Talk:History of centrifugal and centripetal forces

Merge

We had the history repeated and diverging in two articles, in neither of which was it well integrated or a good fit, so I made this place to merge them. Still need to merge from Centrifugal_force#History_of_conceptions_of_centrifugal_and_centripetal_forces. OK? Dicklyon (talk) 17:06, 21 July 2009 (UTC)

Looks good. Adding centripetal force may be tricky. Brews ohare (talk) 17:11, 21 July 2009 (UTC)

I did the merge. It doesn't say much about centripetal; maybe it should say more. Dicklyon (talk) 06:20, 17 August 2009 (UTC)

Johann Bernoulli II

FyzixFighter, you have just removed a perfectly sourced paragraph which contained Johann Bernoulli's views on centrifugal force. Yesterday, you were arguing about the absolute right to insert quotes from secondary sources and now you are taking the opposite point of view. The only common theme here seems to be your ongoing campaign of removing edits which I make. You can't even leave the history section alone where it conflicts with your modern day viewpoint. David Tombe (talk) 11:28, 17 August 2009 (UTC)

As I indicated in the edit summary, I removed it for several reasons. The primary reason is that this has nothing to do with the history of centrifugal force. Why is Bernoulli's use of centrifugal force in this instance notable with respect to the conception of centrifugal force? What impact did his ideas have on the development of the understanding of the centrifugal force? This is not an article about the various now defunct aether theories, but about the history of centrifugal force. From my reading of other history of science sources, Bernoulli's usage was not a unique approach as all the Cartesian mechanical models invented in that era that were based on vortices relied on Huygens' and Descartes' concept of centrifugal force. Are we to include every instance in the history of science where someone used the idea of centrifugal force to support their ideas? Or are we going to actually focus on the subject of the article, and include those instances in history whose notability with respect to the subject are well established by secondary sources? What are the thoughts of the other editors - Dick, David J, Wilhelm, anyone else? --FyzixFighter (talk) 14:39, 17 August 2009 (UTC)

I agree with FF. It's the same reason I omitted the Maxwell 1861 vortex theory when I did the merge. I couldn't see the relevant to the topic. Dicklyon (talk) 15:00, 17 August 2009 (UTC)

Now there's a surprise. When has Dicklyon not sided with FyzixFighter? They both claim that they can't see how the idea of vortices pushing against each other with centrifugal force can be relevant to the topic of centrifugal force! This is just a case of deleting a part of the history of centrifugal force that Dicklyon and FyzixFighter don't want to be reminded about. They are obviously both afraid that there might be too much truth in it. Nobody deletes historical ideas unless those ideas represent a plausible alternative to the existing orthodoxy. David Tombe (talk) 18:27, 17 August 2009 (UTC)

Indeed, I find that idea that EM waves are communicated via a sea of vortices to be quite frighening! Dicklyon (talk) 23:16, 17 August 2009 (UTC)

Dick, I'm not quite sure what you're trying to say here. Are you suggesting that the idea is ridiculous and that Maxwell and Bernoulli were crackpots? If so, then why worry about it being accurately recorded as an item of historical curiosity along with the flat Earth theory? Or are you trying to tell me that you are actually frightened by the idea, and that that's why you and FyzixFighter have deleted all references to it? I'll be quite frank about the matter. I think that Maxwell and Bernoulli were both right. I understand that Euler and Tesla were also sold on the idea. David Tombe (talk) 23:29, 17 August 2009 (UTC)

No, I'm saying that dead-end ideas about the ether don't serve to clarify the conception of centrifugal force, and that I'm not fearful of truth. Dicklyon (talk) 01:16, 18 August 2009 (UTC)

Dick, It doesn't actually matter what your opinion is. If those aether ideas were heavily tied up with centrifugal force, then they should be mentioned in a chronological history of ideas relating to centrifugal force, in respect of that relationship to centrifugal force. This is an example of you and FyzixFighter taking on the self appointed role of the thought police and deciding which aspects of history the public should be allowed to know about.

The current orthodoxy seems to be that centrifugal force is a fictitious force that can only be observed from a rotating frame of reference. This current orthodoxy is strongly upheld by yourself and FyzixFighter. But it is a matter of importance that people should be able to read a history section and take note of the fact that the current orthodoxy wasn't always in existence. Once you start tampering with history, you are taking things too far. The two of you are getting carried away with yourselves because of your own blinkered views on the topic.

You are the one that was so keen to have a special history article. But it is now clear that you have taken on the role of official censor of that article as to what can appear in the history. David Tombe (talk) 11:53, 18 August 2009 (UTC)

Rather than name-calling and throwing out your typical personal attacks, David, which you have been advised multiple times to avoid, why not address the questions and points I brought up. However, if you feel that any reasonable response would not change the minds of the other editors, then you do have other options: providing reliable sources that specifically relate the edit you want to include to the topic at hand (the history of CF), or put in a request for comment to get more input as the next step in WP:DR. Either way, the ad hominem attacks must end. I refuse to engage in any further discussion with you if you continue in this way. --FyzixFighter (talk) 14:28, 18 August 2009 (UTC)

FyzixFighter, I read your comments above and I didn't follow the relevance of your point about Johann II Bernoulli's approach not being unique. I do however know that one should not confuse the large vortex idea of Descartes and Leibniz, (which may also have been bought by the senior Johann Bernoulli), with the sea of tiny vortices that was being advocated by the young Johann II Bernoulli, and later by Euler, Maxwell, Tesla, and perhaps others.

The sea of vortices is intricately tied up with centrifugal force. It's centrifugal force which contributes to its stability, and as far as Maxwell was concerned, gave rise to lateral repulsion between the magnetic lines of force. As a general concept, it can be legitimately introduced into this history section on the basis that centrifugal force played an important role in some aether theories of the 18th and 19th centuries. Don't forget that this is a history section. We know that you fully support the current orthodoxy regarding centrifugal force being merely a fictitious force that can only be observed from a rotating frame of reference. But you cannot allow your own views to restrict the contents of a history article. To do so, would suggest that you are restricting certain historical ideas because they offer a plausible alternative to the existing orthodoxy.

This article was originally entitled something like "History of CONCEPTS of Centrifugal Force", but the word "Concepts" was removed to make the title more readable. Unfortunately this changes the subject of the article. If the article is supposed to be about the history of concepts of centrifugal force, then I don't think the aether theories are relevant, because they didn't involve novel concepts of centrifugal force, they merely employed the existing concept. For example, when Maxwell conceived of the lines of electric force as vortex threads pressing laterally against each other due to centrifugal force, he wasn't introducing a new or novel concept of centrifugal force, so this wouldn't fit in an article on the history of concepts. On the other hand, now that the word "concepts" has been removed from the title, we are left with an article ostensibly on the history of centrifugal force itself. In such an article, one could argue that anything involving centrifugal force (like figure skating, uranium enriching centrifuges, etc) might be legitimate topic for the article. But is this really the intent, or is the intent really to present the history of the CONCEPT of centrifugal force? If the latter, then perhaps the title of the article should be reverted back to the original title.Edcenflee (talk) 17:06, 20 August 2009 (UTC)

If you know of any other famous physicists in the past who advocated the involvement of centrifugal force in a sea of tiny vortices, I would welcome you to introduce this material into the article. But we need to get the chronology and the coherence correct.

As far as I am concerned, the earliest references to the rotating frames of reference approach are probably Lagrange or Coriolis. In the case of Lagrange, it is based on a quote from some source and I am surprised, because rotating frames played no part in the work that he is famous for. In the case of Coriolis, it is not so surprising because his name is heavily tied up with modern textbook chapters on rotating frames of reference. Had I not known about the Lagrange reference, I would have put the beginnings of the concept of rotating frames at the feet of Coriolis. But I don't accept that Daniel Bernoulli saw centrifugal force as a fictitious force in a rotating frame, despite what Meli says. I have a reference here in which Daniel Bernoulli is shown to be advocating a real centrifugal force that opposes gravity, albeit that I don't agree with his idea that it is of constant value. [1].

That reference doesn't "advocate a real centrifugal force", it is simply a commonplace statement that "centrifugal force opposes gravity" in the context of a discussion of the shape of an orbiting body, i.e., why it is elongated along the line toward the gravitating body. In this context one focuses on the orbiting elastic body as if it was fixed and subjected to various deforming forces determining its shape. It's quite conventional to invoke "centrifugal force" in this context, without necessarily implying a rejection of the ordinary understanding of this as an inertial effect.Edcenflee (talk) 13:32, 20 August 2009 (UTC)

I think that you will have to learn to put your own orthodox prejudices aside when contributing to a historical article. I have never attempted to hide historical facts that I don't like. I was very disappointed when I discovered that Gaspard-Gustave Coriolis was responsible for letting the Coriolis force off the hinges, but I have never stated my opinions on that fact in a main article. I have always fully acknowledged Coriolis's role in the development of the concept of rotating frames of reference. I have reported him accurately, using his term 'supplementary forces'. My preferred term is of course 'inertial forces'.

This edit war can be explained on the basis of one single example. You have insisted on using a 1990 source by Meli which stamps Meli's modern viewpoint over the viewpoint of Daniel Bernoulli. You have insisted on giving primacy to this source without clarifying in the text that the opinions expressed are Meli's and not Bernoulli's. Now I don't believe for one moment that you aren't capable of seeing that Bernoulli's statement merely means exactly what it says, ie. that centrifugal force differs from other forces in that varies according to the point of origin. Meli has extended Bernoulli's statement from 'origin' to 'frame of reference' in line with modern attitudes. If you were trying to write the article to reflect the truth, you would not be wanting to give such a high profile to Meli's source. It is no good to claim that you are merely adhering to wikipedia's rules on secondary sources. There is an issue of balance and undue weight to be considered as well, and you are ignoring that. We need to know why. And it appears to me that you are using the Meli source as a means of stamping 20th century attitudes on top of an 18th century observation. So long as you continue to try and blot out historical beliefs using the opinions expressed in late 20th century secondary sources, then this section can never be written in a coherent and readable fashion. It will end up as a patchwork of sources and counter sources.

Basically, you need to ask yourself what is your objective in coming to this page. I see no evidence of any existing interest on your part in the history of centrifugal force. On the other hand, I have been heavily involved in the history of electromagnetism for years. I'm trying to add to these articles, and you have been continually subtracting knowledge which you hadn't previously known about. David Tombe (talk) 19:21, 18 August 2009 (UTC)

Hi Ed, There is no doubt that the inertial forces possess a distinct property that is not found in the ordinary forces. Daniel Bernoulli pointed out this key distinction in his 1746 memoir. Centrifugal force is referenced to a point. And it follows therefore that we can have a different centrifugal force acting on an object according to which point we choose as our reference point. I'm happy enough with the term 'inertial force'. I see the three inertial forces as being an integral part of the inertial path (excluding gravity). They are described mathematically in polar coordinates, but care must be taken regarding which term applies to what when we introduce a gravitational field. The point is of course that the Daniel Bernoulli reference didn't specify a fictitious force either. I agree that it is an inertial force, but it clearly has an outward push associated with it that is real.

There's no need for any debate about "real" versus "fictitious", since this distinction is purely one of definition. In classical mechanics when people talk about the "real" net force on a particle of mass m they simply mean the vector ma where "a" is the second derivative of the particle's rectilinear inertial space coordinates with respect to the associated time coordinate. When they talk about a fictitious force they mean the vector ma where "a" is the second derivative of the space coordinates with respect to the time coordinate of some system of coordinates that does not satisfy the definition given for "real" forces. Of course, each person is free to propose other definitions for words, but Wikipedia is not the best place to advocate new definitions.Edcenflee (talk) 20:46, 20 August 2009 (UTC)

Ed, I would agree with you that there is no need to debate the "real" versus "fictitious" issue, and for the reasons that you have said. I always knew that our views on that issue differed only as regards your willingness to use the term 'fictitious' for the inertial forces. However, I don't like the term 'fictitious' being applied to 18th century concepts of centrifugal force. In my opinion, its a misnomer. I'm not sure when the term 'fictitious' first arose. Do you have any idea? Coriolis talked about 'supplementary' forces. David Tombe (talk) 20:55, 20 August 2009 (UTC)

On your first point, it may well be that alot of the material mentioned might be better dealt with in detail in an 'aether' article, if one exists. Neverthless, I see no harm in a passing mention of these ideas even in this article. It's splitting hairs to specifically avoid mentioning those vortex sea ideas on the grounds that centrifugal force is only of secondary interest in the context. David Tombe (talk) 18:54, 20 August 2009 (UTC)

Again, none of the "aether" and "vortex" discussions involve new conceptions of centrifugal force, they merely are hypothesized phenomena that would exhibit centrifugal force under the existing conceptions, so they aren't relevant to an article on the history of the concept of centrifugal force. A good presentation of the actual history of the concept of force in general, and centrifugal force in particlar, can be found in books such as Barbour's "The Discovery of Mechanics". As Barbour makes clear (from a detailed examination of the source materials), Huygens understood full well that what he called centrifugal force was purely a consequence of the inertial tendency of matter to follow rectilinear paths. This is why Huygens pointed out that Leibniz's hypothesis as to an aetheral induced real centrifugal force was non-sensical, because it would mean we have TWO centrifugal forces, the one resulting from inertia, and the new one hypothesized by Leibniz. But there has never been any sign of any centrifugal force other than the one the arises from ordinary inertia. So, the current article's treatment of Leibniz is very misleading, since it fails to note that every other scientist from Huygens to Hertz has explained the fallacy in Leibniz's reasoning, and since it seems to suggest that Leibniz's train of thought originated that equation, when in fact it appears in Newtonian mechanics as well, and modern scholars have discovered that Leibniz (contrary to his claim) had studied Newton's Principia prior to writing his work on dynamics.Edcenflee (talk) 20:46, 20 August 2009 (UTC)

Ed, I fully agree with you that centrifugal force is a consequence of the inertial tendency. But having accepted that it is a consequence of the inertial tendency, it is still nevertheless a consequence that we can describe as an outward radial effect and to which we can give the name 'centrifugal force'. As regards Leibniz, I do not agree with his large vortex idea. It would restrict planetary motion to a single plane and a single direction. I don't know how Leibniz obtained his equation. In fact, until recently, I didn't even know that Leibniz had such an equation. But having now seen Leibniz's equation, irrespective of how he derived it, it becomes quite obvious that it is the same equation as the modern radial planetary orbital equation. My initial interest in this article was related to introducing the radial planetary orbital equation, and the fact that it contained a centrifugal force term, and that there was no need for the involvement of rotating frames of reference. I think that you have agreed with me already that rotating frames of reference are not necessary in an analysis.

So as regards the material on Leibniz, I have no objections at all if you wish to re-write the story surrounding his equation. I'd be very interested to read the correct account. I didn't write that bit in the first place. I do however recommend that you retain the actual equation itself, irrespective of what story you write around it.

Now at some point, the large vortex idea of Descartes, Leibniz, and even Johann Bernoulli senior, seems to have given way to a new concept of a sea of tiny vortices. I can connect the young Johann II Bernoulli with that idea and perhaps Euler. This is clearly a much more sensible idea because it allows for planetary motion in any plane and in any direction, and perhaps contributes to the zero curl of the gravitational field.

Fluid vortices exhibit centrifugal force, regardless of whether they are large vortices, medium sized vortices, or tiny vortices. But none of them invoke a novel conception of centrifugal force. The particles of the fluid want to move inertially, and their inertia tends to carry them away from the center of rotation (unless countered by some force). The concept of centrifugal force as it applies to fluid vortices is the same, regardless of the size of the vortices, so your comments make no sense - assuming you are talking about concepts of centrifugal force.

You mention that certain kinds of fluid vortices "allow for planetary motion in any plane and in any direction", almost as if you are talking about some kind of mechanistic hypothesis for the origin of gravitation and/or the origin of centrifugal force, which of course is both off-topic and non-sensical. Neither Bernoulli nor Euler proposed molecular vortices or a sponge vortex as an explanation of planetary motion, let alone as an explanation of centrifugal force (which would be idiotic, trying to explain inertia as a consequence of inertia). So your comments are not relevant to this article. (They are also unintelligible, but that's a side issue.)Edcenflee (talk) 15:57, 21 August 2009 (UTC)

With this idea, the emphasis then shifted to the pressure in this 'aether' due to the centrifugal force of the vortices pressing against each other. Maxwell then adopted the idea and used the centrifugal pressure to account for magnetic repulsion. If the centrifugal force that causes pressure between the tiny vortices of the aether was the standard centrifugal force as it was understood in those times, I do think that we could mention those aether theories in this history section because of that fact.

Again, if this article is intended to be a compendium of historical theories that involved the usual conception of centrifugal force, then it might be appropriate to include such topics. (Any such article would have to be gigantic.) But I believe the original intent of this article was to discuss the history of the concept of centrifugal force. If that is still the intent, then the topics you've mentioned are not relevant.Edcenflee (talk) 15:57, 21 August 2009 (UTC)

One more point. Be careful about getting Newton mixed up with Leibniz's equation. There is a story there involving Newton being awkward. But I'd like to hear what you know about the matter. David Tombe (talk) 21:18, 20 August 2009 (UTC)

Naturally Newton (in his later years) was always eager to discredit Leibniz, and was dismissive of anything Leibniz wrote on mechanics, even though this particular equation happens to be consistent with Newton's own theory. The point is that this equation does not entail any unconventional concept of centrifugal force.Edcenflee (talk) 15:57, 21 August 2009 (UTC)

Ed, I was saying that if space were filled with tiny vortices, as per Johann II Bernoulli and James Clerk-Maxwell, then there would be no obstacle to planetary orbits being in any plane or in any direction. I was not suggesting that such a concept explained gravity. I was comparing the merits of this approach to the restrictions that would arise with the large vortex concept of Descartes or Leibniz. If the Sun were at the centre of a large vortex, then the planets would be restricted to orbit in one direction, and in one plane. I didn't say anything in this discussion about a sea of tiny vortices explaining centrifugal force. I pointed out that Maxwell used the centrifugal pressure in such a sea to explain magnetic repulsion. It is specifically Maxwell's explanation of magnetic repulsion, in terms of centrifugal force, which I was suggesting should be included in this historical article about centrifugal force. I cannot see your basis for objecting to a mention of the fact that Maxwell used centrifugal force to explain magnetic repulsion. That is highly relevant to the history of centrifugal force. Whether you believe in Maxwell's idea or not, it is a significant idea in the history of magnetism, aether theories, and centrifugal force.

Getting back to Leibniz again, I can't see how his equation can have been consistent with Newton's aproach to the matter when Newton stated that centrifugal force is the equal and opposite reaction to a centripetal force. With Leibniz's equation, irrespective of how he derived it, the centrifugal force does not have to be equal in magnitude to the centripetal force. Leibniz's equation is the one that we use today in orbital mechanics. I don't therefore see modern planetary orbital theory as being Newtonian mechanics in the literal sense of the word. Once again, we are back to terminologies which are a waste of time. I'm happy enough to consider orbital mechanics to be Newtonian mechanics in the more generally understood sense, in that it is not relativistic mechanics, or quantum mechanics.

Leibniz's equation was a major landmark in the history of centrifugal force. It doesn't matter that we don't know how he derived it, or that his physical model was wrong. I don't see your point about it not being a novel concept. He derived an equation that we still use today, even if we call it by the misnomer of 'Newtonian mechanics'. Can you please make some suggestions as to how we should write this article. Do you want Leibniz, Maxwell, and Johann II Bernoulli written out of it by any chance?

And one more point Ed, could you please make a single response with that deals with all the issues raised. Fragmenting your responses through the previous response makes it more likely that something might be missed. David Tombe (talk) 18:26, 21 August 2009 (UTC)

You say "If space were filled with tiny vortices... there would be no obstacle to planetary orbits being in any plane or in any direction... I was not suggesting that such a concept explained gravity [and] I didn't say anything in this discussion [uh huh] about a sea of tiny vortices explaining centrifugal force". So, in summary, you aren't saying these vortices DO anything. Your claim is simply that they aren't an obstacle to orbital motions. But if our objective is to avoid presenting an obstacle to orbital motion, why inject a system of fluid vortices in the first place? This whole line of discussion is non-sensical, and has no relevance to this article (or any other article).

You mention Maxwell's heuristic notions about mechanistic representations of some aspects of electromagnetism in terms of centrifugal force associated with spinning vortex threads. As I see it, this pertains to the history of the concept of electromagnetism, not to the history of the concept of centrifugal force. Maxwell was not proposing any new concept of centrifugal force. He understood it to be purely an inertial effect, i.e., what we today would call a fictitious force. It was a novel approach to electromagnetism (although it was actually originated by McCaullaugh many years earlier), but it wasn't a novel approach to the concept of centrifugal force. Furthermore, Maxwell himself took pains to make it clear that he did not think the mechanistic representations he described were actually present in nature, and he recognized full well their limitations. You say "Whether you believe in Maxwell's idea or not, it is a significant idea in the history of magnetism, aether theories, and centrifugal force." I agree with the first 2/3 of your statement.

You say "I can't see how [Leibniz's] equation can have been consistent with Newton's aproach to the matter when Newton stated that centrifugal force is the equal and opposite reaction to a centripetal force." Newton used the term "centrifugal force" in three difference senses in the Principia, including each of the various modern definitions. Moreover, the terminology is irrelevant: When one derives the equation for the radial distance of a planet from the sun according to Newton's theory, one arrives immediately at what you call "Leibniz's equation". So, when you say "I don't therefore see modern planetary orbital theory as being Newtonian mechanics in the literal sense of the word", you are simply mistaken. The Principia describes the radial position of an orbiting body in full agreement with that equation (although expressed in synthetic geometrical form).

You say "Leibniz's equation was a major landmark in the history of centrifugal force", but that's ridiculous. Newton give the correct solution of the orbital problem, that entails what you call "Leibniz's equation". The Principia was the major landmark in the history of centrifugal force, in the sense that it clarified the very concept of force as being proportional to acceleration defined in terms of a special class of coordinate systems (rectilinear and non-accelerating). If anything, "Leibniz's formula" was a minor landmark in the history of calculus and mathematical analysis applied to physics (as opposed to Newton's synthetic geometrical approach).

You ask if I "want Leibniz, Maxwell, and Johann II Bernoulli written out of" the article. I think Leibniz needs to be in the article, but not primarily for reasons related to that equation. Leibniz was a prominent advocate of relationism, which is the fundamental conception of dynamics differing from Newton's absolutist view, and this bears crucially on the concept of centrifugal force. Regarding Bernoulli and Maxwell (and MacCaullough and Kelvin and Faraday and etc.), I don't think they originated any concepts of centrifugal force distinct from the concepts already in existence, so I don't see much need to mention them. They should of course be prominent in an article on the history of fluid mechanics and electromagnetism.Edcenflee (talk) 20:19, 21 August 2009 (UTC)

Ed, I'd certainly be interested to see the equivalent of the Leibniz equation in a Newton paper that was written first.

Are you saying that you haven't actually read the Principia, so you honestly hadn't realized that what you call "Leibniz's equation" was actually Newton's? That is really astounding.Edcenflee (talk) 22:21, 22 August 2009 (UTC)

I can see that you take Newton's side in the notorious controversy between Leibniz and Newton. I'm open minded to changing sides if I can see more evidence regarding Newton's position on centrifugal force. Do you have a direct link to his derivation of the Leibniz equivalent equation?

Yes, I know which Proposition in the Principia contains the equivalent equation. I'm astounded that you do not. How can you think yourself qualified to write on this subject without knowing the first thing about it?Edcenflee (talk) 22:21, 22 August 2009 (UTC)

Edcenflee, you're being a bit elitist here; don't let Tombe make you misbehave. It is not an expectation that editors of topics in wikipedia will have an expert level of familiaritiy with primary sources, especially since the policies are to prefer what's verifiable in secondary sources. I also haven't read much Principia, and I'd be very interested in listening as you fill us in on what we've missed. Alternatively, feel free to just ignore David; long history shows that engaging him is universally counter-productive. Dicklyon (talk) 22:30, 22 August 2009 (UTC)

And by all means go ahead and write what you know about Leibniz in the article.

If I were to write what I know about Leibniz in the article, it would be much too long.Edcenflee (talk) 22:21, 22 August 2009 (UTC)

I do know that his equation is good irrespective of how he arrived at it.

Of course it's good, it's a direct consequence of Newton's theory. Leibniz arrived at it by translating the relevant Proposition of Newton's Principia into analytic notation - as you must surely know if you're made even the most cursory examination of this subject.Edcenflee (talk) 22:21, 22 August 2009 (UTC)

As for the title of this article, I had nothing to do with it. I didn't even want it separated off from the main article.

The point is that the title determines what is and what isn't appropriate content. Is this article supposed to be about the history of the development of the concept of centrifugal force, or is it supposed to be about the history of centrifugal force itself? The latter is an overly large subject (in my opinion). Most of the information you are seeking to include in the article is only arguably appropriate if we choose the latter, because your information is not relevant to the development of the concept of centrifugal force.Edcenflee (talk) 22:21, 22 August 2009 (UTC)

We're going to have to agree to differ on the importance, as regards this article, of Maxwell's use of centrifugal force to explain magnetic repulsion. I believe it is important enough to be mentioned. But you and two others don't. Therefore so be it. Maybe you'll help then when I go to the articles you suggested and write about these issues in more detail.

I never object to appropriate and relevant edits to any article. I do, however, think you underestimate the extent to which an individual's crackpotish beliefs (if they have any) tend to contaminate their output, even when they strive to conceal their animating beliefs. It's virtually impossible for someone who holds profoundly crackpotish beliefs on a subject to make appropriate and relevant edits.Edcenflee (talk) 22:21, 22 August 2009 (UTC)

Finally, I meant to say that I am a supporter of Newton against Leibniz on the issue of absolute rotation. I think that Leibniz contradicts his own equation by his stance on this issue. David Tombe (talk) 20:55, 21 August 2009 (UTC)

It's true that Leibniz's ideas on mechanics were very confused and self-contradictory. The equation you're referring to is Newton's. As you've already agreed, "centrifugal force" is simply a consequence of the inertia of bodies striving to maintain their state of uniform rectilinear motion.Edcenflee (talk) 22:21, 22 August 2009 (UTC)

Edcenflee, I'm still waiting to hear your ultimate point. You've so far told us that you are very much in the Newton camp in relation to his notorious dispute with Leibniz. At no stage in the past did I ever argue for the inclusion of the radial planetary orbital equation into the article on the basis of who was the first to propound it. I merely argued for its inclusion because it is correct, and because it exists in modern secondary sources, and because it contains a centrifugal force term. I was recently shown by Dicklyon that Leibniz propounded it. Now you are telling me that Newton propounded it. Dicklyon provided us all with a secondary source which tends to contradict what you are saying. Having said that, I am more than happy to believe that Newton derived it if I can see evidence of this fact. And just one more point. In your last sentence, you talk about bodies striving to maintain their state of uniform rectilinear motion. I don't know about the 'striving' bit. I'm not sure that they do any 'striving'. All I know is that centrifugal force is a consequence of their rectilinear motion, uniform or not. David Tombe (talk) 23:50, 22 August 2009 (UTC)

You say that "centrifugal force is a consequence of rectilinear motion". Hopefully we can agree that no such notion should appear in any wikipedia article. According to the scientific community, extending from Huygens to today, centrifugal force is nothing but the tendency (i.e., striving, also known as the force of inertia) of bodies to moving uniformly in a straight line. This striving becomes manifest when something compells a body to deviate from uniform rectilinear motion. We then observe that the force of inertia on the body tends to make it resist any such deviation, and we give labels to various components of that inertial force. Anyone who "doesn't know about the striving bit" doesn't know anything about inertial forces.

This is closely related to what the article calls "Leibniz's equation". If that equation were expressing something foreign to Newtonian mechanics, it might be seen as support for some "explanation of centrifugal force" different from the standard Newtonian explanation. But since it is actually just an expression of Newton's solution of the orbital problem in analytic terms, it obviously gives no support at all to any exotic non-Newtonian notion of centrifugal force. Of course, it falsifies the Brews ohare claim that centrifugal force terms appear only in rotating coordinates, but that claim never had any merit to begin with, and this is not a historical point, it is as true today as it was in Newton's day, as can be verified in an abundance of reputable modern discussion of centrifugal force. It isn't clear to me why this "historical section" has been split off from the main article - except as a way of trying to combat Mr Tombe's persistent efforts to introduce discussion of the luminiferous ether. This is (unfortunately) a good illustration of how the effort to block certain kinds of non-encyclopedic ideas can lead to all kinds of contortions and problems for an article.Edcenflee (talk) 22:31, 25 August 2009 (UTC)

Ed, Let's deal with the 'striving' bit first. I was very careful with my wording because I didn't want to reveal my own opinions as to the nature or cause of centrifugal force. It would have actually been more accurate if I had merely stated that centrifugal force is a consequence of absolute motion. But I don't think it's a good idea to get into a discussion on inertia here on wikipedia, because it is an archaic term which actually has a number of meanings ranging from inertial mass to momentum. It suffices for the purposes of this article that a body that is undergoing rectilinear motion will experience a centrifugal force relative to any chosen point origin, irrespective of the cause, and that the inertial forces are well described using polar coordinates, providing that a gravitational field is also involved. Without the gravity, the polar coordinate expressions lose an important physical linkage to reality, and it becomes unclear as to exactly which terms apply to what.

Anyhow, let's move on to the Leibniz equation. I could well believe that you are correct when you say that Newton arrived at this equation first, but I would still nevertheless like to know the chapter and section in the Principia, because I have heard other people claiming that Newton doesn't deal with centrifugal force in his Principiae. But of course, they are capable of saying that about Goldstein too despite its presence at equation 3-11. I wouldn't be at all surprised to find centrifugal force in the Principiae despite all the denials. My initial efforts were to get this equation into the article irrespective of who first propounded it. After years of wrangling, it's finally in the main article and also in the history section. In the main article, it is wearing its Lagrangian uniform, as that was the only uniform in which it was permitted entry. In the history section, it is wearing its Leibnizian uniform. You are welcome to put it into both articles again, wearing a Newtonian uniform. Quite frankly, the only reason why I want it in the article is because I know that it is correct, and that it is the most general way to illustrate centrifugal force, and it doesn't involve rotating frames of reference. The strenuous resistance to its explicit inclusion in the article in the absence of any masking uniform has been a total disgrace, and it was no doubt motivated for the very reason that it made a mockery of the argument that rotating frames of reference are essential.

Finally, I realize that you are prejudiced against the luminiferous aether, but at least you are honest enough to realize that its very mention in the history section, which has now incidentally been removed, was indeed the reason why it had to be hidden from view and split from the main article. I, on the other hand was quite happy to mention it in relation to Maxwell's use of centrifugal force to explain magnetic repulsion. But unlike what you have just suggested, I had no desire to discuss the luminiferous aether on the centrifugal force pages.

I'm glad that we are agreed on the rotating frames issue in that rotating frames are not essential, and I'm glad that you backed me up on that point a while back. And of course, that issue was one of my chief motives for wanting to put the radial equation into the article. But at some stage, I would like to hear your opinion on the aspect of the rotating frame analysis which I despise the most. That is of course the extrapolation to stationary objects that are being viewed from a rotating frame. David Tombe (talk) 00:00, 26 August 2009 (UTC)

Latin text of quote

"Corol. Hinc cum vis centrifuga partium Terræ `a diurno Terræ motu oriunda, quæ est ad vim gravitatis ut 1 ad 291, efficiat ut altitudo Aquæ sub Æquatore superet ejus altitudinem sub polis mensura pedum Parisiensium 85200, vis So- laris, de qua egimus, cum sit ad vim gravitatis ut 1 ad 12868200, atque adeo ad vim illam centrifugam ut 291 ad 12868200 seu 1 ad 44221, efficiet ut altitudo aquæ in regionibus sub Sole & Soli oppositis superet altitudinem ejus in locis quæ 90 gradibus distant `a Sole, mensura tantum pedis unius Parisiensis & dig- itorum undecim. Est enim hæc mensura ad mensuram pedum 85200 ut 1 ad 44221." --Alex1011 (talk) 08:19, 8 October 2016 (UTC)