Talk:Celestial spheres/Archive 3

Archive 1

Archive 2

Archive 3

Plato spherist?

Notwithstanding its comments on the Spindle of Necessity, the Sirens and the Fates, the following current claim:

"One of the earliest intimations of celestial spheres appears in Plato's "Myth of Er," a section of the Republic, which describes the cosmos as the Spindle of Necessity, attended by the Sirens and turned by the three Fates."

does not actually evidence Plato was a spherist, rather than merely a bandist as in Timaeaus.

Unless Plato's alleged spherism can be documented, I propose its deletion.--Logicus (talk) 15:13, 24 February 2008 (UTC)

Plato's position in the Timaeus is more complex than this discussion suggests. In discussing the body of the universe he says at Tim. 33b (trans. Cornford):

"And for the shape he gave it that which is fitting and akin to its nature.... accordingly he turned its shape rounded and spherical, equidistant in every way from centre to extremity—a figure the most perfect and uniform of all..."

He then relates the body of the universe to its soul, beginning at Tim. 34a-c:

"According to this plan he made it smooth and uniform, everywhere equidistant from its centre, a body whole and complete, with complete bodies for its parts. And in the centre he set a soul, and caused it to extend throughout the whole and further wrapped its body round with soul on the outside.... the god made soul prior to body ... to be the body's mistress and governor."

When Plato goes on to describe the soul of the universe at Tim. 36b-d he divides the soul-stuff of which the world soul is formed into bands:

"This whole fabric, then, he split lengthwise into two halves; and making the two cross one another at their centres in the form of the letter Χ, he bent each round into a circle and joined it up, making each meet itself at a point opposite to that where they had been brought into contact. He then comprehended them in the motion that is carried round uniformly in the same place, and made the one the outer, the other the inner circle.... And he gave supremacy to the [outer] revolution of the Same and uniform; for he left it single and undivided, but the inner revolution he split in six places into seven unequal circles."

It appears that in the Timaeus Plato advances two complementary points of view. When speaking of the body of the universe, Plato describes it as rounded and spherical; when speaking of the soul of the universe which governs its motions, Plato speaks of circles (or perhaps bands like those of an armillary sphere). --SteveMcCluskey (talk) 14:23, 9 November 2009 (UTC)

Logicus to McCluskey: This is very interestiong stuff, McCluskey. Well done for once ! Will digest later. But please restore my equally interesting stuff on Ptolemy's tambourine model of the spheres/bands that you deleted for no good reason.

--Logicus (talk) 19:05, 11 November 2009 (UTC)

I replaced the passage "Ptolemy likened it to a tambourine in which the epicyclical disc is like the jingles or zils fixed in its circumference, the deferent." because you provided no reference for the "jingles" or "zils" and I could find no mention of them in the sources I consulted. The word tambourine is mentioned there; your embellishments are not. My replacement followed the descriptions in the sources which I cite there. --SteveMcCluskey (talk) 02:22, 12 November 2009 (UTC)

The restoration of Logicus’s contribution on the dynamics of the celestial spheres in the middle ages, invalidly removed by Leadwind.

I hereby propose to restore the original text of my previous contribution to this article’s section on the celestial spheres in the middle ages, imperiously and invalidly removed by Leadwind on 4 May 2009, and put in a new article Dynamics of the celestial spheres. See my comments on the rank invalidity of Leadwind’s action @ User Talk:Leadwind.

At least for the record, below here I also re-present Steve McCluskey’s mistaken objections to my contribution, posted on the Talk:Dynamics of the celestial spheres page of the article created by Leadwind, and at least to give McCluskey the opportunity to strike them out as invalid if he does not wish to resurrect them to try and justify removing my contribution to this article yet again.

Logicus also proposes McCluskey should add his most welcome useful valid contributions to the ‘Dynamics of the celestial spheres’ article to this article, where they most properly belong.

McCluskey’s objections to Logicus’s contribution to the topic of the dynamics of the celestial spheres in the middle ages

Anachronisms in the article One of the central problems with this article is its formulation of ancient and medieval discussions of dynamics in terms of mathematical equations. Such relationships were not used by any of the authors under discussion and to present their discussions in this form falsely leads the reader into the assumption that the logical conclusions one can readily draw from the mathematical formulations could be drawn from the ancient and medieval verbal expressions.

Furthermore, an article about ancient and medieval dynamics should be stated in terms of ancient and medieval concepts. The modern term "force", F in the article, was not clearly defined and generally accepted until sometime after Newton's articulation of the concept in his Principia; attributing that concept to Aristotle and his followers is profoundly misleading. --SteveMcCluskey (talk) 22:02, 20 August 2009 (UTC)

Major rewrite I spent some time looking over this article with an intent to edit it and it soon became clear that mere editing won't suffice; a complete rewrite is called for. The central problems of the old version concern lack of balance; as it stood it failed to give the reader the broad overview of the topic expected in an encyclopedia.

• The article focused on what the principal editor sees as "a major anomaly for Aristotelian dynamics," which the article takes as the center of its discussion. Through this narrow focus, it granted excessive weight to the views of a few persons (especially John Philoponus and John Buridan) and viewed all other actors through their role in resolving this "anomaly".

• The article failed to give what the reader of an encyclopedia expects: a presentation of the variety of views of Celestial Dynamics during the period from antiquity to the renaissance when the celestial spheres were the dominant framework for understanding celestial motions.

• Finally, and perhaps most significantly, the article ignored an extensive body of recent secondary literature that investigates the causes of celestial motion, and selected its materials from primary sources, from secondary literature dealing with general questions of Aristotelian dynamics (e.g., Maier, Moody, Sorabji), and from older literature (e.g., Duhem, Koyré).

There may still be some things of value in the prior version of the article, which is available in the article's history. Other editors may wish to mine it for appropriate material, while retaining the article's encyclopedic balance.

--SteveMcCluskey (talk) 16:30, 11 September 2009 (UTC)

--Logicus (talk) 03:59, 1 November 2009 (UTC)

I'd advise against reintroducing the material to this article in defiance of consensus. Leadwind, SteveMcCluskey, and I think it doesn't belong here; you seem to be the only person who thinks it does. The way things work in Wikipedia, no single editor can add contentious material to an article without gaining a consensus of other editors that it should be added. If you restore the material here, I will revert it and begin dispute-resolution procedures to ensure that it stays reverted. Deor (talk) 04:17, 1 November 2009 (UTC)

Deor: I was just browsing Wikipedia during a break over the weekend when I saw, and reverted, Logicus's restoration of his off topic Original Research. I am still on Wikibreak until mid November but after I return I will contribute, as time allows, to the dispute resolution process you plan to initiate. After over three years of Disruptive editing, Wikipedia has provided Logicus with a soapbox long enough. --SteveMcCluskey (talk) 15:16, 1 November 2009 (UTC)

RfC: Original research?

Closer's note. Content RfCs do not need to be validated. Consensus is that primary sources are insufficient verification for the disputed material, due to the interpretive nature of the material. Removal from active article space is necessary per Wikipedia's no original research policy, pending acquisition of secondary sources to support it. Suggest userfication of that portion. If no secondary sources exist it is possible to generate that by publishing in a reliable vetted venue, then citing that source at Wikipedia. When that is done properly the update becomes uncontroversial. Durova³⁷¹ 17:44, 29 November 2009 (UTC)

Logicus note on Closer’s note: There was no consensus of the ten respondents that primary sources are insufficient verification for the disputed material. Of those ten respondents only Finell is even remotely interpretable as expressing such an opinion in his following comment of 2 November rebutted by Logicus on 20 November: “A majority of the sources that are cited are primary.”. So even if Deor himself also expressed this opinion, that is at most only 2 out of 11 involved in the RfC who do.

So if consensus were decided by some kind of majority vote of respondents to the RfC, the opinion that primary sources are insufficient verification for the disputed material was at best an extremely small minority opinion.

And on the question of whether the material is OR, only 6 out of 11 say it definitely is, a maximally slim simple majority.

But as explained by Logicus in the archived RfC, consensus is anyway not decided by votes according to Wikipedia policy.

The outcome of this meritless RfC, raised in breach of Wikipedia dispute resolution policy that the disputant must first discuss the issue with the editor before raising an RfC. is that Logicus anway as always offers to revise material that is defective or breaches policy once the complainant has identified where and why the material is in breach. But neither Deor nor anybody else has ever done so in this case except Wilson, in accusations of Original Synthesis that Logicus has responded to with proposed revisions posted below on 30 November. But Wilson refuses to discuss them, apparently revealing bad faith that he was never interested in constructively helping improve the material, which appears to be true of the whole coterie of editors involved in this RfC. Thus it seems negotiatons to remedy the material by revision are locked in refusal to do so.

And any charge of irremediable OR remains unproven.

Logicus to Closer: Would you please kindly explain what your following comments mean.

“Content RfCs do not need to be validated” Does it mean that if OR is alleged, nevertheless valid substantiation of the claim is not required ?

“Suggest userfication of that portion.”

“Removal from active article space is necessary per Wikipedia's no original research policy, pending acquisition of secondary sources to support it.” The material already has some secondary sources that support it. So what further secondary sources are required and where ?

And would you please be so kind as to explain by what authority or policy rule you parachute in here to ‘close’ this RfC with your apparently unfounded opinions on consensus, rather than its initiator or a bot closing it ?

Final;ly, you might like to give comment on the following defect of Wikipedia consensus policy raised on its Talk page: ‘This key Wikipedia policy article as currently written crucially fails to specify what constitutes a consensus. Is it a unanimous or a majority agreement of some community ? And what is the relevant community ? Dictionary definitions of consensus typically say it is either unanimity or else majoritarian agreement. So it is clearly important to decide which it is. But such definitions also leave open the further question of whether it is at least a simple majority (i.e. at least 51%) or at least a great majority (i.e. two-thirds) of the relevant community. But the more basic problem here is the article’s failure to identify what the relevant community is. And even more basically, we are told consensus is not even decided by votes anyway. Thus the Wikipedia fundamental policy of editing by consensus is surely in effect empirically empty, whatever all its rubrics about discussion and procedure ? ‘

Thanks you for your interest in this RfC
—Preceding unsigned comment added by Logicus (talk • contribs) 19:26, December 1, 2009

This is the first time in four years that the validity of a content RfC has been challenged in this way. According to Wikipedia's verifiability policy, people who want to include material bear the burden for validating its inclusion to the satisfaction of other volunteers. Setting aside the innovative procedural objections to the attempt at dispute resolution, one aspect of Wikipedian conflicts that does appear more frequently is the attempt to reverse that burden. Essentially, that becomes equivalent to a challenge to prove that there isn't an invisible dragon living in Carl Sagan's garage. Durova³⁷¹ 23:59, 1 December 2009 (UTC)

Logicus to Durova: 1)Thanks for the historical information about content RfC validity challenges, but could you please be more specific on exactly what way I have challenged the validity of a content RfC that was also raised four years ago ? Do you mean its breach of the dispute resolution rule to talk first before RfCing ?

2)I am not trying to reverse any burden of validation whatever as you imply and you misrepresent the logic of the situation here. I am only asking people to show where and why there is a dragon in the material to establish it contains OR and so that it may be exorcised. But nobody has. This is surely utterly unreasonable ? (NB A proof that there isn’t an invisible dragon is to make the dragon visible.) Moreover your comments do not answer the crucial question of what is the constituency of volunteers that has to be satisfied about verification. Would you please kindly do so ?

3) Who is Carl Sagan ? Is he invisible as well as his dragon ?

4) You do not answer any of my four requests for clarifications of some of your comments I just do not understand, nor say what you mean by ‘consensus’ in the light of the critical analysis of the practical vacuity of Wikipedia consensus policy I provided. Would you please kindly do so ? It might help me understand how other editors understand things because I am now even more seriously baffled by much of Wikipedia policy, procedure and practice and how other editors (mis?)interpret and (mis?)use it than I was before this RfC. The experience of this RfC surely gives the unfortunate impression they are kangaroo courts for local tribal gangs who somehow control the editing of specific articles to exclude the good faith contributions of outsider dissenters who try to improve them in ways they disapprove of by means of making bogus invalid charges of breaches of policy rules to be then judged by voting rather than by discussion and demonstration of breaches. They seem like trials where no evidence for or against the charge is considered. --Logicus (talk) 14:15, 2 December 2009 (UTC)

"I am not trying to reverse any burden of validation whatever as you imply and you misrepresent the logic of the situation here. I am only asking people to show where and why there is a dragon in the material to establish it contains OR and so that it may be exorcised." Your statement is contradictory. Site policy is that you need to persuade others that the material is acceptable. You have not done so. They need not demonstrate to your satisfaction why they are unsatisfied. Durova³⁷¹ 17:09, 2 December 2009 (UTC)

Durova the Revelator ?

I am absolutely astonished by this interpretation of Wikipedia policy in respect of the issue of where the burden of proof that an edit is OR lies when it is challenged, whereby it seems it lies with the defendant to prove a negative, that it is not OR, rather than on the prosecution to prove its allegation that it is OR. Thus in criminal law this would be the equivalent of a system of ‘guilty until proven innocent’ rather than the ‘innocent until proven guilty’ system of English law. I would also point out that by virtue of this interpretation, OR policy, supposedly first introduced to exclude cranks, equally becomes a policy for protecting already installed cranks – just accuse challenging edits of OR and deny being satisfied by any attempts to establish they are not !

So could you please kindly tell me where this ‘burden of proof of OR’ policy is stated in Wikipedia policy rules ?

But if correct and it is also the prevailing interpretation amongst Wikipedians, then this revelation certainly explains what I have seen as those otherwise inexplicable or wholly unjustified puzzling accusations of OR and DE to which some of my edits have been subjected, when in my view they were made in good faith and were neither. On my interpretation of policy I was guilty of neither of these and the various accusations were grossly invalid and unsubstantiated, and indeed infuriating.

But in the light of your admirably succinct criticism of it, it now seems I need to review my interpretation of ‘burden of proof of OR’ policy and its consequences in the light of this revelation, in addition to reviewing my interpretation of OR policy in respect of whether translations are primary sources, and also of Consensus policy on what is consensus, in the light of the severely conflicting interpretations of them between myself and other editors that have been revealed for the very first time by this RfC. I have been absolutely staggered.

I am most grateful to you for making this possible interpretation of policy so very clear to me when it had previously been beyond my wildest imagination that Wikipedia policy could possibly be so very profoundly rotten. It would surely add grist to Oliver Kamm’s mill and the recent bad press for Wikipedia !

(By the way, my statement was not contradictory on its intended interpretation, which was that of asking critics to identify where and why they thought it possibly needed to be validated, rather than to shift the onus for validating it from its editor. Otherwise Wikipedia policy would surely be a case of the Kafkaesque nightmare….

’Joseph K awoke in Wikipedialand one morning to find he had been charged with murder, but without ever being told who he had murdered and when and where and how, he was summoned to trial to try and prove his innocence to the Wikipedians….’ )

Surely not ?

Thank you for your most illuminating advice !

--Logicus (talk) 16:36, 3 December 2009 (UTC)

BTW I should say I do not agree with Kamm's critique and wish to see Wikipedia flourish, but I do now think it is profoundy rotten and in urgent need of reform. I may write a critique of Kamm's elitist anti-amateur critique.--Logicus (talk) 17:31, 4 December 2009 (UTC)

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

Does the material added to the article in this edit constitute original research based on primary and selected secondary soures; and, more broadly, does it give undue weight to a particular approach to the topic of the article, overwhelming the encyclopedic treatment of the celestial spheres in antiquity, the Middle Ages, and the Renaissance? Deor (talk) 15:59, 1 November 2009 (UTC)

A plea to prospective RfC respondents from Logicus: If you really must comment on this illegitimate RfC which has bypassed the first stage of dispute-resolution by discussion, please only make focused and constructive comments that aim to demonstrate where the material in question is unreasonable OR (or has undue weight) so that it may be remedied if so, rather than rambling off-topic into other criticisms not raised by Deor, or just giving your bald unproven opinion on whether it contains OR. Just stating an opinion that the material is OR would be irrelevant and pointless. For according to the following illiterately stated Wikipedia RfC policy rule, the outcomes of RfC's should not to be decided by votes, but rather by discussion:

"RfCs [i.e. editors' opinions expressed in response to RfC's ?] are not votes. Discussion controls the outcome; it is not a matter of counting up the number of votes."

So it would be entirely irrelevant if a thousand or even a simple majority of all Wikipedia editors expressed the opinion that the material is OR. For it seems that deciding whether it is OR, and is thus to be deleted as it stands, should depend entirely on discussion and demonstration of the specific breach-of-policy charges raised by Deor. Given the Wikipedia 'consensus' method of editorial decision as opposed to those of truth or of democracy and its consensus method of dispute resolution, this should be discussion between Logicus and Deor aimed at reaching agreement between them, each possibly being informed by comments made by other editors, about whether the material is unreasonable OR to be deleted. And if it is agreed that it is, then a good faith follow-up discussion should surely be about what would be a mutually acceptable text to replace it on the topic in question, namely the emergence and development of the 17th century dynamics concepts of inertia and of impetus in the medieval dynamics of the celestial spheres.

Consequently in the first instance and to help initiate that required discussion that Deor has illegitimately by-passed, on Deor's apparently ill-formed question of whether the material constitutes "original research based on primary and selected soures(sic!)", please note that there is no Wiki OR ban on using primary sources as such, as very many articles do, and certainly no ban on only using selected secondary sources, which probably all Wikipedia articles use, rather than using all sources in the field. The question Deor should have asked is surely just 'Is the material Wiki OR anywhere ?', in response to which just demonstrating any use of primary or selected secondary sources would in itself be logically irrelevant to proving it is OR anywhere.

Furthermore, before identifying any rule against OR in the Wikipedia OR policy text which you think the material breaches somewhere, and before also identifying whereso, and whereby it should therefore all be completely deleted as Deor has deleted it all, please consider whether many Wikipedia articles, if not all, are also in breach of that very same rule, whence by the same token many other Wikipedia articles should also be completely deleted by Deor or others.

Please note that only 4 out of the paltry 9 responses to this RfC to date give any positive response to the RfC question of whether the material is OR, and only 4 state any intelligible reasons why, be they valid reasons or not. And none identify and quote any OR policy rule that is breached, whereby all 9 responses may be irrelevant. Please quote the policy rule itself that is allegedly being breached, rather than just stating your interpretative summary of it. For example Deor's RfC breaches the following rule of RfC and dispute resolution policy:

"Before asking outside opinion here, it generally helps to simply discuss the matter on the talk page first. Whatever the disagreement, the first step in resolving a dispute is to talk to the other parties involved." And all responses to his RfC breach the guideline "Mediate where possible - identify common ground, attempt to draw editors together rather than push them apart.", albeit it is difficult to do so when Deor has not yet stated what it is in the disputed material he regards as OR.

But the greatest absurdity of this RfC is that it is utterly pointless given that Logicus has always shown himself amenable to rational critical discussion and to revising his textual contributions with agreement in the light of valid constructive criticism made in good faith, many examples of which conduct can be documented. And in fact Logicus made several revisions of part of this disputed material, that part on impetus dynamics, in July 2008 by way of improving its sources in response to Deor's complaints of their insufficiency and allegation of OR. But after these improvements, after 3 weeks Deor had made no attempt to substantiate his OR allegation, and then failed to explicitly respond to Logicus's 30 July challenge to either demonstrate where the material was OR or else desist from deleting it. Deor simply stopped deleting it, whereby it remained unrevised in Wikipedia articles for more than a year, thus suggesting Deor accepted it was not OR and nobody else thought it was.

Moreover Logicus is anyway in no way opposed to radical revision of the text to improve it, even if it is not shown to be in breach of any Wiki policy, as it has not been to date. But Deor has simply failed to discuss his fresh objections of OR and undue weight to the material with Logicus before raising this RfC, and has even failed to do so again after Logicus invited him over two weeks ago on 2 November to discuss and specify his OR complaint and identify where he thinks OR is committed, with a view to revising the material if it is so anywhere. This surely reflects bad faith on Deor's part. How on earth can consensual agreement be reached between Logicus and Deor by rational discussion when the complaining editor refuses to discuss his complaint and say where and why the material constitutes OR, and so that it may be improved if so ? It seems Deor's illegitimate RfC has been been raised in thoroughgoing bad faith at the behest of his master McCluskey just to harass Logicus. (See McCluskey grooming and educating his accolyte Deor on RfC policy, for example, @ User Talk:Deor), where McCluskey provides Deor with a pre-prepared statement of what he imagines to be the outcome of Deor's RfC. This and other indicators suggest Deor is here acting as a McCluskey sockpuppet !)

To show good faith in the dispute resolution purpose of Logicus reaching agreement with Deor at least on the issue of undue weight, although Deor has not said why the material gives undue weight to its topic, Logicus agrees it is of undue length as the article now stands. But note that in the 1 November above section 'The restoration of Logicus’s contribution on the dynamics of the celestial spheres in the middle ages, invalidly removed by Leadwind.' Logicus proposed that McCluskey's material in the 'Dynamics of the celestial spheres' article should accompany Logicus's material in this article, whereby it may not have undue length. But this proposal was not adopted, thus arguably causing undue length. However, Logicus has no objection to the material on this particular topic of the medieval dynamics of the celestial spheres being appropriately scaled down. So would Deor care to make constructive proposals for what he considers to be a due length/weight for this important topic within the current article's section on the Middle Ages, namely the origins and development of the 17th century concepts of impetus and inertia in the medieval dynamics of the celestial spheres ?

Please also see Logicus's critical comments on the invalidity of the few responses to this RfC below.

--Logicus (talk) 16:57, 20 November 2009 (UTC)

Comment. I find that the repeated attempts to undermine the validity of the RfC, including outright removal of the RfC tag prior to discussion, as well as the above the WP:TLDR to be extremely disruptive. The fact of the matter is, the disputed content is obvious WP:OR, and moreover your contention that primary sources are sufficient is completely not in line with either of the core policies WP:OR, WP:V. Finally given the length and overall combativeness of your replies, it is obvious that a straight up RfC is much preferable to what would likely be an interminable and tiresome dispute resolution that would be a total waste of time for everyone involved. Sławomir Biały (talk) 17:16, 22 November 2009 (UTC)

I agree completely with Sławomir Biały. Very well stated. —Finell 20:17, 22 November 2009 (UTC)

• The issue raised by Deor is just one more example of a fairly widespread pattern of disruptive editing on pages relating to the history of science, philosophy of science, and even physics. For some examples look at Wikipedia:Requests for comment/Logicus and his Block log.

Turning to the specifics of this incident, I agree totally with Deor's analysis. The lack of balance uses this article as an attempt to advance Logicus's idiosyncratic historical interpretation. --SteveMcCluskey (talk) 18:39, 1 November 2009 (UTC)

I am not commenting on Logicus's editing behavior one way or the other. However, one RfC in February 2007 (which attracted very little comment) and one 24-hour block in October 2008 (with no block before or after that one) does not demonstrate a pattern of disruptive editing. Please confine comments here to the issue raised, not the editor. Thank you. —Finell (Talk) 16:15, 2 November 2009 (UTC)

Comment To clarify any possible ambiguity of my position regarding the specific issues raised in this RfC, I agree that Logicus's addition to the article gives undue weight to one aspect of the topic (mathematical analyses of force / resistance and the role of impetus in medieval analyses of the celestial spheres) and to one point of view about that aspect, a point of view based largely on original research. As others have pointed out, it's lack of balance is totally inappropriate. There are other problems with that addition that I will not discuss here. --SteveMcCluskey (talk) 02:13, 12 November 2009 (UTC)

• Comment: Without full refs the edit in question would appear to be WP:OR. More to the point and more relevant: the text as presented is too big, too obscure and too dense to benefit the general reader. It's not readable, not accessible and therefore not encyclopedic. Wikipedia is WP:NOT PAPER. --Whoosit (talk) 22:25, 1 November 2009 (UTC)

• Comment: The test is quite simple. Does this analysis appear in published sources elsewhere? If the answer is yes, then references to these published sources must be made clear, and attribution should be given. If the answer is no, then it is original research. I am very suspicious that this analysis is an entirely original synthesis, though, given the near complete lack of supporting sources, as well as the overall pattern of behavior of the section's sole proponent. I would like to add that the section under dispute in this RfC has other non-OR problems with it. First, by itself it exceeds the maximum recommended length of an encyclopedia article (see WP:LENGTH). Secondly, it clearly does not observe summary style: there is already an article Dynamics of the celestial spheres. If this content could be made to conform to Wikipedia policies and guidelines (doubtful as it seems), then surely it would belong there instead of here, if anywhere. Thirdly, why are all of the equations displayed in bold face type? At the very least it should be made to conform with the Manual of Style (mathematics). 71.182.189.125 (talk) 16:35, 2 November 2009 (UTC)

I now see that indeed what happened was that the material was already moved to Dynamics of the celestial spheres and subsequently edited to conform to Wikipedia's core principles. Recreating the earlier material here is a clear WP:POVFORK. 71.182.189.125 (talk) 19:06, 2 November 2009 (UTC)

• (after edit conflict): This contribution is clearly original research, among other problems. Long passages have no cited sources. A majority of the sources that are cited are primary. Where secondary sources are cited, it is often an evaluation of the source or a comparison of one versus another. In Wikipedia, secondary sources should be used for what they say, not for commentary about the sources. The contribution also favors one scholar's point of view over the others. Also, this contribution is way too long and is not written in summary style; it reads more like a philosophy paper. —Finell (Talk) 16:41, 2 November 2009 (UTC)

• Clearly inappropriate here. I leave it to other editors whether the reformed version at Dynamics is still original research, essay, and undue. - 2/0 (cont.) 08:05, 3 November 2009 (UTC)

• Comments.

• Undue weight. I agree that the amount of material devoted to explaining Aristotelian terrestrial dynamics in the edit in question is way out of proportion to its relative importance to the article. The edit is also larded with material which is completely irrelevant to the article (such as the material about bodies of different weight falling at the same speed in a vacuum, for instance).
• Original Research. Since very few of the details contained in the edit have been supported with citations to sources, it's difficult for a non-expert like me to judge exactly how much of it is original research or expresses a non-neutral point of view. However, there are certainly several instances where at least one egregious case of the former has been indulged in—namely:

• "v α W/R = W/0 = infinite"
• "[ (i) v α F/R & (ii) F > 0 & (iii) R = 0 ] entail v is infinite." (2 instances)

In modern mathematics^[1], division by zero does not give an infinite result, or any other result at all, for that matter—it is an undefined operation.^[2] The edit cites Aristotle's Physics 215^a24 and the passages following it as the place where Aristotle makes this argument. But nowhere in those passages does Aristotle frame his argument in the form given in the edit, and nowhere in those same passages does he say that a body whose motion is subject to no resistance will move with an infinite velocity.

• Non-neutral point of view or Original Research. As Steve McCluskey has already pointed out at least twice, casting Aristotle's arguments into modern mathematical notation is an anachronism which runs the risk of misattributing lines of reasoning to him which he could not possibly have made with the mathematical tools available to him. The mathematics of that period, for instance, had no concept of ratios of unlike quantities (such as, for instance, the ratio of a force or weight to a resistance, as in the expressions F/R and W/R, used in the edit distance or velocity to a time). It is easy to find reliable sources which document this (e.g.The mathematics of measurement: a critical history by John J. Roche, p.42, Greek Science in Antiquity by Marshall Clagett p.67).

Given the vagueness of the concepts of force and resistance in medieval and ancient natural philosophy it seems conceivable that some philosophers from those times might have regarded a force and a resistance as being magnitudes of the "same kind". and therefore as being capable of forming a ratio. But there is nothing in the passages of Aristotle cited in the edit to indicate that he did so regard them, and nowhere in those passages does he at all mention ratios of forces or weights to resistances (as represented by the expressions F/R and W/R used in the edit).

Logicus's reply to this objection:

"But as the evidence from Philoponus, Averroes and Aquinas clearly shows, the use of ratios, ultimately stemming from Eudoxus, was to the contrary central to their discussions of the physics of the celestial region, in such considerations of the importance of the ratio of the power of the mover to the resistance of the mobile asserted by Aquinas in the reference to his Commentary given, which it seems McCluskey cannot have read."

entirely misses the point. As is clear from book 5 of Euclid's Elements (p.114 of Thomas Heath's translation) and the two secondary sources already cited, the theory of Eudoxan ratios was only ever applied to ratios of like magnitudes (i.e. ratios of one velocity to another, one time to another, one force to another etc.). If force weight^[3] and resistance are regarded as magnitudes of different kinds, as they seem to have been by Aristotle, then the only way of expressing a relation like v α F/R v α W/R in the language of Eudoxan ratios was to state that the ratio of the velocities of two moving bodies was compounded of the ratio of the forces applied to them their weights and the inverse ratio of the resistances of the media through which they were moving. But nowhere in the passages from Aristotle's Physics cited in the edit does Aristotle make any such statement. It is true that such a conclusion can be deduced for natural motion by a reasonably straightforward (but by no means trivial) mathematical argument from statements that Aristotle does make, but that is not sufficient justification for that conclusion to be attributable to him in a Wikipedia article.

It is also true that professional historians will often use modern mathematical notation to explain ancient mathematical ideas, but this is not a task which Wikipedia editors can take it upon themselves to do. Any such explanations provided in Wikipedia must be supported with citations to reliable secondary sources, and follow the source closely, without any editorial embellishments. Otherwise, the explanation would constitute original research and its inclusion in any Wikipedia article would be contrary to policy. Even if such material is properly sourced, however, the neutral point of view policy requires that it must also be accompanied by any significant qualifications or misgivings that have been expressed in other reliable sources about the procedures used.

Footnotes:

1. Which is what Wikipedia readers will take this to be. But, in any case, as far as I am aware, no mathematicians of the past have ever regarded division by zero as giving an infinite result either.

2. To forestall any attempts to educate me about the projective line, in which formal ratios with a zero "denominator" are taken to be the coordinate representations of a "point at infinity", I note that I am already quite familiar with it. It's competeley irrelevant to this discussion.

—David Wilson (talk · cont) 17:24, 19 November 2009 (UTC)

Logicus to Wilson: One of your main arguments here that the material contains OR seems to be that it uses mathematical expressions such as v α F/R and v α W/R to characterise Aristotle's mathematical dynamics in his Physics, but which he did not use there himself. But this characterisation is standard practice in the literature, as has already been pointed out to McCluskey last year. As I recall, those who do this include Clagett, Cohen, Crombie, Dijksterhuis, Drabkin, Grant, Hussey, Kuhn, Maier, Murdoch and Shapere, amongst others. Here I shall just quote Clagett doing it since in your major blunder, now struck out, you cited him as an example of a scholar whose analysis would condemn this practice as OR because it has ratios of unlike quantities, on page 67 of his 1955 Greek Science in Antiquity, but in fact which is on p68.

On page 170 of that same book Clagett presents Aristotle’s various quantitative laws of dynamics found in Physics and On the Heavens, and then continues in summary:

“One could, for the sake of economy, use a single modern formula to express all these cases, although, of course, Aristotle does not do this:

(5) V α S/T α F/R with V as the speed.

Thus the basic dynamic formula which we might deduce from the scattered statements of Aristotle is that "speed is proportional to the ratio of the motive force to the resistance, provided that the force is sufficiently great to overcome resistance and produce movement." Now suppose that we had a natural movement in a vacuum. The density of the medium would obviously be zero and thus the movement would take place instantaneously (or, in the modern formula above, V would go to infinity as R goes to zero). Since an instantaneous movement appears to Aristotle to lead to contradictions, it is unthinkable, and hence a vacuum does not exist. “

So would providing this source in the material in addition to the secondary sources of Aristotle's Physics and Heavens satisfy you that this mathematical characterisation is not OR, but standard in the secondary sources ?

Note that Clagett also scotches your other main objection that division by zero does not give an infinite result. But that was just shorthand in my formulation. Aristotle says the comparison of speed in a plenum and vacuum is “beyond any ratio”, which of course just means the speed in a vacuum has no upper bound, whereby it must be infinite. This can easily be expressed in Clagett’s Cauchyan terms as ‘V tends to infinity as R tends to zero’. Would couching it in these terms satisfy you ? The article could just quote Clagett because I realise it is one of the best summaries to support the material’s characterisation of Aristotelian dynamics. Thanks for reminding me of it, part of my background reading of some 40 years ago. Of course McCluskey might prefer some accompanying quotes from his mentor Grant, such as pp62&86 of his Foundations book.

Setting aside various spurious rules you quote that are not Wikipedia policy rules, does this satisfy you that your two main proofs of OR in the material are essentially invalid or else the material can easily remedied to render it non OR in these two alleged respects ? --Logicus (talk) 18:14, 25 November 2009 (UTC)

Now answered below.

—David Wilson (talk · cont) 19:25, 28 November 2009 (UTC)

PS. In an earlier version of the above comment (now refactored), I had unthinkingly adopted Logicus's conflation of weight as a "measure of the motive force of gravity" in Aristotle's theory of natural motion. But there is nothing in the passages cited by Logicus to justify this conflation.

Moreover, for the case of forced motion—treated in Physics, Book VII, part 5 (249^b27–250^b10), as cited by Logicus—one cannot conclude from what Aristotle says that the ratio of the velocities of two bodies undergoing forced motion are compounded of the ratio of the powers moving them and the inverse ratio of their weights, as would be implied by Logicus's expression v α F/W. Aristotle says quite clearly in 250^a9–250^a27 that the proportionality of velocities to powers^[4] only holds when those powers are sufficiently large. When the motive power is below a certain threshold (which he appears to take as proportional to the weight of the body to which it is applied), Aristotle says that it will not move the body at all. In other words, for this case, Logicus's forumula is flat-out wrong.

—David Wilson (talk · cont) 23:27, 21 November 2009 (UTC)

PPS. Even the use of the word "velocities" here goes somewhat beyond what Aristotle actually says in the cited passages, since he doesn't frame his statements of proportionality in terms of velocities at all, but in terms of distances travelled in a fixed time, or times taken to travel a fixed distance.

—David Wilson (talk · cont) 23:04, 23 November 2009 (UTC)

Logicus to Wilson: Thanks for these reasoned opinions at least on Deor's OR charge if not on that of Undue Weight. However, rather than my identifying if you and I agree anywhere or else rebutting them all, to save effort I suggest we first wait to see whether Deor wishes to adopt any of them to dispute, and indeed whether you will strike any more out (-:. However, it might help if you could possibly clarify how many separate cases just of OR (i.e. not of POV) you are claiming, and what NOR rule(s) you claim is/are breached. Could you please just put them in numbered summary bullet points ? Also please see my comments in Deor's User Talk page. Logicus (talk) 15:58, 22 November 2009 (UTC)

The first seven paragraphs of the disputed edit violate at least this section of Wikipedia's policy on no original research. More specifically:

"Without a secondary source, a primary source may be used only to make descriptive claims, the accuracy of which is verifiable by a reasonable, educated person without specialist knowledge."

The only sources provided for anything in those paragraphs are Aristotle's de Caelo 300^a24–27, 269^a10–12, and Physics, 215^a24ff, Book VII, part 5, all primary sources. But very little of the material in those paragraphs is directly verifiable from those cited sources. So little, in fact, that it would be easier for me to identify the few odd bits here and there which are, than to provide the itemised list of "separate cases just of OR" requested by Logicus. Doing either would require more tedious effort on my part than I can see reasonable justification for expending.

For all I know there might be reliable secondary sources which can be used to support more of the material than is directly supportable from the primary sources given, so I hesitate to claim outright that any more of it is necessarily "original research" than I have already specifically identified. However, since the material has been challenged, Wikipedia's policy on verifiability [more specificially that section of it on burden of proof—this text and link added 22:02, 26 November 2009 (UTC)] places the burden of proof on you to show that it is not original research by providing the necessary sources, not on those who have challenged it to prove that it is.

—David Wilson (talk · cont) 14:02, 23 November 2009 (UTC)

Does the material use primary sources ?: Contrary to the claims of the two respondents Finell and Wilson that the material contains primary sources, in fact it does not use any primary sources. Its only sources identified by anybody as primary sources, namely English translations of Aristotle's On the Heavens and Physics misidentified by Wilson as primary sources, are in fact both secondary sources in real world scholarship, as any serious scholar should know, and as indeed all translations from a foreign language are. Nor to my knowledge has Wikipedia policy idiosyncratically defined translations of primary sources as also being primary sources anywhere. Translations are reports or interpretations by some scholar of what a text says into a different language and conceptual system than that of the text, with all the problems of possible misinterpretation this can produce, hence the adage 'To translate is to betray'.

I recall the first occasion I discovered the crucial importance of checking such secondary sources against its primary source in the history of science was when I discovered the newly published Crew & Salvio 1968 English translation of Galileo's 'Two New Sciences' had mistranslated Galileo's concept 'impetus' as the crucially different concept 'momentum' to create the false impression, contra Duhem, that Galileo abandoned scholastic impetus dynamics and created a new dynamics. And in his 1999 English language Principia Bernard Cohen crucially mistranslated Newton's second law of motion as 'A change of motion....' rather than 'The change of motion...', thus promoting Mach's error that the first law was entailed by the second law and hence logically redundant by creating the impression it referred to all changes of motion rather than to the specific change of motion mentioned in the first law, that is, one due to impressed forces. Cohen also crucially misdated Bradley's 1723 comet as a 1713 comet in Newton's Preface to the third edition of Principia.

I cite these examples of bad scholarship to underline why Wikipedia and Wikipedians should not define translations of primary sources into foreign languages as primary sources in its history of science articles.

I constructively suggest those who wish to demonstrate the material contains OR simply drop invalid claims about the use of primary sources or selected secondary sources just in itself breaching NOR, and instead restrict themselves to trying to demonstrate original synthesis of sources somewhere. --Logicus (talk) 18:38, 25 November 2009 (UTC)

Answered below.

—David Wilson (talk · cont) 15:10, 26 November 2009 (UTC)

Objection to the RfC

Logicus to Deor:

I have deleted the RfC tag you put here as illegitimate, principally for the reason that your procedure is in apparent breach of the following dispute procedure guideline by virtue of your having bypassed its first step required before seeking outside opinion:

“Before asking outside opinion here, it generally helps to simply discuss the matter on the talk page first. Whatever the disagreement, the first step in resolving a dispute is to talk to the other parties involved.“

To recap what has happened here, first of all you reverted my restoration of my contribution on the ground that it defied a consensus that it does not belong here. and you said that if I reverted it you would begin dispute-resolution procedures to ensure it stays reverted, thus apparently revealing your prior prejudice of not being open to discussion about the outcome.

Thus you gave the impression the dispute was about my breaching some alleged Wiki policy consensus rule, albeit you failed to state what that policy rule was. And the material disagreement you raised was about where my contribution belongs, not whether it is Wiki OR or has undue weight. It seemed you maybe thought it belonged to the Dynamics of the celestial spheres article instead.

I then reverted your reversion, and as it happened, before I saw your comments about consensus etc. on the Talk page. I just responded to your Editorial comment ‘no consensus for this addition; seek consensus on the talk page if you want’ by pointing out in my Editorial comment that consensus on the Talk page for an addition is not required. In fact boldness policy is explicitly against any such rule. It seems you just invented a bogus rule to get your own way.

However, you did not revert my reversion, but rather McCluskey did, also in his Talk page comments repeating his usual cavalier allegations of OR and disruptive editing against Logicus, which he has previously notably failed to substantiate.

You then posted an RfC on the Talk page within a few hours of your warning of starting dispute-resolution, before I had responded to your complaints on the Talk page about consensus and where my text properly belongs, and notably not even responding to my Editorial point that your justification for reversion was invalid by demonstrating some rule it breached

But the RfC you posted did not ostensibly concern any dispute about relevancy nor consensus, but rather a quite different dispute about whether my contribution to this article is OR or not, and whether it commits some sin of undue weight.

Thus I had had no prior notification from you that you now regard this contribution as OR and having undue weight, and therefore no opportunity to discuss these two charges with you, and so to find out what OR rule you now claim it breaches and where, and hence to consider whether your two charges have any substance whereby I should somehow revise or withdraw my proposed contribution.

So can you please rewind the tape, and clarify exactly what your beef is before proceeding to the second stage of dispute resolution in seeking outside opinion in an RfC?

Are you complaining that my contribution to this article, which was previously accepted by you and previously stood unedited for most of a year before its invalid removal to another article by Leadwind last May, (1) should have less weight in this article, or (2) should not be in this particular article at all, rather than in some other, or (3) that it is entirely irrelevant to the subject of the dynamics of the celestial spheres, or (4) that it is OR that should not be in any Wikipedia article at all ?

I note the only issues the RfC attempted to raise were those of OR and undue weight.

Therefore in the first instance could you please kindly review what dispute(s) you wish to raise with me out of all these four different disputes you seem to have raised in one way or another.

Then if you wish to initiate dispute-resolution about some dispute, would you please kindly first proceed to its advocated first stage of discussing your complaint(s) with me first, rather than completely omitting that stage and proceeding directly to an RfC , its specified second stage ?

May I also advise you to review whether you wish to invoke dispute-resolution in good faith without prior prejudice to its negotiated outcome, or rather have decided in advance of any discussion and negotiation that the only acceptable outcome is ‘to ensure my contribution stays reverted’. --Logicus (talk) 14:37, 2 November 2009 (UTC)

I have restored the Rfc tag, as there is clearly a dispute which has been extensively discussed on both this talk page and the Dynamics of the celestial spheres talk page without being resolved, or looking at all likely to be resolved, by the parties in dispute.

—David Wilson (talk · cont) 15:04, 2 November 2009 (UTC)

I agree. —Finell (Talk) 16:06, 2 November 2009 (UTC)

Wilson is wrong. There has been no previous extensive discussion. The RfC now raised by Deor is a twofold dispute about OR and about undue weight. The latter has never previously been disputed and discussed by Deor. His main dispute last year was about the relevance of the topic to the article. And the only time OR was very briefly raised by him was in his discussion of 29 June 2008, and to which criticism Logicus responded constructively with a revised text on 2 July. Deor then responded with a repeated OR claim on 3 July, to which Logicus responded with a challenge to Deor to substantiate his OR claim, but which he never did. And until now he never then challenged the text for OR again and it remained unreverted and unedited for a long time, thus suggesting the reasonable conclusion the matter was settled and Deor accepted it was not OR. Thus it seem this present challenge of his that it is OR is a fresh dispute, and he has now found some new aspect of the text that is OR. So the correct procedure is first to raise it with the editor and say what he thinks is OR, for due consideration, before making an RfC. The tag should therefore be deleted pro tem, pending discussion.

Contra Wilson, there has been no dispute about OR or undue weight by Deor on the 'Dynamics of the celestial spheres' Talk Page.

Wilson is also wrong to presume that this particular dispute seems unlikely to be resolved, especially since it has not even begun. Logicus is a reasonable person who has no objection to revising proposed contributions in the light of valid helpful criticism. But he has been unable to get any practical response from critics who make accusations of OR and idiosyncratic POV claims such as Deor and McCluskey, for example. Especially see the section 'What is the McCluskey or the orthodox history of inertia ?' in User Talk:SteveMcCluskey for an example of how one gets no helpful practical response to a request for the substantiation of allegations of OR that could possibly lead to improvements. (But then neither has McCluskey raised an OR RfC since the failure of his last attempt in which my disputed edit was sustained.) So in the first instance Logicus just wants to know what Deor's specific criticism of this text is ? Where does Deor claim Wiki OR policy been breached by his text, and how ? Or is Deor just illegitimately invoking a free-for-all for other editors to find OR breaches in Logicus's text, thus trying to get others to do the job he cannot do himself ?

Logicus will deal with all the other rambling, inconsequential and invalid points made here by other various editors later. —Preceding unsigned comment added by 194.66.226.95 (talk) 18:45, 2 November 2009 (UTC)

Please stop removing the RfC tag User:Logicus. I would notify you on your talk page, but you are now editing (perhaps inadvertently) from an IP address at the British Library. This is considered to be disruptive editing, and you can be blocked for it if you persist. 71.182.189.125 (talk) 19:13, 2 November 2009 (UTC)

Logicus (I presume it's him, using an unfamiliar computer) spoke of the previous RfC "in which my disputed edit was sustained." This implies that there was a conclusion to an RfC, but in fact it was never closed because there was insufficient comment. In the last substantive comment on that RfC I noted: "In the month since this RfC was opened Logicus has not done any editing in Wikipedia and no further comments have been made on this RfC. This suspension of disruptive editing has opened the way for further progress on the affected articles."[1]

I do not take that kind of non-resolution of an RfC as evidence that his previous disputed edits were sustained. --SteveMcCluskey (talk) 19:21, 2 November 2009 (UTC)

Logicus to McCluskey: McCluskey apparently misinterprets the word 'sustained' here, which means 'retained' or 'maintained', as in sustaining a musical note in music. The point made was that the particular Logicus edit of 30 January that prompted the McCluskey-Ragesoss RfC of 1 February, namely the deletion of a mistaken and invalid comparison between pre-Kepler and post-Kepler astronomy, was never reverted and has been maintained, like the great majority of Logicus's improving edits. Thus the point made did not imply that the RfC was closed or concluded. And in fact it attracted no responses whatever, rather than merely insufficiently many. And the last substantive comment on that RfC was not by McCluskey, but by Logicus in July 2008 on his User Talk page, which inter alia said:

"By way of further comment on a likely explanation of how these mistaken charges [of DE and OR] arise, Logicus notes that the mistaken charge of Original Research has only been made against him by editors such as McCluskey and Administrator Ragesoss possibly because they seem evidently insufficiently familiar with the pertinent literature of subjects on which they seem to regard themselves as experts, or at least as more knowledgeable than Logicus. This unfamiliarity seems to consist either of not having read it at all in many cases, or of having misread it without sufficient logical attention or competence to infer logically valid summary interpretations of it, rather than their logically invalid interpretations, conclusions and summaries of it, which thereby constitute OR, whether intentional or not. Many examples can be given of such error on the part of McCluskey, Ragesoss and others, however unintended. Thus it seems they tend to mistake for original research either Logicus's representations of other points of view to be found in the literature they are either unfamiliar with or possibly do not wish to report because they clash with their biassed point of view, or else mistake Logicus's simple corrections of other editors' logically invalid interpretations or expressions of what literature they have read for original research.

As Logicus sees it, obstinate refusal to stand corrected in the face of Logicus's restorations of unjustified reverts of his corrections then leads to such editors getting themselves worked up into a paddy and making untenable wild accusations of Original Research and Disruptive Editing against what is in fact potentially corrective Productive Editing for improving Wikipedia.

However, in the last instance Logicus recognises the rules of Wikipedia seem to be radically confused and confusing from a logical point of view, whereby in addition to the fact that like all of us Logicus is far from infallible, it may be that he could be reasonably construed as having committed original research somewhere amongst his many contributions. But so far as he is aware, nobody has ever demonstrated he has to date. In this context, for an example of Logicus's rebuttal of an unsubstantiated assertion of such, see Logicus's contribution of 10 July 2008 to User talk:Deor for his rebuttal of User:Deor's allegation of such in respect of Logicus's proposed discussion of impetus dynamics in the Celestial spheres article, entitled "Logicus refutes Deor's accusations of irrelevancy and Original Research in 'Celestial spheres' ". --Logicus (talk) 17:29, 10 July 2008 (UTC)

McCluskey’s comments also suggest he does not understand the role and purpose of RfC’s. They are not processes that are resolved or that have conclusions as he implies. Rather they are simply processes of opinion and information gathering from outside sources for some editors in a dispute whose purpose is help the disputing editors reach agreement by rational discussion. RfC’s do not in themselves establish or create consensus. Rather only the editors can achieve this by rational discussion between themselves. And RfC's certainly do not end with 'vote-counting' of what the majority opinion expressed is in order to declare the majority opinion is the consensus. RfC’s simply end in the opinion and information of outsiders have been provided or not. The February 2007 McCluskey-Ragesoss RfC ended without any outside comments being made. And no consensual agreement was ever reached between Logicus and McCluskey-Ragesoss about whether Logicus was guilty of OR and DE.

Logicus (talk) 15:49, 21 November 2009 (UTC)

I have replied to this below. --SteveMcCluskey (talk) 21:11, 21 November 2009 (UTC)

It is junk replete with weasel words and mystical claptrap. Of course it is possible to discuss mystical claptrap long since discredited. Someone who offers this must reasonably say who (the medieval authorities who offered such claptrap as unqualified truth). At the least it must name names of its proponents.

That is separate from the concept of "original research", which the section is. Such claptrap cannot be the result of experiment, a simple and straightforward calculation, or of personal observation. The writing is amateurish enough to be original. --Pbrower2a (talk) 05:16, 6 November 2009 (UTC)

• Agree with removal of section. We can debate whether this is original research, a violation of NPOV, a content fork, tendentious editing, or (most likely) all of the above, but the bottom line is that it doesn't improve the article. And the tl;dr wikilawyering above by Logicus doesn't help either. —David Eppstein (talk) 07:23, 6 November 2009 (UTC)

Logicus’s critical comments on the responses to this illegitimate RfC:

I have inserted my comments in emboldened text within square brackets in each respondents text below:

1) * The issue raised by Deor is just one more example of a fairly widespread pattern of disruptive editing on pages relating to the history of science, philosophy of science, and even physics. For some examples look at Wikipedia:Requests for comment/Logicus and his Block log. [McCluskey has never managed to substantiate any of his repeated charges of DE against Logicus, even just once, in spite of much sadly unprobative verbiage attempting to do so in his entirely failed and illegitimate RfC of February 2007, on which Logicus commented on his User Talk page on 10 July 2008, explaining possibly why such as McCluskey make such invalid accusations of OR and DE. Logicus (talk) 17:18, 20 November 2009 (UTC)]

Turning to the specifics of this incident, I agree totally with Deor's analysis. The lack of balance uses this article as an attempt to advance Logicus's idiosyncratic historical interpretation. [ But what is Deor's analysis? Because Deor has bypassed the first stage of dispute-resolution in failing to talk to Logicus first about his latest complaints, we have yet to hear his beef and analysis. Thus McCluskey's comments are void and irrelevant, establishing neither the OR claim nor the undue weight claim. What is the due weight for analysis of the origin of key concepts of 17th century dynamics in medieval celestial dynamics ?Logicus (talk) 17:18, 20 November 2009 (UTC)] --SteveMcCluskey (talk) 18:39, 1 November 2009 (UTC)

2) I am not commenting on Logicus's editing behavior one way or the other. However, one RfC in February 2007 (which attracted very little comment) and one 24-hour block in October 2008 (with no block before or after that one) does not demonstrate a pattern of disruptive editing. Please confine comments here to the issue raised, not the editor. Thank you. —Finell (Talk) 16:15, 2 November 2009 (UTC) [Correct, except for the fact that the RfC attracted no comment rather than little comment ! But unfortunately Finell's comments below are not confined to the two issue raised.Logicus (talk) 17:18, 20 November 2009 (UTC)]

3) * Comment: Without full refs the edit in question would appear to be WP:OR. [ But most, if not all Wikipedia articles are not fully referenced, and there is no policy rule that they should be. References are only required when an unsourced claim is challenged. Deleting articles just because not all its propositions are referenced would delete virtually all Wikipedia articles.Logicus (talk) 17:18, 20 November 2009 (UTC)] More to the point and more relevant: [No, irrelevant to the RfC raisedLogicus (talk) 17:18, 20 November 2009 (UTC)] the text as presented is too big, too obscure and too dense to benefit the general reader. It's not readable, not accessible and therefore not encyclopedic. Wikipedia is WP:NOT PAPER. [These points are beside the points at issue and so irrelevant, but thanks for the style criticism ! But do try reading the many huge, obscure, dense, unreadable and inaccessible Physics articles, for example, that do not benefit the general reader, and then try mine again for some relatively light relief (-: For example, try reading Hamiltonian mechanics. And please note that it is almost completely unsourced, and commits all the sins you cite, and so must be deleted on the logic of such as yourself, Deor and McCluskey etc., as probably must most Physics articles. Also take a look at Quantum Mechanics Logicus (talk) 17:18, 20 November 2009 (UTC)] --Whoosit (talk) 22:25, 1 November 2009 (UTC)

4) * Comment: The test is quite simple. Does this analysis appear in published sources elsewhere? ['But what analysis is "this" specifically  ? Analysis of the origin of key concepts of 17th century inertial and impetus dynamics as being in medieval celestial dynamics ? If so the answer to this question is Yes ! Just see the sources provided in the text Logicus (talk) 17:18, 20 November 2009 (UTC)] If the answer is yes, then references to these published sources must be made clear, and attribution should be given. If the answer is no, then it is original research. I am very suspicious that this analysis is an entirely original synthesis, though, given the near complete lack of supporting sources, [There is no "near complete lack of supporting sources". Many are supplied.Logicus (talk) 17:18, 20 November 2009 (UTC)] as well as the overall pattern of behavior of the section's sole proponent. I would like to add that the section under dispute in this RfC has other non-OR problems with it. First, by itself it exceeds the maximum recommended length of an encyclopedia article (see WP:LENGTH). [And what is that maximum recommended length in words ? I did not see one in a quick look at WP:LENGTH.Logicus (talk) 17:18, 20 November 2009 (UTC)] Secondly, it clearly does not observe summary style: there is already an article Dynamics of the celestial spheres. If this content could be made to conform to Wikipedia policies and guidelines (doubtful as it seems), then surely it would belong there instead of here, if anywhere. Thirdly, why are all of the equations displayed in bold face type? At the very least it should be made to conform with the Manual of Style (mathematics). 71.182.189.125 (talk) 16:35, 2 November 2009 (UTC)

I now see that indeed what happened was that the material was already moved to Dynamics of the celestial spheres and subsequently edited to conform to Wikipedia's core principles. Recreating the earlier material here is a clear WP:POVFORK. 71.182.189.125 (talk) 19:06, 2 November 2009 (UTC)

(5) * (after edit conflict): This contribution is clearly original research, among other problems. Long passages have no cited sources. [Even were this true, there is anyway no policy ban on such and this is certainly true of very many articles.Logicus (talk) 17:18, 20 November 2009 (UTC)] A majority of the sources that are cited are primary. [Even were this true, there is anyway no policy rule that a majority of sources cannot be primary.Logicus (talk) 17:18, 20 November 2009 (UTC)] Where secondary sources are cited, it is often an evaluation of the source or a comparison of one versus another. [Even were this true, there is no policy ban on evaluation or comparison of secondary sources.Logicus (talk) 17:18, 20 November 2009 (UTC)] In Wikipedia, secondary sources should be used for what they say, not for commentary about the sources. [There is no such policy rule.Logicus (talk) 17:18, 20 November 2009 (UTC)] The contribution also favors one scholar's point of view over the others. [Which scholar? But anyway there is no policy ban on such, and the very many articles that only cite the view of just one scholar to justify a claim, but not of all scholars, inevitably do so.Logicus (talk) 17:18, 20 November 2009 (UTC)] Also, this contribution is way too long and is not written in summary style; it reads more like a philosophy paper. [But are there any policy rules against such? At least it does not read like a bad history paper like many Wikipedia history of science articles do, as mindless and boring collections of dessicated facts, one damned idea after another without rhyme or reason. And if Bolingbroke and Hegel are right that history is just philosophy fabricating examples, then history should indeed read like a philosophy paper, and especially history of science and ideas (-: Logicus (talk) 17:18, 20 November 2009 (UTC)] —Finell (Talk) 16:41, 2 November 2009 (UTC) [So much for Finell's Wiki-barrack-room-lawyering inventing bogus rules ! Logicus (talk) 17:18, 20 November 2009 (UTC)]

(6) * Clearly inappropriate here. I leave it to other editors whether the reformed version at Dynamics is still original research, essay, and undue. - 2/0 (cont.) 08:05, 3 November 2009 (UTC) [But Deor notably did not raise any RfC about appropriateness, having apparently ceded that complaint in our discussions last year: see above. Hence this is an entirely irrelevant commentLogicus (talk) 17:18, 20 November 2009 (UTC)]

(7) It is junk replete with weasel words and mystical claptrap. Of course it is possible to discuss mystical claptrap long since discredited. Someone who offers this must reasonably say who (the medieval authorities who offered such claptrap as unqualified truth). At the least it must name names of its proponents.

That is separate from the concept of "original research", which the section is. Such claptrap cannot be the result of experiment, a simple and straightforward calculation, or of personal observation. The writing is amateurish enough to be original. --Pbrower2a (talk) 05:16, 6 November 2009 (UTC) ['??? Since when was OR that which is not "the result of experiment, a simple and straightforward calculation, or of personal observation" ? This is just very confused ranting. Logicus (talk) 17:18, 20 November 2009 (UTC)]

(8) * Agree with removal of section. We can debate whether this is original research, a violation of NPOV, a content fork, tendentious editing, or (most likely) all of the above, but the bottom line is that it doesn't improve the article. And the tl;dr wikilawyering above by Logicus doesn't help either. —David Eppstein (talk) 07:23, 6 November 2009 (UTC) [Irrelevant! The RfC did not ask for opinion on removal of the material, but rather opinion on whether it is OR.Logicus (talk) 17:18, 20 November 2009 (UTC)]

Logicus will deal with Wilson's late response later, but notes he has already begun the strikethrough of its many blunders, and hopefully awaits his strikethrough of the rest of it to save Logicus the tedious task of pointing out its various defects. --Logicus (talk) 17:18, 20 November 2009 (UTC)

Logicus:

1. Please be civil. Your lengthy post is a tirade, not a reasonable discussion or attempt to reach consensus. Please drop the excessive boldface and stop shouting. Referring to yourself in the third person is also odd.
2. I'm not sure where you get your ideas about what makes the RfC legitimate or illegitimate, but it is really beside the point. If it isn't a "legitimate" RfC, then it is talk page discussion among the editors about the article's content, and the result will be determined by consensus.
3. Your remark (8) is illogical. Policy forbids original research in articles. Therefore, a determination that content is original research is a determination that the article cannot contain the content.
4. Please answer the question that I have asked you repeatedly: Are you the author of the comment above by 194.66.226.95? In determining consensus, it is relevant to know if there is another editor who supports your position or if it is just you by yourself. As I pointed out on your talk page, answering this question would not "out" your real world identity because the IP address is assigned to the British Library, a large, public institution. Placing you in London on the one day would not jeopardize your privacy. Thank you. —Finell 22:27, 20 November 2009 (UTC)

Towards a Summary

I have tabulated the comments raised within the discussion concerning Logicus's edits:

	WP:NOR	WP:WEIGHT	Other Negative Comments	Other Positive Comments
SteveMcCluskey	Yes	Yes	Disruptive Editing
Whoosit	Yes		Too big, too obscure, and too dense
71.182.189.125	Yes		WP:SYNTH; WP:LENGTH, WP:POVFORK
Finell	Yes		POV, Length, incivility
2/0			Clearly inappropriate here
David Wilson	Yes	Yes	NPOV, citation fails verification
Pbrower2a	Yes		weasel words and mystical claptrap
David Eppstein	likely	likely	wikilawyering
Sławomir Biały	Yes		WP:V, Disruptive Editing, WP:TLDR
Logicus	Unproven	Unproven

Perhaps this will assist us in arriving at a consensus on the RfC. --SteveMcCluskey (talk) 16:58, 21 November 2009 (UTC) --updated 19:02, 22 November 2009 (UTC); further update 19:07, 22 November 2009 (UTC)

Logicus's Alternative Summary: The following alternative Counter Summary to the above McCluskey Summary summarises the pertinent outcome of the 10 responses so far to the RfC question of whether the material is “OR based on primary and selected secondary sources”:

1) Respondents who say material is ‘OR based on primary and selected secondary sources’ - - 0/10

2) Respondents who claim the material is definitely OR - - - - - - - - - - - - 5/10

3) Respondents who say where and why the material is OR - - - - - - - - - 1/10

4) Respondents with valid proofs of OR - - - - - - - - - - - - - - - - - - - - - 0/10 ?

The question mark in 4 questions whether all Wilson’s efforts to prove where and why the material is OR are now refuted by Logicus’s response of 25 November, or any remain standing. --Logicus (talk) 19:18, 26 November 2009 (UTC)

No they are not. I will reply to the rest of Logicus's latest salvo some time this weekend. But Logicus still appears to be labouring under the misapprehension that it is up to other editors to "prove" to his satisfaction that his material is original research. As I have already pointed out to him, Wikipedia policy on verifiability quite clearly places the onus on him to show that his material is not original research by providing reliable sources which support it. To quote:

"The burden of evidence lies with the editor who adds or restores material. All quotations and any material challenged or likely to be challenged must be attributed to a reliable, published source using an inline citation. The source should be cited clearly and precisely, with page numbers where appropriate, and must clearly support the material as presented in the article."

Logicus can no longer rely on the pretext that the material has not been challenged to avoid sourcing it properly, since it very clearly has now been challenged.

—David Wilson (talk · cont) 22:33, 26 November 2009 (UTC)

Logicus to Wilson: You are surely quite wrong. The onus is surely on the challenger to say where and why the material is OR, at least so that those propositions are identifiable and so may be remedied if necessary. You and Deor are surely not claiming every proposition is OR, or that every proposition of an article must be sourced ? The latter rule would surely delete virtually all Wikipedia articles. Please stop your nonsense and get on with the business of identifying where and why it is OR. As I see it all components of your previous challenge have entirely collapsed with my provision of the Clagett source quotation. --Logicus (talk) 17:30, 27 November 2009 (UTC)

Logicus to Wilson: All you need to do is identify which of your 'demonstrations' of OR in the material still stands in the light of the rebutting Clagett source with quotation provided, and identifying which proposition(s) in the material commit the Wiki original sin of OR you allege. Since the whyfore of all your previous 'demonstrations' of OR is the commission of Original Synthesis, you therefore need to identify which propositions in the material commit OS in your view. That's all !

And in saying "Logicus is now at last trying to provide some decent secondary sources" you most misleadingly imply Logicus is somehow responsible for the delay in such. Rather the delay was that nobody said where and why the material was OR for almost 3 weeks after the RfC was first raised by Deor, until you did only recently, and whereupon I responded after only 6 days, after first trying but failing to elicit from Deor whether these are the particular commissions of OR alleged by Deor in the dispute he has started, or those he wants to adopt for discussion.

I await your forthcoming ‘Wilson downunder but not out!’ (-: --Logicus (talk) 15:36, 28 November 2009 (UTC)

Logicus on McCluskey's Summary Table proposal of 21 November: No it will not ! I shall delete this table because it cannot possibly assist Deor and Logicus to reach a consensus in any way, and it also promotes the mistaken belief that in Wikipedia policy reaching consensus between two editors in dispute is somehow decided by head counting of other editors' opinions. It is just nastily provocative and unhelpful to the Wikipedia dispute resolution aim of the two editors in dispute reaching agreement and possible compromise by rational discussion. It is also wrong in various respects. What would possibly be helpful for Deor to summarise the RfC responses would be summaries of any reasons given where and why the material is OR, if any have been provided, for Deor to choose from if he has none of his own. --Logicus (talk) 19:04, 23 November 2009 (UTC)

Logicus: The above table by McCLuskey misrepresents the responses to the RfC question raised by Deor about OR for commen, which was

"Does the material added to the article in this edit constitute original research based on primary and selected secondary soures(sic!)? " (My italics)

But no respondent has yet said it was original research based on both primary and selected secondary sources, and nobody has said being based on primary and selected secondary sources is OR.

Therefore the summary table's first column of outcomes should be blank in every case.

On this non-neutral question raised by Deor, apparently biased to promote the mistaken prejudice that being based on primary sources and selected secondary sources constitutes OR if it means 'Is the material OR because it is based on primary sources and selected secondary sources ?, then this question itself raises two questions, namely

1) Is material based on primary sources and selected secondary sources thereby OR ?

and

2) Is this material based on primary sources and selected secondary sources ?

The correct answers to these questions are

1) No, there is no such policy rule

and

2) No, the material only uses secondary sources as references.

The table also misrepresentes the number of people who definitely said the material was OR. I shall offer an alterntive summary --Logicus (talk) 19:24, 25 November 2009 (UTC)

I saw Logicus's recent post after I posted my tabulation here. His point that RfCs do not end with "vote counting" is correct, they end after a thorough discussion of the issues raised in the RfC, but with no requirement that the resulting consensus be unanimous. In an effort to achieve consensus on the points of Original Research and Undue Weight, I anticipate reading Logicus's promised reply to David Wilson's cogent discussion of those matters. --SteveMcCluskey (talk) 18:26, 21 November 2009 (UTC)

Logicus on McClusekey's comments here: This suggests McCluskey misunderstands the aim and intended outcome of Wikipedia dispute resolution, the Wikipedia RfC process and Wikipedia consensus? The simple situation here is that two editors are in dispute and the aim of Wikipedia dispute resolution is apparently to get them to reach consensus by means of rational discussion and possible compromise between them. Surely the only opinions that count are theirs in achieving this two person unanimity based on reasons not votes. The following policy rules imply this model of dispute resolution:

"Before asking outside opinion here, it generally helps to simply discuss the matter on the talk page first. Whatever the disagreement, the first step in resolving a dispute is to talk to the other parties involved."

In this case the other party is just Logicus. But Deor has never talked with Logicus on the talk page to say where and why he now thinks the material is OR, whereby Logicus cannot possibly agree or disagree with Deor, and thus Deor has breached Wikipedia dispute resolution policy.

"An RfC...is a tool for developing voluntary agreements and collecting information."

But it is not a tool for deciding a dispute by identifying a consensus by counting votes by other editors:

"RfCs are not votes. Discussion controls the outcome; it is not a matter of counting up the number of votes."

and

"Wikipedia does not base its decisions on the number of people who show up and vote; we work on a system of good reasons. At the same time it is normal to invite more people into the discussion, in order to obtain new insights and arguments."

"Developing consensus requires...an effort to reach a compromise that everyone can agree on."

So this dispute can only be resolved by Deor and Logicus reaching agreement by discussion, reasoning and possible compromise.

Wikipedia consensus in a dispute process is not a unanimous, great majority or simple majority vote of all those who comment in an RfC or of any wider Wiki constituency, but rather agreement between the two disputants.

RfCs do not necessarily "end after a thorough discussion of the issues raised in the RfC". They may end with no discussion between the two parties at all, as in this RfC to date. And McCluskey's 2007 RfC ended even without any responses.

And contrary to McCluskey's suggestion otherwise, there may be no resulting consensus if the two disputing parties do not agree.

Nor have I promised a reply to Wilson’s reasons for claiming the material is OR as McCluskey says. Such a reply is not relevant UNLESS the disputant Deor actually adopts any of them himself. The purpose of an RfC is surely not to create even more disputes with a number of other editors in conflict escalation, but rather to help settle the dispute with the editor in question ? --Logicus (talk) 19:19, 23 November 2009 (UTC)

I have restored the table (edits overlapped; Deor's restoration preceded mine); despite the abbreviated nature of tabular format, it summarizes the community consensus.

I would also correct Logicus's mistaken impression that an RfC involves achieving a consensus between two editors: himself and Deor. It involves reaching a consensus among all the members of the Wikipedia community participating in the RfC.

As per the Essay, What is consensus?, "it may become necessary to ignore someone or afford them less weight in order to move forward with what the group feels is best.... Insisting on unanimity can allow a minority opinion to filibuster the process." --SteveMcCluskey (talk) 19:28, 23 November 2009 (UTC)

Logicus to McCluskey: Wrong on policy yet again McCluskey ? Wikipedia consensus has nothing to do with voting.

1) As per the following notice at the head of the non-policy Essay, What is consensus ? that you quote:

"While this essay is not a policy or guideline itself, it is intended to supplement WP:CONSENSUS. Please defer to the relevant policy or guideline in case of inconsistency between that page and this one."

But the principle from this essay you quote contradicts that Consensus policy, whereby it cannot apply by virtue of the deference-to-policy rule. In fact it even contradicts the intro to the Essay that again confirms the Consensus policy article's specifications that consensus is not formed by nor achieved by voting, as follows:

"Disputes on Wikipedia are settled by editing and discussion, not voting. Discussion should aim towards building a WP:consensus. Consensus is a group discussion where everyone's opinions are heard and understood, and a solution is created that respects those opinions. Consensus is not what everyone agrees to, nor is it the preference of the majority. Consensus results in the best solution that the group can achieve at the time."

But the principle you quote contradicts this policy at least in appealing to a voting model essentially opposed to Wikipedia's emphatically non-voting consensus model. For in introducing a principle that unanimity is not required, it appeals to a voting model of consensus as nevertheless decided by some specific proportion of votes by some group, which contradicts, for example, the policy principle "Wikipedia does not base its decisions on the number of people who show up and vote; we work on a system of good reasons.".

2) You state that "An RfC involves reaching a consensus among all the members of the Wikipedia community participating in the RfC." But there is no such dispute resolution policy rule in the RfC policy. This is entirely your invention. And more generally, nowhere that I know of does Wikipedia specify what the relevant community is that should reach a consensus, such as all history of science editors or all editors of an article, or "all member of the community participating in the RfC", the latter being an obvious recipe for corrupt arbitrary mob-rule and vulnerable to rent-a-mob etc. Certainly the principle you quote does not specify what "the group" should be.

3) RfCs are clearly meant to be a process for the two disputants to reach consensus and harmony together, possibly in a compromise edit, not to subdue one of the disputants and create even more division by baldly voting them down by gather-a-mob tactics. It seems you and Deor seek to the replace the Wikipedia unifying consensus model of dispute resolution in favour of a McCluskey-Deor divisive conflict model, in which instead of helping an editor to improve a contribution you consider to be in breach of policy, you just seek to eliminate it altogether. --Logicus (talk) 18:50, 25 November 2009 (UTC)

Your implication that I'm trying to eliminate any trace of your ideas is overdrawn. When I rewrote the Dynamics of the celestial spheres article, which had earlier been created by User:Leadwind by moving your material from Celestial spheres, I made the following comment.

There may still be some things of value in the prior version of the article, which is available in the article's history. Other editors may wish to mine it for appropriate material, while retaining the article's encyclopedic balance.

That openness to balanced and properly sourced material still stands. --SteveMcCluskey (talk) 20:54, 25 November 2009 (UTC)

Does the material use primary sources ?

• Even if Logicus's dubious claim^{[see below]} that translation of primary sources are not themselves primary sources were correct the disputed edit would still fail at least one condition of Wikipedia's verifiability policy—namely:
  

"Sources should directly support the information as it is presented in an article ... "

There is nothing in this condition which limits it to apply only to primary sources, and as I have already pointed out, the material in the edit in question is not directly supported by the sources originally provided. I see that Logicus is now at last trying to provide some decent secondary sources in support of at least a modified version of some parts of the original text. If such a modified version of the text were to be properly supported by the sources provided, and all other text not supported by those sources were to be removed, then of course that modified text would no longer constitute original research.

• Logicus wrote:
  

" ... English translations of Aristotle's On the Heavens and Physics misidentified by Wilson as primary sources, are in fact both secondary sources in real world scholarship, as any serious scholar should know, and as indeed all translations from a foreign language are. ... "

It will take more than Logicus's say-so to convince me that this is anything more than bluster on his part. In about half an hour's googling on the web I found the following impeccable sources, all of which state or imply unequivocally that their authors consider translations of primary sources to be primary sources themselves as well:

• Kerry MaGruder, curator, Oklahoma University Libraries' History of Science Collection:

"A Primary Source is an original text or translation from the historical period that is studied in its own right. ... A translation of Galileo's Dialogo (1632) is a primary source;

• University of California at San Diego Libraries' web site:

"Do not assume that just because an item is in a different language, it’s not a primary source. For example, a translation of Marco Polo’s memoirs would be considered a primary source."

• Simon Fraser University Library's web site:

"Primary sources offer an inside view of a particular event. Some types are:

Original Documents (excerpts or translations acceptable)"

• The later Roman empire, AD 284-430 by Averil Cameron, p.199ff lists modern English translations of works from late antiquity amongst its primary sources.
• Church history: an introduction to research, reference works, and methods by James E. Bradley and Richard Alfred Muller, p.40:

"Thus, manuscript copy of an original transcript of one of Calvin's sermons is surely a primary source — but so also is the sixteenth-century printed text of the sermon, the sixteenth-century English translation, a microfilm or microfiche version of any of the sixteenth-century forms of the text, and any modern edition or translation. ... Translations must always be checked against the original if possible, but they do fall into the category of primary sources."

I was unable to find a single source which claimed that translations of primary sources were not primary sources, even after a further 45 minutes or so of trawling through google searches, when I finally gave up. So unless I have been particularly unlucky in my searches it would appear that Logicus's opinion on this matter is out of step with mainstream scholarship. I would be genuinely interested if either he or anyone else can provide a decent source which asserts or implies unequivocally that translations of primary sources are not primary source. Please note, I am not interested in:

1. Long-winded arguments on why the above-quoted sources are wrong, or exegetical analysis of definitions which are not themselves completely unequivocal on the matter (if they are, then such exegetical analysis would be superfluous); or
2. Arguments that translations of primary sources are secondary sources. The two categories are not mutually exclusive, and I am already aware that such translations might be categorised as secondary sources as well as (at least according to the above-quoted sources) primary sources. The point at issue here is not whether they can be considered secondary sources, but whether they are normally considered to be primary sources by professional historians.
   

—David Wilson (talk · cont) 15:10, 26 November 2009 (UTC)

Wikipedia's policy on Primary and Secondary sources confirms Wilson's understanding:

"The key point about a primary source is that it offers an insider's view to an event, a period of history, a work of art, a political decision, and so on."

Secondary sources "rely for their facts and opinions on primary sources, often to make analytic, synthetic, interpretive, explanatory, or evaluative claims."

A translation with commentary may provide such analysis, interpretation, explanation, and evaluation (e.g., Cornford's translation with extended commentary of the Timaeus, which he entitled Plato's Cosmology; even a simple translation may provide explanatory footnotes and such notes or commentary count as secondary sources. The translation itself, however, provides an insider's view and hence is a primary source.

PS Happy Thanksgiving from the States, SteveMcCluskey (talk) 16:43, 26 November 2009 (UTC)

Does Clagett's Greek Science in Antiquity support the disputed edit?

Logicus apparently now wants to claim that the material on page 170 of Marshall Clagett's book Greek Science in Antiquity vitiates the objections I have raised here against some of the material in his disputed edit. I'm afraid the claim doesn't stand up to scrutiny. The disputed edit's treatment suffers from several serious defects which I have already indicated, and which are nowhere to be found in Clagett's. Some of the more significant are:

• Nowhere does the disputed edit indicate, as Clagett does, that expressions of the form F/R are written in a modern mathematical notation which was unavailable to Aristotle and which he did not use.
• Nowhere does the disputed edit indicate, as Clagett does, that ratios of unlike magnitudes were not used in Greek mathematics, and consequently that relations expressible in terms of such ratios in modern mathematical notation would have to have been expressed by Aristotle in the more cumbersome and roundabout language of Eudoxan proportionality.
• Nowhere does the disputed edit indicate, as Clagett does, that although we can use the modern mathematical formula V α F/R to express a relation which all Aristotle's separate cases of proportionality can be considered special cases of, Aristotle himself ("of course") does not do so.
• Nowhere does the disputed edit indicate, as Clagett does, that the "basic dynamic formula" that "speed is proportional to the ratio of the motive force to the resistance" is something that "we [emphasis mine] might deduce" from "scattered fragments" of Aristotle, but which Aristotle himself, in fact, does not. (I realise that Clagett does not say explicitly that Aristotle nowhere deduces this "basic dynamical formula", but if Clagett had thought that Aristotle had so deduced it I would have expected him to have said so).
• Nowhere does the disputed edit indicate, as Clagett does, that the "basic dynamical formula" that "speed is proportional to the ratio of the motive force to the resistance" is subject to the proviso that "the force is sufficiently great to overcome the resistance and produce movement."
• Nowhere does Clagett perpetrate, as the diputed edit does, either of the following mathematical travesties:

"v α W/R = W/0 = infinite"

"[ (i) v α F/R & (ii) F > 0 & (iii) R = 0 ] entail v is infinite."

or anything like them. Logicus's says that these are "just shorthand", although he doesn't actually say what they are supposed to be shorthand for—presumably, he means something like "W/R → ∞ as R → 0". But in the first place, if this is the case, then this "shorthand" would in fact be no shorter than the correct expressions which they are supposedly "shorthand" for. In the second, this supposed "shorthand" is one which will not be found in any decent mathematical text-book or monograph (and which would lose marks for anyone who used it in any university exam paper in mathematics). If anyone contests this, I challenge them to find any such use of this "shorthand" in a credible mathematical publication.

Logicus asserts that "Clagett also scotches your other main objection that division by zero does not give an infinite result", but he cites nothing out of Clagett to back up this assertion. Immediately after making it he provides another dubious interpretation of Aristotle's Physics which he then asserts "can easily be expressed in Clagett’s Cauchyan terms as ‘V tends to infinity as R tends to zero’". There are at least a couple of problems with this:

• I'm afraid I don't see how Clagett's perfectly correct mathematical statement that if V satisfies the relation V α F/R (with F > 0 fixed, and R > 0) then "V would go to infinity as R goes to zero" in any way contradicts my (also perfectly correct) statement that division by zero is an operation which is undefined and therefore cannot properly be said to give any result, let alone an infinite one. The statement that division by zero is undefined is such a mathematical commonplace that it is ridiculously easy to document it from both elementary texts (such as Painless Algebra, by Lynette Long, Hank Morehouse, p.11, Elementary Algebra, by Ron Larson, Robert P. Hostetler, Kimberly Nolting, p.45) and more advanced ones (such as CRC concise encyclopedia of mathematics, by Eric W. Weisstein, p.802, The rise of modern logic: from Leibniz to Frege, by Dov M. Gabbay, John Woods, p.356, and An introduction to abstract algebra, by F.M. Hall, p.75).
  

Logicus's failure to accept this appears to stem from a basic misunderstanding of the concept of limits in mathematics. Since Wikipedia's talk pages are not the place for expositions of the fundamentals of mathematical analysis I will simply refer him to page 27 of J.C. Burkill's A First Course in Mathematical Analysis, and, in particular, to the following statement, halfway down the page:

"After all this, you should not need to be warned that ' n = ∞ ' is nonsense."

Note that on page 11 of the same book we can find Burkill's version of the statement that division by zero is undefined in his axiom A10 for a field (of which the normal, everyday real and complex numbers used to represent physical quantities are special cases).

• Clagett's statement "V would go to infinity as R goes to zero" is given as a parenthetical remark which asserts nothing more than that bare fact. He does not use it to conclude that V would be infinite when R = 0, let alone misattribute that conclusion to Aristotle. The statement to which this parenthetical remark is appended—namely:

"The density of the medium would obviously be zero and thus the movement would take place instantaneously."

follows immediately from the fourth of the "quantitative laws" listed at the top of the page:

"(4) T₁:T₂ :: R₁:R₂ when S₁ = S₂, F₁ = F₂, and movement occurs."

by putting R₁ (the density of the medium) = 0, whence it follows immediately from the proportionality that T₁ = 0 (i.e. the movement would take place instantaneously). So there is no need to assume that Clagett was deducing this result himself by an invalid, roundabout (and completely unstated) argument of the form that because the velocity in media of ever decreasing densities tends to infinity, then the velocity in the void must be infinite and therefore that the travel would take place instantaneously, nor that he was attributing such a deduction to Aristotle.

Finally, I should like to clear up some further misunderstandings. Logicus wrote:

"But this characterisation is standard practice in the literature, ... "

But nowhere in the disputed edit was anything cited from "the literature" to support its apparently defective version of this practice. All that was cited was an English translation of Aristotle's works which quite clearly did not directly support much of the material, as is required by the Wikipedia policy I have already cited.
Next

"Here I shall just quote Clagett doing it since in your major blunder, now struck out, you cited him as an example of a scholar whose analysis would condemn this practice as OR because it has ratios of unlike quantities, ..."

This puts words which I never uttered into my mouth. Nowhere did I make any judgement about what Clagett's analysis would or would not "condemn as OR". If Logicus could find some reliable source which actually did support all of the material in the disputed edit that I have objected to (which—except for the mathematical travesties—I have already acknowledged as a possibility here) then that text would of course not be original research. Nevertheless, in view of the differences I have pointed out between Clagett's exposition and that of the disputed edit, it would, however, still be giving a non-neutral point of view which would therefore have to be balanced by some acknowledgement of those differences.
Nor has Logicus demonstrated any mistake on my part, let alone a "major blunder". In my struck out statement I gave force, weight and resistance as examples of magnitudes which I believed Aristotle would have regarded as being of different kinds, and therefore not capable of forming ratios. But nowhere that I can see does Clagett contradict this. When Clagett himself uses such a ratio (F/R) on page 170 he says explicitly that "of course, Aristotle does not do this", so there is no contradiction whatever between this statement of Clagett's and the belief that Aristotle would have regarded forces, weights, and resistances as magnitudes of different kinds that are incapable of forming ratios.
—David Wilson (talk · cont) 19:24, 28 November 2009 (UTC)

David: There is no need to belabor this. And we should not make one editor's TLDR style the norm for this, or any, talk page discussion. —Finell 20:05, 28 November 2009 (UTC)

Ok. I already had half a mind not to respond further to any forthcoming reply by Logicus. In light of your comment I have now made up the other half. Thanks.

—David Wilson (talk · cont) 20:24, 28 November 2009 (UTC)

I have also now removed some of the more intemperate language, which was entirely inappropriate, from the above remarks, and refactored the text to make it somewhat less personal. My apologies to Logicus and other readers of this page for this breach of discipline.

—David Wilson (talk · cont) 22:24, 28 November 2009 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Logicus to Wilson: I find this quite beside the main point I intended, which was not that Clagett's text verifies my text as it stands as you imply, but simply that Clagett's text shows that reconstructing Aristotle's dynamics as having a general law of motion v α F/R is not OR on my part, but a standard practice of historians of science.

And I would kindly ask you to seriously consider whether your points here are now anything more than rather nitpicking objections which may be easily avoided by a few revisions. So let me offer some revisions of my text that I hope will render it no longer OR in your view.

As far as I can determine, your criticisms amount to claiming the following four sentences are OR, namely (i) Para 1 Sentences 1 & 2, (ii) Para 6, Sentence 3, (iii) Para 10, Sentence 3 and (iv) Para 13. I therefore offer the following revisions of them for consideration.

1) Para 1 Sentence 2 to have a footnote to become of the following ilk:

'However, the motions of the celestial spheres came to be seen as presenting a major anomaly for Aristotelian dynamics, and as even refuting its general law of motion v α F/R[ref> According to this law all motion is the product of a motive force (F) and some resistance to motion (R), and whose ratio determines its average speed (v).[ref> This is strictly intended as a law for motions, and not for rest when there is no motIon because the motive force is too small to overcome the resistance(s) to motion. Although Aristotle did not express his dynamical rules of motion in terms of this algebraical summary formula, historians of science have traditionally interpreted his various rules of motion articulated in Physics 4.8 and 7.5 as effectively endorsing a general mathematical law of motion that is expressible as v @ F/R (where v = s/t, s = distance travelled and t = time taken) without misrepresenting any of his logical conclusions. For example, see Clagett's 1955 Greek science in antiquity p170. [/ref>'

2) Para 6 Sentence 3 to become of the following ilk with a footnote:

'Yet in dynamically similar terrestrial motion, such as in the hypothetical case of gravitational fall in a vacuum,[4]driven by gravity (i.e. F = W > 0), but without any resistant medium whereby R = 0, Aristotle's rules of motion predicted the movement would take place instantaneously, or, in terms of the formula v @ W/R, v would go to infinity as R goes to zero and so v is unbounded and hence the speed is infinitely fast).[ref> See Clagett's 1955 Greek science in antiquity p170. In Aristotle's terms, the resistance to motion of a medium is measured by its density D, and for the same motive force and distance travelled in two different media of different densities D1 and D2, T1:T2 = D1:D2 where T is time taken. Hence when D1 = 0 as in a vacuum, then T1 = 0. See pp351&3 Aristotle Physics Books I-IV Wicksteed & Cornford Loeb 1996 [/ref>'

3) Para 10 Sentence 3 to become of the following ilk:

'The prediction of the speed of the spheres' rotations in Aristotelian celestial dynamics is given by the following logical argument with three premises:

[ (i) v α F/R & (ii) F > 0 & (iii) R = 0 ] entails the motion is instantaneous.

4) Para 13 to become of the following ilk:

Hence the alternative logic of Averroes' solution to the refutation of the prediction of Aristotelian celestial dynamics

[ (i) v α F/R & (ii) F > 0 & (iii) R = 0 ] entails the motion is instantaneous

was to reject its third premise R = 0 instead of rejecting its first premise as Philoponus had, and assert R > 0.'

OK ? Satisfied now ? Would such a revised text mean that those respondents who have produced valid proofs of OR in such material would now be 0/10 ?

--Logicus (talk) 18:59, 30 November 2009 (UTC)

No. But I have no desire to discuss this matter further and see nothing to be gained in doing so.

—David Wilson (talk · cont) 22:37, 30 November 2009 (UTC)

Logicus to Wilson: OK. But I would be most grateful for your possible clarification of your following comment in the above RfC:

"However, since the material has been challenged, Wikipedia's policy on verifiability [more specificially that section of it on burden of proof—this text and link added 22:02, 26 November 2009 (UTC)] places the burden of proof on you to show that it is not original research by providing the necessary sources, not on those who have challenged it to prove that it is."

Are you interpreting the following policy rule to be found in your link here that

"The burden of evidence lies with the editor who adds or restores material." [my italics]

to mean that the burden of proof lies with the editor who adds or restores material to prove that it is not OR when challenged, rather than with the challenger to prove that it is OR ?

As you may realise, logically it could well be that the burden of providing sources that verify an edit, and thus the burden of evidence, lies with its editor once challenged rather than with anybody else, but nevertheless the burden of proof that it is OR lies with the challenger, rather than the burden of proof that it is not OR lying with the challenged.

Your clarification of this point may possibly help me understand some possible reasons for past conflicts with some other editors by understanding how they might interpret some policy rules quite differently from myself. Please see my above comments to Durova of today for the context of my inquiry. My apologies for asking you to revisit a matter you wish to be finished with. Thank you ! --Logicus (talk) 19:01, 3 December 2009 (UTC)

I have now responded on your talk page.

—David Wilson (talk · cont) 12:48, 8 December 2009 (UTC)

Unusual style of discussion

The style of discussion on this talk page is not typical. Many of the posts are in the style of a "letter" from one editor to another, in the form Editor A to Editor B. Typical talk page discussion topics address a particular issue concerning the article, rather than a message from one editor to another. Collaborative editing and building consensus would be better served by discussion of the issues, rather than personal messages from one editor to another; that is, discuss the issue(s) rather than the editor(s). Also, some posts are excessively long, and the extensive use use of boldface type looks like shouting. —Finell (Talk) 15:58, 2 November 2009 (UTC)

Archiving

This talk page is quite long and retains some very old discussions. Unless other editors object, I intend to implement automatic archiving of this talk page. —Finell (Talk) 16:02, 2 November 2009 (UTC)

I think it would be a good idea to refrain from archiving until the RfC above is concluded, as a number of the threads on this page are related to the topic under discussion. That aside, I agree that archiving is needed. Deor (talk) 16:16, 2 November 2009 (UTC)

OK, that's reasonable. —Finell (Talk) 16:43, 2 November 2009 (UTC)

Since the RfC is now closed and noone has objected, I have now gone ahead and set up automatic archiving. Please feel free to adjust the parameters if you don't like the present ones. Within 24 hours the bot should archive threads which have received no traffic in the last two months.

—David Wilson (talk · cont) 13:48, 1 December 2009 (UTC)

Thanks for taking care of this. —Finell 17:28, 1 December 2009 (UTC)

Well done. I've tweaked the archive parameters to add a navigation header to the archive pages. --SteveMcCluskey (talk) 17:57, 1 December 2009 (UTC)

Eudoxus

I've downplayed the role of Eudoxus in the creation of the Celestial spheres. As Dreyer says in his History of Planetary Astronomy..., pp. 90-1:

"It does not appear that Eudoxus speculated on the causes of all these rotations, nor on the material, thickness, or mutual distances of the spheres.... Whether he merely adopted the spheres as mathematical means of representing the motions of the planets and subjecting them to calculation thereby, or whether he really believed in the physical existence of all these spheres, is uncertain. But as Eudoxus made no attempt to connect the movements of the various groups of spheres with each other, it seems probable that he only regarded them as geometrical constructions suitable for computing the apparent paths of the planets."

A similar view of the lack of a mechanical model in Eudoxus and Callippus is expressed by G. E. R. Lloyd, Aristotle..., p. 150.

--SteveMcCluskey (talk) 18:00, 9 November 2009 (UTC)

Elsewhere (pp. 121-2) Dreyer speaks of "the system of homocentric spheres which Aristotle had borrowed from Eudoxus and Kalippus, and modified from a mathematical theory into a physical representation of the Kosmos." --SteveMcCluskey (talk) 01:16, 10 November 2009 (UTC)

Logicus to McCluskey: Interesting, but Dreyer’s argument is invalid at least inasmuch as Ptolemy has real bands/spheres that are mechanically disconnected, but act in harmony together like a roosting flock of birds. As I understand it, Eudoxus and Kalippus did not have their spheres mechanically connected, or at least the separate groups of spheres for each planet were not connected up together. It was Aristotle who mechanically joined everything up together and so had to introduce all the extra ‘unrollers’, and it was Ptolemy who tore them asunder again in his more animistic ‘unmechanical’ tambourines model. That boy had soul and music (-: --Logicus (talk) 19:16, 11 November 2009 (UTC)

"Dreyer's argument is invalid" = Original Research, and hence is irrelevant on Wikipedia. In addition, Dreyer's interpretation is echoed by Lloyd's more recent research, cited in the article at notes 8 and 9, which suggests some scholarly consensus on the matter. --SteveMcCluskey (talk) 19:44, 11 November 2009 (UTC)

I suspect Logicus is referring to what is in fact a genuine problem with Dreyer's account of the Ptolemaic system. But I am baffled as to why he thinks this has any bearing on what Dreyer has to say about Eudoxus and Kalippus. Nor do I think that the statement " ... Dreyer’s argument is invalid ..." is a very good way way of describing what's wrong with his account of the Ptolemaic system.

The problem with Dreyer's account is that it was made long before a complete copy of Ptolemy's Planetary Hypotheses became accessible to historians (through Bernard Goldstein's translation of an Arabic copy). As a consequence, Dreyer asserts that Ptolemy's system was a "mere geometrical representation of celestial motions, and did not profess to give a correct picture of the actual system of the world ..." (History of Planetary Systems p.202). In light of the information now available from the complete version of Planetary Hypotheses, this no longer appears to be the view of modern scholars. But since the current version of the article seems to contain an accurate account of the modern scholarly view, I don't see the point of raising the matter here.

—David Wilson (talk · cont) 13:53, 12 November 2009 (UTC)

PS: On the issue of Eudoxus and Kalippus, it's not difficult to find good modern sources whose assessments are similar to Dreyer's. e.g.:

• Michael Crowe, Theories of the world from antiquity to the Copernican Revolution, p.23 (or p.25, in my 1990 Dover paperback edition);
• Edward Grant, Planets, Stars, & Orbs, p.272
• Christopher Linton, From Eudoxus to Einstein, p.27.

One dissenting voice, however, is cited by Linton—namely, Wright, L. (1973). The astronomy of Eudoxus: Geometry or physics?, Studies in History and Philosophy of Science, 4, pp.165–72.

—David Wilson (talk · cont) 14:39, 12 November 2009 (UTC)

Thanks for the ref on Wright's article; I just ordered it through ILL. His different approach probably should be mentioned somewhere. --SteveMcCluskey (talk) 15:05, 19 November 2009 (UTC)

Wright makes the interesting argument that Eudoxus's system is so inaccurate that he would have used another model unless he considered this one to represent physical reality. I'm not convinced but I've added it to a footnote. Whatever we make of the physical reality, Wright makes the nice point that Aristotle converted Eudoxus's systems into a single unified planetary system. --SteveMcCluskey (talk) 17:12, 20 November 2009 (UTC)

Nice work in the Antiquity section. Personally, I would rather have the one textual sentence in the article's body, with a footnote after the comma citing the majority-view sources and a footnote after the period citing Wright. But then, maybe it would be better to very briefly describe the models of Eudoxus and Callippus, followed by how Aristotle used them. That would also give the complete chain from Plato to Aristotle. What do others think? —Finell 22:59, 20 November 2009 (UTC)

Steve: Excellent job! —Finell 20:06, 22 November 2009 (UTC)

Ptolemy

Logicus: I disagree. The great majority of its 14 sentences are problematical and confused in varying degrees and in need of revision. You might like to start these corrections with the following problems.

The following two sentences are unsourced, incidentally justifying the whole article's deletion on the ludicrous (but spurious) rule that all propositions must be sourced that is deployed by Finell, Whoosit and Wilson in the current RfC, and possibly also by Deor, to justify entirely deleting Logicus’s material.

"The astronomer Ptolemy (fl. ca. 150 AD) defined a geometrical model of the universe in his Almagest and extended it to a physical model of the cosmos in his Planetary hypotheses. In doing so, he achieved greater mathematical detail and predictive accuracy than had been lacking in earlier spherical models of the cosmos."

On the first sentence here, who claims the Almagest model is not a physical model and what is their evidence for that ?

On the second sentence here, who claims the Planetary hypotheses models "achieved greater mathematical detail and predictive accuracy". And what did that greater detail and predictive accuracy consist of ? (To help you here, I believe one aspect of PH's greater detail than the Almagest was providing the distances of the planetary rings/spheres.)

But who on earth, if anybody, claims that greater mathematical detail and predictive accuracy was achieved just ‘in extending a geometrical model to a physical model’ ? Surely not?

I suggest these two sentences should be replaced by something like:

'The astronomer Ptolemy defined a purely spherist model of the universe in his Almagest, but later presented an alternative more economical planetary rings model in his Planetary Hypotheses, saying observation could not decide between his spherist and rings models.'

It can be sourced by Goldstein.

I'll start beating the tambourines later (-: !

Also the sphere count in para 2 sentence 2 is wrong. Contrary to the erroneous counting of some innumerate historians of science, it should at least be ‘either 48 or 56’ according to the source given. See my unfinished discussion section above ‘How many spheres are there in Aristotle's model ?’ But no doubt you guys may want to start arguing about primary versus secondary sources and reliable sources (-: I recommend common sense !

And re the very first sentence of this section, you might like to start researching who first proposed the body of the cosmos was a sphere at least in ancient Greek philosophy. I'll give you a clue. Read Popper's wonderful essay Back to the Presocratics in his brilliant The World of Parmenides ! And then there's the Chinese to consider (-: --Logicus (talk) 16:59, 27 November 2009 (UTC)

Your comments received. I look forward to you citing the passage references in the Almagest, Planetary Hypotheses, and Goldstein to support your interpretation.

--SteveMcCluskey (talk) 20:58, 27 November 2009 (UTC)

(undent)

Logicus wrote:

"The following two sentences are unsourced, ..."

Not any more.

Next:

" ... incidentally justifying the whole article's deletion on the ludicrous (but spurious) rule that all propositions must be sourced that is deployed by Finell, Whoosit and Wilson in the current RfC, ..."

This is a blatant falsehood. It is not my view that all propositions in Wikipedia must be sourced and I have given noone any reasonable grounds for presuming that it is.

—David Wilson (talk · cont) 07:00, 28 November 2009 (UTC)

PS. Logicus wrote:

"On the second sentence here, who claims the Planetary hypotheses models "achieved greater mathematical detail and predictive accuracy"."

You did—with this edit, which had slightly mangled an earier version of the claim originally introduced by Steve McCluskey. Steve has now unmangled it, and, I think, made it even clearer that the statement "he achieved greater accuracy ... " in the second sentence is intended to refer to the geometrical model defined in the Almagest and then extended in the Planetary Hypotheses and not merely to that latter extension, as Logicus appears to have taken it to be doing. At any rate, I have based my choice of the sources I cited on that understanding.

—David Wilson (talk · cont) 11:55, 28 November 2009 (UTC)

Logicus to Wilson: Thanks for this sort out. But I don't accept the Pederson reference. It only refers to 'the abstract geometrical character of the theory', but not of the spheres themselves. A failed verification ? Are the other 2 refs any better ? --Logicus (talk) 15:57, 28 November 2009 (UTC)

Logicus:

"A failed verification ?"

No. The statement in support of which Pedersen was cited makes no statement whatever about any spheres. In my opinion it is so obviously well supported by the page cited as to make youre objection appear frivolous.

—David Wilson (talk · cont) 20:09, 28 November 2009 (UTC)

In addition to the passages quoted above, near the end of Pedersen's (p. 87) he contrasts Ptolemy's view in the Almagest with that in the Planetary Hypotheses:

But they, too [Ptolemy's tables], were completely free of any reference to the physical properties of the universe. However in his Planetary Hypotheses written sometime after the Almagest Ptolemy subscribed to a physical universe composed of spheres.

This confirms the primarily mathematical nature of the Almagest and the primarily physical nature of the Planetary Hypotheses. I have the Almagest on call from the library to check the content (and context) of Book IX, where Ptolemy discusses the distance of the planets. --SteveMcCluskey (talk) 21:20, 28 November 2009 (UTC)

Logicus to McCluskey & Wilson: Some clinching evidence that Ptolemy's spheres in the Almagest were physically real spheres rather than purely mathematical calculating models without any embodiment may be indicated by Lindberg on p104 of his 2007, where he says the Almagest "...made claims about the nature of the heavens - arguing that, unlike terrestrial substance, they offer no hindrance to motion." Hence it seems the Almagest posited that the spheres were real quintessential spheres whose physical substance had no resistance to their rotations. (It was of course this principle that was crucially rejected by Averroes in claiming the spheres do resist their motions, whereby they do not move with infinite speed as v @ F/R would predict if R = 0.) The trouble with all the efforts to make out that the Almagest was not physically realist is that they fail to provide any evidence of this claim. It cannot be concluded from a work of mathematical analysis of entities that it presumes those entities are not real just because it provides little or no discussion of their physical nature. Wilson, your comment here is surely utterly tendentious when "the model of the universe" so obviously refers to the spheres and their phyical reality of not. It is a failed verification, as is also the Linton reference.--Logicus (talk) 19:17, 30 November 2009 (UTC)

Logicus to McCluskey: Pederson would be wrong in claiming the Almagest is completely free of any reference to the physical properties of the universe, and his claim that its tables are is obviously irrelevant since all astronomical tables are anyway. But even if the Almagest were completely free of any references to the physical properties of the universe, which it is not, that would still not entail the spheres are only mathematical fictions without any physical substance, unless it positively says so. --Logicus (talk) 19:27, 30 November 2009 (UTC)

"Pederson [sic] would be wrong" = WP:OR. --SteveMcCluskey (talk) 02:11, 1 December 2009 (UTC)

In any case, Pedersen did not claim that "the Almagest is completely free of any reference to the physical properties of the universe" and neither does the article. Since the relevant page of Pedersen is available online other editors can read it and judge for themselves whether or not it supports the article's current text. I stand by my assertion that it quite obviously does, as do the pages cited in Linton's book From Eudoxus to Einstein. The most relevant quotation from p.63–64 of Linton is "Ptolemy does not mention any physical interpretation of his system [i.e. in the Almagest]: his aim is to represent the heavenly phenomena by purely kinematic hypotheses. He returned to this question in a later work, the Planetary Hypotheses. However, Ptolemy did use physical arguments to justify his choice of a fixed Earth at the centre of the Universe". Further on, on p.81, he writes " ... the latter [i.e. the Planetary Hypotheses] contains his physical interpretation of the mathematical models he developed in the Almagest. I see that I inadvertently omitted this latter page from the citation when I first added it. I have now corrected the omission.

I also disagree with Logicus's interpretation of the text he quotes from Lindberg's book. For the convenience of other editors, here is some of the context in which this text is embedded:

"It may appear that Ptolemy was engaged in a purely mathematical exercise. He titled the treatise Mathematical Syntaxis (or Mathematical System). Moreover, in the preface to this treatise he announced that speculation about divine causation of celestial motion or about the material nature of things leads only to "guesswork"; if the goal is to achieve certainty, the mathematical way is the only way. And at several points in the work he argued that astronomical models should be chosen on the basis of mathemtical simplicity—apparently without concern for physical plausibility.

 Nevertheless, if we look closely we see that nonmathematical considerations did, in fact, enter into the analysis. Ptolemy presented physical arguments for the centrality and the fixity of the earth—which for him was not merely a mathematical hypothesis, but an important physical belief. He made claims about the nature of the heavens—arguing that, unlike terrestrial substance, they offer no hindrance to motion. And in another treatise, the Planetary Hypotheses, he tried to work out a materialized version of his mathematical models. Thus, although Ptolemy was committed to a mathematical approach, his mathematical approach did not exclude physical concerns, but functioned within the framework of traditional natural philosophy.

 For all of this interest in the physics of the cosmos, the balance of Ptolemy's astronomical work was weighted towards the geometrical/numerical approach that he had learned from Hipparchus."

I see nothing there which either contradicts the article's current text, or indicates that anywhere in the Almagest Ptolemy provided any physical interpretation of the mathematical models he presented in that work. Nevertheless, since the aticle's current text doesn't mention anything at all about the physical matters discussed in the work, it might mislead readers into thinking that they were entirely absent from it. Thus, it certainly seems to me that it would be worth adding a (very) brief footnote to confirm that it did in fact discuss some such matters.

—David Wilson (talk · cont) 12:56, 1 December 2009 (UTC)

An authoritative interpretation of Almagest, IX, 1 is provided by Otto Neugebauer, A History of Ancient Mathematical Astronomy, or HAMA, pp. 111-12:

Ptolemy's planetary theory, as derived in the books IX and X of the Almagest, contains no absolute dimensions for the planetary orbits. For each planet the deferent is given the value R = 60 and eccentricities and epicycle radii are measured in each case with reference to this R. The only structural hypothesis mentioned in the Almagest (IX, 1) is the assumption that the three planets which can reach opposition to the sun are further away from us than the sun whereas the two planets of limited elongation are located between the moon and the sun. No consequences, however, are drawn from this hypothetical arrangement. Only the remark is added that the two inner planets must be located so near the sun that their parallax remains below the limits of direct observation because no parallax had been found for either or these planets. Since the lunar parallax is easily measurable, reaching values of about 1̊, it follows from this remark that Ptolemy considered the inner planets far removed from the moon.

In the second book of Ptolemy's "Planetary Hypotheses,"however, one finds a very different statement. Here the assumption of an inferior position of /page break/ Venus and Mercury is supported by the argument that the otherwise empty and useless space can be accurately filled by the two planets.

Neugebauer relates the discussion in Almagest IX, 1 to that in the Planetary Hypotheses at HAMA, p. 148, where he concludes:

Ptolemy explicitly states [in Almagest IX, 1] that the problem of planetary distances could only be solved by the measurements of parallaxes and thus has to remain unanswered. It is evident from this discussion that he did not yet think of an arrangement of contiguous planetary spheres, a hypotheses which he later on developed in his "Planetary Hypotheses".

--SteveMcCluskey (talk) 14:45, 1 December 2009 (UTC)

Logicus: Thanks for all this, which I have not yet digested to see whether I agree or not. But can I just simplify things here by cutting to the following chase.

There has always been a major problem in the literature with the instrumentalist thesis that Ptolemy’s spheres, or just his spheres in the Almagest but not in PH, were just mathematical fictions without any physical reality. It is this. If the spheres are just fictions, but the stars and planets are real as they surely are in the Almagest, then they must surely just be whizzing around in empty space according to Ptolemy. Hardly !

Are we happy to promote this conclusion by the current text ? It says:

“The astronomer Ptolemy (fl. ca. 150 AD) defined geometrical predictive models of the motions of the stars and planets in his Almagest and extended them to a unified physical model of the cosmos in his Planetary hypotheses.”

This surely implies the spheres in the Almagest were not physically real. So what filled space then ?

I suggest it be replaced by something of the following ilk:

'The astronomer Ptolemy (fl. ca. 150 AD) dealt just with the applied mathematics of his predictive models of the motions of the stars and planets in his Almagest with hardly any discussion of the physical nature of its spheres, but which he then dealt with in his Planetary hypotheses in hypothesising about their specific shapes.'

Tambourines

I just came across this explanation of Ptolemy's tambourines in Andrea Murschel, "The Structure and Function of Ptolemy's Physical Hypotheses of Planetary Motion," JHA, 26(1995) at p. 40:

"Since an entire sphere is not necessary for the celestial machine, Ptolemy cuts some of the spheres into segments (manshūrāt, πρίσματα) that extend somewhat above and below the great circles that play a role in his mathematical astronomy. Like their complete counterparts, these sawn-off pieces may be hollow, like bracelets or whorls (falaka, pl. falak), in Platonic terminology, or else they may be solid disks, like tambourines (dufūf). The tambourine-like sawn-off pieces are the solid epiciycles in which the planets are located, and all other spheres are necessarily hollow. The sphere containing the fixed stars must itself be complete since stars appear in every part of it, but spheres such as the eccentric deferents have large amounts of surface area that fulfil no real function, hence they are truncated."

Murschel goes on to point out that in creating this model Ptolemy also aimed "to provide instrument makers with a description of instructional models of celestial motion. Unlike a set of full shells, an instrument composed of rings allows the student to view planetary positions through the shells, just as the semi-fixed armillary spheres of the renaissance were constructed to teach the rudiments of astronomical coordinates."

It seems Ptolemy's motives in the Planetary Hypothesis were physical both cosmologically and "instrumentally" (not in the philosophical sense but in the sense of describing a physical instrument). Things don't appear to be simple with Ptolemy. --SteveMcCluskey (talk) 15:45, 2 December 2009 (UTC)

PS I just found a passage in Liba Taub's Ptolemy's Universe, p. 112 that confirms Murschel's comment on "instruments" and also the difference between the cosmological nature in PH and the mathematical model in the Almagest:

"At the beginning of the Planetary Hypotheses Ptolemy explained that he wanted to present planetary models in a way that would be useful to instrument makers or builders of equatoria.... His discussion of the order and distance of the planets indicates that he was not only interested in the models of motion, but in the physical arrangement of the planets as well. Accordingly, the Planetary Hypotheses represents Ptolemy's cosmological conception, based on the assumption that his mathematical models of planetary motions have physical reality, not merely limited to the construction of planetaria."

Taub then goes on (p. 113):

"Ptolemy began Book Two by noting that while he had already provided an account of the motions of the celestial bodies, based on observations extending over a long period of time, the task remained to describe the form of those bodies. In offering such a description, Ptolemy explained that he sought to comply with what is appropriate to the nature of the bodies of the spheres...."

Thus Ptolemy distinguished the Almagest's mathematical "account of the motions of the celestial bodies" from the Planetary Hypotheses's concern with "the bodies of the spheres." --SteveMcCluskey (talk) 16:10, 2 December 2009 (UTC)

Ptolemy's Ptambourines

I am pleased to see you are following up my research into Ptolemy's tambourines with this Lisa and Andrea stuff, and look forward to the restoration of something about them in the article before I have to start beating them again (the tambourines that is, not Andrea and Lisa)(-:

But what is the relevance of this to the issue here of whether the Almagest was a purely geometrical work which denied there are any physically real spheres rather than a work of mathematical physics on the mathematical aspects of real spheres ? A purely mathematical description of entities does not in itself entail they are physically unreal purely mathematical entities as the article currently implies.

As a result of my reading on Ptolemy's planetary rings, Plato's planetary rings and pre-Socratic wheels/rings/spheres cosmologies from 6th century BC Greece I am beginning to think the article itself needs to be re-titled 'Celestial rings/spheres'. And there are many important issues involved in the crucial differences between rings and spheres. For one thing note that on the rings cosmology space is mostly empty rather than an Aristotelian plenum. And note that on the principle of material economy rings are much more rational than spheres, if not on the principle of mechanical connectedness inasmuch as rings that are not the rims of wheels have nothing within which their poles can be held as axles, even if there is a celestial sphere within which such poles could be embedded. And I used to think the empirical rationale of the spheres was that on a clear night in the Med the stars actually look just like the inner concave surface of a sphere, and this empirically based perception was then extended to the planets, albeit 'irrational' because there was no empirical reason to put the single planets on whole spheres rather than just on single wheels or rings once it had been decided they were nearer than the stars rather than also on the stellar sphere. But it seems I was wrong because the rationale was the opposite, with at least Sun and Moon being on wheel rims/rings and the stellar sphere itself built up out of rims/rings i.e. rings preceded spheres.

I suggest such things should go into improving the article where possible.

And I am delighted to see you are coming to realise what an interesting and beautifully poetic great African scientist Ptolemy was, and maybe even the greatest scientist and cosmologist of all time in terms of longevity and predictive power ? --Logicus (talk) 16:55, 3 December 2009 (UTC)

You've addressed an interesting question: how did ancient writers relate celestial spheres, celestial rings and wheels? Your hypothesis is an interesting one, but before putting it in the article, it needs a good literature search to find out what there is about it in the secondary sources.

I hope you appreciate my efforts towards providing at least a good and well-sourced beginning about that issue. I think the interesting question it leaves us with is why did Eudoxus invent the planetary spheres rather than just having planetary rings or bands as in Plato? Or has he been mistranslated ? Maybe he was trying to construct mechanically interconnected systems, with the poles of spheres embedded in the next sphere, which is not possible with rings that are not wheel rims ? --Logicus (talk) 16:47, 8 December 2009 (UTC)

Besides such physical celestial entities, there is the closely related question of how ancient thinkers related them to the mathematical circles Ptolemy discussed in the Almagest and the bands of soulstuff that Plato talked about in the Timaeus. This gets into the whole issue of the relationship of Physical Things to Mathematicals to Ideas that Plato talks about in the Republic (especially in the metaphors of the Divided Line and the Cave) and that Aristotle and Ptolemy both allude to when they speak of the relationships of the study of Divine things, Mathematics, and Physics. Looking at these conceptual / ontological issues really helps us understand the relationship between the Almagest and the Planetary Hypotheses and between Eudoxus and Aristotle's Metaphysics. I've thought about these issues for a long time -- and addressed them in my undergraduate history of science courses -- but, as far as I know, there's not much on it in the secondary literature so whatever I'd have to say would be Original Research and not appropriate for Wikipedia. --SteveMcCluskey (talk) 20:43, 3 December 2009 (UTC)

Logicus to McCluskey: Well then why not consult Logicus on how to commit original sin and get your interesting sounding Original Research into Wikipedia, since according to you Logicus has been successfully doing so for years (-:

But seriously, I don't understand the problem here. Starting with Aristotle, surely it is evident that the circles are just the great circles of the rotating spheres that determine the planetary orbital paths ? The heavens i.e. the spheres, don't locomote in circles. Rather they just rotate. Rather it is any point(s) on their surface, such as a planet in the case of those with planets, that move(s) in a circle, just because it's/their sphere rotates. And surely Ptolemy is no different. OK ?

Another interesting issue to consider for the article is when did the Greeks discover the 5 planets (the wandering stars such as Lee Marvin(-: ) other than the Sun and Moon, and so when they were first assigned their own rings/spheres/wheels. As I understand it Anaximander does not have them, but only the Sun and Moon, but it seems they first appear with Anaximander's student Anaximinese in the 6th century BC. The Greeks may have got them from the Chaldeans or Egyptians.

To my mind the most fascinating related issue here is how it came about that people thought the Sun, Moon and planets are not all in/on the sphere of the fixed stars, just being unique in respect of wandering backwards through them, rather than also being outside of and well below it. I reckon the issue of the detection of daily parallax is crucial here, namely that of the Moon and possibly the Sun, just for the very notion that there are wandering stars not in the sphere of the fixed stars. But inasmuch as parallax is naked eye indiscernible for the 5 wandering stars, then why should they be assumed to be beneath the fixed stars rather than amongst them ? Did wandering become associated with being nearer just because of the observed parallax of the lunar/solar wanderers ? Ptolemy is fascinating on parallax. (But unintelligible on some dictionary definitions of parallax that define it as due to motion of observer (-: ) --Logicus (talk) 16:57, 8 December 2009 (UTC)

Logicus to McCluskey: Will comment on your OR later. But meanwhile could you please kindly provide the Crowe quotations that supposedly verify the claim made about Almagest just geometrical ? --Logicus (talk) 16:00, 5 December 2009 (UTC)

I have already provided you with quotations from Neugebauer, Murschel, and Taub. Since the only citations of Crowe I can find in this discussion [2] [3] were provided by David Wilson, you might direct your query to him. However, you cannot expect other editors to do your research for you.

--SteveMcCluskey (talk) 17:12, 5 December 2009 (UTC)

It would appear that Logicus may be reading more into the article's current text than what it actually says. It does not say that the Almagest was "just" geometrical. It says (as do all the cited sources) that the predictive models presented in the Almagest were mathematical and that physical interpretations of the mathematics were later provided in the Planetary Hypotheses. Of course this strongly implies (as stated explicitly on p.63 in Linton's book, though not currently in the article) that whatever physical interpretations of the mathematical models Ptolemy might have had in mind when he wrote the Almagest he did not provide them in that work. I have quoted some of the more relevant pieces of text from Crowe's book below. However, to understand these properly their surrounding context really needs to be read as well. But since Crowe's book is readily available (in just about any half-decent university library), I have no intention of transcribing any more than what I have already done below. The page numbers are for the 1990 Dover paperback edition.

• p.45. "In his Almagest, ... , Ptolemy presented his astronomical system in a quite highly mathematical manner. ... , it remained for over thirteen centuries as the premier presentation of mathematical astronomy.

" ... [he] also wrote an important work named Planetary Hypotheses, in which he adopted a more physical approach to the planetary motions. For example, he tried to compute the distances of the planets. This was not a topic treated in the Almagest, in which he had adopted the traditional ordering of the planets ... without attempting to assign distances to them."

• p.49–50. Here, Crowe notes that the moon's apogee in Ptolemy's model is nearly twice as far from the Earth as its perigee, which would require its apparent size to be nearly twice as large when at the latter than when at the former, whereas the actual variation in the moon's apparent size is only about 10%. Crowe remarks that Ptolemy must have been aware of this discrepancy and that "This suggests that Ptolemy viewed his lunar models as calculational devices, rather than representations of the actual physical system. In other words, his eccentrics, epicycles and deferents were seen by him as only hypothetical constructs for use in computation."
• p.72. Here Crowe quotes a passage from the Almagest and then writes:

"This passage and others suggest that Ptolemy did not attribute reality to his eccentrics, epicycles, deferents and equants; rather he viewed them as only mathematical devices to account for the phenomena."

Note that in this passage, Crowe is referring to the mathematical constructions used for all the planets, and not just those used in the model of the moon's motion, as he had been on pages 49–50.

—David Wilson (talk · cont) 13:35, 6 December 2009 (UTC)

Thanks for picking up on my note, providing the quotations from Crowe, and relating them to the article so well. These should remove any possible excuse for questioning the accepted view of the relation of the Almagest and the Planetary Hypotheses. --SteveMcCluskey (talk) 15:22, 6 December 2009 (UTC)

Logicus to Wilson and McC: David thnaks for this, will digest, stuff I put below on realism drafted before I read this. Steve, not requesting you do my research, but rather provide verifying quotation --Logicus (talk) 16:00, 6 December 2009 (UTC)

But some spheres move !

The article currently claims:

"For medieval scholars, on the other hand, celestial spheres were actually thick spheres of rarefied matter nested one within the other, each one in complete contact with the sphere above it and the sphere below.[5] Since each sphere was perfect and only spun around in place, it always occupied the exact same space.[5]"

But this is surely false going on such as the article's Peuerbach diagram and the illustration on p106 of Grant’s Foundations..... . For the deferent spheres are not in complete contact with the spheres in which they are embedded and nor do the epicyclical spheres always occupy the same absolute space as they rotate around on the deferent. See Dennis Duke’s animated Ptolemy’s cosmology @ http://people.sc.fsu.edu/~dduke/ptolemy.html These two sentences must surely be deleted. --Logicus (talk) 15:54, 29 November 2009 (UTC)

Good eye, I haven't read that section for some time and this edit added some mistaken material. The concentric spheres stay in a single place, the epicyclic spheres, however, are carried around by the spheres in which they are embedded. Unfortunately, the edit doesn't cite an exact page in Lindberg where the editor got this mistaken idea.

I'll find an appropriate source to put in an appropriate revision. --SteveMcCluskey (talk) 20:15, 29 November 2009 (UTC)

I can't find it in Lindberg and, as you point out, it's clearly false (in the Ptolemaic version at least) that all spheres always occupy the same space. I've deleted that sentence. --SteveMcCluskey (talk) 20:39, 29 November 2009 (UTC)

I found something like that in Lindberg at pp. 251-2, but Lindberg speaks of "thick planetary spheres, packed contiguously, without wasted space" in which "each of Aristotle's planetary spheres [was endowed] with thickness sufficient to contain the Ptolemaic deferent and epicycle within it." That simplified sense of sphere, where there is only one sphere for each planet but that single thick sphere contains an eccentric deferent and epicycle seems to account for the text in the article.

Re-reading that paragraph in isolation, it is dealing with that "simplified version of the cosmos, preferred by medieval writers on cosmology", (Lindberg pp. 248-9) which Lindberg also employs at pp. 248-52. It is clearly misleading in the context of the article's later discussion of more complex models of concentric spheres (Eudoxus and Aristotle) or spherical epicycles and eccentrics (Ptolemy). Our work would have been easier if that edit had cited specific pages. --SteveMcCluskey (talk) 14:59, 30 November 2009 (UTC)

And Grant (Planets, Stars, and Orbs, pp. 293–96) discusses the opinion of Albertus Magnus, who held that even in what you're calling "the simplified sense" the spheres are not contiguous and do not always occupy the same space as they rotate. I don't think this isolated view vitiates the general statement in question here; the wording in the article clearly represents the almost universal opinion, derived from Aristotle, in the Middle Ages. One (or a few) dissenters doesn't change that. Deor (talk) 16:06, 30 November 2009 (UTC)

Logicus to Deor: Thanks for this most interesting info. I suggest Albert's allegedly fringe view certainly deserves a mention given his great weight, even if only in a footnote. But I personally find Grant an unreliable muddler sometimes, so it is worth first somehow checking he has not misrepresented Albert.

But you are surely grossly wrong that the statement in question here represents an almost universal medieval opinion inasmuch as neither the deferential nor epicyclical spheres are in complete contact with the spheres above and below them in the diagrams of the three-orb planetary models provided by Peuerbach, Grant(Foundations p106) and Lindberg 2007 p270 for example. And neither of them occupy the same space as they and their whole primary containing sphere all rotate. Perhaps you overlooked these diagrams because you were so exhausted by your entirely fruitless efforts to find just one single example for your RfC of where my material commits OR(-:? --Logicus (talk) 15:09, 6 December 2009 (UTC)

Remedying the number of spheres confusion

Logicus to McCluskey:As I have noted and I think you agree, there is conflict and confusion in the article about the number of spheres in the middle ages because of a failure to distinguish between the popular simplified (essentially Eudoxan concentric) model with at most only about a dozen or so spheres and the much more complex scientific model with over two dozen by virtue of its eccentric deferential and epicyclical spheres. I therefore propose a distinction be introduced between the primary spheres for each planet and its secondary and tertiary etc spheres contained within them. In short, a primary sphere for a planet should be defined as its containing sphere that contains all its other spheres.

I therefore propose the following current text:

“In Ptolemy's geocentric model adopted in the middle ages, the planetary spheres (i.e. those that contained planets) were arranged outwards from the spherical, stationary Earth at the centre of the universe in this order: the spheres of the Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. The planetary spheres were followed by the stellar sphere containing the fixed stars; other scholars added a ninth sphere to account for the precession of the equinoxes, a tenth to account for the supposed trepidation of the equinoxes, and even an eleventh to account for the changing obliquity of the ecliptic.[1]”

should be replaced by this text:

‘In Ptolemy's geocentric model adopted in the middle ages, the planets were arranged outwards from the spherical, stationary Earth at the centre of the universe in this order: the Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. The seven primary planetary spheres for each of these, that is, those spheres that contained all a planet's other secondary spheres within them, were followed by the stellar sphere containing the fixed stars; other scholars added a ninth sphere to account for the precession of the equinoxes, a tenth to account for the supposed trepidation of the equinoxes, and even an eleventh to account for the changing obliquity of the ecliptic.[1]’

I shall implement this immediately on the assumption you concur, but of course it may be tweaked and improved. I actually think some more explanation is required for this distinction as to why secondary spheres were required, and which could go in a footnote to the clause "that is, those spheres that contained all a planet's other secondary spheres within them," these secondary spheres being required to explain anomalies for the primary spheres alone.

OK ? --Logicus (talk) 11:53, 2 December 2009 (UTC)

I have two problems with your edit:

First, it reverted a change I had already made. As of 14:53, 1 December 2009 the text read:

In the geocentric model adopted in the middle ages, the planetary spheres (i.e. those that contained planets) were arranged outwards from the spherical, stationary Earth at the centre of the universe in this order: the spheres of the Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. The planetary spheres were followed by the stellar sphere containing the fixed stars; other scholars added a ninth sphere to account for the precession of the equinoxes, a tenth to account for the supposed trepidation of the equinoxes, and even an eleventh to account for the changing obliquity of the ecliptic.

That change omitted "Ptolemaic" to deal with the point that you mentioned above that some medieval writers (mainly philosophers) dealt with the Aristotelian/Eudoxian (or even al-Bitrujian) model of concentric spheres while others (mainly astronomers) dealt with the model of solid eccentrics and epicycles found in Ptolemy's Planetary Hypotheses, Ibn al-Haitham, and the various Theorica Planetarum texts. Sphere counting tends to be found in the popular literature, using the simplified model of one sphere for each planet. Finding proper sources for all of this requires more research into the secondary literature than I have time for at the moment.

Secondly, it deletes the discussion of spheres (however counted). Since this article is about the Celestial spheres, discussing the planets without addressing the planetary spheres misses the point. I will restore my revision with some minor changes reflecting your comments.

--SteveMcCluskey (talk) 14:33, 2 December 2009 (UTC)

And another problem about the number of spheres: Further to this, the following current two sentences

“In the Ptolemaic model, each planet is moved by two or more spheres, but in Book 2 of his Planetary Hypotheses Ptolemy depicted circular bands rather than spheres as in its Book 1. One sphere/band is the deferent, with a centre offset somewhat from the Earth; the other sphere/band is an epicycle embedded in the deferent, with the planet embedded in the epicyclical sphere/band.”

are also surely puzzling inasmuch as the first sentence says a planet is moved by two or more spheres, but the second seems to presume there are only two and no more. I am currently not myself yet sure which is correct . But this surely needs sorting out. --Logicus (talk) 12:22, 2 December 2009 (UTC)

How many spheres does each planet have in Ptolemy's cosmology ?

The article currently claims

“In the Ptolemaic model, each planet is moved by two or more spheres,..."

But this claim would seem to false insofar as it means some planets are moved by two spheres only, whilst some others are moved by more than two spheres. And that is surely what it must mean since otherwise if all planets are moved by more than 2 spheres then it is as perversely Pickwickian to say they are moved by 2 or more as to say they are moved by '1 or more' or '3 or more'.

But it is false that any planet is moved by only 2 spheres if the diagrams of a typical set of spheres for each planet in Ptolemy's cosmology such as Peuerbach's shown on this page, Grant's on p106, Lindberg's 2007 on p270, and Toomer's , for example, all of which show at least 3 spheres, namely (i) the primary containing sphere and the (ii) deferential and (iii) epicyclical spheres. Indeed Grant even refers to "the three-orb compromise" (p105-6), albeit his analysis of it seems highly confused. And in the extract from his PH given below, Ptolemy's himself identifies at least 3 orbs for a planet.

A better text might be

“In the Ptolemaic model, each planet is connected with three [or more] spheres,..."

once it is established whether any single planetary system has more than three spheres.

Also see the problem identified in the following section for this text's phrasing.--Logicus (talk) 15:53, 6 December 2009 (UTC)

Relevant comment made by McCluskey elsewhere, copied here for its more relevant location by Logicus

Langermann's quotation lists three orbs for each planet but, without seeing the context, I suspect he was discussing the five (lesser) planets; the Sun (also a planet for Ptolemy) has only two orbs, an eccentric orb and an orb whose center is the center of the world. Can you find a text to resolve that issue?

--SteveMcCluskey (talk) 15:39, 6 December 2009 (UTC)

Logicus to McCluskey:Thanks for this and for your editing and flagging of the 2 orbs claim.

If you are right that the Sun is unique in only having 2 orbs in the Almagest, it looks like you may have put your finger right on why such as Grant are wrong about its 3 planetary orbs claims, namely simply because it forgets the Sun is a planet in geocentrism. Well done !

I cannot yet find anybody saying the Sun has 2 orbs, but Lindberg’s 2007 analysis on p100 of a purely eccentric model for Sun suggests you may well be right.

Do you happen to know just how many spheres Ptolemy did have ? 21 in all, 2 for the Sun, 3 for each of the other 6 planets, plus the stellar sphere ? Or more ? The question is important for the philosophical debate over the possible role of a principle of simplicity/economy in scientific method, especially re Ptolemy v Copernicus. --Logicus (talk) 18:31, 7 December 2009 (UTC)

It appears that Ptolemy, in totaling the number of spheres, considered those spheres that were divided in two to allow a place for other contained spheres to be counted as two spheres. Neugebauer, HAMA, pp. 922-926 provides a detailed account which

"would give a total of 43; Ptolemy, mysteriously giving the sun only one sphere, finds 41. Since he is not sure that the planets need the outside moving ether-spheres, instead of participating in the daily rotation by their own initiative, he is willing to reduce the number of required spheres to 41 - 7 = 34. By some speculations replacing the complete "spheres" by "rings" and "tambourins" he comes as low as 22 necessary pieces."

Returning to the issue of the planet with the smallest number of spheres, it appears that by Neugebauer's interpretation, the planet with the smallest number of spheres is the Sun with three; according to Ptolemy, the Sun only has one. If Ptolemy himself is inconsistent here, we cannot demand too much precision on this point. --SteveMcCluskey (talk) 19:03, 7 December 2009 (UTC)

Grant (Planets, Stars, and Orbs, pp. 309-10) addresses the question of how the spheres were counted in the Middle Ages:

"There were thus two basic ways to count orbs in the Aristotelian-Ptolemaic compromise system. Duns Scotus, for example, assigned 5 eccentric orbs to Mercury and 3 to every other planet, for a total of 23 eccentric, mobile orbs. To this he added 1 orb for the eighth sphere of the fixed stars and 1 for the ninth, or crystalline heaven, for a total of 25 orbs.... But if Scotus had counted only concentric or total orbs, he would have only 9 orbs. Thus we may attribute to Scotus a total number of partial, eccentric orbs, say 25, or a total number of concentric orbs, say 9....

"Fortunately, between the thirteenth and seventeenth centuries most scholastic philosophers left little doubt about their intentions: when inquiring about the number of celestial spheres in the universe, they counted only concentric orbs, although well aware that the latter were constituted /page break/ of eccentric, or partial orbs."

Although Grant speaks here of scholastic philosophers, not mathematical astronomers, the distinction he makes between concentric spheres and their eccentric constituent spheres is something we should bear in mind. --SteveMcCluskey (talk) 21:09, 7 December 2009 (UTC)

Logicus to McCluskey: Thanks very much indeed for this detailed info, not yet fully digested. Quite bewildering trying to sort it all out. Immediately on the issue of the edit in question, on your info it seems we cannot say "2 or more", because on Neugebauer it is 1 or more and on Ptolemy 3 or more. So does nobody you know of say 2 for the Sun? I cannot find anybody saying so.

BTW, do you agree with my now archived discussion on the number of Aristotle's spheres that he had 48 or 56 rather than 47 or 55 as some historians have claimed, because they forgot to count the stellar sphere ? If so, can anybody be found who gets it right ? --Logicus (talk) 19:07, 8 December 2009 (UTC)

Do the spheres move the planets or the planets move the spheres in Ptolemy ?

The article currently claims

“In the Ptolemaic model, each planet is moved by two or more spheres,..." [My itals]

But Langermann's 1990 p20 quotes Ptolemy's PH to the contrary

"We hold that each one of the stars in its [individual] ranking possesses an animate power. It moves by itself, bestows motion upon the bodies naturally connected to it beginning with that which is close to it, and passes it on to that which is adjacent to it. For example, it bestows motion first on the epicyclic orb, then on the eccentric orb, and then on the orb whose centre is the centre of the world."

It seems that rather than being movers that move the planet, rather the spheres/rings function more like railtracks that constrain the planet's motive power and motion into specific orbital paths.

Consequently I shall double flag the claim requesting sources both for the claim of only 2 or more spheres for each planet, and also for the claim that the spheres move the planets rather than vice versa. Both claims may possibly be somebody's OR.

An interesting situation may arise if some secondary source does claim the spheres move the planets in Ptolemy when it is so flagrantly contradicted by what I regard as a secondary source in Langermann’s English translation of his PH but some may regard as a primary source. If so, should secondary source claims have to be supported by the primary source (-: ?

On your last paragraph, Wikipedia policy does not extend to the evaluation of secondary sources. We only report what the secondary sources, whether Grant, Neugebauer, Langermann, or whomever, say. If secondary sources disagree, we only report that disagreement -- perhaps noting which seems to be the preponderant view among the secondary sources.

Langermann's quotation lists three orbs for each planet but, without seeing the context, I suspect he was discussing the five (lesser) planets; the Sun (also a planet for Ptolemy) has only two orbs, an eccentric orb and an orb whose center is the center of the world. Can you find a text to resolve that issue?

His question about what moves which can most easily by resolved by removing the dynamic issue here. Ptolemy's understanding of the dynamic relation of the planets to their orbs has already been discussed in Dynamics of the celestial spheres#Later Greek interpreters.

--SteveMcCluskey (talk) 15:39, 6 December 2009 (UTC); revised 16:08, 6 December 2009 (UTC)

Logicus To McCluskey: Thanks for removing your OR about spheres moving planets which I believe contradicted your own Dynamics article stuff, and for flagging the two spheres claim. Please see my comments today above. --Logicus (talk) 18:59, 7 December 2009 (UTC)

The Almagest is physically realist.

The article currently claims

"The astronomer Ptolemy (fl. ca. 150 AD) defined geometrical predictive models of the motions of the stars and planets in his Almagest and extended them to a unified physical model of the cosmos in his Planetary hypotheses.[17]"

This surely suggests the spheres in his Almagest were not physically real spheres, but only empty disembodied geometrical figures rather than solids and that only became physically real solids in PH. But this is not so, as the following passages from the Almagest attest.

These passage seem to show that Ptolemy regarded the spheres of the Almagest as solid physical spheres, and also because, of all solids, spheres offer the least resistance to motion, and indeed offer no resistance to their motion whatever.

'...since the movement of the heavenly bodies ought to be the least impeded and most facile the sphere among solids offers the easiest path of motion; likewise that, since of different figures having equal perimeters those having the more angles are the greater, the sphere is the greatest of solid figures, and the heavens are greater than any other body.' Book1.2 [My paraphrasing]

"For there is no impeding nature in [heavenly things], but one proper to the yielding and giving way to movements according to the nature of each planet, even if they are contrary, so that they can all penetrate and shine through absolutely all the fluid media; and this free action takes place not only about the particular circles, but also about the spheres themselves and the axes of revolution. We see the complication and sequence in their different movements difficult and hard to come by for the freedom of the movements in the likely stories constructed by us, but in the heavenly thing never anywhere impeded by this mixture." Book 13.2

For those who regard an English translation of the Almagest as a primary source rather than a secondary source, that its spheres are real solid physical spheres on whose physical natures such as their not resisting their motion is backed up by Lindberg 2007 p104.

I do not necessarily think the quotes from Pedersen and Lindberg, and possibly Crowe, conflict with the fact that Ptolemy’s Almagest clearly is a work of mathematical physics in solid geometry + physical hypotheses, but I do think the article’s claim misrepresents them.

I am currently considering the following replacement text, but needs more thought:

'The astronomer Ptolemy (fl. ca. 150 AD) dealt largely with the applied mathematics of his spherist models of the motions of the stars and planets in his Almagest with little discussion of their physical natures, but he then dealt with them more in his Planetary hypotheses in hypothesising about their specific shapes for the construction of real instrument models of his cosmology.' --Logicus (talk) 15:47, 6 December 2009 (UTC)

Your proposed replacement, based on your lengthy presentations above, contains two undocumented assumptions:

1. That Ptolemy had developed "spherist models of the motions of the stars and planets in his Almagest".
2. That Ptolemy "dealt with [these spherist models] more in his Planetary hypotheses".

There is no evidence that Ptolemy developed such a spherical model in the Almagest or that he modified the pre-existing model in the "Planetary Hypotheses". Although Ptolemy occasionally speaks of "spheres" in the Almagest, the secondary sources cited above, especially Murschel and Neugebauer, see Ptolemy's planetary models as using mathematical circles, not physical spheres.

No secondary source has been cited that asserts Ptolemy had developed a spherical model for the motions of the planets -- to say nothing of a model employing physical spheres -- in his Almagest. Before inserting your proposed replacement, please document it with scholarly opinion from appropriate reliable sources. --SteveMcCluskey (talk) 16:49, 6 December 2009 (UTC),

Logicus, supposedly paraphrasing text from the Almagest, wrote:

'...since the movement of the heavenly bodies ought to be the least impeded and most facile the sphere among solids offers the easiest path of motion; likewise that, since of different figures having equal perimeters those having the more angles are the greater, the sphere is the greatest of solid figures, and the heavens are greater than any other body.' Book1.2 [My paraphrasing]

This is not a paraphrase—it is a word-for-word transcription of a part of Taliaferro's translation (from Vol 16 of Great Books of the Western World), but with two significant passages omitted unmarked, and two phrases transposed to complete sentences which the omissions would otherwise have left incomplete. Here is the full text, with the omissions in italics and the transposed text in bold italics:

" ... since the movement of the heavenly bodies ought to be the least impeded and most facile, the circle among plane figures offers the easiest path of motion and the sphere among solids; likewise that, since of different figures having equal perimeters those having the more angles are the greater, the circle is the greatest of plane figures and the sphere of solid figures, and the heavens are greater than any other body." (and it's actually from Book I.3, not I.2)

But, in any case, the context from which this proof text has been plucked shows unequivocally that this passage has nothing whatever to do with the mathematical models of the planet's motions. Even on a cursory reading of Book I.3, it is patently obvious that Ptolemy is there arguing nothing more than that the universe as a whole is spherical, and that it rotates daily about the Earth at its centre, carrying all the fixed stars with it, each at a constant distance from that centre. The paragraph containing the above quotation is introduced with the sentence "The following considerations also lead to the spherical notion", which makes it quite clear that the arguments in the quotation are merely intended to provide more support for this notion of a spherical universe and its daily rotation.

—David Wilson (talk · cont) 13:12, 7 December 2009 (UTC)

Thanks for this but I don't agree. Immediately just take a look at the last para of B1.3. But more crucially, you don't rebutt the 13.2 passage. I'll try to explain more carefully why I still think you are wrong later. --Logicus (talk) 19:21, 8 December 2009 (UTC)

Spheres and rings in Greek antiquity before Plato

The article currently claims

“One of the earliest intimations of celestial spheres is found in Plato's Timaeus , “

But in respect of positing any celestial sphere(s) Plato was preceded much earlier by some two centuries by Anaximander and then Xenophanes and Parmenides. Moreover Plato had bands/rings rather than spherist planetary models.

I propose a new beginning for this section along the following lines:

'In Greek antiquity the ideas of celestial spheres and rings first appeared in the cosmology of Anaximander in the early 6th century BC. In his cosmology both the Sun and Moon are circular open vents in tubular rings of fire enclosed in tubes of condensed air that constitute the rims of rotating chariot-like wheels pivoting on the Earth at their centre, shaped rather like the space station in the film 2001. The fixed stars are also open vents in such wheel rims, but there are so many such wheels for the stars that their contiguous rims altogether form a continuous spherical shell encompassing the Earth. But according to Anaximander's cosmogony, all these wheel rims had originally been formed out of an original sphere of fire wholly encompassing the Earth that had disintegrated into many individual rings. Hence in Anaximanders's cosmogony, in the beginning was the sphere, out of which celestial rings were formed, and from which the stellar sphere was then composed from some of those rings. The order of the distances of the wheel rims of the Sun, Moon and stars was: Sun highest, Moon next and then the sphere of the stars the lowest.

Following Anaximander, both Xenophanes and Parmenides held that the universe was spherical. And much later in the fourth century BC Plato's Timaeus proposed that the body of the cosmos was made in the most perfect and uniform shape, that of a sphere containing the fixed stars.[8] But it posited that the planets were spherical bodies set in rotating bands or rings rather than wheel rims as in Anaximander's cosmology. However instead of bands Plato's student Eudoxus then developed a planetary model using geo-concentric spheres for all the planets, with three spheres each for his models of the Moon and the Sun and four each for the models of the other five planets, thus making 27 spheres in all ' --Logicus (talk) 17:48, 7 December 2009 (UTC)

Before I take a close look at this, would you please format your citations in accordance with Wikipedia citation guidelines. Providing this full information is a simple courtesy to allow other editors to readily verify your sources. --SteveMcCluskey (talk) 18:14, 7 December 2009 (UTC)

And especially, please do not use ibid. or other similar references back to a preceding footnote. Such references can easily get broken by subsequent edits, and you should not expect other editors to carry the burden of readjusting your citations whenever they insert another footnote that does so break them.

—David Wilson (talk · cont) 22:28, 7 December 2009 (UTC)

Logicus to McC and Wilson: Sorree ! In haste, I forgot to make the citations formatted for the article page also evident on the talk page. But they now seem to have appeared. Can I take it they now conform to the guidelines you cite ? Thanks to Wilson for the ibid stricture ! Will amend asap !--Logicus (talk) 16:53, 8 December 2009 (UTC)

A contiguous plenum?

The article currently claims

"For medieval scholars, on the other hand, celestial spheres were actually thick spheres of rarefied matter nested one within the other, each one in complete contact with the sphere above it and the sphere below.[5]" ( = Lindberg p251)

But in Lindberg’s diagram of the 3 orb system neither the deferential nor epicyclical spheres R & I are in complete contact with the spheres they are each nested in, R for I and S for R.

I suggest either delete the last clause or replace it with the following clause

‘and each of the primary spheres for each planet that contained all its other spheres such as deferential and epicyclical spheres was in complete contact with the sphere above it and the sphere below.’

Another issue here or elsewhere is that Lindberg 2007 claims p259 "No interstices or gaps existed within individual spheres." But both ring R and epicycle I appear to be empty spheres, and S may be partly empty, unless black indicates some filling material. His model says epicycle I rolls through ring R, which suggests R must be empty. And what does the thickened spherical space S that contains the hollow ring R consist of, what does it contain if not empty ? The issue is whether there is an Aristotelian plenum or not.

I shall delete last clause pro tem pending plenum issue being sorted, because otherwise the point made seems pointless.

Logicus to McCLuskey : Your Lindberg page refs are to first edition. I think p251 in 1st edition may be 259 in second. Could you please check Steve ? I don’t have first edition. --Logicus (talk) 18:49, 7 December 2009 (UTC)

You've misunderstood the intent of the diagram. The black and white spheres in Lindberg's presentation of "Ibn al-Haytham's solid-sphere model" (Fig. 11.10, p. 266 in the first edition) are not empty, they are different spheres of celestial material. Hence Lindberg shows the solid sphere R in direct contact with the sphere(s) surrounding it, which he labels S, apparently considering it to be a single sphere because its two parts share the same motion. The Epicyclic sphere, I, is in direct contact with the sphere R in which it is embedded. The celestial spheres provide a contiguous solid spherical body, except when Ptolemy modifies the spheres to ring and tambourine like slices, an idea which is not found in Alhacen, the medieval Theorica planetarum texts, or other medieval cosmological discussions.

That existence of solid material bodies is what distinguishes the physical spheres this article discusses from the circles of mathematical astronomical models, such as that found in Ptolemy's Almagest. If you want an illustration of how the solid sphere model relates to the mathematical model, see McCluskey, Astronomies and Cultures in Early Medieval Europe, pp. 20-4, figs. 3-4. Come to think of that, that provides another WP:Reliable source for our debate above (I can cite myself since it's published elsewhere). --SteveMcCluskey (talk) 19:37, 7 December 2009 (UTC)

Logicus to McCluskey:Thanks for this patient explanation, but I still find it puzzling and the commentary on the diagram suggestive of the spherical ring R being empty except for its epicycle. For Lindberg says: "..the epicycle [I] "rolls" through the ring [R] in the sidereal period of the planet..." Why he puts 'rolls' in scarequotes I have no idea, but if it does roll around inside the ring this surely suggests the ring is empty. Or does it roll along whilst pushing a ring plenum filling the ring of aetherial fluid around ? Or does R rotate carrying I around embedded in aetherial matter filling the ring, whereby it is contiguous because it is wholly immersed in the aetherial contents of R ? And is R actually a ring, rather than a fully spherical shell ?

I find Grant’s commentary on his diagram ever more unintelligible.

Certainly these issues need greater clarificatory exposition, not an easy task. I hope you agree and hope we can cobble something together.

(BTW, please see my response to your 'paddy' com plaint on my User Talk opage that I have only just seen)

--Logicus (talk) 19:18, 8 December 2009 (UTC)

Failed verifications of Ptolemy v Geo-concentrism claim ?

The article currently claims

"By using eccentrics and epicycles, [Ptolemy’s] geometrical model achieved greater mathematical detail and predictive accuracy than had been exhibited by earlier concentric spherical models of the cosmos.[26]."

and cites "Taliaferro, Translator's Introduction to the Almagest, p,1" as a verifying source.

But in fact Taliaferro only says

"The works of the greatest Greek astronomers - Eudoxus, Heraclides of Pontus, Aristarchus of Samos, Apollonius of Perga, and Hipparchus - are lost for the most part, and we only know their contents from this treatise and other very meagre sources. For detail, completeness and perfection the 'Composition of Ptolemy' might be said to contain all those which preceded it; ..." [My italics]

Now the two italicised words of this passage simply suggest Polemy's work might include/express the detail, completeness and perfection of all the 5 preceding works listed. But it does not say Ptolemy's work 'achieved any greater mathematical detail and predictive accuracy' than "earlier concentric spherical models of the cosmos" did. And the only (geo) concentric model listed is that of Eudoxus. Ptolemy's work may at best only have equalled the detail and predictive accuracy of all those preceding works listed without superseding it, or even have been less accurate in some respect(s). And moreover it would obviously be very silly for Taliaferro to make any such comparative accuracy claim given his admission that these preceding works are mostly lost.

As for the 2 Dreyer refs to pp160 and 167, on neither page could I see any such claim that Ptolemy’s geometrical model achieved greater mathematical detail and predictive accuracy than had been exhibited by earlier concentric spherical models of the cosmos by using eccentrics and epicycles.

So is this claim OR or can some source possibly be found ?

It needs explaining here what any greater math detail and predictive accuracy over concetrist models possibly was.

And the more interesting issue here is whether Ptolemy achieved greater predictive accuracy than all preceding models. But this issue is probably indeterminable. --Logicus (talk) 19:26, 9 December 2009 (UTC)

I don't have Taliaferro at hand but as far as I can see, these are apparently the passages in Dreyer that the editor had in mind:

Dreyer p. 160: "In the days of Apollonius, however, the theory of movable eccentrics ... and the rival epicyclic theory were capable of representing the phenomena of planetary motion, as far as they were then known, in a much more satisfactory manner than the theory of homocentric spheres could do."

Dreyer, p. 167: "In the second century B.C. ... mathematical astronomy had made considerable progress since the days of Eudoxus."

Hope this helps. --SteveMcCluskey (talk) 14:06, 11 December 2009 (UTC)

Logicus: Thanks for these refs, but I was aware of them. The problem with the second one is that it omits the post-Eudoxan geoconcentric models of Kallippus and then of Aristotle. And the problem with the first is that “more satisfactory” is just too vague. In what respect ? It does not specify in respect of greater math details nor greater predictive accuracy, nor say what phenomena geoconcentrism could not explain and why. If Aristotle’s model was the final and best development of geoconcentrism, then presumably this is what Ptolemy’s must be compared with ? But nobody does so far as I am aware. And the literature also claims eccentrics and epicycles were regarded by many as unsatisfactory because they broke some Platonic rule of equidistance, that is a requirement of the planet's orbit itself being geoconcentric.

I think one big problem here may be this. I recall some of the literature claims epicyclical models had greater explanatory/predictive power than geoconcentric models just because they explained variable brightness as a function of variable distance. But those claims omit the crucial fact mentioned in other accounts (e.g. Hoskin’s etc) that the variation in lunar distance predicted by Ptolemy’s model was massively refuted ! It predicted the Moon at perigee should have double its diameter at apogee, which is about double the distance of perigee according to Ptolemy. But it has nothing like twice the diameter. So the variable distance predictions may all be anomalous rather than successful in saving the phenomena of variable brightness.

I suspect it will turn out to be indeterminable whether Ptolemy's model had any greater math detail and greater predictive accuracy than Aristotle's geoconcentric model, neither as a matter of fact nor in principle for geoconcentric models. So I anticipate this whole claim may have to be deleted. --Logicus (talk) 15:11, 12 December 2009 (UTC)

Checking Google's snippet view I find that, once again, your selection of the quotation omits the part which discusses the issue at hand. Right after you leave off, Taliaferro continues:

"... preceded it; its prediction of the phenomena is on the whole as adequate as the instruments used—they were surprisingly accurate—could possibly allow for."

That a challenge to what a source has to say about predictive accuracy would omit its explicit discussion of accuracy seems somewhat less than fair. --SteveMcCluskey (talk) 17:03, 11 December 2009 (UTC)

Logicus: Not unfair. I omitted it simply because it seemed logically irrelevant, and still does. It does not tell us what that instrumental level of accuracy was nor whether any better than that for geoconcentric models. Will explain more later. --Logicus (talk) 15:11, 12 December 2009 (UTC)

The article's comment on "mathematical detail and predictive accuracy" reflects the fact that there is no evidence that Eudoxus ever developed a mathematical model capable of predicting the angular position (in Celestial Longitude and Latitude) of the planets; as Ptolemy (and other astronomers) later did.

Where Eudoxus does venture into quantitative astronomy, the synodic periods attributed to him by Simplicius are either round number approximations or are outright wrong (in the case of Mars where he has 8 months and 20 days as opposed to the correct value of 780 days). (Evans, The History and Practice of Ancient Astronomy, p. 309) In contrast, the Almagest's tables of anomalistic motion reflect synodic periods within a hundredth of a day of modern values.

Evans goes on to note that "It is unlikely that Eudoxus gave numerical values for the angle between the axes of spheres 3 and 4 [which generate the Hippopede]. In the case of Venus and Mars, he could not possibly have done so, for it turns out that, for these two planets, Eudoxus's model is not acutally capable of producing retrogradation at all!" (p. 309). In Evans's view, Eudoxus did not consider his model "to be literally true, or that it was believed to represent the motions in quantitative detail. Rather, the model was ... a continuation of the tradition of physical speculation characteristic of Ionian philosophy of the preceding century" (p. 310).

Hugh Thurston, Early Astronomy,, p. 117 also criticizes Eudoxus's model:

"In any case, the theory does not represent the [planets'] motions very well. It makes the wrong proportion of the synodic period spent in retrogression and it makes the planets cross the ecliptic four times in each synodic period; in fact they cross it only twice."

This absence of "mathematical detail and predictive accuracy" is what the contested passage refers to. From these examples, Eudoxus clearly falls far short of Ptolemy, although none of the authors cited provide an explicit comparison of the two astronomers' systems. --SteveMcCluskey (talk) 19:10, 13 December 2009 (UTC)

If we ignore Evans's conclusion that sets Eudoxus in the realm of "physical speculation," rather than predictive astronomy, we can look at Dreyer's History of the planetary systems..., (pp. 102-3) for an analysis of it's predictive accuracy:

"But with all its imperfections as to detail the system of homocentric spheres proposed by Eudoxus demands our admiration as the first serious attempt to deal with the apparently lawless motions of the planets. For Saturn and Jupiter, and practically also for Mercury, the system accounted well for the /page break/ motion in longitude, while it was unsatisfactory in the case of Venus, and broke down completely only when dealing with the motion of Mars. The limits of motion in latitude were also well represented by the various hippopedes, though the periods of the actual deviations from the ecliptic and their places in the cycles came out quite wrong."

Given all this supporting evidence, I see no reason to question the verification. --SteveMcCluskey (talk) 14:45, 14 December 2009 (UTC)

Logicus to McCluskey: Thanks for all this interesting stuff on the defects of Eudoxus's model that should surely go into the article. (Wright’s article also has some useful stuff.) But on the main issue, surely at least one reason to question the verification is that this material is not supporting evidence that geoconcentric models could not explain the phenomena in principle, nor that the post-Eudoxan models of Kallippus and Aristotle did not do so better than Eudoxus and possibly as well as Ptolemy. (Presumably the geoconcetric v geoeccentric models contest gets even more interesting with al-Bitruji.) And moreover as you say "none of the authors cited provide an explicit comparison of the two astronomers' systems." --Logicus (talk) 15:17, 14 December 2009 (UTC)

P.S. Hope you like the Anaximines stuff I posted. There's lots more to be put in thereafter, e.g. with Pythagoras introducing the planets on bands or wreaths etc.--Logicus (talk) 15:17, 14 December 2009 (UTC)

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