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A procedural matter: GenKnowitall -- you should revert revisions, both major and minor, only because you have a specific reason that the revisions made the article worse, and you should announce that reason at the moment you revert. You should ''not'' revert just because the reversion was not discussed beforehand. That's just the usual procedure here on Wikipedia (c.f. [[WP:OWN]].). I don't doubt that you ''do'' have a specific reason that you think that Melchoir's edits made the article worse...I'm only criticizing the fact that you did not articulate this reason at the moment that you reverted Melchoir's edits. You should have. Anyway, you may articulate it now. --[[User:Sbyrnes321|Steve]] ([[User talk:Sbyrnes321|talk]]) 22:11, 27 May 2011 (UTC) |
A procedural matter: GenKnowitall -- you should revert revisions, both major and minor, only because you have a specific reason that the revisions made the article worse, and you should announce that reason at the moment you revert. You should ''not'' revert just because the reversion was not discussed beforehand. That's just the usual procedure here on Wikipedia (c.f. [[WP:OWN]].). I don't doubt that you ''do'' have a specific reason that you think that Melchoir's edits made the article worse...I'm only criticizing the fact that you did not articulate this reason at the moment that you reverted Melchoir's edits. You should have. Anyway, you may articulate it now. --[[User:Sbyrnes321|Steve]] ([[User talk:Sbyrnes321|talk]]) 22:11, 27 May 2011 (UTC) |
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: Your actions constitute vandalism and you should cease. You state you are a graduate student at Berkeley. You were on notice in the article to review discussion before editing yet you took the actions without discussion, or consensus. Your opinion as to the "convincing power" of anything has not been tested by discussion and is not an authoritative opinion. If you do anything further without appropriate review and discussion I will seek your removal. I hope that is crystal clear. |
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:There are alternative definitions out there, that is beyond much debate. Alternative definitions should be presented here for discussion and included after consensus. Offer one if you have it. Your opinion, student, is garbage unless it is supported, or may god help you at thesis defense. I am now reverting your changes. You should not do anything like that again. [[User:GenKnowitall|GenKnowitall]] ([[User talk:GenKnowitall|talk]]) 23:27, 27 May 2011 (UTC) |
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New Article - Please Read Before Editing
The present article, as submitted today by me, is a physics article based on a definition given in a REAL textbook on the subject, used to teach REAL physics upper division classes in MECHANICS by REAL physicists, and written by a REAL physicist who is still alive and winning prestigious awards in physics (Symon), and is additionally supported by a REAL encyclopedia (Britannica) whose owners would be literally lynched if they dared to screw-up something that had anything to do with Isaac Newton. Before revising, editing, or vandalizing this article, discuss your proposed changes here and have your scholarly references and sound argument at the ready.
The previous article on this subject met with an apparently well-deserved deletion, but was also unfortunately redirected to a subject that had nothing to do with it. Unfortunately some of the writers or editors seemed to have confused concepts of center of mass and center of gravity. I don't really want to see that happen again, nor to engage in silly debate over just how confusing some high school textbooks have become to those who don't understand the subject but think writing a wikipedia article on it would somehow unconfuse matters. I say the article is right, but can be added to and improved. Let that be the goal. GenKnowitall (talk) 05:37, 24 May 2011 (UTC)
Reversion of Major Edit - Call for Orderly Process
The major edit by Melchoir is objected to as disorderly and is being summarily reverted by me immediately. I call for an orderly and good faith process of editing which has so far eluded this article and its prior incarnation. Let there be order. I have called in an admin to supervise process (and editors) if matters become disruptive. Prior discussion has contained representations made in bad faith, failure to provide good faith response, and lacked scholarly support, now article vandalism by undiscussed major revisions. Let there be some discipline and scholarship. The contentions contesting the Britannica citation were not demonstrated as meritorious, but were instead, whatever true merits it may have had, argued in bad faith. One does not get to the truth or good wikipedia article that way. Melchoir is now apparently disputing his own article, what the heck is that about?
Now Melchoir's new proposed article has some merit, improves prior scholarship, and I am even somewhat pleased by it, he shows moxie (which is apparently his style), but it also contains objectionable material. But let there be an orderly process, consensus or (clear and reasonable disagreement) between scholars, not a foodfight by bigots. Gentlemen, I call you to order. We will get there, and a good article too, if you have faith in the process, just be ye in order.
Netheril96's objection concerning the Symon reference was clearly not meritorious AS TO SYMON, he failed to respond on topic and instead morphed his argument into a challenge along the same argument line as Melchoir's Britannica objection. I must say Netheril96 objection was somewhat better stated. Netheril96 apparently likes Melchoir's submission, but no surprise there as they were both eventually making the Feynman argument, which this STILL not quite rightly done. Order, gentlemen, and scholarship you are not authorities.
The article will improve, editors will improve, wikipedia will improve, and subject will advance if scholarly discussion in good faith is done. I am confident. Let us show how it is done in physics. Proceed with reason, not reversion.
First things first. Do we agree on the Symon cited definition as a bone fide definition used in the field of mechanics, yes or no? If so it is IN the article and the article is distinct from center of mass. Is that agreed or not?
Second, if there are alternative definitions then let us discuss them here, not just dump them in the article. Perhaps, Melchoir will propose a Feynman supported definition and we can discuss how it should fit.
I am reverting changes Now. Please use the Wikipedia editing process and good faith discussion to improve the article. GenKnowitall (talk) 20:07, 26 May 2011 (UTC)
Responses to the Call for Orderly Process
- The only one that disrupts editing is you. Aside gross characterization of everyone who disagrees with you as disruptive and in bad faith, you don't point to anything that is truly objectionable.
- You can't support your comments, and I can. That's one difference. I'm not characterizing disagreement, I'm not doing that, I don't think you mean that because only an argumentative twit would so understand my comments which call attention to objectionable editing behavior, such as a refusal to concede a point on an objection you started then abandoned without concession or resolution. Are you used to making wild claims which when answered are abandoned for new wild claims, and so on ad nauseum? Because I think that is grounds for a complaint about your editing participation, don't you? You have yet to answer my request regarding the Symon definition. Are you going to do that? GenKnowitall (talk) 05:30, 27 May 2011 (UTC)
- It is evident from new references added that the subject is highly contentious even in academic circle, so per WP:Neutrality, all points of view should be addressed and that was properly done by Melchoir. I do agree with Feynman's view most, but that attitude was not shown in the article, and which one is better was left entirely for the readers to choose. What you do, on the other hand, is to force one view on everyone and you call that "order"?--Netheril96 (talk) 02:11, 27 May 2011 (UTC)
- So far, you have conceded no point, entered no debate, proposed no sensible resolution, and cited no authority for your view. Get on board fast, or folks may lose interest in your hot air. This is physics. Do some physics. GenKnowitall (talk) 05:30, 27 May 2011 (UTC)
- I have already made concession that Synmon's can now be included in the article, as opposed to summary dismissal before Melchoir's revision. I discontinued discussion because I saw no point, when someone else addressed my concern by including other authorities' view. And it is really hard to communicate with you; you said a lot but I can't find any meaning except for "objection". Now, enlighten me, on what grounds do you object to Melchoir's revision? That it fails to comply with WP:NPOV by giving credit to fringe views? Or mere procedural wrongdoing that Melchoir didn't consult with you before revising?--Netheril96 (talk) 08:44, 27 May 2011 (UTC)
- Enlighten you? Now there is a challenge, one I must decline. I remind of the obvious: We are editing an article I submitted, adding to it based on proposal and discussion. I have insisted, because of the previous editorial history of this article, that the proposals be specific, supported, and discussed in an orderly way. You are invited to participate, not make meaningless snipes. If you are participating then responsive reply is requested. Here, if you have conceded Symon this is the first you have said it, but "can now be included in the article" is not an acknowledgment of anything. If you decline to reply and participate, then just say so. If you are not competent in the field, then fine, step aside. You may reserve your view on whether the Britannica citation is correct, but YOU raised a Symon objection, meritless as it plainly appears, and begin to appear a person who makes meritless objections to things. Are we to take you seriously and acting in good faith? SO: Do you now agree the Symon definition is properly stated and cited, at least as far as Symon's textbook? Do you agree it is a bone fide definition used in the classical physics discipline of mechanics. A clear and proper statement of your position on this would be proper.
- I have already made concession that Synmon's can now be included in the article, as opposed to summary dismissal before Melchoir's revision. I discontinued discussion because I saw no point, when someone else addressed my concern by including other authorities' view. And it is really hard to communicate with you; you said a lot but I can't find any meaning except for "objection". Now, enlighten me, on what grounds do you object to Melchoir's revision? That it fails to comply with WP:NPOV by giving credit to fringe views? Or mere procedural wrongdoing that Melchoir didn't consult with you before revising?--Netheril96 (talk) 08:44, 27 May 2011 (UTC)
- So would you object if I restore the 430984802 version of the article? Of course, I'm not saying that 430984802 is the final word on the subject, but it sounds like we agree that it's a step forward. Melchoir (talk) 03:25, 27 May 2011 (UTC)
- Of course I know about your view of the subject before I posted the article, and how things went last time. I read the notes, do you seriously take me for a fool? Not really, I trust. I insist on editing process to avoid the previous editorial malfunction. I will suggest, since you have already reasonably conceded Symon, that you be invited to offer approximately one paragraph (or so) definition derived from Feynman (or an authority of your choosing) concerning CM to introduce the alternate view into the article. The overall subject introduction is NOT included and will come later after some agreement has been reached concerning the definition and its place in the article. Will that satisfy you as a starting point. Place it in discussion, in a separate section, and I will be pleased to join you and aid in a supported addition to the article. GenKnowitall (talk) 05:30, 27 May 2011 (UTC)
- I have read both the last version by GenKnowitall and the last version by Melchoir. I felt that Melchoir wrote a discussion, but starting half-way through the argument while GenKnowitall didn't really expand on the difference between Centre of Gravity and Centre of Mass. IMO, we should use GenKnowitall's version as a start point, followed a short section to explain the difference between Centre of Gravity and Centre of Mass, possibily using the "mountain" example in one of the references. Ideally the new section could be repeated in the article "Centre of Mass". Some of Melchoir's material could be added as the next section. Finally, we should always remember that somebody is going to read these articles, so what is written should be targeted at them - in the case of this article, 16 to 18 year-olds (or people trying to recall what they were taught at that age) rather than fully-fledged philosophers or university professors.
- BTW, GenKnowitall, you wrote some good stuff - please register and include a short note so that we know a bit about you - sufficient at least so others know where to pitch their discissions when replying to you. Martinvl (talk) 14:12, 27 May 2011 (UTC)
- I'm not sure exactly what you're envisioning, but it sounds like you're proposing that the article still begins with the current definition, "that point in space which, to an observer at P, is the apparent source of gravitational attraction"? That doesn't satisfy Wikipedia:Neutral point of view. Melchoir (talk) 15:24, 27 May 2011 (UTC)
- Your proposal to make this accessible to a high school student is predicated on one incontrovertible definition on what is center of gravity, upon which we can then elaborate and expand this article. But that has clearly been ruled out by Melchoir new references on alternative views. This article can only serve as a collection of all kinds of views on the definition of CG held by authorities.
- Actually, since center of gravity rarely has any practical use in non-uniform gravitational field, and the concept is so messy, it should have been deleted in the first place, as had been done multiple times before.--Netheril96 (talk) 15:48, 27 May 2011 (UTC)
- "Rarely"? "any practical use"? Actually, the rain in Spain falls mainly on the plain, Netheril96. Unlike your platitude I'm pretty sure I can dig up a reference on that, if you need one. Or you could just 'google it' like melchoir suggests. You are not an authority, Netheril96. Deletion decisions are premature, and here probably meritless, they only worked last time becuse the articel was so mucked up by incompetence. You are past becoming disruptive without contributing. Please participate constructively in the EDITING of the article, or if you must babble, please place your comments under the Peanut Gallery category below where they can be properly ignored. GenKnowitall (talk) 21:09, 27 May 2011 (UTC)
- On Martinvl's comment: Your comments are sensible. To clarify: The basis is the article I submitted which has now been agreed as correct as stated by both Melchoir and Netheril96. An objection on the Britannica citation has not been proved but is still unresolved and reserved, but I think will be resolved with clarification in the addition process. The submission by Melchoir has been reverted and is NOT presented for discussion. I have asked and insisted on orderly editing process of submission and discussion An alternative definition has yet to be formally proposed by anyone, but Melchoir appears to have something based on an approach by Feynman, which Netheril96 seems also to cherish and apparently claims, in an nearly incoherent rant, will balance POV. I have no objection to such a proposal, have twice invited it for discussion, expect I will be commenting on it, but so far, after several specific invitations, such has not been offer as proposal. I again invite a properly cited alternative definition proposed for addition HERE for discussion. Adjustments for age appropriate description may (hopefully) follow. That is the proper way to proceed to a balanced and informative article. GenKnowitall (talk) 21:09, 27 May 2011 (UTC)
Britannica Citation
- The Britannica citation doesn't support the definition given here.
- Symon: Given an extended body M and a reference point P, the center of gravity of M relative to P is a point G such that the gravitational force exerted at P by M is the same as the gravitational force exerted at P by an equivalent mass collected at G.
- Britannica: Given an extended body M inside an external gravitational field g, the center of gravity of M is a point G such that the gravitational force exerted on M by g is equivalent to the gravitational force exerted on an equivalent mass collected at G by g.
- Do you see how these are different? Melchoir (talk) 06:37, 24 May 2011 (UTC)
- Thank you for your comment, Melchoir. It is late here, so I will consider the comment and give later reply. GenKnowitall (talk) 07:26, 24 May 2011 (UTC)
- Replying to Melchoir 24 May comment: Yes, I think I see. Thank you for the thoughtful comment and your courtesy in using the talk pages and in offering discussion to improve the article. You are contending that the Britannia citation does not support the definition given, and have given argument in support. If I concur we can discuss what action should be taken, removing the reference or rewording/revising the article or alternatively the point may be withdrawn as answered. We keep in mind that discussion may help others understand the article better. PRELIMINARY: I believe I understood your point, but there is a fundamental problem with your argument that should first be resolved. ASKING: (0) Do you concur that CM and CG are different concepts in physics? (1) Do you agree the Brittanica citation at issue is http://www.thefreedictionary.com/gravity ? (2) Do you agree the Symon reference supports the definition given? If all these answers are "yes", then (a) I have re-read the Brittanica citation for consistency with the Symon definition and still find it consistent, therefore find it in support (b) I have not read the Brittanica article to determine if it is also consistent with the interpretation you have offered, which is from the reference point of a "gravitational field",which is interesting but also appears provocative from the classical physics POV. I do not normally object to thoughtful provocation or alternative definitions appearing in a classroom or in an article, nor to modernization of concepts, if all is made clear, but here I will suggest, arguendo (for purposes of discussion, inviting clarification), that MY Brittanica citation does not appear to say what YOU say it says. If it did say that, or even if it was consistent with your representation, we might still discuss that with some care. Thank you again, I look to your clarification. GenKnowitall (talk) 16:55, 24 May 2011 (UTC)
- (0) In principle, yes; but not enough to support a separate article. We'll get to that.
- (1) No, I'm referring to the link you added to the article in this edit yesterday: http://www.britannica.com/EBchecked/topic/242556/centre-of-gravity
- (2) Yes, from the snippets I can see in Google Books, the definition given is Symon's definition.
- Let me give you an example of the difference between your two sources. Brittanica states that the center of gravity of the Moon is "slightly displaced toward the Earth" and implies that it would be displaced even if the Moon were spherically symmetric. Symon's definition does not allow external fields to affect the center of gravity of an object; under his definition, a spherically symmetric Moon has a center of gravity that is at its geometric center, for any observer. Melchoir (talk) 17:24, 24 May 2011 (UTC)
- (0) Ok. We agree CG and CM differ. Combined article is another subject. I think you see how I view that. We can discuss though.
- (1) oops. how did that get in there? ghosts in the machine. yes, I meant the link given for the on-line Britannica. We are agreed here.
- (2) I can quote it to you verbatim but both your version and my version appear correct with Symon, in my opinion. I might actually prefer your word-smithing to my own, but we might get to that. We appear to agree here.
- Interesting distinction, but a moment on that if you please, as you now raise two distinct problems, proposed as errors if that does not offend. First, you are correct to say that under Symon a spherically symmetric object has CG (and CM) at its center, but disagree where you assert that Britannica says different. Instead the Britannica article states "The location of a body’s centre of gravity may coincide with the geometric centre of the body, especially in a symmetrically shaped object composed of homogeneous material.". Further it states that "the Moon’s centre of mass is very close to its geometric centre (it is not exact because the Moon is not a perfect uniform sphere)" (my emphasis added). These are consistent with Symon. I do not think you have the article quite right, but to further explain a spherically symmetric object has a central CG (and CM) from EVERY point of reference, easily shown by calculus, including for every imagined gravitational field derived from external matter which assumes classical Newtonian inverse-square law gravitational forces obeying the third law, which we are presently assuming, yes? That was also demonstrated by Newton in his Principia. You may rebut by demonstrating a classic gravitational field for which that is not so, however. I am skeptical you can do so, but certainly remain open to a demonstration. I withhold for present explaining the second problem. I merely conclude that Britannica is consistent with the article (Symon's) definition, therefore is properly cited in support. GenKnowitall (talk) 20:05, 24 May 2011 (UTC)
- Melchoir, the shape of planetary bodies is a complex subject we need not address because "the Moon is not a perfect uniform sphere" is also a simple direct quote from Britannica, unchallenged by me, and is especially relevant to the issue at hand because if the moon were otherwise a perfect sphere then under Symon its CG would be at the center for ALL observers, not "slightly displaced". Thus assuming (arguendo) Britannica is correct that the CG is "slightly displaced" then EITHER Britannica is inconsistent with Symon as you have contended OR "the Moon is not a perfect uniform sphere". As you can see, Britannica asserts the latter and therefore does not prove the former. Does that make matters more clear? If you have any references supporting your "gravitational field" alternative definition wouldn't now be a good time to offer them up? GenKnowitall (talk) 22:37, 24 May 2011 (UTC)
- You really don't have to talk down to me about the shape of planetary bodies. I've published an article in the Astrophysical Journal founded on the premise that a spinning planet isn't a sphere, and considering one of the consequences for its gravititational interactions.
- You claim that Britannica's "slightly displaced" center of gravity may be explained away by the shape of the Moon. But that's a red herring, and Britannica itself does not claim such a connection. It says "its centre of gravity is slightly displaced toward the Earth because of the stronger gravitational force on the Moon’s near side." Melchoir (talk) 22:56, 24 May 2011 (UTC)
- Not talking down, discussing with you and others, as I mentioned earlier. Not so many people can have this discussion. So no offense is intended on my part, and none need be taken. Further I have no idea of your credentials, I must consider what you say, not what you are. That is how we must work here. I nonetheless congratulate you on your publications, sincerely, even if they have no present relevance because, as I explained, "the shape of planetary bodies is a complex subject we need not address". If it were relavant, we would not need to consider spin to explain non-spherical distortion of a planet or Earth's Moon, isn't that so? It is for this reason your reference to a red herring is itself a red herring because, as you profess to know and understand the implications, "the Moon is not a perfect uniform sphere". So if, as you contend, the article makes no connection, then a refutation cannot be simultaneously inferred. You thus prove your argument specious and argumentative. That could demonstrate bad faith argument, which I suggest is unwise to do here. So you should now offer a reference that actually supports your contentions, that you are by self-confession trained to provide (if one exists) and which you have been previously asked for and have ignored, or concede what you you have been unreasonably evading, what you should now concede, that the Britannica citation is correct. May we please have one of those now? GenKnowitall (talk) 00:15, 25 May 2011 (UTC)
- Relevance of the question? Boxed in? No, 'backing up' is not amusing, rarely productive, it may waste my time which I value, and is done only for good cause shown. Here you have offered no reason, no good cause, no direction or proposition to demonstrate, no reasoning, only a simple question which requires no fantasy flight of inference to obtain from the simple text of the on-line source, and which has been previously quoted and carefully discussed. If you need time for research, that is automatically granted upon withdrawal of your objection. Take all the time you need. Thereafter, with someone at your professed skill level I would expect that if you find something it will be cogently and efficiently provided as a professed scholar should know how to do. If you have a point that is supported, now is the time to offer it plainly and to provide real support, or withdraw your objection. In any event I thank you for your comments. GenKnowitall (talk) 01:11, 25 May 2011 (UTC)
- Symon defines a concept of the center of gravity of an object relative to a point. His definition does not depend on external gravitational sources or fields. Britannica states that the center of gravity of the Moon is influenced by the gravitational field of the Earth. These are obviously contradictory treatments. They are talking about different things using some of the same words, and I'm trying to get you to realize as much. Since I seem to have failed so far, I need to ask questions to figure out what you do agree with.
- Meanwhile, if you want other attestations for a concept of a center of gravity relative to an external field, try this query. Melchoir (talk) 02:05, 25 May 2011 (UTC)
- Vague references to google search terms is not scholarship, Melchoir, nor authority for anything. I've already signaled a warning in my "READ ME FIRST" article that high school texts commonly approach this subject from the standpoint of a flat gravitational field, thereby confabulating center of mass and center of gravity. This was the malfunction of the previous article, a malfunction you participated in I might remind. So enough Melchoir, put your mind in careful gear. Sentence 1 and 2 are agreed. Sentence 3 is about what Britannica states, but is a restatement made through the lens of some alternative view you hold which you have refused to either state or cite any authority for. Not trying to be rude, trying to be CLEAR. AT MOST, and the only issue you have raised, is the possibility that Britannica is AMBIGUOUS, but I have not even agreed with that proposition since an non-spherical moon would have the properties stated by Britannia when using the definition of Symon. Do you see that? In short, Britannica is consistent with Symon and is properly cited in support. I cannot imagine a person who is published as you state you are needing a mathematical demonstration of that point, but do you? GenKnowitall (talk) 17:42, 25 May 2011 (UTC)
(rewrap) Here's the problem. My contention is that introductory physics textbooks are the only sources that ever discuss a "center of gravity" that's distinct from the center of mass. Engineers and astrophysicists alike have no use for this concept. If you care about the field of a non-spherical body, you should be expanding it in a series of 1/r^n potentials and spherical harmonics, with the origin at -- you guessed it -- the center of mass.
So it's not the case that there exists an authoritative treatment of "center of gravity" that I can point to and say, look, Symon is wrong! I can only point out that Symon's definition, although a reasonable one, conflicts with the rest of the literature. Google Books should be enough to make that point, but if you really want me to pick out sources, I can do that too.
I'll grant you that my opening statement about Britannica is an original interpretation of the text. (You should note that Britannica doesn't refer to a reference point, either.) It's clear to me that Britannica is referring to the Earth's gravity acting on the Moon. Let me ask you this. Consider the phrase "the stronger gravitational force on the Moon’s near side". Do you think this phrase refers to the gravitational force exerted upon a particle in the Moon's near side by the whole Earth, or the gravitational force exerted by a particle in the Moon's near side upon an observer at the center of the Earth? Melchoir (talk) 18:15, 25 May 2011 (UTC)
- (rewrap appropriate) Here is the problem. Your "restatement" of the Britannica article were not only original, they were actually "fantastic" fabrications. Such fabrications do not create a genuine dispute, they fabricate one out of thin air. That could be bad faith. Your formulation was interesting, however, creative and I liked that, and so I went along to see what you could do and whether you could cite an authority which used it. You didn't and you haven't. Creativity is cool, as I said, but without compensating discipline it cannot long survive in the physics we know and love, look to Newton and Einstein, creative genius with discipline. Beautiful.
- Now attend to discipline: You continue to evade and fail to respond to my replies in rebuttal, wandering off into ever-more vague and widening circles of philosophy. We are not on a walk in the woods Melchoir, although I am sure we could enjoy such discussion, as did Einstein, we are here attending to the business of editing this article. Its past time for you to focus on what I have been explaining, and make appropriate reply. Symon is no exotic source, he is an acknowledged and distinguished authority in the field, with a textbook used throughout the United States. Before you contest him you will need someone of equal or greater stature. For example, if you are who you say then you have taken upper division physics MECHANICS, so what does YOUR book say??? Well?? Reply! Before you dispute the Britannica citation you should verify that it actually doesn't support the material, not just fabricate some disagreement based on your "original" thoughts. So please reply to my preceding point about the consistency of Britannica with Symon... do the math if you have to, or politely ask me to show you, but don't ignore it because that will not be good faith discussion. Britannica is properly cited, isn't that correct? If you think not you should demonstrate it is inconsistent with Symon, prove it up as I have suggested, not just waive your arms. You are a trained and disciplined scholar and know what I am saying, or not, which?
- As to "conflicts" you have failed to demonstrate any authoritative conflicts. You have already agreed that CG and CM are not the same concept. I have also already warned you, please attend, that sources which confabulate the two concepts at the high school level do not ACTUALLY conflict with Symon, they merely confabulate by seeming simplification. I will EXPLAIN the confusion to you if you like, its not that hard once exlained, but so far you haven't even cited one of these sources to raise the issue. If you do, however, have a good faith belief that it actually supports you, then I will explain, nicely, how it actually supports Symon. Now, please make RESPONSIVE reply on the issue of the Britannica citation.
- Fine, I've pulled the mechanics textbooks out of my bookshelf. The two textbooks by Feynman and Goldstein refer to a center of gravity; I've added them to the article with quotations and page numbers. On the other hand, the following textbooks define the center of mass but not a center of gravity:
- Arnold, Mathematical Methods of Classical Mechanics
- Marion and Thornton, Classical Dynamics of Particles and Systems
- Kleppner and Kolenkow, An Introduction to Mechanics
- Jose and Saletan, Classical Dynamics: A Contemporary Approach
- I haven't decided what to do with them. Melchoir (talk) 06:15, 26 May 2011 (UTC)
- Oh, and most importantly:
- Murray and Dermott, Solar System Dynamics
- This book is the closest thing to being "my textbook". It's an entire book about Newtonian gravity in the real world, and it doesn't mention a center of gravity. Melchoir (talk) 06:18, 26 May 2011 (UTC)
- OK then, better. Yes, I know. No CG anywhere in that book. Therefore CG doesn't exist, "poof, voila" only CM. That's about what happened last time editing this article, right? Still, we have similar interests (although I have others too). We don't always get to do what we love the most, but a few lucky ones do, and if that is you then my very best regards. I've reverted your changes for now, for process violation, but I expect we may bring them back into the article in an orderly way. Lets try. GenKnowitall (talk) 21:51, 26 May 2011 (UTC)
- First, "CG doesn't exist" is not what I wrote. Second, editing an article under dispute is not a process violation. On the contrary, I find that when a talk page becomes gridlocked, in order to move the article forward it is helpful to have concrete versions to compare. Third, by "orderly way" you seem to be suggesting that you hold some kind of veto power over the article, and other editors need to get new material approved by you. Hopefully that's not what you think, but if it is, see Wikipedia:Ownership of articles. Melchoir (talk) 03:48, 27 May 2011 (UTC)
- I submitted the original article and am here actively discussing in good faith and willing to collaborate with other supposed scholars. If you don't intend to collaborate here, then perhaps you would prefer to author a book? Happy to quote it if it is good. Again, melchoir, the article will be improved by good faith collaboration, good physics, and some common sense editing. You should not try to hijack the process or article again to impose your view. Please do reply to my requests for agreement above, that will be a sensible beginning. GenKnowitall (talk) 04:56, 27 May 2011 (UTC)
- First, "CG doesn't exist" is not what I wrote. Second, editing an article under dispute is not a process violation. On the contrary, I find that when a talk page becomes gridlocked, in order to move the article forward it is helpful to have concrete versions to compare. Third, by "orderly way" you seem to be suggesting that you hold some kind of veto power over the article, and other editors need to get new material approved by you. Hopefully that's not what you think, but if it is, see Wikipedia:Ownership of articles. Melchoir (talk) 03:48, 27 May 2011 (UTC)
- OK then, better. Yes, I know. No CG anywhere in that book. Therefore CG doesn't exist, "poof, voila" only CM. That's about what happened last time editing this article, right? Still, we have similar interests (although I have others too). We don't always get to do what we love the most, but a few lucky ones do, and if that is you then my very best regards. I've reverted your changes for now, for process violation, but I expect we may bring them back into the article in an orderly way. Lets try. GenKnowitall (talk) 21:51, 26 May 2011 (UTC)
- Fine, I've pulled the mechanics textbooks out of my bookshelf. The two textbooks by Feynman and Goldstein refer to a center of gravity; I've added them to the article with quotations and page numbers. On the other hand, the following textbooks define the center of mass but not a center of gravity:
Melchior's edits to the article seem very reasonable to me, and I would say they should be re-instated, particularly the citations to various textbooks. Melchior's above comment, "If you care about the field of a non-spherical body, you should be expanding it in a series of 1/r^n potentials and spherical harmonics, with the origin at -- you guessed it -- the center of mass." is also correct, and the article should probably state something to that effect. You are behaving as of you had ownership of this article, GenKnowitall, which is not conducive to a collaborative atmosphere. Also, the ISBN for Symon in your preferred version appears to be incorrect. - Parejkoj (talk) 17:07, 27 May 2011 (UTC)
- Thank you for your comments. Parejkoj. I have called for orderly editing, which IS the collegial process, with specific proposals for addition to be discussed here. If you have specific proposals to add, put them in a section for discussion. I have been assured by a professional librarian that the ISBN for Symon is correct. Please verify your claim, and either make it or withdraw it formally. That is courteous, collegial, and advances the article. If you have further proposals concerning spherical harmonic whatchamdojiggies and other mathematical models used to do stuff in physics, you may make them but these are probably premature to discuss while the basic definitions are under debate. Please give responsive reply to sort out your ISBN objection, and if not withdrawn please make your objection specific, ie what makes you think the ISBN is wrong? Thank you. GenKnowitall (talk) 21:34, 27 May 2011 (UTC)
- Parejkojam, I am rechecking the ISBN. The book is an 'ancient text' (but still available on amazon) issued before the ISBN number system (1970). I have been informed that the Catalog number was adopted as the ISBN number, but that may be technically incorrect. I am now informed that books prior to 1970 have an adaptation which is recognized as the ISBN , in this case ISBN B003XYZQKYY applies. I'm checking further but my librarians are heading home for a three day weekend. If you are able, please see if that ISBN works. Thank you for your comment. GenKnowitall (talk) 22:04, 27 May 2011 (UTC)
Symon Definition Discussion
Center of gravity is always associated with torque. You don't need to know the point of exertion to calculate the translational motion; you only need it when rotation is taken into account. By this article's definition, center of gravity in a uniform gravitational field would be anywhere, rather than the center of mass.--Netheril96 (talk) 04:15, 25 May 2011 (UTC)
- Sorry. Symon uses a reference point with respect to the gravitating body. If you have another definition you may cite it here. Thank you for your comment. GenKnowitall (talk) 17:02, 25 May 2011 (UTC)
- Netheril96, have entered the discussion with the above comment and, if I understand the history markers, entered a dispute tag in the article. That seems improper and I dispute that marker is appropriate as there is presently no bona fide dispute over the article accuracy. If you placed the tag you will please immediately remove it. It may be a genuine dispute will appear, at which time I will not object to an appropriate tag, but at the moment neither Melchoir or you have raised any genuine dispute regarding content, and indeed Melchoir has agreed that the Symon definition IS properly stated and cited. Here your comments have confused Symon's definition with one of your own, but you have stated no alternate definition or cited any authority. Your confusion does not create a genuine dispute. Please attend to that tag immediately. GenKnowitall (talk) 16:53, 25 May 2011 (UTC)
- Tag removed as inappropriate. No genuine dispute with Netheril96. Notice given to author. Do not place inappropriate tags or vandalize the article. Raise discussion points here.GenKnowitall (talk) 01:04, 26 May 2011 (UTC)
- From center of mass, The term center of mass is often used interchangeably with center of gravity, but they are physically different concepts. They happen to coincide in a uniform gravitational field, and my reasoning is based on this.--Netheril96 (talk) 02:27, 26 May 2011 (UTC)
- And that center of gravity and center of mass coincides in uniform gravitational field is in Britannica's entry too. My point is that the two definition, one in uniform and one in non-uniform field, are inconsistent.--Netheril96 (talk) 02:41, 26 May 2011 (UTC)
- OK. Thank you Netheril96 for the above two comments. These do not yet raise a factual dispute in the article. Wikipedia is useful but not, regrettably, an authority, please do not treat it so. It is late, so I should reply more fully tomorrow. Meanwhile please consult any undergraduate physics text in mechanics, in English if you please, and cite its page references to 'center of gravity', with any definitions given. State whether you believe these are consistent, or inconsistent, with Symon and explain if needed. This should advance discussion between us. Thank you. GenKnowitall (talk) 05:36, 26 May 2011 (UTC)
- Isn't a debate on the merit of the article content the meaning of factual debate? And this discussion is moot, now that my concern is properly addressed by new references. Which definition is the best can now be left to readers themselves to decide.--Netheril96 (talk) 07:35, 26 May 2011 (UTC)
- Its not 'moot' unless I concur, which I don't. I've reverted what we should first discuss (see Call to Order above) . This isn't really a debate per se, it is an editing process which employs debate as a means of resolving editorial decisions. But if you cannot focus on the issue, what good are you here? The issue you raised was an objection to SYMON. You have now morphed that to the Britannica objection, which I admit is better stated than melchoir managed, but stick to the subject so we may in good faith resolve editing decisions. Do you now withdraw your supposed objection to the Symon definition, and confess it is properly stated and cited (whether or not you personally disagree with it or think it useful or whatever -geez ). Good faith requires that you concede what you reasonably should, not just refuse to concede any ground at all, which is bad faith argument. OK? So do we have some agreement here, or not? GenKnowitall (talk) 20:30, 26 May 2011 (UTC)
What is a Genuine Dispute?
- There's no such thing as a non-genuine dispute. There are just disputes, and we're in one!
- I've agreed that Symon's definition is properly cited, but I don't agree that it is used appropriately. We shouldn't refer to Symon's definition as "the center of gravity", because his definition is not widely used, and it conflicts with other sources. As far as I can tell, Netheril96 is right in that most textbooks that speak of a "center of gravity" mean a location that can be used to calculate torque; note that this is yet another definition, apart from Symon or Brittanica.
- So yes, the present article is factually inaccurate, because it suggests that all definitions of center of gravity are equivalent, when they aren't. It's also misleading in another way: it gives the reader the wrong idea about the state of the literature. Melchoir (talk) 17:53, 25 May 2011 (UTC)
- I'm sorry you disagree, Melchoir, and that you lack an understanding of the meaning of the term 'genuine dispute', but (explaining) vague and unsupported claims do not raise a genuine dispute. Ignorance does not create a genuine dispute, only a dispute. You should attempt, in good faith, to identify a specific point of genuine disagreement, which should have support on both sides, and more usefully get your 'opponent' to agree on the issue in dispute. Until a genuine dispute arises that tag is improper and if it is not removed I will remove it myself and if necessary call in an admin. A previous genesis of this article was subject to gross incompetence and editorial malfunction, and it appears we are heading that way again for much the same reasons. Lets try to avoid that this time, shall we?
- You are otherwise swinging arms wildly Melchoir, without ANY support, about "conflicts" and "widely used". Specifically, your contentions about "widely used" need to be discussed before claiming a dispute. Did you want to discuss that or its relevance to the wikipedia? Then make a separate heading above, state your point, show some REAL support (not google search terms), and I may decide to reply. GenKnowitall (talk) 18:32, 25 May 2011 (UTC)
Draft version
There's a draft version of this article located at User:GenKnowitall/Center of gravity (physics). Perhaps a history merger should be performed with that into this? 65.95.13.213 (talk) 05:44, 25 May 2011 (UTC)
- I would take that as an abuse 65.95.13.213. Drafts are drafts to avoid unnecessary disruptive discussion. Instead the submitted article is before us and its fundamentals under discussion. That is the topic for review. GenKnowitall (talk) 16:07, 25 May 2011 (UTC)
Reverted to Melchoir revision
I reverted from GenKnowitall's revision to Melchoir's revision. Melchoir's convincingly demonstrates with many sources that there is more than one definition in the literature for the phrase "center of gravity", and summarizes them all well. Whereas GenKnowitall's revision only gives one definition and ignores all the others. So Melchoir's revision is better.
A procedural matter: GenKnowitall -- you should revert revisions, both major and minor, only because you have a specific reason that the revisions made the article worse, and you should announce that reason at the moment you revert. You should not revert just because the reversion was not discussed beforehand. That's just the usual procedure here on Wikipedia (c.f. WP:OWN.). I don't doubt that you do have a specific reason that you think that Melchoir's edits made the article worse...I'm only criticizing the fact that you did not articulate this reason at the moment that you reverted Melchoir's edits. You should have. Anyway, you may articulate it now. --Steve (talk) 22:11, 27 May 2011 (UTC)
- Your actions constitute vandalism and you should cease. You state you are a graduate student at Berkeley. You were on notice in the article to review discussion before editing yet you took the actions without discussion, or consensus. Your opinion as to the "convincing power" of anything has not been tested by discussion and is not an authoritative opinion. If you do anything further without appropriate review and discussion I will seek your removal. I hope that is crystal clear.
- There are alternative definitions out there, that is beyond much debate. Alternative definitions should be presented here for discussion and included after consensus. Offer one if you have it. Your opinion, student, is garbage unless it is supported, or may god help you at thesis defense. I am now reverting your changes. You should not do anything like that again. GenKnowitall (talk) 23:27, 27 May 2011 (UTC)