel pleased about getting). However, if you truly believe what you're saying, I'm sure you'll be happy to see the xkcd comic replaced with something I've scribbled on a piece of paper (it's a comic featuring stick-men explaining the principles of centrifugal forces). Being completely neutral about xkcd I'm sure you will be happy to see this included. WeDon'tWantAny (talk) 17:35, 5 December 2009 (UTC)

Feel free to scribble stuff and upload, and I'm sure we'll treat it according to its applicability to the article. In the meantime the XKCD cartoon is actually notable in this context.- Wolfkeeper 17:49, 5 December 2009 (UTC)

Ridiculous, you even say yourself that the comic will probably get removed because of tone in that original discussion. Why not run with that feeling instead of rabidly defending its inclusion because *you like it*? WeDon'tWantAny (talk) 22:32, 5 December 2009 (UTC)

The cartoon is on topic and entirely appropriate and to the point; indeed I want it in the article and this was agree by the other editors, and the only reason it isn't is because we haven't been able to negotiate a license. If you read the WP:EL guidelines, you'll find that makes it eligible for inclusion in the external links section; we are allowed to include references to things we are not able to include- that is correct linkage.- Wolfkeeper 22:40, 5 December 2009 (UTC)

By that same token, I could point out that your link matches the profile of "Links normally to be avoided"; see points 1, 13 and possibly 11. WeDon'tWantAny (talk) 22:57, 5 December 2009 (UTC)

At the moment there are license issues, I did send a request to the copyright owner to see if he would agree to relicense it; I never got a reply, but I may ask this again though; apparently he gets swamped with emails, so he may not have read it.- Wolfkeeper 13:55, 5 December 2009 (UTC)

If it's something that we'd like to include in the article, but can't due to licensing issues, then that's what external links are for. Dicklyon (talk) 08:17, 6 December 2009 (UTC)

RfC: Does a link to a web-comic belong in this article

Does a link to a web-comic that references the article material warrant inclusion in the article? WeDon'tWantAny (talk) 22:54, 5 December 2009 (UTC)

Looking at the last version with it in I would say include it: it does illustrate the common (mis)understanding of the term. But it doesn't need a cute title. Something like "XKCD comic 123" is all that's needed. Those who want to be entertained, or find out what xkcd is, can follow the link. JohnBlackburne (talk) 23:53, 5 December 2009 (UTC)

• Keep - While it is a 'webcomic' it's written by a professional physicist, is about physics, the cartoon is technically accurate and illustrates in a fun way the physics involved. I'm not hung up on the title, but it needs to describe in some sense what the link does for the user.- Wolfkeeper 02:14, 6 December 2009 (UTC)
• Keep xkcd offers a unique, often humorous view of physics topics we cannot easily integrate into an encyclopedia article. -Atmoz (talk) 02:38, 6 December 2009 (UTC)
• Remove I'm a fan of xkcd and the comic is entertaining, but it has as much to do with Goldfinger as with Centrifugal force. The criteria for inclusion of external links are pretty clearly spelled out in WP:EL and while it may be fun, the strip is does not have information that is not already in the article, nor does it constitute a unique resource. It's would tempting to link to many of the xkcd strips from corresponding wikipedia articles, but it's not encyclopedic to do so.--RDBury (talk) 04:05, 6 December 2009 (UTC)

• On the contrary, we've found in the past that pointing people who were working on the article to it immediately reduced the arguments about the topic. It's a unique resource because the artist managed to get the key parts of whether 'centrifugal force' is "real" or not into just 4 small pictures and a tiny bit of text; and it's unique resource because it's copyrighted, and cannot be easily duplicated.- Wolfkeeper 15:37, 6 December 2009 (UTC)

• Remove Ditto RDBury. While it may possibly expose the misconception, that's not an adequate reason to have it linked per WP:EL. --Izno (talk) 05:58, 6 December 2009 (UTC)
• Keep - It's a decent illustration of a common misperception. That's an excellent reason to include the graphic. The external link is optional IMO... Yes, people can google XKCD for themselves, but why not save them a few clicks? That's the purpose of a hyperlink anyway, right? Plvekamp (talk) 06:15, 6 December 2009 (UTC)
• Keep - the web comic is a valuable illustration of the concepts discussed in the artile. It is a "unique" resource in the sense of providing an accessible illustrating of the crux of the confusions in this area. A link to it seems appropriate. Dicklyon (talk) 08:15, 6 December 2009 (UTC)
• Remove - The comic is fancruft. It doesn't serve to explain the confusion about centripetal and centrifugal forces because the comic requires you to know this in the first place in order to appreciate the joke. It could easily be replaced by one of many other sources. WeDon'tWantAny (talk) 08:33, 6 December 2009 (UTC)

• I haven't found that to be the case at all; you can point people to other sources as much as you want; but it's a rare case of where the maxim "a picture is worth a thousand words" is really true.- Wolfkeeper 15:39, 6 December 2009 (UTC)

I think it's more a case of "I like xkcd and I want to keep it in the article". I really don't see how it is defensible. It's not reference material, its value is highly dependent on point of view, and it's not Misplaced Pages's responsibility to enrich people's lives with popular culture references. This should be discouraged as much as possible, otherwise we would end up with xkcd in every science article, as the comic's formula is making references to science topics. If you take your reasoning out of context you must see how ridiculous it is; by the same logic I should be adding "why did the chicken cross the road?" jokes to the Chicken article, to "illustrate the hazards of chickens in urban environments in an accessible way". As a side note, please don't tally up the votes from an RFC merely hours after it is opened and when no consensus is reached. The point of RFCs is not to "win votes", but to help people come to an agreement about content. WeDon'tWantAny (talk) 16:32, 6 December 2009 (UTC)

Your point is both a facile view of the issue and deliberately deceptive, since 'why did the chicken cross the road jokes' are not really about chickens in any material way. It seems to me that the difference between 'cruft' and non 'cruft' is whether the material is really on-topic or not. In this case it really, is on topic; it really is about the difference between centrifugal force as a completely fictitious concept and something that appears in the equations and represents something that is real enough that it can actually kill you. In this way it adds to the topic, as opposed to adding to the subject of the cruft. If you really can't tell the difference, I would strongly recommend you not write any more for the Misplaced Pages.- Wolfkeeper 16:45, 6 December 2009 (UTC)

We could both keep moving the goalposts on this until the end of time, but that wouldn't change Misplaced Pages's actual policies, which have been laid out for you by three editors now. I suggest you read what the other pro-removal people have said and try to take it in objectively. Pretend it isn't about xkcd, but something you don't hold dear to your heart instead (as RDBury did). As you're now telling people that they probably shouldn't be editing Misplaced Pages when their views differ from yours, I think you should probably step away from this issue until you have regained your cool. WeDon'tWantAny (talk) 16:57, 6 December 2009 (UTC)

The only goalposts are the policies, and they aren't especially movable. If you believe this violates a policy, you will have to quote it for us; as I'm pretty sure there is no violation here; nothing you has said so far identifies any policy violation at all.- Wolfkeeper 00:44, 7 December 2009 (UTC)

WeDon'tWantAny : You asked for comment; you're getting it. This assumption that anyone who disagrees with removing the link must be a fan of XKCD is erroneous. I, for one, am no fan; I think most of his cartoons are banal and barely amusing. This particular one is on-topic and quite illustrative. If we can get a copyright release, I think we should include the graphic itself in the article. I note that the only edits you've made to the Wiki are for the purpose of removing XKCD links... Have you read WP:SPA? Plvekamp (talk) 17:19, 6 December 2009 (UTC)

I'm not sure where I complained about comments being made. Could you please quote the text that implied this? I did complain about being rudely told that I probably shouldn't be editing Misplaced Pages, but that is not the same thing! Please read my talk page where I explain that I have simply noticed a lot of xkcd links that don't belong, and have been removing them. If you want to make accusations about my motives please go through an more appropriate channel where you can justify your reasons for doing so (such as getting the behaviour stopped), as otherwise it just looks like a snide attack. This is a RFC about the article, not about a user. I do see that I shouldn't be adding "mission statements" to my user page, so thanks for pointing that out. I wrote that I am removing inappropriate links from Misplaced Pages as an explanation of what I am currently doing per my routine, not to lay out a singular goal. If I have to suffer criticism for removing an easily identifiable body of cruft in a short space of time, so be it! WeDon'tWantAny (talk) 17:35, 6 December 2009 (UTC)

• Remove: fanboy cruft. 86.153.8.118 (talk) 16:15, 6 December 2009 (UTC)
• Keep, I can't think of a valid reason to remove it.Chhe (talk) 19:21, 7 December 2009 (UTC)

Misplaced Pages:Xkcd_in_popular_culture#Inappropriate_references —Preceding unsigned comment added by 90.215.124.158 (talk) 19:23, 13 December 2009 (UTC)

Well, if the license is ever compatible, I have no intention of adding it as popular culture, nor is it there now; it will be a proper diagram that is part of the text.- Wolfkeeper 22:25, 13 December 2009 (UTC)

• Remove. The comic is funny for someone who is familiar with the quasi-controversy it refers to, but it adds essentially no encyclopedic value. (Funny is not an encyclopedic value). If it had a compatible licence, I would support it as an inline image -- but that is different from an external link. –Henning Makholm (talk) 23:39, 13 December 2009 (UTC)

• Remove: The comic doesn't seem necessary and the website is commercial (sells the comic). TheGoodLocust (talk) 21:50, 27 December 2009 (UTC)

Can you–in good conscience and without trying to twist reality–explain how the strip satisfies points 1-3 in this section?90.215.124.158 (talk) 18:11, 1 January 2010 (UTC)

That section is neither guideline nor policy; it is only an essay. You cannot claim it as authoritative. The comic illustrates a concept quite well in this article. Considering your incivil edit summary towards me ("grow a pair of balls, get cancer in them"), along with your contribution history, I'd suggest your apparent obsession on this issue is prejudicial against the case you're trying to make. Plvekamp (talk) 19:52, 1 January 2010 (UTC)

Yes, but WP:ELNO#11 is guideline. What xkcd in pop culture does is explain when ELNO#11 is best to apply w.r.t. xkcd. If you can make a case against the three points that the IP makes, then you may have legitimate reasoning to keep the link. --Izno (talk) 20:12, 1 January 2010 (UTC)

WP:ELNO#11 reads: 11. Links to blogs, personal web pages and most fansites, except those written by a recognized authority. This link is not a blog, personal web page, or fansite. It is simply a comic. Misplaced Pages:Xkcd in popular culture is an essay against indiscriminate spamming of xkcd into articles; this particular case is not spam, and the essay is not applicable. Further, this section of WP:ELYES item 3 reads:

What should be linked

3. Sites that contain neutral and accurate material that cannot be integrated into the Misplaced Pages article due to copyright issues, amount of detail (such as professional athlete statistics, movie or television credits, interview transcripts, or online textbooks) or other reasons.

This xkcd graphic, as noted above by several editors, cannot be integrated into the article due to a copyright issue. It is therefore incorporated as an external link according to this guideline. Several editors of this article with professional knowledge of the subject have expressed value for it above. Plvekamp (talk) 03:42, 2 January 2010 (UTC)

1) Its supposed value is entirely POV. Editors with professional knowledge of the field aren't the same thing as reliable outside sources 2) Not being a blog, fansite or personal web page (and you have purposely taken a narrow view of this criteria) doesn't mean that comics are fine. The page doesn't give extra information on the topic and it's not written by a recognised authority. 3) Why isn't it spam? Why do the rules not apply to this comic? Why is "it can't be embedded and so it is a valid external link" valid reasoning (you've twisted that guideline for your own purposes; it's only there for things that should be embedded content, and this most certainly shouldn't be)? Why do you think those three points you were asked to satisfy aren't a valid condensed form of the linking guidelines and why do you refuse to answer them?

It's important not to let Misplaced Pages get bunged up with things just because people like them. Go read an article about vampires and imagine if an excerpt from Twilight was added because somebody claimed it helped people understand the concepts, even though it obviously didn't. Would you be happy to see that stay? xkcd is no more golden than Twilight, and shouldn't be given preference in Misplaced Pages articles the way it is. Many people are of the viewpoint that xkcd's writing process involves the author scanning Misplaced Pages for concepts that will appeal to its fanbase and then basing comics around them in order to pander to them. We don't need this being fed back into Misplaced Pages. It's not a reliable source. 90.215.124.140 (talk) 09:35, 2 January 2010 (UTC)

Furthermore, have you thought about the precedent you would be setting? Can I now go and scour the Internet for my favourite comics that reference a subject and add those under the pretense that it makes the subject matter easier to understand, or is this just a special case for comics you like? You can't have a special rule for one thing. xkcd's entire basis is referencing scientific topics. If your addition is valid then we'll end up with xkcd on far too many pages, and it would be ridiculous and selfish. 90.215.124.140 (talk) 09:54, 2 January 2010 (UTC)

You evidently didn't read my comments above. I said, "I, for one, am no fan; I think most of his cartoons are banal and barely amusing. This particular one is on-topic and quite illustrative. If we can get a copyright release, I think we should include the graphic itself in the article." An external link is a reasonable alternative to an embedded image, by guideline. This is not an "xkcd in popular culture"-type use; it is an "xkcd gives a useful image"-type use. I'm not about to go spamming links into any articles. Worries about precedent-setting are a bit paranoid, in my opinion.

Also, thanks for calming down the vitriol, and stating your reasons calmly. We may disagree, but at least now I can understand the motivation for your opinion. WP:CIVIL is just as important as WP:EL; probably more so. Plvekamp (talk) 17:43, 2 January 2010 (UTC)

Could you stop putting the link back in with the edit summary "per talk", as if a consensus has been reached? I can't help but feel that you are trolling or trying to pull the wool over people's eyes with that one. You can't say "per talk" when an agreement clearly hasn't been reached!

If you let the xkcd link in then why should any other editor feel like they can't just add anything they've taken a liking to? And the question remains, how does this comic satisfy WP:EL? You *personally like the comic*; I really feel that this is the only reason anybody would keep it. Again, how does the link satisfy the the guidelines? It needs to do better than being "descriptive" (I don't believe it is even that). It needs to give information and to be a source of knowledge, not just to reference something that the article is about. This is supposed to be a repository of information, not an accessible, chummy textbook with little cartoons to keep students happy in class. 90.217.104.238 (talk) 19:39, 2 January 2010 (UTC)

And could you also stop removing the link, as if a consensus has been reached ? This is a tiresome argument. I personally do not like the comic, in general, only this one particular use, and most editors with knowledge of the subject have agreed with keeping it. An image is worth a thousand words, as the saying goes. I have no agenda, as some apparently do, I simply think this image is an improvement to the article. I won't edit-war; if someone else wants to put the link back in, great. If no-one else puts it back in, then perhaps the image isn't as valuable as I thought. Either way, I'm fine with it. Let consensus be shown by actions. Plvekamp (talk) 19:53, 2 January 2010 (UTC)

• Keep. It is a very good example, and I believe it can engage many readers to re-read (and actually understand :) the article. As has been said above, it would have been a great illustration for the article if it could have been included. PS! it is always useful to provide the link being discussed so non-involved editors can quickly understand what it being discussed, so here is the link to the comic: Labongo (talk) 08:10, 2 January 2010 (UTC)
• Keep. Astute, to the point and highly on-topic. DVdm (talk) 21:57, 2 January 2010 (UTC)

I don't believe the link is appropriate in the article; it's just a joke related to the article's topic. (It might come under #13 of the WP:EL counter-examples.) What other articles should have XKCD comics linked? (I know of one page where it would have been just as relevant, but for obvious reasons I won't link it here.) I don't want to be revert-warring, so take my edit and this message as just my opinion, I won't press it any further. - Mike Rosoft (talk) 20:29, 8 January 2010 (UTC)

There isn't much consensus for this (although I do respect your opinion). We would really much rather have the graphic image on the page instead of a link; I think most of the editors above agree it does help illustrate the difference between centrifugal and centripetal force. Without license to include it, however, we've deep linked to the graphic. Indeed, the last sentence of #13 says: "If a section of a general website is devoted to the subject of the article, and meets the other criteria for linking, then that part of the site could be deep linked." The intent was certainly not to spam XKCD, and thank you for not accusing anyone of such. Your civility is appreciated!! Plvekamp (talk) 22:43, 8 January 2010 (UTC)

• As the actual author of WP:XKCD, I'd say that it's more than applicable here. The comic is hardly the best way to represent what little descriptive material it has on centrifugal force; it most certainly does not "provide unique value to the article beyond that which the article would contain itself at FA class" (contrary to the gainsaying above). As such, it fails to meet the inclusion criteria at WP:EL, and people don't get to override that by a show of hands. I'll be removing this again in a couple of days, and if I see it being reverted back using popups in by editors who should know better (you know who you are) then I'll be taking it to the edit warring noticeboard. Chris Cunningham (not at work) - talk 14:19, 26 January 2010 (UTC)
• Remove I'm here from ELN. I've dealt with a lot of EL issues, and this one is pretty obvious. I'm really suprised at all the non-policy-based "keep" opinions here since this link should most definitely be removed as per our WP:EL guidelines. It doesn't contribute to an encyclopedic understanding of centrifugal force at all, so it fails WP:ELNO point 1 which reads that Any site that does not provide a unique resource beyond what the article would contain if it became a featured article. should be avoided. The site also isn't very informative about the subject matter, it's just a joke, so it fails WP:ELYES as it doesn't provide an encyclopedic understanding of the subject (don't get me wrong, I love xkcd, but its really not acceptible for linking unless the subject matter in the article directly relates to the comic strip). ThemFromSpace 05:07, 4 February 2010 (UTC)
• Remove. I am responding to the notice at WP:ELN. While IMO the link is not actually prohibited by WP:EL (thousands and thousands of links are not actually prohibited by WP:EL), although I understand the WP:ELNO #1 concerns that several editors have expressed, it does not add to my understanding any more than a single, plain sentence would. That is, as a non-specialist who has read (only) the comic and the lead, I learned nothing about centrifugal force from the comic that I didn't know after reading the lead to the article. It's cute, it's succinct, it's memorable, and it's kind of funny (and, oddly enough, I'm wearing #552 today), but it doesn't strike me as either encyclopedic or really useful to the reader. I would remove the link. WhatamIdoing (talk) 03:21, 9 February 2010 (UTC)

Summary of arguments

So it seems that people are going to keep edit warring unless there's a definite conclusion here.

The arguments against including the comic are:

1. It's non-free. This means that it cannot be included in the body of the article, but only as an external link.
2. It does not provide unique value in explaining the subject. (There's a lot of gainsaying about this above; I find it disingenuous to suggest that one could not draw a diagram which explains the science just as well as the comic.)
3. The primary motivation behind its inclusion appears to be not that it clarifies the subject in a way that we could not do ourselves, but rather that it's amusing. This is not an argument grounded in our guidelines. Furthermore, the use of humour in articlespace is not generally in line with our guidelines on article tone.

If anyone wants to refute those points, be my guest. Chris Cunningham (not at work) - talk 10:28, 28 January 2010 (UTC)

1. As a matter of fact it is free. It's licensed with a non commercial GPL license; unfortunately it's incompatible with the Misplaced Pages's license.
2. It's funny, which a 'diagram to explain the science' is extremely likely not to be.
3. You do not appear to be assuming good faith. I added because it did actually clarify the subject, and I checked on the talk page here before adding it. I even tried to get it relicensed, but never got a reply from the author; I understand he has since declared email bankruptcy so it might be worth trying again.

- Wolfkeeper 23:58, 3 February 2010 (UTC)

1. CC-NC-SA isn't a "GPL" license; the GPL forbids non-commercial clauses as well. For Misplaced Pages's purposes it's non-free, even if it has additional rights beyond fair use. Were it to be available under CC-BY-SA then we could have it on Commons; as you say below, you've tried but haven't had any luck.
2. Humour should not be a factor in considering the desirability of links. This isn't Digg.
3. My characterisation of your motive for getting it included is exactly what you said in the response to point 2 above, so I can't see how I'm making assumptions which aren't correct.

Chris Cunningham (not at work) - talk 09:31, 4 February 2010 (UTC)

There's no policy about humour in the wikipedia at all, and ignoring the humour aspect in fact nobody has managed to come up with a diagram that is nearly as succinct or nearly as clear. At the very least, until that happens this is a unique resource.- Wolfkeeper 16:08, 4 February 2010 (UTC)

Anyway, this farce has gone on long enough; the poll has been running for almost exactly two months, normally RFCs run for just one month, and you've been totally unable to drum up enough 'cruft' deletionists to remove it, that alone should tell you something; in the meantime, this is an advanced physics article, and most of the editors with advanced physics support its presence. You have not been able to get consensus for its removal. It's time to close the poll.- Wolfkeeper 16:08, 4 February 2010 (UTC)

The comic's actual artwork is irrelevant to the explanation (which is contained entirely within the text of the second panel), so it could (and indeed has to be) explained in the article body. Head counting is a non-argument, and appeals to authority from pseudonymous editors are even less compelling. This is not a "poll": it's a discussion, and it would be best if someone who wasn't vociferously on one side or the other judged the outcome. Chris Cunningham (not at work) - talk 21:03, 4 February 2010 (UTC)

• It is made available under a CC licence so could be included: not that anyone is advocating that. The other points are much more subjective. I would say it does illustrate the different ways of thinking of it, in a way WP with its encyclopaedic writing style cannot, or at least cannot so easily. Subjective though I know. --JohnBlackburne_deeds 10:37, 28 January 2010 (UTC)

• Unfortunately, although it is a free license, it's the wrong license. I've requested the author relicense it for us. I really, really hope he does.- Wolfkeeper 16:08, 4 February 2010 (UTC)

• Edit warring was not really what I had in mind. I made a few remarks on my talk page. DVdm (talk) 10:43, 28 January 2010 (UTC)

• Comment: I've requested editors who hang around WP:External links/Noticeboard to see if they have an opinion to give, as it currently appears to me a deadlock now (with some edit warring around the edges). --Izno (talk) 01:07, 4 February 2010 (UTC)

Conclusion

It's been another week, and Wolfkeeper (talk · contribs) (who for some time has been the only editor strongly in favour of the link) has deleted the discussion on his talk page while declining to respond further here. I think at this point there's consensus that the link does not provide enough value to warrant inclusion. Chris Cunningham (not at work) - talk 10:23, 11 February 2010 (UTC)

I am strongly in favour of the link, and so are others. I think we're just not prepared to repeat our arguments sixteen times. There is no consensus for removal, so it should really stay where it was. DVdm (talk) 12:21, 11 February 2010 (UTC)

Your argument, quoted from above, was: "Astute, to the point and highly on-topic". This is no argument at all. I do wish people would also stop repeating the phrase "there is no consensus" as if it were an argument in itself. And the only reason you're being asked to repeat your arguments is that I'm not prepared to hit the undo button repeatedly when someone disagrees with me, which has thus far been the only reason this link has stayed on the page. Chris Cunningham (not at work) - talk 14:11, 11 February 2010 (UTC)

First, if you think that my comment was no argument at all, then perhaps I should have used "comment or vieuwpoint on the RFC with title Does_a_link_to_a_web-comic_belong_in_this_article?". So let me rephrase part of my previous reply as follows: I think we're just not prepared to repeat our comments or viewpoints on that RFC sixteen times.

Second, you stated that "...there's consensus that the link does not provide...". I don't think that there is such a consensus. That is not an argument, but a fact. Also note that if there is no consensus to change something (in casu removing a link), then generally the proposed change should not take place - at least I think I've read something along these lines in one of the guidelines or policies. DVdm (talk) 14:45, 11 February 2010 (UTC)

I'm prepared to accept that I was premature here, but that's what happens when people are prepared to edit war until they get their way and then stop contributing to talk until prodded again. I'm taking things slowly to try to avoid that. As for inertia taking precedence in argument like this, I would note that the link has been removed by over half a dozen different editors over the last year, which would hardly seem to indicate that it was a stable element in the first place. Chris Cunningham (not at work) - talk 14:52, 11 February 2010 (UTC)

For the record, I'm not prepared to editwar over anything. Furthermore, I think we can safely reduce this "over half a dozen different editors" to "a few editors", as it is clear that {90.220.88.171, 90.217.104.238, 90.215.124.158, 90.215.124.140, 90.214.85.123} belong to one and the same person. DVdm (talk) 15:06, 11 February 2010 (UTC)

Actually, it is only one shy of that figure even if you dismiss the IPs altogether, and you could include me if I didn't have the patience to sit through a discussion about it. Chris Cunningham (not at work) - talk 15:28, 11 February 2010 (UTC)

I'm also in favour. That you've not heard so for a long time is as this discussion has been going on for a long time and I've not seen the point in repeating myself, unless prompted to by something like this. My own view of the consensus is there's none, i.e. there have been contributions in support of both sides of the argument and no-one has really changed their views.--JohnBlackburne_deeds 14:21, 11 February 2010 (UTC)

It's not a matter of people "changing sides". Consensus does not mean taking the original argument and see who does and does not agree with it; it' a matter of making arguments for one's position, figuring out what parts of those arguments we do agree on and working from that. In this case, there are good arguments and significant precedent in the guidelines not for including this as an external link (and indeed both of the editors contributing in the survey by way of the post at WT:EL agreed with this), and there has been no counter-response to suggest that there isn't broad agreement with the points made. On the other hand, the only part of the keep argument which people generally agree with is that it's a funny comic. Chris Cunningham (not at work) - talk 14:44, 11 February 2010 (UTC)

Radians per second

I always end up forgetting whether the formula is in radians per second or revolutions per second. I'm pretty sure it is the former here, but I don't want to screw up. Can someone confirm this is true throughout the text - and please sprinkle those units liberally so that people feel more comfortable working the equations? Also, the examples given include some mathematics, but they don't come down to concrete answers. I think that if you want to include an example, you should include something familiar like rotation of the earth at the equator and work it out to a plain number for the force.

N.B. the actual value for that is 1/289 of gravitational force , but their derivation leaves something to be desired (force measured in feet?). But to use their numbers, the radius is 20926202 feet, the period of revolution is 86164 seconds, and pi is 3.1415926. So the angular velocity is 2pi radians/86164 seconds = 7.2921 x 10 radians/second. The centripetal acceleration is the angular velocity squared times the radius = 5.3175 x 10 radians/second * 20926202 = 0.11128 radians feet/second. Now at this point radians, rather magically to the uninitiated, make their disappearance, leaving 0.11128 ft/s acceleration. The force experienced is this number times the mass of the object in pound-masses., which can then be converted to pound-force by dividing by standard gravity 32.174 feet/second = 0.0034585 pound-force (per pound-mass). (Perhaps a sane metric version should also be given, but if you can follow this you can follow that! ;) ) Wnt (talk) 00:12, 11 December 2009 (UTC)

It's mentioned in a footnote, which I've made clearer. I've also added a wikilink to angular velocity which explains it further, tidying up a few other things in that section at the same time. In general though units are not given as the formulae are independent of units. Even the units for angular velocity would be wrong if you chose to work in e.g. Tonnes, Miles and Hours (you would need radians/hour) but seconds are almost always used even in non-SI systems so I think it's OK.

As for adding a concrete example, this is not appropriate to Misplaced Pages , as per WP:NOTHOW. Especially in a long article like this where there are a lot of examples, all quite different, as it would needed worked examples for all of them to fully cover the topic. But that would make the article a lot longer and just dilute the mathematical content. You perhaps want to look on Wikihow to see if that covers the topic in the way you want, or if you can add it there. --JohnBlackburne (talk) 10:10, 11 December 2009 (UTC)

Well, the article says that living on Earth is living in a rotating frame of reference, so the example is already used - just not explained. And the working of this precise example is sourced; I think it's one of the most common such questions asked. By comparison, several other examples such as the whirling table and the skywriter are not very informative, and the one about centrifugal force of the Universe is just plain bizarre. Wnt (talk) 13:11, 11 December 2009 (UTC)

Oh, and it doesn't matter whether you use radians per hour or radians per second, because the point is that the acceleration and force value you come up with is denominated in those units. The reason why clarifying radians or revolutions is particularly important is that those units don't exit the formula in as obvious a way. Wnt (talk) 13:29, 11 December 2009 (UTC)

I've rewritten the planet shape section - the galaxy stuff was pretty odd and unsourced, and there's a well written section on orbits later on so that serves much better so I removed it. There was also some Newtonian mechanics which duplicated something further up so I moved the reference then removed it.

The reason radians does not need clarifying is the formulae only work with radians: any other rotation measure introduces a scale factor. The need of radians in mathematics is pretty fundamental, and is considered background knowledge similar to e.g. the cross product and second derivative used in this article. None of these are explained but they are linked to where it makes sense, and readers can follow the links, including the category links at the bottom, for more information.

The links I've added include some such as flattening and rotation period with data. But again in general Misplaced Pages is not the place for detailed calculations of this data. Better to give the more interesting results and leave calculations it up to the reader, or to other sites like Wikibooks.--JohnBlackburne (talk) 14:59, 11 December 2009 (UTC)

I don't believe Misplaced Pages should be "dumbed down", but when possible an article should try to get at least some of the basic concepts across to laypersons and grade school students. People don't actually need to know calculus or trigonometry to run the numbers through the basic equation or to understand the general concept. This is the appropriate place to explain that radians are necessary, and for that matter why radians are necessary. Wnt (talk) 17:19, 11 December 2009 (UTC)

The problem is there are a lot of things going on "behind the scenes" in the few lines of algebra here. E.g. the fact that acceleration is a second derivative, or that the cross product is used to get from Ω to the derivative of Q, or what the cross product is, or that the magnitude of the final term is mΩr. All of it is explained, but it's explained elsewhere. That's how an encyclopaedia works: it covers everything but not all in one place. To include all or a significant portion of that into this article would result in considerable duplication and make an already long article longer and more difficult to read (and edit!). --JohnBlackburne (talk) 18:23, 11 December 2009 (UTC)

Removed Parachutist section again

With this edit user Brews ohare (talk · contribs) restored the Parachutist section he added in the version of 16 May 2009. The section was deleted on 22 dec 2009 by Wnt (talk · contribs), because "it has one reference that doesn't seem to talk about parachutes.". So I have removed the section again per wp:NOR and wp:UNSOURCED. DVdm (talk) 18:08, 6 August 2010 (UTC)

This section was rewritten, and not the same as the earlier version. To suggest that a source referring to parachutes be provided is strange. The section is not about parachutes, per se, but about straight-line motions as seen in a rotating frame. The notion of a parachutist is immaterial, just give a concrete picture. An arbitrary object could be chosen instead, obviously. Of course, straight-line motions require zero net force. As there is always a centrifugal force in a rotating frame, that means an agency is required to counteract this force if straight-line motion is to occur. I fail to see any OR here, nor any need to refer to a source on parachutes. Brews ohare (talk) 18:24, 6 August 2010 (UTC)

If this is not OR, then it will be easy to provide one or more good sources for the entire section. Please do so. DVdm (talk) 18:28, 6 August 2010 (UTC)

Um, perhaps you could provide some guidance that would illuminate for me just what in this section is OR? As I have pointed out, the point is simply that straight-line motion requires zero net force. Also, that centrifugal force is present in a rotating frame. These items hardly require further sourcing. Perhaps you are having difficulty with the way it is explained. Please advise. Brews ohare (talk) 18:31, 6 August 2010 (UTC)

Same case as before with this on Redefinition of the metre in 1983. Provide a source and you're in business. And please have a look at WP:BRD. It is not WP:BRDRD.... DVdm (talk) 18:35, 6 August 2010 (UTC)

Not helpful, DVdm. I guess there is some problem in being straightforward. However, here is a source for you: “Suppose that an object moves along a straight line in a rotating frame of reference. To an outside observer in an inertial frame the object's path is curved – thus there must be some force acting on the object to maintain the straight line motion as viewed by the rotating observer.” I would assume you would be very happy to work with me to apply this observation to the example of the parachutist to avoid any impression that this example involves complex logic or extrapolating conclusions implying OR? IMO it is a rather simple application of this principle, simple because the general case involves an apparent velocity and hence a Coriolis force, while this example does not. Brews ohare (talk) 18:45, 6 August 2010 (UTC)

It is not up to me to be helpful. It is up to you to provide sources when challenged. The source you just provided is sufficient for the sentence you quoted. It is not sufficient for the lecture you are trying to insert into the article. You really should know that by now. DVdm (talk) 19:18, 6 August 2010 (UTC)

You want a source for the parachute example? Do you have any objections to the physics, or are you just wikilawyering? /Pieter Kuiper (talk) 19:53, 6 August 2010 (UTC)

Pieter, the only thing I have is an objection to an unsourced, originally researched lecture. Misplaced Pages is wp:NOTTEXTBOOK. DVdm (talk) 20:29, 6 August 2010 (UTC)

Hi DVdm: I'm sorry that this example does not strike you as a useful addition to the article. I think it is, because it provides the flip side of the dropping ball example, and as such illuminates the concepts.

An invitation to help make the example meet your objections is not to say it is your obligation to do so. What it is, is an invitation to collaborate on building an encyclopaedia.

This example is obviously not OR in any sense of the word, and you have not made any effort to explain in any way the origin of your assessment. The above source provides the principle behind the example. The mathematics is given in the first paragraph of the WP subsection. This example follows not only qualitatively, as presented, but mathematically if one wants to follow through the provided math. If you really think this is my own idea or a projected conclusion beyond the principles, it is a commentary upon your understanding, or maybe your capacities.

That seems implausible. Brews ohare (talk) 20:08, 6 August 2010 (UTC)

I think you are in the same situation as here and here. Consider adding another RFC. I have nothing to add to my (4 times repeated) comments. DVdm (talk) 20:29, 6 August 2010 (UTC)

OK; I have made an RfC. Brews ohare (talk) 21:01, 6 August 2010 (UTC)

RfC: Is the following example a useful contribution to Centrifugal force (rotating reference frame)?

Please consider joining the feedback request service. An editor has requested comments from other editors for this discussion. Within 24 hours, this page will be added to the following list: Maths, science, and technology When discussion has ended, remove this tag and it will be removed from the list. If this page is on additional lists, they will be noted below.

Is the following example a useful addition to the subsection Apparent motion of stationary objects?

Objections have been raised regarding an example, suggesting that it is WP:OR. The example is provided at this link. Please comment upon its suitability and, if possible, provide suggestions for its improvement. Brews ohare (talk) 21:00, 6 August 2010 (UTC)

• Here is the example:

Descending bird

As a contrast to the above example of the dropping ball, which follows a straight-line path in a stationary frame, let's look at the change in fictitious forces when the straight-line path is seen in a rotating frame, rather than one that is stationary. To be concrete, imagine a bird descending onto a carousel, represented as a rotating flat platform.

Let us suppose the bird is initially hovering vertically above the destination site on the rotating carousel below, and therefore traveling at the same speed as the target below. The bird therefore starts with the necessary speed tangential to its path (ωR) to track the destination site. The bird aims to land upon the point on the rotating carousel directly below the drop-off point at the time of starting to drop.

The figure shows the vertical straight-line path of descent seen in the rotating frame. The bird drops at constant speed, occupying successively the vertically aligned positions one, two, three. Because the bird has zero horizontal velocity from the viewpoint of the rotating observer on the carousel, there is no Coriolis force in this example. There is, however, a centrifugal force.

From the viewpoint of the stationary frame, however, the bird must descend downward on the spiral path shown in the figure because the target position on the carousel is rotating. The stationary observer sees a uniform circular motion of the bird when the spiral motion is projected downward, as in the left panel of the figure.

How do the observations from the stationary frame and the rotating frame compare?

The stationary observer and the observer on the rotating carousel agree that there is no vertical force involved: the bird travels vertically at constant speed.

However, the horizontal motion is seen differently by the two observers. The rotating observer has this view: there is always a centrifugal force in the rotating world. Without a exercising an opposing radial thrust, the bird would be carried away by this centrifugal force and land far off the mark. From the bird's viewpoint, trying to keep the target directly below, the same appears true: as it falls vertically, a steady thrust radially inward is necessary, just to hold a position directly above target.

However, the stationary observer looking at the motion in the horizontal plane at the left of the figure, sees a centripetal force at work, -m ω R. This centripetal force is necessary to maintain the circular path. According to the stationary observer, the bird needs a thrust to provide this force. Without thrust, the bird follows the dashed vertical path in the left panel of the figure, obeying Newton's law of inertia.

Unlike the dropping ball case, where the fictitious Coriolis and centrifugal forces conspired together to produce no need for external agency, in this case they require intervention to achieve the trajectory. The basic rule is: if the inertial observer says a situation demands action, the fictitious forces of the rotational frame will lead the rotational observer to the same conclusion, albeit by a different mechanism.

References

1. Bruno Siciliano, Oussama Khatib (2008). Springer handbook of robotics. Springer. p. 481. ISBN 354023957X. Suppose that an object moves along a straight line in a rotating frame of reference. To an outside observer in an inertial frame the object's path is curved – thus there must be some force acting on the object to maintain the straight line motion as viewed by the rotating observer.
2. Angie Bukely, William Paloski, and Gilles Clément (2007). "Chapter 2: Physics of artificial gravity". In Gilles Clément, Angelia P. Bukley (ed.). Artificial gravity. Springer Science + Business Media. p. 42. ISBN 0387707123. When v is parallel to the rotation axis, the Coriolis acceleration is zero{{cite book}}: CS1 maint: multiple names: authors list (link)

Comments upon RfC

• Please add your comments below, beginning with an asterisk *. It should be noted that this example is not in a vacuum; the mathematical background and another example precede it in the subsection. Brews ohare (talk) 21:05, 6 August 2010 (UTC)

• The fact that "the mathematical background and another example precede it in the subsection", is precicely what makes this section WP:OR. This is not a routine calculation. This section might belong in a textbook or in a lecture, but wikipedia is WP:NOT the place for this. DVdm (talk) 21:15, 6 August 2010 (UTC)

To the contrary, this is a completely trivial consequence of the material presented immediately preceding. If you have a problem making this connection, please point out what changes would fix that. Brews ohare (talk) 21:52, 6 August 2010 (UTC)

It belongs in a textbook or in a set of lecture notes. This is a request for comments. It is not a request for arguing whether Brews should be allowed to ignore all rules. DVdm (talk) 09:07, 7 August 2010 (UTC)

• There are only sources for the first paragraph, and not even all of that. Where are the sources for the rest of it? And the second link doesn't work: it gives me a "You have either reached a page that is unavailable for viewing or reached your viewing limit for this book" message. As I've not looked at the book (and can still look at other pages) it must just be outside the range of pages available for preview.--JohnBlackburne_deeds 21:21, 6 August 2010 (UTC)

I changed the source to one that still has a Google books access. As pointed out above, there is no need for further sources given the immediately preceding material. If you feel more is necessary, please be specific. Brews ohare (talk) 21:52, 6 August 2010 (UTC)

Yes there is: see WP:OR which is very clear on this: everything should come from sources, especially such a long and involved section which goes far beyond routine calculations.--JohnBlackburne_deeds 22:06, 6 August 2010 (UTC)

In fact, the presentation is qualitative. If the section appears involved, that may be a question of either your understanding of the topic (I don't claim any insight into this matter) or a question of clarity of exposition (which you could help me with by pointing out items you find are not obvious and so require sources or a better description). IMO the whole example is very straightforward, contains no logical complexity, is adequately sourced, and simply makes the basic ideas concrete. If that isn't working for you, please provide some specific guidance. That way, evolution can happen. Otherwise, you are in the position of making objections with no real intent of being constructive. Brews ohare (talk) 22:18, 6 August 2010 (UTC)

The constructive advice is "find sources for it". That's how Misplaced Pages works, content if challenged requires reliable sources, as it made clear at WP:OR. An exception is made for routine calculations that are easily checked and editors can agree on, but the unsourced content above consists of far more than routine calculations.--JohnBlackburne_deeds 22:34, 6 August 2010 (UTC)

John, you say "find sources for it". That is too vague. What exactly do you need sources for? The word it referring to everything is not specific. My feeling is that you haven't read this entire article and don't understand the concepts. That can make this particular example hard to follow, but is not my fault, and sources won't help. Brews ohare (talk) 23:28, 6 August 2010 (UTC)

BTW, there are no so-called routine calculations here, in fact, there are no calculations. The entire discussion is qualitative, needs no math at all (although math can be used if you prefer it), and falls into the regime of English discourse. Brews ohare (talk) 23:34, 6 August 2010 (UTC)

• This is routine reasoning, but rather wordy for a -pedia. The sourcing requirement leads to invocations of somewhat absurd references, like the robotics text. /Pieter Kuiper (talk) 21:44, 6 August 2010 (UTC)

Yes, insistence on verbatim sourcing means you have to look in strange places. Probably the example could be shortened, but even at its present length, DVdm and Blackburne have trouble understanding it. They think it is OR. Brews ohare (talk) 21:52, 6 August 2010 (UTC)

• My primary concern is that the edit in question completely fails WP:NOTTEXTBOOK. Specifically, "It is not appropriate to create or edit articles that read as textbooks, with leading questions and systematic problem solutions as examples." IMO, the example appears to be more to instruct rather to inform. As others have said above, it is more appropriate for a lecture or textbook, but not for a WP article (perhaps it could be used at Wikiversity). I believe the current examples in the article are more than sufficient to inform (in fact I'd recommend removing one or two based on the same WP:NOT argument) the reader. --FyzixFighter (talk) 22:24, 6 August 2010 (UTC)

This objection is both more germane and more difficult to support. The theses are: (i) Other examples accomplish the same thing. Please indicate which examples do that. And (ii) The example instructs rather than informs. If that has a meaning, I'd say that this objection means the example serves to teach skills (like exercises to master the mechanical details) more than it serves to sharpen understanding of the concepts. I can believe that opinion may vary on that judgment. My own is that this example, by treating a straight-line motion in a rotating frame, the flip side to treating a straight-line motion in a stationary frame, shows the following: in this case, centrifugal force has to be physically counteracted by a thruster, illustrating how real it is to the parachutist; on the other hand, in the dropped ball example, the centrifugal and Coriolis forces join up to produce exactly no need for any action. That illustrates the two faces of the fictitious forces, and is illustrative of the concept, not simply a teaching of manipulative skills.

Should we ultimately disagree about the impact of this example upon understanding, I'd opine that there is no need to drop the example inasmuch as it does have explanatory value, whether or not it has other benefits. Brews ohare (talk) 22:46, 6 August 2010 (UTC)

• Excellent text with a very nice illustration! I don't see what the problem here is. Sources are not needed when explaining a previously treated concept using an example. Examples and derivations are exempt from being challenged on the grounds of OR simply from lacking direct sourcing, unless a reasonable case is made that there is, (or that there can reasonable be), something wrong with the text. Also whether or not this fails WP:NOTTEXTBOOK is a matter of taste. Some Misplaced Pages articles by consent do read very much like textbooks (many of the articles I contributed to are of that nature), so this is not a blanket rule. What you probably don't want to do is rewrite a good encyclopedic FA class article into a dry textbook text that would lead to the article dropping from FA Class right back to Start Class :). Count Iblis (talk) 23:44, 6 August 2010 (UTC)

• As explanatory examples go, a long-winded explanation about a parachutist with a thruster seems overly complicated and confusing. The style is sort of text-booky, yet not very clear. The illustration is packed with info, yet not very clear. It's typical of Brews to defend this kind of article-bloating material that he likes to make up, and since he got kicked off of speed of light, he's attacking other topics now. Seems like a bad idea. Dicklyon (talk) 04:53, 7 August 2010 (UTC)

• This section should not be added to the article, because it is wrong. A parachutist falling at constant speed towards the center of Earth does experience a Coriolis force in the frame rotating with Earth, unless he falls straigt to one of the poles. Not over the poles his velocity is not parallel to rotation axis, and there will a Coriolis force East. This is called the Eötvös effect. −Woodstone (talk) 07:26, 7 August 2010 (UTC)

Don't you mean Buys Ballot's law? But this "parachutist" carries a litle thruster, keeping him above the target. So it is not wrong, but Dicklyon has a point, that this example can be confusing. /Pieter Kuiper (talk) 09:24, 7 August 2010 (UTC)

The problem's not that it's right or wrong, but that it's OR. One reason for disallowing OR is that if an editor is allowed to write what they want not based on any source it's very difficult to tell if it's correct, and editors can be tied up forever debating the correctness of an article, or even a section or paragraph. The rules on OR are in place to prevent that – you should always be able to point to a source for every argument and example.

What is clear on top of it being OR it fails , which says "It is not appropriate to create or edit articles that read as textbooks, with leading questions and systematic problem solutions as examples". The article already has a number of (sourced) examples, with a couple overlong already. It does not need another (unsourced) one.--JohnBlackburne_deeds 10:42, 7 August 2010 (UTC)

Woodstone: Thanks for your observations. Apparently the example is not sufficiently clear. The "Earth" is idealized, as is the parachutist falling at a uniform speed, and as the figure indicates is modeled as a rotating flat disk, not as a sphere. The problem is in cylindrical geometry. Its the same model used in the dropping ball example as well. So your objections are for the wrong situation. Brews ohare (talk) 12:49, 7 August 2010 (UTC)

I have added a disclaimer that the "Earth" is a flat disk, not a sphere. Brews ohare (talk) 13:10, 7 August 2010 (UTC)

Blackburne: Your objections are fully discussed above in response to FyzixFighter. You have replied to none of the points, and appear to be engaged in rhetoric, not useful discussion. Brews ohare (talk) 12:53, 7 August 2010 (UTC)

Dicklyon: Your comments are a bit confusing: the section is "bloated" yet it is "packed with information". It is "made up" and "unclear". It would be helpful, if instead of making gratuitous abrasive remarks about my being "kicked off" and "attacking other topics" that are violations of WP:Civil, you were to attempt to point out changes to make things shorter and clearer. Brews ohare (talk) 12:59, 7 August 2010 (UTC)

Pieter Kuiper: I appreciate your comments on the section. I see that the mention of "Earth" as a picturesque term for the rotating flat disk has derailed Woodstone, despite the figure showing a flat rotating disk. Of course, we all like to complicate our lives. Do you have any suggestions for improving the example? I like this example because it complements the preceding one that is very similar. The contrast is more illustrative than a totally new example. However, in view of the barrage of non-specific and nonconstructive complaints above, that make no effort to improve matters, maybe a different example would be better? Brews ohare (talk) 13:33, 7 August 2010 (UTC)

Maybe instead of a parachutist falling to "Earth", it should be phrased as a bird dropping onto a carousel? The dropping ball problem becomes the "dropping droppings" from the bird before it starts flight, and the second one is the descending bird problem. : ) Brews ohare (talk) 13:43, 7 August 2010 (UTC)

You see what happens (again), brews? Non of this would be necessary if you had sources for your lecture. The only thing that can improve matters, is sources, sources and sources. This is a request for comments on whether your lecture is OR or not. Consensus says that it is OR. It stops being OR when it is sourced. So please source it and stop disrupting this talk page? DVdm (talk) 13:48, 7 August 2010 (UTC)

DVdm: So now an RfC is a disruption of a Talk page? I thought it was about improving a proposed contribution. My requests for specifics about what is OR exactly, and what is unclear exactly, and what needs further sourcing exactly, are stonewalled by editors who dismiss this effort with no specific justification, but instead provide vague, nonconstructive assertions, apparently unmotivated by any interest in improving the exposition. Brews ohare (talk) 14:05, 7 August 2010 (UTC)

I have rewritten the example to refer to a bird and a carousel to avoid misinterpretation of the cylindrical geometry shown in the figure. Brews ohare (talk) 13:59, 7 August 2010 (UTC)

And your source for that is? Again, the point of WP is not for editors to write whatever they want but to write an encyclopaedia based on sources. You've been asked repeatedly for sources for what you've written, but you've yet to produce any. Repeatedly ignoring these requests, instead posting an RfC, for the second time in a few days, is certainly not a productive use of your time or anyone else's.--JohnBlackburne_deeds 14:19, 7 August 2010 (UTC)

This is not how WP:OR is used in practice on many math and physics articles. While WP:OR explicitely says that simple unsourced deductions are allowed (if the editors agree that it is valid), it does not say that more complex unsourced deductions can never be ok. Like I said before, I've added a quite a few far more complex unsourced derivations (for good reasons) to some Wiki articles without anyone giving a peep. WP:OR is in practice only invoked on such pages if there are real questions about the correctness of the proposed edits and a verification from sources is really needed. Count Iblis (talk) 14:46, 7 August 2010 (UTC)

Blackburne: OK, let's look at this in detail to assist you in becoming specific. Let's ask: What needs to be sourced?

• The first four paragraphs are simply describing the situation to be examined, setting up the discussion. As simply a set-up describing what is to be discussed, that hardly needs to be sourced.
• The statement about no vertical force can be sourced to Newton's law F=ma if you really need that.
• The next paragraph describes the horizontal motion in the rotating frame. There isn't any. I don't think we need a source here, that is simply the description of the vertical path.
• The assertion is made that there is a centrifugal force present in the rotating frame. That can be sourced if you insist, but of course that is the entire subject of this article and so hardly requires a new source. Rotating frames always have centrifugal force.
• The second from last paragraph describes the projection of a spiral path on the horizontal plane as a circular arc. I believe that to be an obvious point: do you want a source describing projection of a spiral down a cylinder as a circle in plane perpendicular to the cylinder?
• The next statement is that circular motion implies a centripetal force. Again, this connection is clear; a link to Centripetal force can be provided if you wish.
• The last paragraph is a summary.

Please go down this list and suggest where you have dissatisfaction. So far as I can see, there is nothing here of such import as to require an OR label or extensive sourcing. I find myself perplexed trying to understand specifically what you object to. Please try to clarify. Brews ohare (talk) 14:49, 7 August 2010 (UTC)

• Redirect-Class physics pages
• High-importance physics articles
• Redirect-Class physics articles of High-importance
• Redirect-Class physics history pages
• Physics history articles
• NA-Class history of science pages
• High-importance history of science articles
• WikiProject History of Science articles
• NA-Class psychology pages
• Low-importance psychology articles
• WikiProject Psychology articles
• Misplaced Pages requests for comment