Wikipedia:Articles for deletion/Centrifugal force (planar motion)


 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review).  No further edits should be made to this page.

The result was   Closed after speedy delete at request of sole author. Bduke   (Discussion)  22:57, 13 October 2008 (UTC)

Centrifugal force (planar motion)
Brews_ohare (originator, sole contributor and defender of this page) wishes to withdraw this article from further discussion and have it deleted entirely ASAP. Brews ohare (talk) 19:32, 13 October 2008 (UTC)


 * ( [ delete] ) – (View AfD) (View log)

This article is scoped, defined and edited to be purely and simply a Content fork of Centrifugal force (rotating reference frame). It consists of material that was deleted from that original article. - (User) Wolfkeeper (Talk) 22:52, 10 October 2008 (UTC)
 * This AfD requires an expert in the subject.  Schmidt,  MICHAEL Q. 23:23, 10 October 2008 (UTC)


 * I am opposed to deletion; this article is not a content fork; see the discussion below and look at the article itself. There is very little overlap, neither in topics, nor figures, nor equations. Brews ohare (talk) 00:03, 11 October 2008 (UTC)


 * Yes, well, since you wrote it, you would be opposed. The reason there's no overlap is because the material was removed from the original article, by consensus. There may be ways to keep material within the wikipedia, but a simple content fork which overlaps in scope with the original article isn't one of them.- (User) Wolfkeeper (Talk) 16:17, 11 October 2008 (UTC)


 * The usage of the term Centrifugal force is synonymous with the main article. Under the wikipedia policies articles that are on synonymous usages should be merged see: Wikipedia is not a dictionary. Here, because the material was removed from the original article, you can't do that. So the article should be deleted or made not to be a content fork.- (User) Wolfkeeper (Talk) 16:20, 11 October 2008 (UTC)


 * The article Wikipedia is not a dictionary is cited based upon the notion that the the two articles refer to the same concept (centrifugal force) and therefore must be in the same article. However, the two pages are not discussing the same thing: they discuss different aspects of the topic, namely, centrifugal force in the context of a uniformly rotating reference frame with a fixed axis on one page, and centrifugal force in a more general context on another page. It is not similar to the example case given in Wikipedia is not a dictionary of discussing gasoline on one page and petrol on another. For more detail on the reasoning behind two pages, see this link. Brews ohare (talk) 14:16, 12 October 2008 (UTC)


 * Yeah, right.- (User) Wolfkeeper (Talk) 18:07, 12 October 2008 (UTC)

Keep The content of the article Centrifugal force (planar motion) is in no way a duplication of the companion articles on this subject. It concerns the details of describing centrifugal effects upon particle motions as observed from a variety of inertial and non-inertial frames of reference, and using a variety of coordinate systems (arc-length, polar, Cartesian, curvilinear). It also provides guidance to a good deal of cited work.

In contrast, the companion article Centrifugal force (rotating reference frame) deals very specifically with centrifugal force as observed in reference frame rotating around a fixed axis. That's it.

To simply delete Centrifugal force (planar motion) would eliminate a good deal of useful material from Wikipedia not available elsewhere. To combine it with Centrifugal force (rotating reference frame) would make that article much longer, and make it cover a wider range of topics.

In addition, Centrifugal force (planar motion) addresses the Lagrangian formulation of the problem (which applies to very general coordinate systems) and points out that "generalized" fictitious forces differ from plain old Newtonian fictitious forces, a point that has caused some debate on talk pages.

I am inclined to think Wolfkeeper does not grasp the issues here. Brews ohare (talk) 00:01, 11 October 2008 (UTC)


 * The article is about fictitious forces acting in a rotating reference frame. This is synonymous with that covered at the original article Centrifugal force (rotating reference frame). Under the policy WP:Wikipedia is not a dictionary synonymous definitions are merged into a single article.- (User) Wolfkeeper (Talk) 00:52, 11 October 2008 (UTC)


 * I think it is pretty clear from the article and from what was said above that the article Centrifugal force (planar motion) is not about fictitious forces in a rotating reference frame. It is about observation of a moving particle in planar motion. It can be viewed from a variety of frames. In contrast, the examples in Centrifugal force (rotating reference frame) describe motion as seen strictly from a rotating frame, and, moreover, that article is devoted to objects in uniform circular motion, not in general planar motion. Brews ohare (talk) 04:32, 11 October 2008 (UTC)


 * I don't see that we are reading the same article that is up for deletion. The lead says, and I quote: The centrifugal forces considered here arise when observing a moving particle from several different non-inertial frames. So, unless your centrifugal force that the article is supposed to be about is to do with a non-inertial frame that doesn't rotate(!!!!), then that's exactly opposite to what the article itself claims. Therefore, I simply cannot reconcile your comments with what the article's lead itself claims.- (User) Wolfkeeper (Talk) 04:57, 11 October 2008 (UTC)


 * Wolfkeeper: The article lead says "This article describes the centrifugal force that acts upon objects in planar motion when observed from non-inertial reference frames."


 * I believe you have adopted a very narrow meaning for "planar motion" and for "non-inertial frames" that is far more restricted than these terms imply, and also far narrower than the subject of the article. If you find this lead is unclear, the debate should be over modifying the lead, not over deleting the article because you have misconstrued its subject. Your remarks seems to imply that you think all non-inertial frames are rotating. Yes, the article discusses (in part) a non-inertial frame that doesn't rotate (!!!!) Please don't get rhetorical here. This is a serious matter. Brews ohare (talk) 05:34, 11 October 2008 (UTC)


 * Well, I simply believe you've done a content fork, and you're trying not to get it removed. The scope of the article as defined in the lead overlaps almost completely with centrifugal force (rotating reference frame) and the article body mostly contains the fraction of the material that was removed from there.- (User) Wolfkeeper (Talk) 16:15, 11 October 2008 (UTC)


 * The rationale can be found at this link. Brews ohare (talk) 14:29, 12 October 2008 (UTC)


 * Nah.- (User) Wolfkeeper (Talk) 18:07, 12 October 2008 (UTC)

Delete The less articles on centrifugal force the better. There are some issues to be discussed regarding what Brews has said. There is the issue of the fact that there are situations in which a centrifugal force is claimed to exist from the perspective of a rotating frame of reference, yet where no such centrifugal force exists from the perspective of polar coordinates in the inertial frame. Agreement may never be reached on whether such a centrifugal force does actually exist or not in the rotating frame in that scenario. But the issue should be discussed on the talk page of a unified article. There will probably be fringe sources supporting both points of view, and a consensus may be reached to avoid the controversy altogether since the mainstream textbooks tend to be silent on that issue. The overall aim should be to have one drastically simplified article with distinct sections, and to minimize, but not necessarily eliminate the mention of Coriolis force and Euler force. David Tombe (talk) 01:20, 11 October 2008 (UTC)
 * There is some dispute, and it would be great to resolve it. I don't think the best approach to resolution is to delete pages that are inconvenient for some participants in the discussion. Brews ohare (talk) 04:32, 11 October 2008 (UTC)
 * Yes, because creating fake distinctions among topics is much better idea.- (User) Wolfkeeper (Talk) 18:07, 12 October 2008 (UTC)

Comment. IMHO the centrifugal force article(s) on Wikipedia have grown excessively due to long-standing disputes and maybe a bit of original research. Perhaps a better solution would be to write a wikibook on centrifugal force and try to write one concise encyclopedic article for Wikipedia. --Itub (talk) 07:59, 11 October 2008 (UTC)
 * Note: This debate has been included in the list of Science-related deletion discussions.   -- the wub  "?!"  11:27, 11 October 2008 (UTC)


 * We need to identify the key areas of conflict. I can point to at least three of these,


 * (1) The issue of whether the fictitious forces as derived for the purposes of rotating frames have restrictions on their applicability. I have suggested that the terms only apply to situations in which the objects in question possess the same actual rotation as the rotating frame itself. In other words, any actual effect arises from actual rotation.
 * (2) There is the issue concerning the fact that centrifugal force becomes inertia when we use Cartesian coordinates. I have been advocating that polar cordinates are the only realistic way of describing the centrifugal force effect.
 * (3) There is the issue of what has been described in these articles as 'reactive centrifugal force'. It is a knock on effect, just as weight is to gravity. Some have argued that since reactive centrifugal force doesn't act on the same object as centrifugal force, then they must be something completely different, deserving of two separate pages. I would say that the so-called reactive centrifugal force would show up implicitly in any coherent and well written article on centrifugal force without the need to even bring attention to the concept in its own right.


 * The aim should be for a united article, and all discussions towards that end should be on the talk page of centrifugal force (rotating frames of reference) since that is the page from which all the forks emerged, and since that is the page that google hits direct us to.David Tombe (talk) 14:52, 11 October 2008 (UTC)

David: You raise some interesting points that require attention, but all that matters for this particular debate is this very specific question: "Is Centrifugal force (planar motion) a content fork of  Centrifugal force (rotating reference frame)?" There is, in fact, no basis for considering it a content fork. For example,

1. The above link to Wiki definition of forking says: it is generally acceptable to have different levels of detail of a subject on different pages, provided that each provides a balanced view of the subject matter.

There can be little doubt that the level of discussion is more mathematical and more detailed on Centrifugal force (planar motion) than on Centrifugal force (rotating reference frame).

2 .The above link to Wiki definitions says: ''Articles on distinct but related topics may well contain a significant amount of information in common with one another. This does not make either of the two articles a content fork.''

There may be some overlap between the articles, but the amount of overlap is way below "significant". For example, Centrifugal force (planar motion) deals with the non-inertial frame attached to the moving particle and with the co-rotating frame. Each of these examples brings out a very important aspect of centrifugal force for planar motion not addressed in the other article. Another example, Centrifugal force (planar motion) discusses a variety of coordinate systems, including the arc-length and curvilinear coordinate systems. The other article does not. Centrifugal force (planar motion) contains Figures not in the other article, illustrating points not raised in the other article.

In short, this motion to delete on the basis of Centrifugal force (planar motion) being a content fork of Centrifugal force (rotating reference frame) is groundless. Brews ohare (talk) 15:22, 11 October 2008 (UTC)


 * The article was only created after material was removed from the primary article, and largely consists of material that was removed by consensus from there. That's a content fork. Content forks are highly undesirable in the wikipedia, and I strongly encourage everyone to vote for the removal.- (User) Wolfkeeper (Talk) 16:12, 11 October 2008 (UTC)

Keep. I think this article is an excellent supplement to the existing articles on classical mechanics. We should all be grateful to Brews Ohare for willing to spend so much time and effort here to write physics articles.

I don't understand why the "content forking" issue is seen as a problem. Content forking is only a problem if someone's edits are deleted because the edits are wrong, not if they are too technical for the article. In this case, you don't want to write in an introductory article about centrifugal force about the Lagrangian approach, certainly not about the formalism of differential geometry.

However, the Lagrangian formalism is the standard formalism to solve problems in classical mechanics. No one I know actually uses the cumbersome formalism presented in the wiki article about fictitious force for anything but the simplest cases, except perhaps if you are a first year physics student doing his homework.

Wikipedia should be a place where an interested high school student should be able to read an article about fictitious force at his/her level, and it should be a place where a physics student can read an article that explains how one can write down the equations of motion for a particle moving in a rubber tube that is moving and deforming in some arbitrary way. Count Iblis (talk) 15:49, 11 October 2008 (UTC)


 * So, if I understand you correctly, you agree that this is a content fork. You also seem to say that a high school student should be able to read the article, but I wasn't aware that Lagrangians were really high school level material.- (User) Wolfkeeper (Talk) 16:05, 11 October 2008 (UTC)


 * My concerns are that the article was only created when material was removed from the centrifugal force and follows none of the norms for content forks that are outlined at WP:Content forking, and is not on any well-defined encyclopedic topic, and the introduction reads like a content fork when you compare it with the original article.- (User) Wolfkeeper (Talk) 16:05, 11 October 2008 (UTC)


 * No, what I'm saying is that wikipedia should have articles at different levels suitable for people ranging from complete lay persons to profdessional physicists. Should we delete an article useful to students just because there exists an article on the same topic, but which is written for kindergarten level students? Count Iblis (talk) 16:55, 11 October 2008 (UTC)


 * We're not supposed to invent terms just to keep professional physicists happy, no. This is an encyclopedia which is primarily intended for a general audience, not a highly specialised one. If there are aspects of the topic that are especially complex they need to go in subarticles or be referred out to a full treatment where that's more appropriate, not by creating content forks and pretending that they're new topics entirely.- (User) Wolfkeeper (Talk) 17:26, 11 October 2008 (UTC)


 * Hey, keeping a professional physicist happy is tougher than inventing terms. :-) You appear to be recommending creation of a broad summary page referring out to several branch articles. That would supplement the existing disambiguation page, and be linked by it, right? Brews ohare (talk) 18:14, 11 October 2008 (UTC)


 * I doubt it.- (User) Wolfkeeper (Talk) 18:07, 12 October 2008 (UTC)

Key question – I haven't studied the citation or this discussion yet enough to know if it has been addressed, but I think the key question is whether the distinction between these two articles is a distinction that can be found in a reliable source. Can someone point out a source that makes such a distinction, as opposed to just different sources that adopt diffferent approaches to centrifugal force? Dicklyon (talk) 16:25, 11 October 2008 (UTC)


 * I really, really doubt that there's anything like that out there that says that there's distinct sorts of centrifugal force 'planar' and 'non planar'.- (User) Wolfkeeper (Talk) 16:37, 11 October 2008 (UTC)


 * This is a key question. Wiki guidelines say: Summary style articles, with sub-articles giving greater detail, are not content forking, provided that all the sub-articles, and the summary conform to Neutral Point of View. Maybe some such summary style article is needed? Brews ohare (talk) 17:42, 11 October 2008 (UTC)


 * Possibly, but this isn't. It's simply a content fork.- (User) Wolfkeeper (Talk) 17:54, 11 October 2008 (UTC)


 * Brews, I'm inviting you to answer it. Since it's your fork, please tell us what source this kind of fork comes from.  If there's no source for splitting the treatment of centrifugal force this way, then I don't see why we should do it.  The issue of doing a summary and subarticles seems completely independent – an alternative proposal. Dicklyon (talk) 19:50, 11 October 2008 (UTC)


 * Rationale: Well, as explained elsewhere in this discussion, there is no claim that there are "distinct sorts" of centrifugal force, "planar" or otherwise. The idea is simply that the topic is broad and a division of topics seems to make for a more useful discussion. The division is helpful in separating simple examples from the more complex.
 * It places a number of popular and simple examples on the page Centrifugal force (rotating reference frame). These examples employ constant angular rotation about a fixed axis of rotation. Probably this page will be accessible to most readers and will be sufficient for their purposes.
 * However, a great many topics are not covered. Some of these are now on Centrifugal force (planar motion), and are discussed, not in the context of uniform rotation about a fixed axis, but in the context of a particle moving in an arbitrary path on a plane with arbitrary time-dependence. These examples are not a re-hash of what was said on the other page, and present some significant new results and approaches.
 * Centrifugal force (planar motion) is more demanding of the reader, and probably not everyone will look at it. So its separation from Centrifugal force (planar motion) is based largely upon expectation of a different audience.
 * For a broad subject, a division of some kind seems useful. I do not think this particular division is followed by any particular textbook, but then they have a thousand pages to do stuff, and their division is affected by that fact. They also expect a committed readership (students, maybe), and not browsers with varying degrees of interest and background.
 * In any event, Centrifugal force (planar motion) certainly is not a content fork, and covers different material intended for a different audience with a different background. As said at the link just cited: It is generally acceptable to have different levels of detail of a subject on different pages, provided that each provides a balanced view of the subject matter. and: Articles on distinct but related topics may well contain a significant amount of information in common with one another. However successfully this pair of pages covers the subject, deleting one of them is not going to improve matters. Brews ohare (talk) 23:04, 11 October 2008 (UTC)
 * Insertion of response from Dicklyon added at bottom of page that seems pertinent here: Brews ohare (talk) 00:25, 12 October 2008 (UTC)
 * Given that the other article is already 68 KB, I agree that some kind of division is needed. And a division based on this more general and more complex approach makes some sense.  And there's some interesting content here.  So the discussion really ought to be more general, about organization and naming; deletion doesn't seem like a logical way to address the problem. Dicklyon (talk) 00:03, 12 October 2008 (UTC)


 * Great, now you're even content forking other people's comments!!!- (User) Wolfkeeper (Talk) 02:04, 12 October 2008 (UTC)


 * Addressing the points. This article doesn't address a balanced view of the subject matter, it artificially restricts itself to a subset of the material that 'just happens' to match the material deleted from the main article. It's like an article Brown horse (white feet). In some cases, where a brown horse with white feet might have some genetic trait that make the topic notable it might be fair enough to create an article on a restricted topic. There's nothing like that here. The "(planar motion)" sic works just the same as any other centrifugal force in a coordinate system.- (User) Wolfkeeper (Talk) 20:04, 12 October 2008 (UTC)
 * Of course the article treats a "subset of the material"; how could a finite length article do otherwise? That length restriction is not evidence for a lack of balance, per se. Lack of balance suggests one view of something is unfairly emphasized. If you believe that, provide support. Mere assertion is insufficient.
 * The rationale provided at this link explains why the article has been separated from Centrifugal force (rotating reference frame). Instead of inventing straw men, address the issues. Brews ohare (talk) 21:24, 12 October 2008 (UTC)

Provisional Keep My own comment above was this rather involved article would require the attention of an expert in the field, as I am unable to read/understand the article and make a determination as to whether the content is accurate or not. But that flaw is my own and not the article's, as I am not an advanced mathematician. But I did not know that Wiki was designed with the goal of being understood by high school students. I would think that like any encyclodia, if a subject being covered requires the language and explanations of that subject matter, as long as it is accurate and sourced it may be included. Again, this requires the attention of experts in that field... and hopefully such experts will come forward and qualify theeir expertise when making an educated comments. If the author states that it is not a content fork, I will assume good faith that it is not so. That it contains informations removed from a seperate article, should not defacto make it a fork, as the language of mechanical physics is universal to the subject. As for "content forking", I am of the opinion if a parent article was so lengthy and in-depth that informations were removed in the interest of simplicity/clarity/length, it would make sense to then have a second article that covered the removed informations if they were important enough to merit aa seperate article. Not using any specific WP:WAX, there are satelite articles for other subjects that cover aspects of their parent articles. This may well be the same. But again, I do not have the technical expertise to know one way or the other. My keep is "provsional" as I watch this AfD. The article does not look or feel like a hoax. It is well sourced. In the field of mechanical or astrometric physics it may be a notable as Tom Crise's latest film. Perspective gentlemen... perspective.  Schmidt,  MICHAEL Q. 16:38, 11 October 2008 (UTC)


 * The problem is that it's not advertising or describing itself as a satellite of the main article, it's saying that it's a different sort of centrifugal force. But it self evidently is not that.- (User) Wolfkeeper (Talk) 16:48, 11 October 2008 (UTC)
 * Good. Then as an independent article, that should be fixed and the article remain. Cleanup is never a valid reason for deletion. Was this discussed in the article's talk page?  Schmidt,  MICHAEL Q. 19:46, 11 October 2008 (UTC)


 * The problem is, because it's a content fork, it's not an independent article, neither in scope, nor material. And yes, the removal of this sort of material was discussed in Centrifugal force (rotating reference frame).- (User) Wolfkeeper (Talk) 02:04, 12 October 2008 (UTC)


 * Your objection might be met by rewriting the intro. The article Centrifugal force (planar motion) is not intended to indicate it deals with a fundamentally different kind of centrifugal force; its intention is to deal with the determination of the centrifugal force for the case of general planar motion as seen from a variety of non-inertial frames. Maybe an analogy is finding the bandwidth in two different amplifier designs: bandwidth is still bandwidth, but its dependence on the circuit variables is different. For example, in a frame attached to the particle, centrifugal force is related to the center of curvature of the path; in a co-rotating frame it is related to the distance of the particle from the origin of the frame. Brews ohare (talk) 17:05, 11 October 2008 (UTC).
 * Exactly. A rewrite addresses this concern.  Schmidt,  MICHAEL Q. 19:46, 11 October 2008 (UTC)


 * Oh well, if it's only a rewrite of all this consensus-deleted material and the introduction that's all right then.- (User) Wolfkeeper (Talk) 21:41, 11 October 2008 (UTC)
 * ... and the article title. Hint: I'm being ironic.- (User) Wolfkeeper (Talk) 18:07, 12 October 2008 (UTC)
 * I can't actually find any connection between the lead and the body, they actually talk about different things. The body is just material removed from the main article, and the lead is just the original lead with a few words changed here and there to make the content fork less obvious. Apparently a lot of people are being taken in by this ruse.- (User) Wolfkeeper (Talk) 17:49, 11 October 2008 (UTC)
 * Then the lead can be nodified to nore coherently (in your opinion) flow into the body.  Schmidt,  MICHAEL Q. 19:46, 11 October 2008 (UTC)


 * No, articles are supposed to be on a topic. There's no overarching topic.- (User) Wolfkeeper (Talk) 21:41, 11 October 2008 (UTC)


 * The lead is not the issue; the content of the article is the issue, and it is not a content fork according to the directly quoted excerpts from content fork. Brews ohare (talk) 18:06, 11 October 2008 (UTC)
 * Then if its not a fork, what's the deal?  Schmidt,  MICHAEL Q. 19:46, 11 October 2008 (UTC)


 * The deal is that most of this material was previously in another article. But Oh dear, it got deleted, but that's OK, we can always OR up a completely non standard topic, add it to the disambiguation page, and add that to the wikipedia, right?- (User) Wolfkeeper (Talk) 21:41, 11 October 2008 (UTC)


 * All the topics discussed on Centrifugal force (planar motion) are standard topics and are cited extensively. They are grouped together here as they apply to a particular subject, namely general planar motion of a particle. Brews ohare (talk) 23:45, 11 October 2008 (UTC)


 * As it says in WP:Wikipedia is not a dictionary encyclopedia articles are on a (singular) topic, not all the topics; A topic.- (User) Wolfkeeper (Talk) 02:09, 12 October 2008 (UTC)


 * As noted at this link, the topic for one page is centrifugal force in the context of a uniformly rotating reference frame with fixed axis, and the topic for the second page is centrifugal force in the context of general planar motion of a particle as seen from various reference frames and employing various coordinate systems. In no way does this division contradict any guidelines in WP:Wikipedia is not a dictionary. Brews ohare (talk) 14:22, 12 October 2008 (UTC)


 * B******s.- (User) Wolfkeeper (Talk) 18:07, 12 October 2008 (UTC)

Keep: It seems to me like Centrifugal force (rotating reference frame) is about the centrifugal force that comes about in a uniformly rotating reference frame, and Centrifugal force (planar motion) is about the centrifugal force in reference frames in general motion. The second is more general, the first is simpler and more often used. Sure, I think there's room for improvement in explaining the scope and divvying up the content of both articles, but I don't think deletion is called for. --Steve (talk) 17:33, 11 October 2008 (UTC)


 * Unfortunately for this theory, the original article covers non uniformly rotating reference frames as well, and does it in 3-space, whereas this one only covers the bits that were removed, and only then in 2D.- (User) Wolfkeeper (Talk) 17:49, 11 October 2008 (UTC)


 * No material has been created that deals with particle motion on 3-D space curves; of course, it could be done, but involves some additional vectors and concepts from differential geometry. I doubt that added complexity would affect your point of view positively. 2-D planar motion is a half-way house.


 * The maths in the original article deals with all 3-D space curves as you well know, including the subset that are 2-D.- (User) Wolfkeeper (Talk) 21:41, 11 October 2008 (UTC)


 * Maybe you could provide a link to the old material you refer to. I am saying no material for 3D motion analogous to the arc-length description here has been developed. Brews ohare (talk) 15:06, 12 October 2008 (UTC)


 * Wolfkeeper, I'm confused, are you saying that Centrifugal force (rotating reference frame) has a discussion of non uniformly rotating reference frames? If so, I don't see it.... Thanks, --Steve (talk) 20:21, 12 October 2008 (UTC)


 * There's no special equation or behaviour for centrifugal force for non uniformly rotating reference frames. The article doesn't limit itself to uniformly rotating reference frames in any way.- (User) Wolfkeeper (Talk) 20:34, 12 October 2008 (UTC)
 * I assume you mean to say that Centrifugal force (rotating reference frame) "doesn't limit itself to uniformly rotating reference frames in any way." Having written all the examples and provided all the figures for these examples with the exception of potential energy, I am confident that they deal with uniform rotation. Brews ohare (talk) 21:05, 12 October 2008 (UTC)
 * Hmm, I'm mostly with Wolfkeeper here; someone should add couple sentences to Centrifugal force (rotating reference frame) to take care of general reference frame motion, but that would be sufficient, and then Centrifugal force (rotating reference frame) would be 100% general. I change my vote to Keep but reorganize and/or re-title. There's two articles' worth of content, none of it is really worth throwing out, but there isn't yet a good philosophy guiding what goes where. Perhaps Centrifugal force (planar motion) could be re-titled along the lines of "Centrifugal force details in various coordinate systems". It would be thought of as a spin-out article. --Steve (talk) 23:34, 12 October 2008 (UTC)
 * I have broached this option several times and in several ways. The extension of Centrifugal force (rotating reference frame) to rotation about a fixed axis but at variable angular rate is simple unless an example of some interest is needed. (Got any suggestions?) It just adds the Euler force. However, that slight generalization would not bring the topics in Centrifugal force (planar motion) within its purview. So two pages still seems most practical. Do you have something else in mind? Brews ohare (talk) 23:58, 12 October 2008 (UTC)
 * Of course, even the 2-D planar motion examples agree with Steve's description of the article Centrifugal force (planar motion) as more general, though less often used than Centrifugal force (rotating reference frame). Again, not a content fork. Brews ohare (talk) 18:06, 11 October 2008 (UTC)

We first have to decide if the two centrifugal forces are the same or not. If they are the same, then there should only be one article. If they can be shown to be different, then that might make a case for having two articles. However, if there is an endless dispute about whether or not they are the same or different, it means that the two are sufficiently associated together to be presented in different sections of the same article. The claim for them being different is that in 'rotating frames' there is a school of thought that the centrifugal force applies to every object irrespective of its relative motion, whereas it is only in the case of co-rotation that this centrifugal force coincides with the outward force of planetary orbits. It is this latter effect which is the centrifugal force as is understood by the man in the street. Quality university textbooks such as Goldstein's are silent on the issue of whether or not centrifugal force in rotating frames applies to objects that are not co-rotating. But all the worked examples assume co-rotation. Any examples that involve the Earth's rotation will always assume co-rotation. There are however websites and scientific journal articles which specifically focus on the idea that centrifugal force acts on objects at rest in the inertial frame as observed from a rotating frame. There are also scientific journals which claim the opposite and state that centrifugal force is something which applies to objects that are at rest in a rotating frame of reference. In order to resolve this dispute, I would draw attention to centrifugal potential energy. It only occurs when absolute rotation occurs. The counter argument is that centrifugal force as observed on an object at rest in the inertial frame is overridden by a radially inward Coriolis force. But we would then need to have a Coriolis potential energy in order to cancel out the centrifugal potential energy. And the Coriolis potential energy would have to be a tension. No such thing exists. That is the argument that needs to be resolved as a priority. I say DON'T KEEP because I believe that there is only one universal centrifugal force. It is the outward force associated with absolute rotation. David Tombe (talk) 18:58, 11 October 2008 (UTC)


 * Aside from various side-issues, your argument is simply "If the topics are the same, then one page should suffice." However, completely putting to one side for the moment whether this premise is valid, the conclusion is not valid. Quoting content forking it is generally acceptable to have different levels of detail of a subject on different pages, provided that each provides a balanced view of the subject matter.


 * In addition to false conclusion, the premise is false. One page treats a limited subset of examples, the other a more general set. Brews ohare (talk) 22:00, 11 October 2008 (UTC)


 * Given that the other article is already 68 KB, I agree that some kind of division is needed. And a division based on this more general and more complex approach makes some sense.  And there's some interest content here.  So the discussion really ought to be more general, about organization and naming; deletion doesn't seem like a logical way to address the problem. Dicklyon (talk) 00:03, 12 October 2008 (UTC)


 * So far as I am concerned, this content fork does not constitute an article. In that sense it must be deleted. I don't mind if the material finds somewhere more appropriate, but this 'article' is a charade.- (User) Wolfkeeper (Talk) 00:29, 12 October 2008 (UTC)


 * I'm disturbed that you believe pronouncements supported only by your say-so are a contribution to the discussion. It would be more appropriate to engage with the alternatives to deletion suggested on this page, please. Brews ohare (talk)


 * So you're claiming to be disturbed that an Article For Delete discussion consists of people arguing for and against deletion???-(User) Wolfkeeper (Talk) 18:07, 12 October 2008 (UTC)


 * Nope; just disturbed by the quality of argument. Brews ohare (talk) 20:58, 12 October 2008 (UTC)

Dicklyon, The problem about the 68KB could easily be remedied by drastically simplifying the article. There is not that much to centrifugal force. It is the outward force associated with rotation. All we need is a few examples such as the centrifuge, artificial gravity and planetary orbits. The existing section on centrifugal potential energy, which is the most interesting section in the whole article, should of course be retained. It's a pity that the lesson inherent in that section has been to no avail so far.

There is no end of stuff that could be removed from all the existing articles. I have never before seen descriptions of simple circular motion situations that involve the Coriolis force. I don't know what you mean about the more complex approach. The existing articles don't even touch on complex scenarios such as elliptical orbits. Any semblance of complexity merely reflects an ever proliferating confusion about something that is relatively simple. David Tombe (talk) 01:50, 12 October 2008 (UTC)


 * David: All that matters for this particular debate is this very specific question: "Is Centrifugal force (planar motion) a content fork of Centrifugal force (rotating reference frame)?" Your remarks do not address this issue. Brews ohare (talk) 13:51, 12 October 2008 (UTC)

Brews, The question is whether or not I think that the centrifugal force (planar motion) article should be deleted. I think it should. There are no restrictions on what my reasons are allowed to be. The participants should be asking themselves which of the below categories do they perceive themselves to belong to,

(A) Centrifugal force is a purely fictitious force that is only ever observed from rotating frames of reference, and that it acts on all objects in the rotating frame, irrespective of their relative motion in that frame.

(B) Centrifugal force is a real effect which is induced by actual rotation, but that the term only applies when we are using polar coordinates. When we are using Cartesian coordinates, we must then talk in terms of Newton's law of inertia. It follows therefore that centrifugal force is only a fictitious force.

(C) Centrifugal force is an effect which is observed from a rotating frame of reference. In cases in which the object in question is co-rotating then it is a real effect. In cases of partial co-rotation it is a fictitious effect to the extent that it is not rotating, and a real effect to the extent of its own actual rotation.

(D) Centrifugal force is a real outward radial effect which occurs when actual rotation occurs.

(E) None of the above.

I fall into category (D). My guess is that the rest of you will be split between (A) and (B) but that many of you will claim to fit into (E).

And to those who disgagree with (D), then take a look at the section on centrifugal potential energy. It begins with an explanation as per (A). But it finishes with a very real hydrostatic pressure for cases of co-rotation. For zero rotation in the inertial frame, there is zero centrifugal potential energy. David Tombe (talk) 15:16, 12 October 2008 (UTC)
 * David: You are mistaken in thinking that the subject is deletion of the page Centrifugal force (planar motion). It is a narrower question, that suggests the grounds for deletion is that this page is a content fork. So I choose to defend on the narrower ground that Centrifugal force (planar motion) is not a content fork. If the whole subject comes up again with new grounds, I'll cross that bridge later. Brews ohare (talk) 15:40, 12 October 2008 (UTC)

Keep – I'm usually more of a deletionist, but the reasons given here for deletion don't seem to address the real issue, which is how best to organize the treatment of centrifugal force. Wishful thinking like that of David Tombe, who believes that centrifugal force would be simple if we treated it as a real force, instead of the way the physics texts do, is not helpful to the discussion. Wolfkeeper has a point about content forking, but hasn't proposed a good way to re-integrate the material. I recommend he take this discussion back to a merge/split/rename/reorg proposal on the article talk page. Dicklyon (talk) 16:44, 12 October 2008 (UTC)


 * It's not up to me to defend the material. Under the wiki rules, the person that added it has to do that. He's completely failed so far, this is a fake article topic written to look like a unique definition of the term, created entirely due to the content forking caused by the material that was removed elsewhere. I also would point out that an AFD is not about the material, it's more about the article topic. Unless you're arguing that the article topic is suddenly going to go or already is legitimate, you can't legitimately argue a keep. I'm not arguing against the material. If Brews takes it and puts it somewhere sensible, that's fine. But that's not my problem. People creating fake article topics make me, and everyone else here look bad, as does a vote to keep. Please change your vote.- (User) Wolfkeeper (Talk) 17:52, 12 October 2008 (UTC)
 * This wild response does not address the reasons for the article laid out at this link, simply a rant. Brews ohare (talk) 22:17, 12 October 2008 (UTC)


 * Keep so far. As a theoretical physicist, I think this article has a right to exist. It contains more advanced math, which may be unsuitable for another article (Centrifugal force (rotating reference frame)). The scope and even the title of this article, of course, should be discussed separately. However outright deletion does not seem to be the best solution at this moment. Ruslik (talk) 18:20, 12 October 2008 (UTC)


 * But that's just the problem. It doesn't have a right to exist. Why is it talking about centrifugal force in isolation to the other fictitious forces? Why is it here, and not in curvilinear coordinates and polar coordinates. It's only here because Brews Ohare content forked it here. It makes no sense here the lead definition of the topic doesn't cover the article, doesn't distinguish it from the original article it was forked off from, and there's much better places it should go anyway. It also breaks almost every major guideline and policy you can name, WP:NOR WP:VER WP:Wikipedia is not a dictionary WP:Notability I've probably missed some.- (User) Wolfkeeper (Talk) 18:45, 12 October 2008 (UTC)
 * "There's much better places it should go anyway" "It also breaks almost every major guideline and policy you can name" … - uh-huh. Pile on the specifics. Brews ohare (talk) 22:32, 12 October 2008 (UTC)
 * I am still not convinced that the article should be deleted. The names of both articles are bad in my opinion. It is better to have one article named Centrifugal force as a simple introduction, and the second Centrifugal force (advanced concepts). Or it may be better to have just one article called Inertial forces (advanced concepts), because it is difficult to separate various forces, if an arbitrary non-inertial frame is considered. However I am sure the deletion will not solve any these problems. Ruslik (talk) 11:35, 13 October 2008 (UTC)

Ruslik, I'm not sure what 'advanced concepts' that you are talking about. All attempts to introduced concepts beyond simple circular motion have been stringently resisted. What we are witnessing here is the introduction of mathematical tools that are normally only used to deal with advanced concepts, but they are here being used to deal with either no concepts at all or with simple circular motion concepts. And they are being used wrongly, and hence totally confusing what is a relatively simple topic.

If someone wants to write a section on the treatment of centrifugal force using Lagrangian mechanics, I'd be fascinated to read it. But it should be a section lower down on a single unified article on centrifugal force. David Tombe (talk) 11:48, 13 October 2008 (UTC)


 * The present objection to the article is based upon only the content fork objection, and this laundry list of policies is an attempt by Wolfkeeper to broaden the attack after its initiation. Here are the policies mentioned and how they apply to Centrifugal force (planar motion):


 * 1) WP:NOR - Wolfkeeper has not illustrated any instances of original research, and the article is supported by numerous citations and extended quotations from reputable sources.
 * 2) WP:VER - again, the article is very well sourced and verified
 * 3) WP:Wikipedia is not a dictionary - the article Centrifugal force (planar motion) and Centrifugal force (rotating reference frame) are not an example of two pages discussing the same material (like gasoline and petrol), and therefore are not candidates for merger. Wolfkeeper implemented a Centrifugal force (disambiguation) page where the differences are spelled out. In particular, Centrifugal force (planar motion) applies to arbitrary planar motion of a particle as seen from various observational frames and using a variety of coordinate systems. Centrifugal force (rotating reference frame) applies to the restricted case of rotation about a fixed axis. The split rationale is found at this link.
 * 4) WP:Notability - Centrifugal force (planar motion) contains a number of results not found on Centrifugal force (rotating reference frame), and which require some mathematical background not expected of the reader of Centrifugal force (rotating reference frame). Among these results on Centrifugal force (planar motion) are the connection between the Lagrangian formulation (for which a brief outline and numerous references and links to other articles are provided) and the Newtonian formulation in the co-rotating frame. This topic is discussed in Taylor, which is referenced. Another result is the development of the form of the centrifugal force in a non-inertial frame attached to a moving particle, and its connection to the radius of curvature of the particle's path. Both of these examples are outside the scope of Centrifugal force (rotating reference frame) as described on the Centrifugal force (disambiguation) page. Perusal of the page will show that there are many, many examples of formulations not found on the other page, and outside its scope. Brews ohare (talk) 08:56, 13 October 2008 (UTC)
 * Note: This debate was posted to Wikipedia talk:WikiProject Physics. - Eldereft (cont.) 21:08, 12 October 2008 (UTC)


 * Delete Content fork at a bizarre title making a completely meaningless and arbitrary distinction. There is no reason for any such division of the topic; this is why no reliable sources treat it so. I have not checked what was or was not in Centrifugal force (rotating reference frame) or the (I am quite sure) lengthy talk page discussions leading up to this, so it may be desirable to establish a temporary redirect or otherwise preserve the article history to make certain that anything useful (read: not trivial or redundant) is included. As a side note - where are all the tangent bundles? - Eldereft (cont.) 19:16, 12 October 2008 (UTC)
 * The assessment that the article is a "Content fork at a bizarre title making a completely meaningless and arbitrary distinction." does not address the reasons supporting this division outlined at length above. See here. The terms "bizarre" and "meaningless" are pejorative and inflammatory, not exactly following the "be polite" admonition for Wiki discussions. If there had been "lengthy talk page discussions leading up to this" it never would have happened. Instead Wolfkeeper unilaterally and unexpectedly posted this banner for deletion without discussion. There is nothing "trivial or redundant" in the article Centrifugal force (planar motion). As a side note, look at the article, eh?  Brews ohare (talk) 20:47, 12 October 2008 (UTC)

- (User) Wolfkeeper (Talk) 19:23, 12 October 2008 (UTC)
 * Note to moderator The following notifications by Brew Ohare may constitute WP:CANVAS (he could have simply tagged them):
 * Sbharris:
 * Rogerbrent
 * Dicklyon
 * 'Steve' Sbyrnes
 * I did not know how to tag them; what I did was simply to ask for an opinion, as you can determine by reading my request for opinion on their talk pages. Brews ohare (talk) 20:42, 12 October 2008 (UTC)
 * You've been here a long while, I think it's reasonable for us to expect you to know and follow the rules. Merely notifying them is perfectly OK (and even then you're supposed to do it in an even handed way), telling them what you think is invalid.- (User) Wolfkeeper (Talk) 20:51, 12 October 2008 (UTC)


 * You don't have to "expect" anything. Just look at it. Brews ohare (talk) 21:26, 12 October 2008 (UTC)


 * Wolfkeeper: Do you think special pleading for change in vote on user talk pages like yours at User_talk:Ruslik0 is ethical? Brews ohare (talk) 00:07, 13 October 2008 (UTC)


 * You know what? Maybe it might be just barely unethical. But there's a world of difference doing it after they've already voted, rather than dropping a leading question on their talk page to tell them about it in the first place. People are very much less likely to change their vote than starting off by giving them an initially stacked deck.- (User) Wolfkeeper (Talk) 00:53, 13 October 2008 (UTC)
 * You know what, it is unethical. In fact it is WP:CANVAS: Campaigning. But more than that it's impractical. I do not want to chase after the talk page of every editor that has commented here to see whether you've bad-mouthed me (not that you ever would do that) and presented a lopsided case to persuade a change in vote (nor would you even think of such a thing as that). And then what? Does every other edtior have to check every other editor to see what has been going on? You are simply undermining the entire process, turning it into a morass of interlinked arguments on multiple pages.
 * However, you can go underground and get the editor's e-mail addresses to do the same thing. You've already contacted me directly this way. Brews ohare (talk) 05:32, 13 October 2008 (UTC)


 * Merge. Eldereft describes the situation very well. If we deleted all the forked articles and reverted "Centrifugal force" to one year ago, that'd be an improvement over the current situation, i.m.o. --PeR (talk) 19:33, 12 October 2008 (UTC)
 * PeR: Your comments are unresponsive to the issues already raised in support of the article. See here. I do not see any reasoning leading to the conclusion that the topics discussed, documented, and illustrated on Centrifugal force (planar motion) are a backward step, and reversion to a situation without this material would be a forward step. You have advanced no support for your views and conclusions, and apparently have not looked at the article in any detail. Going through the article topic by topic there is no parallel article or material in Centrifugal force (rotating reference frame). Brews ohare (talk) 20:44, 12 October 2008 (UTC)

Dicklyon, I've gone to quite a bit of effort to draw attention to centrifugal force as it arises in central force theory in the classical mechanics textbooks that I used. And here's you once again trying to push the idea that I hold some kind of unorthodox view of centrifugal force that is not to be found in the textbooks.

What about the section on centrifugal potential energy? Is centrifugal potential energy a real effect or not? Does it occur in buckets of water that are stationary if we view them from rotating reference frames? If you think that my position on centrifugal force is contrary to what's in the textbooks, then let's hear what your position is.

And regarding your view that the article for deletion is to cater for a higher level, I think you've got it all wrong. The article in question doesn't even tell us what centrifugal force is. There is alot of maths in it, some of which involves the polar coordinate tools that might be used for analyzing planetary orbital motion. But there is no actual application of these maths tools. There are no physical contexts presented for the purposes of applying the maths. Had there been a coherent demonstration of how polar coordinate expressions are used in the solving of complex planetary orbital situations, then I might have agreed with you that the article would be good for the purposes of catering to a higher level. But that is clearly not the case here. The article in question uses advanced methods wrongly.

Centrifugal force is the radially outward force that comes with rotation. If you think that it's more complicated than that, can you please give me an example of centrifugal force that is not catered for by that simple definition? David Tombe (talk) 03:12, 13 October 2008 (UTC)


 * David, I'm sorry if I've misunderstood you, but I find your comments generally to be too "elliptical". If you can give links to sources sometimes, like specific textbooks that support your statements, then maybe I could learn what's behind your viewpoint.  Just saying "standard textbooks" is not that helpful to me, as I don't have a collection of mechanics texts, and I don't know what's standard.  You can start by explaining, and sourcing, your statement "Centrifugal force is the radially outward force that comes with rotation".  Force on what?  The rotating object?  Or something else?  It sounds a lot like the reactive centrifugal force; is that what you mean?  Dicklyon (talk) 03:24, 13 October 2008 (UTC)

Dicklyon, in the past I've even given page numbers to Goldstein's classical mechanics. In an elliptical orbit, there is a centripetal force supplied by gravity and a centrifugal force acting outwards. The two are not in general equal in magnitude. However when we look at the simple case of circular motion, centripetal force and centrifugal force will always have the same magnitude. This is the source of the confusion because high school students then identify the centripetal force with the centrifugal force expression and assume that there only is centripetal force in play. Make it elliptical and you'll see both of the effects working in tandem. This confusion would not arise in a more advanced article. However, we don't have a more advanced article. We have an article which has the semblance of being advanced, but when it is all stripped down and analyzed it is shown to be simply noise about coordinate systems, with the odd simple circular motion example thrown in and totally confused. It tells us nothing about centrifugal force. Centrifugal force is a real force that causes hydrostatic pressure in buckets of water when the water is actually rotating. We don't need Lagrangian mechanics to explain that simple fact. David Tombe (talk) 03:36, 13 October 2008 (UTC)


 * Well maybe we're both being too lazy; me too lazy to search all your earlier comments, and you too lazy to be specific. But on your detailed point here, how is it that is the forces are balanced, the planet doesn't just travel in a straight line at constant speed?  As for the bucket of water, each particle moving in a circle needs a centripetal force to provide the acceleration; that force comes from gravitiy acting on the slope of the water; for the force to be acting outward on the water as you suggest, you need to be looking at it from the rotating frame, and the pseudoforce in that case is known as fictitious.  If you have a book that treats it differently than that, can you provide a link, or title and page number? Dicklyon (talk) 03:59, 13 October 2008 (UTC)

Dicklyon, In the circular motion scenario, both the centrifugal force and the centripetal force act in the radial direction. They are balanced. What you are doing is taking the centripetal force to be in the radial direction and then switching into cartesian coordinates for the centrifugal force and arguing that it doesn't exist. Either we treat the whole problem in cartesian coordinates or we treat the whole problem in polar coordinates. If you want to do it in cartesian coordinates, then centrifugal force as a term disappears, although the effect is still there and it is explained in terms of Newton's law of inertia.

Anyway, I didn't come back here again to go over that argument ad finitum. I'm trying to highlight exactly what everybody's position is on this. It is very naive to think that this dispute will be resolved by looking up a textbook. Everybody seems to believe that they are interpreting the textbooks correctly. I can only assume from what you say, that you fall into category A above. In other words, you believe unequivocally that centrifugal force is a purely fictitious effect which can only ever be observed from a rotating frame of reference.

Or maybe you are in category B? Here is the list again,

(A) Centrifugal force is a purely fictitious force that is only ever observed from rotating frames of reference, and that it acts on all objects in the rotating frame, irrespective of their relative motion in that frame.

(B) Centrifugal force is a real effect which is induced by actual rotation, but that the term only applies when we are using polar coordinates. When we are using Cartesian coordinates, we must then talk in terms of Newton's law of inertia and the centripetal force as being a force that causes the object to continually change direction. It follows therefore that centrifugal force is only a fictitious force.

(C) Centrifugal force is an effect which is observed from a rotating frame of reference. In cases in which the object in question is co-rotating then it is a real effect. In cases of partial co-rotation it is a fictitious effect to the extent that it is not rotating, and a real effect to the extent of its own actual rotation.

(D) Centrifugal force is a real outward radial effect which occurs when actual rotation occurs.

(E) None of the above.

Where do you see yourself on that list? If your answer is (E) could you please clarify your position on the matter.

If we can establish a consensus on the above categories, then we can discuss the problem within that viewpoint, and then we can decide if we need to fork the subject into many articles or not. David Tombe (talk) 11:23, 13 October 2008 (UTC)


 * Hi David: I think you are a bit ahead of things with your proposals about how to treat the material on the two pages. At the moment, Wolfkeeper has initiated this deletion review that can lead to complete removel of Centrifugal force (planar motion) along with its history and copies. I am unsure what happens to the Figures it uses. Of course, waste of everybodys' time could have been avoided were the whole matter discussed in advance of Wolfkeeper's drastic and unexpected action. Attempts made subsequent to his action, aimed at initiating such discussion on Wolfkeeper's talk page are met with his simple ultimatum: Move it or lose it.- 
 * Your own vote is for deletion, so I'd guess removal of everything on the page is fine with you. Deletion makes any discussion of how to use or address its contents moot. Brews ohare (talk) 15:04, 13 October 2008 (UTC)

Brews, regarding the contents, you don't seem to grasp the fact that polar coordinates don't actually describe any particular motion. They merely give us mathematical expressions which can be matched up with actual forces in actual physical scenarios. We need to introduce those scenarios. And if you are going to limit those scenarios to simple cases of circular motion, then you don't need to use polar coordinates ot Lagrangian methods.
 * You need not patronize me. Brews ohare (talk) 18:49, 13 October 2008 (UTC)

And so on that basis, the content of the article in question is fundamentally wrong.
 * You have no basis for this statement, and this is not the forum for its discussion. Brews ohare (talk) 18:49, 13 October 2008 (UTC)

I am now backing PeR's idea that we should return to the single article of a year ago. I was not happy with that article but at least it provided a single unified forum for the purposes of debating improvements. The situation has now degenerated into such a mess that we have no choice but to return to that point again and pick up the pieces. David Tombe (talk) 16:43, 13 October 2008 (UTC)

Restore the Article of One Year go, despite the fact that it is not satisfactory
I go along with PeR's suggestion. We should restore the single unified article on centrifugal force of one year ago and then discuss improvements on the talk page. The situation has now got totally out of hand with all the forks and all the confusion surrounding the application of polar coordinates. David Tombe (talk) 16:48, 13 October 2008 (UTC)
 * David: your proposal is unclear. First, there was no page Centrifugal force (planar motion) at that time (it was formed in September 2008). Second, Centrifugal force (rotating reference frame) is not under discussion in this forum. Brews ohare (talk) 18:49, 13 October 2008 (UTC)

Deleted per author request
I deleted the article as per the request of its author Brews ohare (WP:CSD).

If this was not a satisfactory resolution, I invite undeletion by any other admin and have no quarrel with it. Thank you. — Athaenara ✉  22:17, 13 October 2008 (UTC)


 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.