Talk:Celestial spheres

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This is an old revision of this page, as edited by Durova (talk | contribs) at 17:44, 29 November 2009 (→‎RfC: Original research?: closing). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Proposed merger with Sphere (geocentric)

Comparing these two articles I think a merger is in order. Sphere (geocentric) has a somewhat better overall presentation on the background in Greek philosophy, the Ptolemaic system, and on the literary impact.

The section on Kepler in Celestial spheres is extraneous; it would be better to discuss the continued use of the spheres by Copernicus and their ultimate rejection by Tycho and Kepler.

There is a definite need for a consideration of the philosophical and theological implications, on which Grant spends 670 pages, plus a hundred more of notes.

As for title of the merged article, I'd recommend Celestial spheres or Celestial orbs; but then I'm a medievalist and would look there. --SteveMcCluskey 20:55, 23 January 2007 (UTC)[reply]

For the moment, I have begun to edit and expand the two articles into a more coherent and fully documented one here. --SteveMcCluskey 01:53, 24 January 2007 (UTC) (Edited 14:47, 24 January 2007 (UTC))[reply]

Merger implemented

OK, I've rewritten the article; saved it as Celestial spheres; and made Sphere (geocentric) a redirect. There are still some gaps but I think it's an improvement. --SteveMcCluskey 15:37, 25 January 2007 (UTC)[reply]

Unmoved mover

Deor: Recently we've been involved in an edit skirmish -- it certainly hasn't escalated to the level of a war -- involving changes back and forth between the Prime Mover to the Primum Mobile. The changes have improved the precision of the discussion, but I think it would help if we clarified the intent of the paragraph being revised.

The paragraph involved concerns the movers of the spheres, not the spheres themselves. In that context the discussion of the first moving sphere should concentrate on its mover, the Prime Mover (who is, as Aristotle says, unmoved), not on the first moving sphere, the Primum Mobile, itself.

I'm going to revise again to take this approach; I hope it meets your concerns. let me know what you think. SteveMcCluskey 14:58, 17 February 2007 (UTC)[reply]

I'm not going to push it any farther. Before I began editing the article, it contained the sentence "The outermost mover, whose movement affected all others, was referred to as the Prime Mover and identified with God," which was clearly muddled, since the whole point of the Prime Mover is that it has no "movement" itself. In an effort to fix that, I seem to have stepped on your toes. I'm still not exactly sure what objection you have to linking the mention of "the first moving sphere" to the Primum Mobile article, but it's not worth arguing about. Deor 15:11, 17 February 2007 (UTC)[reply]
Ah; now I see. It was the link to the Primum Mobile that you wanted. I think we've already resolved the muddle you saw and since I've no problem with the link, I've added it now. (It's always hard to understand what's in an other editor's mind.) SteveMcCluskey 18:22, 17 February 2007 (UTC)[reply]

Harmonia Mundi

Why has the reference to Kepler's work Harmonia Mundi been removed?

Johannes Kepler dealt with the concept of the spheres in his work Harmonia Mundi. Kepler drew together theories from the world of music, architecture, planetary motion and astronomy and linked them together to form an idea of a harmony and cohesion underlying all world phenomena and ruled by a divine force.

This work remained untranslated into English for over 400 years, until astronomer and mathematician Dr J. Field translated the Latin into English for publication by the American Philosophical Society in Philadelphia in 1997.

Above removed 25 January 2007 by SteveMcCluskey Lumos3 19:57, 18 February 2007 (UTC)[reply]

Two reasons:
  • First, the removal was part of a total rewrite of the article. In that rewrite I made it clear that Kepler largely abandoned the idea of the spheres, which he had used in several of his earlier works, not just the Harmonia Mundi. I didn't feel like mentioning all the specific works where he used the spheres. My replacement read:
Although in his early works Johannes Kepler made use of the notion of celestial spheres, by the Epitome of Copernican Astronomy (1621) Kepler was questioning the existence of solid spheres and consequently the need for intelligences to guide the motions of the heavens. An immobile sphere of the fixed stars, however, was a lasting remnant of the celestial spheres in Kepler's thought.
  • I thought the paragraph about Field's translation cluttered the body of the article.
Hope this explains my changes. SteveMcCluskey 22:41, 18 February 2007 (UTC)[reply]

Spheres not geocentrist

The current opening paragraph is:

"The celestial spheres, or celestial orbs, were the fundamental element of Earth-centered (geocentric) astronomies and cosmologies developed by Plato, Aristotle, Ptolemy, and others. In these geocentric models the stars and planets are carried around the Earth on spheres or circles."

But it is profoundly misleading in respect of ahistorically tying spherism to geocentrism, historically refuted by the case of Copernicus's heliocentric spherism and geoheliocentric celestial models such as those Wittich and Ursus etc. Also Plato did not propose spheres, but rather mere bands for each planet in his Timaeus. Rather it seems it was Aristotle who first introduced spheres, and instead of mere bands for some reason as yet unexplained. And to say the planets are carried around on circles is obviously both physically absurd and geometrically false re planetary orbital paths. I therefore propose this first paragraph be replaced by the following historically less misleading paragraph:

'The celestial spheres, or celestial orbs, were the fundamental celestial entities of the cosmological celestial mechanics founded by Aristotle and developed by Ptolemy, Copernicus and others. [ref] Before Aristotle, in his Timaeus Plato had previously proposed the planets were transported on rotating bands.[ref] In this celestial model the stars and planets are carried around by being embedded in rotating spheres made of an aetherial transparent fifth element (quintessence), like jewels set in orbs. In Aristotle's original model the spheres have souls and they rotate because they are endlessly searching for love, which is the scientific historical origin of the popular saying 'Love makes the world go round'. Arguably nobody has ever proposed a more beautifully romantic cosmology, or at least until the great Yorkshireman Fred Hoyle proposed we are all made of stardust.'

One potential important function of the last two sentences here is to promote educational interest in the article and the fundamental historical importance and cultural influence of cosmology, and thus interest in physics. In his 2005 Lakatos Award lecture, Patrick Suppes emphasised how the theory of the celestial spheres was the most brilliantly successful longstanding cosmology of all time, but ironically so little understood by historians and philosophers of science, especially including the reasons for its termination.

The current untenable geocentrist bias of the remainder of the article should also be corrected. --Logicus (talk) 19:15, 20 February 2008 (UTC)[reply]

Anti-Deor: Deor reverted this edit implemented on 20 Feb, with the mistaken justifying comment "rv edit introducing unsourced info and POV - you should wait for feedback on the Talk page)". But in fact (i) the revised text was no more unsourced than the original and (ii) nor did it introduce a POV, but rather corrected the existing untenable geocentrist biassed POV of the original. And whilst Logicus is happy to await feedback before reverting, and indeed in most instances normally both posts proposed edits for discussion first, unlike most other editors, and also awaits feedback except perhaps where text is apparently unquestionably mistaken, he would be grateful if in future Deor would devote his efforts to reverting all other breaches of the rule he proposes before reverting Logicus's, whose edit Deor reverted just 9 minutes after its implementation. --Logicus (talk) 19:58, 22 February 2008 (UTC)[reply]

"Arguably nobody has ever proposed a more beautifully romantic cosmology, or at least until the great Yorkshireman Fred Hoyle proposed we are all made of stardust" was unacceptable POV in more than one respect. And the sentence preceding that one was factually incorrect. Deor would be grateful if Logicus eschewed personal comments. Deor (talk) 21:23, 22 February 2008 (UTC)[reply]
Logicus to Deor:I would be grateful to know what you claim is factually incorrect in "the sentence preceding", and why. It is

"In Aristotle's original model the spheres have souls and they rotate because they are endlessly searching for love, which is the scientific historical origin of the popular saying 'Love makes the world go round' "

Re personal comments, Logicus has not made any personal comments about you, but you issued the following very personal dictatorial instruction to Logicus: "YOU should wait for feedback on the Talk page."

I propose to implement at least the uncontested part of the proposed edit pro-tem whilst you explain the alleged error in the following sentence, supplemented with a diagram of a heliocentric model of celestial orbs to correct the historically untenable geocentrist bias.--Logicus (talk) 19:59, 23 February 2008 (UTC)[reply]

I would be grateful to know what you claim is factually incorrect in "the sentence preceding." No problem: "Endlessly searching for love" is a misrepresentation of what Aristotle wrote ("endlessly moved by their love for the Unmoved Mover" would be more accurate), and the extremely unlikely "is the scientific historical origin of the popular saying 'Love makes the world go round'" is unacceptable without some source other than your say-so. Deor (talk) 15:57, 24 February 2008 (UTC)[reply]

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)[reply]

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)[reply]
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)[reply]
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)[reply]

Was Dante's God simultaneously in two different places?

The article currently claims:

"Near the beginning of the fourteenth century Dante, in the Paradiso of his Divine Comedy, described God as a light at the center of the cosmos.[15]. Here the poet ascends beyond physical existence to the Empyrean Heaven, where he comes face to face with God himself and is granted understanding of both divine and human nature."

Is this contradictory ? i.e. was God both at the centre and also in the Empyrean Heaven at the same time ? Or is his light at the centre and his face in Heaven ?

This is not a frivolous issue. If both human beings (e.g. Scipio) and/or also God can ascend through the spheres or interpenetrate them, then why not comets also ? --Logicus (talk) 15:22, 24 February 2008 (UTC)[reply]

As you probably know, God isn't in any "place"; note "beyond physical existence" in the sentences you've quoted from the article. As C. S. Lewis wrote: "All this time we are describing the universe spread out in space; dignity, power and speed progressively diminishing as we descend from its circumference to its centre, the Earth. But I have already hinted that the intelligible universe reverses it all; there the Earth is the rim, the outside edge where being fades away on the border of nonentity. … [refers to the passage in Dante referred to in the article] The universe is thus, when our minds are sufficiently freed from the senses, turned inside out."
What this has to do with the penetrability or nonpenetrability of the physical spheres (which Dante himself has already passed through to reach the Empyrean) is, to say the least, unclear. Deor (talk) 16:09, 24 February 2008 (UTC)[reply]

Proposed section on inertia and the celestial spheres

Logicus proposes the following text be added to the end of the current 'Middle Ages' section. Another user has deleted a previous posting of it with the clearly mistaken justification that it is irrelevant.

I agree that it's irrelevant in this article. You may want to add some of it (with better sourcing) to the appropriate sections of Inertia. Deor (talk) 15:47, 14 June 2008 (UTC)[reply]
I have now made the footnoted sourcing refs visible. You are both wildly wrong about relevance. The physics of the celestial spheres is absolutely central.--Logicus (talk) 14:46, 15 June 2008 (UTC)[reply]

The crucial notion of inertia as an inherent resistance to motion in bodies that was to become the central concept of Kepler's and then Newton's dynamics in the 17th century first emerged in the 12th century in Averroes' Aristotelian celestial dynamics of the spheres to explain why they do not move with infinite speed and thus avoid the refutation of Aristotle's law of motion v @ F/R by celestial motion (where v = average speed of a motion, F = motive force and R = resistance to motion). For in Aristotle's celestial mechanics the spheres have movers but no external resistance to motion such as a resistant medium nor any internal resistance such as the gravity or levity of sublunar bodies that resist 'violent' motion, [ref>Aristotle's quintessence has neither gravity nor levity such as resist violent motion, including rotation, in Aristotle's sublunar physics.</ref] and hence whereby R = 0 but F > 0, and so speed must be infinite. But yet the fastest sphere of all, the stellar sphere, observably takes 24 hours to rotate. In the 6th century Philoponus had sought to resolve this devastating celestial empirical refutation of mathematical dynamics by rejecting Aristotle's core law of motion and replacing it with the alternative law v @ F - R, whereby a finite force does not produce an infinite speed when R = 0.[ref>Some regard this rejection of the core law of Aristotle's dynamics as the overthrow of Aristotelian dynamics tout court. See Sorabji's 1987 Philoponus and the Rejection of Aristotelian Science.</ref]

But some six centuries later Averroes rejected Philoponus's 'anti-Aristotelian' solution to this celestial counterexample, and instead restored Aristotle's law of motion by adopting the 'hidden variable' approach to resolving apparent refutations of parametric laws that posits a previously unaccounted variable and its value for some parameter. For he posited a non-gravitational previously unaccounted inherent resistance to motion hidden in the spheres, a non-gravitational inherent resistance to motion of superlunary quintessential matter. Thus Averroes most significantly transformed Aristotle's law of motion v @ F/R into v @ F/M for the special case of celestial motion with his auxiliary theory of what may be called celestial inertia M. However, Averroes denied sublunar bodies have any inherent resistance to motion other than their gravitational (or levitational) inherent resistance to violent motion.

But Averroes’ 13th century disciple Thomas Aquinas rejected this denial and extended this development in the celestial physics of the spheres to sublunar bodies.[ref>For Aquinas's innovation in extending Averroes' purely celestial inertia to the sublunar region and thus universalising inertia, see Bk4.L12.534-6 of Aquinas's Commentary on Aristotle's Physics Routledge 1963. See Duhem's analysis of this - St Thomas Aquinas and the Concept of Mass - on p378-9 of Roger Ariew's 1985 Medieval Cosmology, an extract also to be found at <http://ftp.colloquium.co.uk/~barrett/void.html>. But Duhem notably fails to accord Averroes his originating innovatory due compared with Avempace and Aquinas, as more clearly accorded by Sorabji's 1988 Matter, Space and Motion p284.</ref]He thereby claimed this non-gravitational inherent resistance to motion of all bodies would also prevent infinite speed of gravitational motion of sublunar bodies in a vacuum, as otherwise predicted by the law of pre-inertial Aristotelian dynamics in one of Aristotle's famous examples of the impossibility of motion in a vacuum (i.e. a void with natural places and therefore with gravity, as opposed to a pure void without any natural places, and thus without gravity, 'the great inane'.) in which the variant of the law for the special case of natural motion v @ W/R thus became v @ W/0. [ref> See Aristotle's Physics 215a24f </ref]

But some four centuries later it was Kepler who first dubbed this non-gravitational inherent resistance to motion in all bodies universally as 'inertia' at the beginning of the 17th century,[ref> See e.g. the section on Kepler's physics in Koyre's Galilean Studies</ref] and then Newton at the end of the century who revised it to exclude resistance to uniform straight motion, a purely ideal form of motion.[ref> Thus Newton annotated his Definition 3 of the inherent force of inertia in his copy of the 1713 second edition of the Principia as follows: "I do not mean Kepler's force of inertia, by which bodies tend toward rest, but a force of remaining in the same state either of resting or of moving." See p404 Cohen & Whitman 1999 Principia </ref] Hence the crucial notion of classical mechanics of the resistant force of inertia inherent in all bodies was born in the heavens of medieval astrophysics, in the Aristotelian physics of the celestial spheres, rather than in terrestrial physics or in experiments. This Aristotelian auxiliary theory of inertia, originally devised to account for the otherwise anomalous finite speed rotations of the celestial spheres for Aristotle's law of motion, was the most important development in Aristotelian dynamics in its second millenium of progress in its core law of motion towards the quantitative law of motion of classical mechanics a @ (F - R)/m by providing its denominator, whereby acceleration is not infinite when there is no other resistance to by virtue of the inherent resistant force of inertia m that prevents this.[ref>Its first millenium had seen Philoponus's 6th century innovation of net force in which those forces of resistance by which the motive force was to be divided in Aristotle's dynamics (i.e. media resistance and gravity) were rather to be subtracted, and also Avicenna's most important 10th century terrestrial impetus dynamics innovation, which maintained that gravitational free-fall under a constant gravitational force would be dynamically endlessly accelerated, rather than only initially accelerated as in the analysis of gravitational fall in the Hipparchan impetus variant.</ref]

--Logicus (talk) 14:52, 14 June 2008 (UTC) --80.6.94.131 (talk) 15:51, 16 June 2008 (UTC)[reply]

I now provisionally propose something like the following on inertia and the celestial spheres, to be improved, footnotes to be revealed:


Inertia in the celestial spheres

However, the motions of the spheres came to be seen as presenting a major anomaly for Aristotle's celestial dynamics and even refuting his general law of motion v α F/R, according to which all motion is the product of a motive force (F) and some resistance to motion (R), and whose ratio determines its average speed (v). And the ancestor of the crucial classical mechanics concept of inertia as an inherent resistance to motion in bodies was born out of attempts to resolve it. To understand this major problem first we must understand Aristotle's sublunar dynamics, in which all motion is either 'natural' or 'violent'. Natural motion is motion driven solely by the body's own internal 'nature' or gravity (or levity), that is, a centripetal tendency to move straight downward towards their natural place at the centre of the Earth and universe and to be at rest there. And its contrary, violent motion, is simply motion in any other direction whatever, including motion along the horizontal, and it is resisted by the body's own nature or gravity, thus being essentially anti-gravitational motion. Thus gravity is the driver of natural motion but a brake on violent motion.

The only two resistances to sublunar motion Aristotle identified were this gravitational internal resistance to violent motion, measured by the body's weight, and also the external resistance of the medium of motion to being cleaved by the mobile in the sublunar region he held to be a media plenum with no voids. Finally, in sublunar natural motion the law v α F/R becomes v α W/R (because Weight is the measure of the motive force of gravity), with the body's motion driven by its weight and resisted by the medium.[1]But in the case of violent motion the general law then becomes v α F/W because the body's weight now acts as a resistance that resists the violent mover F, whatever that might be, such as a hand pulling a weight up from the floor or a gang of ship-hauliers hauling a ship along the shore or a canal..[2]

However, in Aristotle's celestial physics, whilst the spheres have movers, whereby F > 0, there is no resistance to their motion whatever since Aristotle's quintessence has neither gravity nor levity, whereby they have no internalresistance to their motion, and there is no external resistance such as any resistant medium to be cut through, whereby altogether R = 0. Yet in such terrestrial dynamical conditions as in the case of gravitational fall in a vacuum,[3]driven by gravity but with no resistant medium, Aristotle's law of motion predicts it would be infinitely fast or instantaneous, since then v α W/R = W/0 = infinite.[4]But in spite of these same dynamical conditions of (celestial) bodies with movers without any resistance to them, in the heavens even the fastest sphere of all, the stellar sphere, apparently takes 24 hours to rotate. Thus when interpreted as a cosmologically universal law, Aristotle's basic law of motion was cosmologically refuted by his own dynamical analysis of celestial natural motion as a driven motion without resistance.

In the 6th century Philoponus argued that the rotation of the celestial spheres empirically refuted Aristotle's thesis that natural motion is instantaneous in a vacuum where there is no medium the mobile has to cut through as follows:

"For if in general the reason why motion takes time were the physical [medium] that is cut through in the course of this motion, and for this reason things that moved through a vacuum would have to move without taking time because of there being nothing for them to cut through, this ought to happen all the more in the case of the fastest of all motions, I mean the [celestial] rotation. For what rotates does not cut through any physical [medium] either. But in fact this [timeless motion] does not happen. All rotation takes time, even without there being anything to cut through in the motion." [5]

Philoponus sought to resolve this devastating celestial empirical refutation of Aristotelian mathematical celestial dynamics by Aristotle's own rotating celestial spheres by rejecting Aristotle's core law of motion and replacing it with the alternative law v α F - R, whereby a finite force does not produce an infinite speed when R = 0.[6][7]

But some six centuries later, in the 12th century Averroes rejected Philoponus's 'anti-Aristotelian' solution to this refutation of Aristotelian celestial dynamics, and instead restored Aristotle's law of motion by adopting the 'hidden variable' approach to resolving apparent refutations of parametric laws that posits a previously unaccounted variable and its value(s) for some parameter. For he posited a non-gravitational previously unaccounted inherent resistance to motion hidden in the celestial spheres, a non-gravitational inherent resistance to motion of superlunary quintessential matter, whereby R > 0 even when there is neither any gravitational nor media resistance to motion.[8] Thus Averroes most significantly revised Aristotle's law of motion v α F/R into v α F/M for the case of celestial motion with his auxiliary theory of what may be called celestial inertia M, whereby R = M > 0. But Averroes restricted inertia to celestial bodies and denied sublunar bodies have any inherent resistance to motion other than their gravitational (or levitational) inherent resistance to violent motion, just as in Aristotle's original sublunar physics.

However, Averroes’ 13th century disciple Thomas Aquinas rejected this denial of sublunar inertia and extended his development in the celestial physics of the spheres to all sublunar bodies, whereby he posited all bodies universally have a non-gravitational inherent resistance to motion.[9]He thereby predicted this non-gravitational inherent resistance to motion of all bodies would also prevent an infinite speed of gravitational free-fall as otherwise predicted by the law of pre-inertial Aristotelian dynamics in one of Aristotle's famous examples of the impossibility of motion in a vacuum. Thus by eliminating the prediction of its infinite speed, Aquinas made gravitational fall in a vacuum possible in an alternative way than Philoponus had.

But some four centuries later it was Kepler who first dubbed this non-gravitational inherent resistance to motion in all bodies universally as 'inertia', [10] and then Newton who revised it to exclude resistance to uniform straight motion, a purely ideal form of motion.[11] Hence the crucial notion of 17th century early classical mechanics of a resistant force of inertia inherent in all bodies was born in the heavens of medieval astrophysics, in the Aristotelian physics of the celestial spheres, rather than in terrestrial physics or in experiments.

This Aristotelian auxiliary theory of inertia, originally devised to account for the otherwise anomalous finite speed rotations of the celestial spheres for Aristotle's law of motion, was the most important conceptual development in physics and in Aristotelian dynamics in its second millenium of progress in the transformation of its core law of motion towards the quantitative law of motion of classical mechanics a α (F - R)/m. For it provided what was eventually to become its denominator, whereby acceleration is not infinite when there is no other resistance to motion by virtue of the inherent resistant force of inertia m.[12]

--Logicus (talk) 18:17, 18 June 2008 (UTC) Updated 19 June --Logicus (talk) 18:16, 19 June 2008 (UTC)[reply]

It seems that Logicus is proposing to use the discussion of the celestial spheres as a coatrack on which he wishes to hang a discussion of his idiosyncratic pov on the history of inertia. Strangely, his discussion ignores the elemental distinction between the terrestrial and celestial realm and the nature of the motion (circular and unchanging) that was natural to the substance (Aether or quintessence) which makes up the celestial region. As mentioned above, this is increasingly irrelevant to the topic of this article.
Secondly, the anachronistic use of ratios to discuss Aristotle's (and Philoponus's) concepts of celestial motion moves this article away from a proper discussion of the physics of the celestial region. A good start would be the studies by G. E. R. Lloyd and Edward Grant on these matters. --SteveMcCluskey (talk) 14:33, 19 June 2008 (UTC)[reply]
Logicus commentary on McCluskey (emboldened in square brackets):
It seems that Logicus is proposing to use the discussion of the celestial spheres as a coatrack on which he wishes to hang a discussion of his idiosyncratic pov on the history of inertia. [Not at all. Rather the history of the concept of inertia is of central relevance to the physics of the celestial spheres, just as was also the concept of impetus.] Strangely, his discussion ignores the elemental distinction between the terrestrial and celestial realm and the nature of the motion (circular and unchanging) that was natural to the substance (Aether or quintessence) which makes up the celestial region. [Strangely, McClusky ignores the fact that Logicus's discussion does not in any way ignore this distinction in this context, albeit the very medieval question at issue here was precisely whether there was such a distinction.] As mentioned above, this is increasingly irrelevant to the topic of this article. [Aux contraire, as revealed by the quotation from McCluskey's mentor Grant provided by Logicus below on 20 June, it is increasingly relevant.]
Secondly, the anachronistic use of ratios to discuss Aristotle's (and Philoponus's) concepts of celestial motion moves this article away from a proper discussion of the physics of the celestial region. [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.] A good start would be the studies by G. E. R. Lloyd and Edward Grant on these matters.[Perhaps McCluskey would be good enough to show why the studies of Lloyd and Grant, with which Logicus is well familar, would be a good start, rather than possibly a bad start, for example. But at least Grant apparently agrees with Logicus on the central relevance of the physics of the spheres, contra McCluskey] --SteveMcCluskey (talk) 14:33, 19 June 2008 (UTC)

--Logicus (talk) 16:25, 20 June 2008 (UTC)[reply]

Proposed restoration of the section on the history of inertia of the spheres

There has been no response in 3 months to Logicus's proposed invitation to objections and corrections to his proposed text on the history of inertia in the spheres. The history of the introduction of the notion of inertia as an inherent force of resistance to motion within the context of the Aristotelian dynamics of celestial motion and the spheres is clearly of central importance and relevance both to the history of physics and of the celestial spheres, as revealed by Pierre Duhem's important pioneering work in deconstructing the Enlightenment-positivist historical model of a 17th century revolution in physics by demonstrating the origins of the concepts of 17th century dynamics of such as Galileo and Newton in scholastic physics. Logicus therefore proposes the restoration of this section with the following hopefully improved text:

The dynamics of the celestial spheres

Inertia in the celestial spheres

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, according to which all motion is the product of a motive force (F) and some resistance to motion (R), and whose ratio determines its average speed (v). And the ancestor of the central concept of Newtonian mechanics, the concept of the force of inertia as an inherent resistance to motion in all bodies, was born out of attempts to resolve it. This problem of celestial motion for Aristotelian dynamics arose as follows.

In Aristotle's sublunar dynamics all motion is either 'natural' or 'violent'. Natural motion is motion driven solely by the body's own internal 'nature' or gravity (or levity), that is, a centripetal tendency to move straight downward towards their natural place at the centre of the Earth (and universe) and to be at rest there. And its contrary, violent motion, is simply motion in any other direction whatever, including motion along the horizontal, and such motion is resisted by the body's own 'nature' or gravity, thus being essentially anti-gravitational motion. Hence gravity is the driver of natural motion, but a brake on violent motion, or as Aristotle put it, a principle of both motion and rest. And gravitational resistance to motion is virtually omni-directional, whereby in effect bodies have horizontal 'weight' as well as vertically downward weight. The former consists of a tendency to be at rest and resist motion along the horizontal wherever they may be on it, as distinct from their tendency to centripetal motion as downwards weight that resists upward motion.

The only two resistances to sublunar motion Aristotle identified were this gravitational internal resistance to violent motion, measured by the body's weight, and also the external resistance of the medium of motion to being cleaved by the mobile in the sublunar plenum, measured by its density. Finally, in sublunar natural motion the general law v α F/R becomes v α W/R (because Weight is the measure of the motive force of gravity), with the body's motion driven by its weight and resisted by the medium.[13]But in the case of violent motion the general law v α F/R then becomes v α F/W because the body's weight now acts as a resistance that resists the violent mover F, whatever that might be, such as a hand pulling a weight up from the floor or a gang of ship-hauliers hauling a ship along the shore or a canal.[14]

However, in Aristotle's celestial physics, whilst the spheres have movers, each being 'pushed' by its own soul towards its own god as it were, whereby F > 0, there is no resistance to their motion whatever, since Aristotle's quintessence has neither gravity nor levity, whereby they have no internal resistance to their motion. And nor is there any external resistance such as any resistant medium to be cut through, whereby altogether R = 0. Yet in such terrestrial dynamical conditions as in the case of gravitational fall in a vacuum,[15]driven by gravity but which has no resistant medium, Aristotle's law of motion predicts it would be infinitely fast or instantaneous, since then v α W/R = W/0 = infinite.[16]But in spite of these same dynamical conditions of (celestial) bodies having movers but no resistance to them, in the heavens even the fastest sphere of all, the stellar sphere, apparently took 24 hours to rotate. Thus when interpreted as a cosmologically universal law, Aristotle's basic law of motion was cosmologically refuted by his own dynamical model of celestial natural motion as a driven motion without any resistance to it.[17]

In the 6th century Philoponus argued that the rotation of the celestial spheres empirically refuted Aristotle's thesis that natural motion would be instantaneous in a vacuum where there is no medium the mobile has to cut through, as follows:

"For if in general the reason why motion takes time were the physical [medium] that is cut through in the course of this motion, and for this reason things that moved through a vacuum would have to move without taking time because of there being nothing for them to cut through, this ought to happen all the more in the case of the fastest of all motions, I mean the [celestial] rotation. For what rotates does not cut through any physical [medium] either. But in fact this [timeless motion] does not happen. All rotation takes time, even without there being anything to cut through in the motion." [18]

Consequently Philoponus sought to resolve this devastating celestial empirical refutation of Aristotelian mathematical dynamics by Aristotle's own rotating celestial spheres by rejecting Aristotle's core law of motion and replacing it with the alternative law v α F - R, whereby a finite force does not produce an infinite speed when R = 0. The essential logic of this refutation of Aristotle's law of motion can be reconstructed as follows. The prediction of the speed of the spheres' rotations in Aristotelian celestial dynamics is given by the following logical argument [ (i) v α F/R & (ii) F > 0 & (iii) R = 0 ] entail v is infinite. These premises comprise the conjunction of Aristotle's law of motion in premise (i) with his dynamical model of celestial motion expressed in premises (ii) & (iii). But the contrary observation v is not infinite entails at least one premise of this conjunction must be false. But which one ? Philoponus decided to direct the falsifying arrow of modus tollens at the very first of the three theoretical premises of this prediction, namely Aristotle's law of motion, and replace it with his alternative law v α F - R. But logically premises (ii) or (iii) could have been rejected and replaced instead.[19]

But some six centuries later, in the 12th century Averroes rejected Philoponus's 'anti-Aristotelian' solution to this refutation of Aristotelian celestial dynamics, and instead restored Aristotle's law of motion by adopting the 'hidden variable' approach to resolving apparent refutations of parametric laws that posits a previously unaccounted variable and its value(s) for some parameter, thereby modifying the predicted value of the subject variable. For he posited a non-gravitational previously unaccounted inherent resistance to motion hidden within the celestial spheres. This was a non-gravitational inherent resistance to motion of superlunary quintessential matter, whereby R > 0 even when there is neither any gravitational nor any media resistance to motion.

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 v is infinite was to reject its third premise R = 0 instead of rejecting its first premise as Philoponus had. Thus Averroes most significantly revised Aristotle's law of motion v α F/R into v α F/M for the case of celestial motion with his auxiliary theory of what may be called celestial inertia M, whereby R = M > 0. But Averroes restricted inertia to celestial bodies and denied sublunar bodies have any inherent resistance to motion other than their gravitational (or levitational) inherent resistance to violent motion, just as in Aristotle's original sublunar physics.

However, Averroes’ 13th century follower Thomas Aquinas rejected this denial of sublunar inertia and extended Averroes' innovation in the celestial physics of the spheres to all sublunar bodies. He posited all bodies universally have a non-gravitational inherent resistance to motion constituted by their magnitude or mass.[20]In his Systeme du Monde the pioneering historian of medieval science Pierre Duhem said of Aquinas's innovation:

"For the first time we have seen human reason distinguish two elements in a heavy body: the motive force, that is, in modern terms, the weight; and the moved thing, the corpus quantum, or as we say today, the mass. For the first time we have seen the notion of mass being introduced in mechanics, and being introduced as equivalent to what remains in a body when one has suppressed all forms in order to leave only the prime matter quantified by its determined dimensions. Saint Thomas Aquinas's analysis, completing Ibn Bajja's, came to distinguish three notions in a falling body: the weight, the mass, and the resistance of the medium, about which physics will reason during the modern era....This mass, this quantified body, resists the motor attempting to transport it from one place to another, stated Thomas Aquinas."[21]

He thereby predicted this non-gravitational inherent resistance to motion of all bodies would also prevent an infinite speed of gravitational free-fall as otherwise predicted by the law of motion applied to pre-inertial Aristotelian dynamics in Aristotle's famous Physics 4.8.215a25f argument for the impossibility of natural motion in a vacuum i.e. of gravitational free-fall. Thus by eliminating the prediction of its infinite speed, Aquinas made gravitational fall in a vacuum dynamically possible in an alternative way to that in which Philoponus had.

Another logical consequence of Aquinas's theory of inertia was that all bodies would fall with the same speed in a vacuum because the ratio between their weight, i.e. the motive force, and their mass which resists it, is always the same, or in other words in the Aristotelian law of average speed v α W/m, W/m = 1 and so v = k, a constant. But it seems the first known published recognition of this consequence of the Thomist theory of inertia was in the early 15th century by Paul of Venice in his critical exposition on Aristotle's Physics, as follows:

"It is not absurd that two unequal weights move with equal speed in the void; there is, in fact, no resistance other than the intrinsic resistance due to the application of the motor to the mobile, in order that its natural movement be accomplished. And the proportion of the motor to the mobile, with respect to the heavier body and the lighter body, is the same. They would then move with the same speed in the void. In the plenum, on the other hand, they would move with unequal speed because the medium would prevent the mobile from taking its natural movement."

As Duhem commented, this "glimpses what we, from the time of Newton, have expressed as follows: Unequal weights fall with the same speed in the void because the proportion between their weight and their mass has the same value."[22] But the first mention of a way of testing this novel prediction of Aristotelian dynamics seems to be that of comparing pendulum motions in air as detailed in the First Day of Galileo's 1638 Discorsi.[23]

But some five centuries after Averroes' innovation, it was Kepler who first dubbed this non-gravitational inherent resistance to motion in all bodies universally 'inertia'.Cite error: A <ref> tag is missing the closing </ref> (see the help page). Hence the crucial notion of 17th century early classical mechanics of a resistant force of inertia inherent in all bodies was born in the heavens of medieval astrophysics, in the Aristotelian physics of the celestial spheres, rather than in terrestrial physics or in experiments.[24]

This auxiliary theory of Aristotelian dynamics, originally devised to account for the otherwise anomalous finite speed rotations of the celestial spheres for Aristotle's law of motion, was a most important conceptual development in physics and Aristotelian dynamics in its second millenium of progress in the dialectical evolutionary transformation of its core law of motion into the basic law of motion of classical mechanics a α (F - R)/m. For it provided what was eventually to become its denominator, whereby when there is no other resistance to motion, the acceleration produced by a motive force is still not infinite by virtue of the inherent resistant force of inertia m. Its first millenium had seen Philoponus's 6th century innovation of net force in which those forces of resistance by which the motive force was to be divided in Aristotle's dynamics (e.g. media resistance and gravity) were rather to be subtracted instead to give the net motive force, thus providing what was eventually to become the numerator of net force F - R in the classical mechanics law of motion.

The first millenium had also seen the Hipparchan innovation in Aristotelian dynamics of its auxiliary theory of a self-dissipating impressed force or impetus to explain the sublunar phenomenon of detached violent motion such as projectile motion against gravity, which Philoponus had also applied to celestial motion. The second millenium then saw a radically different impetus theory of an essentially self-conserving impetus developed by Avicenna and Buridan which was also applied to celestial motion.

--Logicus (talk) 18:25, 15 September 2008 (UTC)[reply]

Did Ptolemy have spheres or discs ?

The article currently claims:

"In Ptolemy's model, each planet is moved by two or more spheres (or strictly speaking, by thick equatorial slices of spheres): one sphere is the deferent, with a center offset somewhat from the Earth; the other sphere is an epicycle embedded in the deferent, with the planet embedded in the spherical epicycle." [My italics]

But what does the italicised text mean ? A thick equatorial slice of a sphere is surely just a thick disc. So did Ptolemy have spheres or discs ? Or maybe even anular discs ?

If discs, surely following proposed edit would be better ?:

'In Ptolemy's model, each planet is moved by two or more discs: one disc is the deferent, with a centre offset somewhat from the Earth; the other disc is an epicycle embedded in the deferent, with the planet embedded in the epicyclical disc.'

--Logicus (talk) 14:35, 20 June 2008 (UTC)[reply]

Good point. The reason for this ambiguity is that later interpreters of Ptolemy (e.g., Alhacen and the authors of the various theorica planetarum texts) interpreted the Ptolemaic model as referring to solid spheres and that became the dominant interpretation. Perhaps it could best be clarified by transforming the text to:
"In the Ptolemaic model, each planet is moved by two or more spheres (Ptolemy himself considered sometimes spoke of them as thick equatorial slices of spheres while later interpreters generally considered them to be complete spheres): one sphere is the deferent, with a center offset somewhat from the Earth; the other sphere is an epicycle embedded in the deferent, with the planet embedded in the spherical epicycle."
--SteveMcCluskey (talk) 19:44, 21 June 2008 (UTC)[reply]
Rechecking the reference cited in the article (Murschel, JHA, 1995), I find that Ptolemy was inconsistent, speaking in Book I of spheres and in Book II of thick equatorial slices. Murschel considers this as a concession to the needs of instrument makers while Neugebauer, HAMA, p. 923 considers them "a return to the plane figures of the Almagest". Incidentally, since the citation was provided at the end of the paragraph, the citation needed template was unnecessary. --SteveMcCluskey (talk) 20:14, 21 June 2008 (UTC)[reply]
Logicus comments:Thanks a lot for this interesting clarification. But re the citation I was seeking was rather to what Ptolemy himself actually said with a reference to where he said it (in some English translation). Is “thick equatorial slice” a literal translation of something he actually wrote, or if not what phrase did he use and where ? You must appreciate I am by long experience sceptical of claims made by historians of science that do not provide the original reference for them, as so often false re claims made e.g. about Aristotle’s physics that give no reference in his texts. Ultimately I am just trying to make any possible mechanical sense of the celestial physics of spheres/bands about which historians of science are terribly equivocal. I drafted the following before seeing your response here.
‘However, if 'sphere' is interpreted as a 'hollow sphere' or spherical shell rather than a solid sphere, then a thick equatorial slice of it is simply a thick ring or short cylindrical band with a convex rather than flat outer surface, or in other words, a band as in Plato's Timaeus cosmology rather than a sphere as in that of Eudoxus and Aristotle. But how can an epiyclical ring possibly be physically "embedded in" the deferential ring without physically impossible intersection if these two rings are solids? The only possibility would seem to be if the epicyclical band were somehow axially mounted on the circumference of the deferential band, somewhat like a catherine wheel pinned through its centre onto a point on the perimeter of another catherine wheel. But then the epicylical ring must in fact be a disc or like a cartwheel with spokes for there to be a physical centre. Can anybody make any physical sense of this model ?
But whatever, since Ptolemy's model is not spherist, but rather bandist, it has no place in an article on the celestial spheres on Deor and McCluskey type reasoning.(-:’
The philosophical problem that looms in the background is that of the possibility or not of interpenetrating substances, of which there was much discussion as Sorabji 1988 most interestingly reveals. And that relates to crucial questions e.g. like whether comets can pass through spheres, of whether Christ could achieve Ascension, problem of the Eucharist, or whether the Martian and solar orbits can interpenetrate.
It should also be clarified whether the spheres are indeed solid spheres or not, or rather nested spherical shells, because if they are solid all through, then we have interpenetrating spheres, as some people did. I reckon they were spherical shells.
I provisionally propose the following edit of your re-edit:
‘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 as in Plato’s model rather than spheres as in its Book 1.[ref to where he says this.] Later interpreters [of Ptolemy ?] generally considered them to be spheres. 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.’
But the problem with this still remains that of what on earth physical sense can be made of the bands model, as opposed to the spheres model which allows for physical embedding ? I suspect all celestial mechanics was ultimately based on terrestrial mechanics somehow. --Logicus (talk) 17:06, 22 June 2008 (UTC)[reply]
I think you're overlooking the possibility that for Ptolemy and for some others, including many Muslim and early Renaissance astronomers, the spheres (however interpreted) were primarily computational models, and that Ptolemy, for one, didn't devote much thought to the problems and consequences associated with positing the physical existence of spheres, epicyles, etc. Deor (talk) 18:17, 22 June 2008 (UTC)[reply]
Logicus on Deor:No, Logicus has not overlooked that possibility. Rather he has never seen it established with reliable evidence that for Ptolemy and many other astronomers the spheres were primarily or only idealistic computational models rather than real, albeit some historians of science have claimed such, but without evidence. The latter have been unduly influenced by the philosophical 'realism versus instrumentalism' debate, or rather 'realism versus idealism' debate, stemming from the philosophies of science of such as Duhem and Mach. History of science is typically (rotten) philosophy fabricating examples. It is, for example, patently false as Deor claims that Ptolemy "didn't devote much thought to the problems and consequences associated with positing the physical existence of spheres, epicyles, ", as his Planetary Hypotheses amply reveals to the contrary of this standard mantra of historians of science parroted by Deor. But the ultimately idiotic nature of the claim that "the spheres (however interpreted) were primarily computational models," is that only geometrical circles were mathematically required as computing devices, not spheres, so why bother positing or mentioning spheres at all rather than circles, since they were not practically used as such in computation ? And even more idiotically, what does 'spheres (however interpreted)' mean ? Interpreted as cubes or as cones or as cylinders, for example  ? The point is the geometrical computational model was only the circle and no other geometrical figure, not spheres however interpreted, but only if interpreted as a circle. Logicus would appreciate it if Deor would desist from his frequent apparently ignorant and silly comments on Logicus's contributions.
--Logicus (talk) 17:59, 3 July 2008 (UTC)[reply]

Logicus on McCluskey's Ptolemy inconsistency claim:

McCluskey wrote above "Rechecking the reference cited in the article (Murschel, JHA, 1995), I find that Ptolemy was inconsistent, speaking in Book I of spheres and in Book II of thick equatorial slices. Murschel considers this as a concession to the needs of instrument makers while Neugebauer, HAMA, p. 923 considers them "a return to the plane figures of the Almagest".

But in apparent contrast with McCluskey's above claim that Ptolemy is inconsistent about the shapes of the celestial bodies between Bk 1 and Bk 2 of his Planetary Hypotheses, according to Langermann 1990 rather he simply set out two alternative possible models that could not be decided by mathematical investigation. And also to confirm Logicus's realist speculation above that astronomers were concerned with developing real physical models based on terrestrial mechanical models rather than purely idealistic computational models, just like Aristotle, Ptolemy was certainly concerned with fashioning his celestial mechanics on terrestrial mechanical models, such as the tambourine, for example. For Langermann wrote [p19]:

"In Book II [of Planetary Hypotheses] Ptolemy undertakes to establish the shapes of the bodies that carry out the heavenly motions....He states

'For each of these motions, which are different in quantity or kind, there is a body that moves freely on poles and in space and which has a special place...'

Ptolemy then postulates two possible paths of approach to the physical explanation of the workings of the cosmos.

'The first of them is to assign a whole sphere to each motion, either hollow like the spheres that surround each other or the earth, or solid and not hollow like those which do not contain anything other than the thing [itself], namely those that set the stars in motion and are called epicyclic orbs. The other way is that we set aside for each one of the motions not a whole sphere but only a section (qitcah) of a sphere. This section lies on the two sides of the largest circle which is in that sphere, namely that from which the motion is longitude [is taken]. That which this section closes from the two sides is [equal to] the amount of latitude. Thus the shape (shakl) of this section, when taken from an epicyclic orb, is similar to a tambourine (duff). When taken from the hollow sphere, it is similar to a belt (nitaq), an armband (siwar) or a whorl (fulkah), as Plato said. Mathematical investigation shows that there is no difference between these two ways that we have described.' [Nix 113:16-33 Goldstein 37:9-17]

However, it may be that McCluskey is right that Ptolemy was also inconsistent and asserted both of these two alternative mutually exclusive models in two different places in his Planetary Hypotheses. But in the light of Langermann's above analysis, and especially given the notorious traditional difficulties historians of science have in identifying logical inconsistencies or not in scientific works, then McCluskey surely needs to produce and source Ptolemy's statements in this work that are claimed to be inconsistent, showing that he asserted both of two mutually incompatible physical models, before any such logical claim is accepted.

--Logicus (talk) 18:17, 30 June 2008 (UTC)[reply]

The unjustified disruptive deletions of Deor?

Logicus writes: User Deor has adopted McCluskey's practice of unjustifiably deleting highly relevant and informative material on the celestial spheres added to the article, in compliance with Wikipedia's request for expansion in general, and in particular in line with the views of Edward Grant, whose views were advocated by McCluskey above on 19 June, that discussion of the physical nature of the celestial spheres was a central topic of medieval science.

Logicus added at the beginning of the section 'Middle Ages': "Since it was unanimously agreed [in the middle ages] that the planets and stars were carried round on physical spheres, numerous questions were posed about the nature and motion of those spheres. How many are there ? Does God move the primum mobile or first moveable sphere, directly and actively as an efficient cause, or only as a final or ultimate cause ? Are all the heavens moved by one mover or several; and if by several, what kinds are they ? Are the celestial movers conjoined to their orbs or distinct from them ? Are the spheres moved by intelligences, angels, forms or souls, or by some principle inherent in their very matter ? Do celestial movers experience exhaustion or fatigue ? Does the celestial region form a continuous whole, or are the spheres contiguous and distinct ? Are the orbs all of the same specific nature or of different natures ? Are the orbs concentric with the Earth as common centre, or is it necessary to assume eccentric and epicyclic orbs ? The nature of celestial matter was widely discussed. Was it like terrestrial matter in possessing an inherent substantial form and inherent qualities such as hot, cold, moist and dry ? Does it undergo change involving generation and corruption, increase and diminution ?"[ref>Quotation from Edward Grant's Cosmology, Chapter 8 of Science in the Middle Ages Lindberg(Ed)1978 Chicago p268. To this list should surely be added the following two most crucially important questions: Do the spheres obey the laws of terrestrial motion ? Do the spheres have any inherent resistance to motion or not ?</ref>

Arguably this list also provides a most useful guide to issues that need discussing in the article.

But Deor deleted this addition with an untenable justification, namely "noninformative long quotation". Why ? It is surely highly informative about the issues discussed on the nature of the spheres in the middle ages.

Deor also deleted the highly informative centrally relevant section added by Logicus on the Parisian impetus dynamics of the spheres. This issue is traditionally regarded as of great relevance in the history of physics and astronomy because of allegedly being the very first elimination of animistic explanations of celestial motion that explained the sphere's rotations in terms of their supposed souls instead of its explanation in terms of terrestrial physics, namely impetus dynamics.

Logicus had added the following text to the end of the 'Middle Ages' section 

Parisian impetus dynamics and the celestial spheres

In the 14th century the logician and natural philosopher Jean Buridan, Rector of Paris University, subscribed to the Avicennan variant of Aristotelian impetus dynamics according to which impetus is conserved forever in the absence of any resistance to motion, rather than being evanescent and self-decaying as in the Hipparchan variant. In order to dispense with the need for positing continually moving intelligences or souls in the celestial spheres, which he pointed out are not posited by the Bible, he applied impetus theory to their endless rotation by extension of a terrestrial example of its application to rotary motion in the form of a rotating millwheel that continues rotating for a long time after the originally propelling hand is withdrawn, driven by the impetus impressed within it.[ref>According to Buridan's theory impetus acts in the same direction or manner in which it was created, and thus a circularly or rotationally created impetus acts circularly thereafter.</ref> He wrote on the celestial impetus of the spheres as follows:

"God, when He created the world, moved each of the celestial orbs as He pleased, and in moving them he impressed in them impetuses which moved them without his having to move them any more...And those impetuses which he impressed in the celestial bodies were not decreased or corrupted afterwards, because there was no inclination of the celestial bodies for other movements. Nor was there resistance which would be corruptive or repressive of that impetus."[ref>Questions on the Eight Books of the Physics of Aristotle: Book VIII Question 12 English translation in Clagett's 1959 Science of Mechanics in the Middle Ages p536</ref>

However, having discounted the possibility of any resistance due to a contrary inclination to move in any opposite direction and due to any external resistance, Buridan obviously also discounted any inherent resistance to motion in the form of an inclination to rest within the spheres themselves, such as the inertia posited by Averroes and Aquinas. And in fact contrary to that inertial variant of Aristotelian dynamics, according to Buridan "prime matter does not resist motion". But this then raises the question within Aristotelian dynamics of why the motive force of impetus does not therefore move them with infinite speed. The impetus dynamics answer seemed to be that it was a secondary kind of motive force that produced uniform motion rather than infinite speed, just as it seemed Aristotle had supposed the planets' moving souls do, or rather than uniformly accelerated motion like the primary force of gravity did by producing increasing amounts of impetus.

Logicus proposes Deor attempts to justify his arguably vandalous deletions in this forum or else desists from such deletion. —Preceding unsigned comment added by Logicus (talk • contribs) 15:48, 20 June 2008 (UTC)[reply]

The article should deal with exactly what its title implies—the spheres, their natures, and their history in human thought—not the theories of impetus or inertia or the details of planetary motions. If those are the topics that you are interested in, I suggest that the relevant sections of Inertia or Theory of impetus or Celestial mechanics may be appropriate places for various portions of the information you want to add, inappropriately, to Celestial spheres. We have different articles on different topics for a reason; one doesn't need to attempt to regurgitate everything one knows (or thinks one knows) in any one of them. In addition, the unintroduced quotation you added at the beginning of the "Middle Ages" section consisted entirely of a series of questions and provided the general reader with no relevant information.
I'll assume that "arguably vandalous" was just a poor attempt at humor on Logicus's part. You've brought various lengthy suggestions to this Talk page and have found no editors who agree with you about them. I'd say that insisting on inserting the information in the article anyway is what borders on disruption. Deor (talk) 16:30, 20 June 2008 (UTC)[reply]
Logicus on Deor's invalid justifications: Thanks for making the gross invalidity of your justification for excluding material on the physics of the celestial spheres from this article so transparent on these pages, as I had anticipated. See my inserted critical comments emboldened in square brackets:
The article should deal with exactly what its title implies—the spheres, their natures, and their history in human thought—not the theories of impetus or inertia or the details of planetary motions. [WRONG. Both the theories of impetus and of inertia are exactly of central relevance to the issue of the natures of the spheres, namely to whether they have inertia in their natures as an essential inherent resistance to motion, and to whether they have essentially divine natures with souls that move them around or only accidental internal impetus which assimilates them to the nature of inanimate terrestrial physics such as projectile motion. And the details of planetary motions are crucial to whether the spheres intersect or not, and thus what their physical nature must be e.g. solid or fluid and whether interpenetrable.]
If those are the topics that you are interested in, I suggest that the relevant sections of Inertia or Theory of impetus or Celestial mechanics may be appropriate places for various portions of the information you want to add, inappropriately, to Celestial spheres. [WRONG, my information is highly appropriate.] We have different articles on different topics for a reason; one doesn't need to attempt to regurgitate everything one knows (or thinks one knows) in any one of them. [So do you want an entirely separate article on the Physics of the Celestial Spheres then, in order to bring all the relevant information on it together in one place ?] In addition, the unintroduced quotation you added at the beginning of the "Middle Ages" section consisted entirely of a series of questions and provided the general reader with no relevant information.[WRONG AGAIN! Here you make an elementary literacy error. These are not questions to the reader, but are rather informing the reader of the kinds of questions that were asked about the physical nature of the spheres in the middle ages, and they also provide a list of topics on the physics of the spheres that should be discussed in the article. The quotation is thus highly informative, and has the added virtue that its author is revered by McCluskey. We are dealing here with an article on the most long lasting and successful cosmology in the history of physics, and one that surely deserves detailed treatment of its physics at least for what it reveals about the scientific enterprise, rather than being stifled by Deleting Deor.]
I'll assume that "arguably vandalous" was just a poor attempt at humour on Logicus's part. [No, serious !] You've brought various lengthy suggestions to this Talk page and have found no editors who agree with you about them. [Have you made you made up some spurious rule that one must find other editors to agree with it before implementing an edit ? All has happened here is that only a mere two editors have objected, and both with utterly invalid reasons.]
I'd say that insisting on inserting the information in the article anyway is what borders on disruption. [I’d say that if I had done that, it would be educational good sense against the apparently short-minded attitudes of yourself and McCluskey. The article should obviously go into all the physics of the spheres, just as its current discussion of whether they were solid or fluid does, which I note you have inconsistently not deleted.]

Deor (talk) 16:30, 20 June 2008 (UTC)

I suggest you critically review your perspicuously untenable position on this issue. Do you also think an article on the atom, for example, should not go into the physics of the atom and its laws of motion ? --Logicus (talk) 18:48, 22 June 2008 (UTC)[reply]

--Logicus (talk) 18:48, 22 June 2008 (UTC)[reply]

How many movers does each planetary sphere have ?

The article currently claims that in the 'Middle Ages'

"Each of the lower spheres was moved by a subordinate spiritual mover (a replacement for Aristotle's multiple divine movers), called an intelligence."

But this is ambiguous between the following two meanings

1. Each lower sphere had its own single spiritual mover whereas Aristotle had many divine movers in each sphere.

OR

2. Just a single spiritual mover moved every inner sphere, whereby altogether there were only two spiritual movers for the whole system of spheres, namely God who moved the outermost sphere and the other single spiritual mover who moved all the other spheres, rather than the 48 or 56 spiritual movers in Aristotle's system, comprising the 47 or 55 who moved each of the 47 or 55 inner spheres plus the mover of the primum mobile.

Now 1 is definitely false because in his Metaphysics 12.8 Aristotle only assigned one god as mover to each one of the inner spheres rather than many to each sphere.

As for 2, it is definitely false at least inasmuch as there were those who retained Aristotle's model of each inner sphere having its own single spiritual mover, typically an angel in the Christian cosmology. But further, did anybody at all propose just a dual mover model for the whole system ?

Immediately I shall flag citation needed for these claims, but suggest this sentence should be replaced by

'Each lower sphere was moved by just one subordinate divine mover per sphere.'

Called an intelligence ?

"...called an intelligence. " is false in general inasmuch as there was also an ontology according to which the actual mover was the soul of the sphere, and its intelligence was only the navigator or driver regulating the movement, not its mover nor motor. Thus, for example, in denying this medieval ontology for the case of the Sun, in his 1630 Epitome (p516) Kepler argued the although the Sun had a soul that moved it, the constancy of its rotation was not regulated by any intelligence, but rather just by the law of inertial dynamics that governed it:

"I think a soul must be postulated [for the Sun] rather than an inanimate form...[But] there is absolutely no need of mind or intelligence for the functions of [its rotating] movement. [For] the constancy of the revolution and of the periodic time [of the solar body]...depends upon the ratio of the constant power of the mover to the obstinacy [i.e. inertia] of the matter [ i.e. v @ F/m ]."

This, by the way, is why it is ludicrous to claim as Wikipedia does that Kepler invented celestial physics, at least in the sense of a non-animistic physics. It seems that important innovation in the middle ages must be attributed to Buridan who in the 14th century replaced the spiritual movers of the spheres by incorporeal but inanimate impetus, which is permanently conserved in the absence of any resistance. But impetus as a celestial mover was not an option in Kepler's Thomist inertial dynamics, in which all bodies have an inherent resistance to motion he called 'inertia', unlike Buridan's dynamics in which prime matter does not resist motion, whereby such impetus would be destroyed by this inertia. But important information about Buridan's crucial innovation in the physics of the spheres added by Logicus has unjustifiably been deleted from this article by Deor. --Logicus (talk) 17:33, 23 June 2008 (UTC)[reply]

Planetary attachments?

In its Antiquity section the article currently claims

"The planets are attached to anywhere from 47 to 55 concentric spheres that rotate around the Earth."

But this claim is arguably false because the 7 planets are only directly attached to 7 spheres, namely to one each. The great majority of spheres - 39 or 47 in all ? - have nothing whatever attached to them. Maybe the author meant 'attached to' in the sense of 'somehow interconnected to' ?

For greater clarity I propose this sentence be edited to become something like

'The planets are moved by anywhere from X to Y uniformly rotating geo-concentric nested spheres. Each planet is attached to the innermost of its own particular set of spheres.'

The numbers of spheres X and Y here are to be determined according to the outcome of a forthcoming Logicus discussion about just how many celestial spheres there are in Aristotle’s model, a matter of interpretation about which historians of science disagree, as per usual. --Logicus (talk) 17:48, 23 June 2008 (UTC)[reply]

Are the astronomers the experts on the exact numbers of spheres and of gods for Aristotle?

In its 'Antiquity' section the article currently claims

"Aristotle says [in his Metaphysics] that to determine the exact number of spheres and the number of divine movers, one should consult the astronomers." with the two footnotes "^ G. E. R. Lloyd, Aristotle: The Growth and Structure of his Thought, pp. 133-153, Cambridge: Cambridge Univ. Pr., 1968. ISBN 0-521-09456-9. ^ G. E. R. Lloyd, "Heavenly aberrations: Aristotle the amateur astronomer," pp.160-183 in his Aristotelian Explorations, Cambridge: Cambridge Univ. Pr., 1996. ISBN 0-521-55619-8."

It is G.E.R. Lloyd whose studies McCluskey recommends, along with those of Grant, as a good starting point for "a proper discussion of the physics of the celestial region." compared with Logicus's discussion McCluskey condemns as improper.

But this claim is significantly false and misleading in various respects, two of which are as follows:

1) Its most misleading aspect is its apparent meaning that Aristotle said that to know the exact number of spheres and divine movers one should simply ask the astronomers what they are and simply take their word for it i.e. ask the experts. But Aristotle did not do so. For he reported the astronomer Eudoxus as having 27 spheres and Callippus as having 34 spheres (on one reckoning), whereas he argued 56 spheres or at least 48 are required to explain the observed planetary motions.. The reason for the difference seems to have been that Aristotle wanted the otherwise separate spheres for each planet to be interconnected such that the daily rotation of the outermost stellar sphere was automatically transmitted inwards to each planet.'s own spheres without the additional specific motions of any intervening planet also being transmitted to the next inner planet, thus requiring sets of counteracting 'rollers' to nullify the differences in their motion from that of the daily stellar rotation in the motion transmitted to the next planet inwards. So rather than saying one should consult the astronomers to know the exact number of spheres, Aristotle said (in Ross's translation):

"But in the number of the movements [i.e. of uniformly rotating spheres] we reach a problem which must be treated from the standpoint of that one of the mathematical sciences which is most akin to philosophy - viz. of astronomy; for this science speculates about substance which is perceptible but eternal, but the other mathematical sciences, i.e. arithmetic and geometry, treat of no substance." Metaphysics 1073b

So what he said was that the question of the number of spheres must be dealt with from the standpoint of astronomy, which speculates about the observable eternal planets. Not that we should get the exact number of spheres and movers from astronomers.

But he then quotes what some astronomers say about the number of spheres, but only in order to start the ball rolling from some definite figures from which to determine the exact number for himself. For he says:

"But as to the actual number of these movements, we now - to give some notion of the subject - quote what some of the mathematicians say, that our thought may have some definite number to grasp; but for the rest, we must partly investigate for ourselves, partly learn from other investigators, and if those who study this subject form an opinion contrary to what we have now stated, we must esteem both parties indeed, but follow the more accurate." Metaphysics 1073b

So it seems Aristotle learnt from Eudoxus and Callippus to some extent, largely followed the more accurate Callippus re their differences, and then added another 22 spheres himself. Aristotle's real disagreement with them seems to lay in the nature of the celestial mechanics involved, and whether the spheres were one totally interconnected system, rather than 7 unconnected independent sub-systems of spheres for each planet, plus the stellar sphere itself.

In conclusion, one does not get the EXACT number of spheres from the astronomers, but rather one must do astronomy oneself to get it.

2) "...and the number of divine movers...

Whilst one may get the exact number of spheres from doing astronomy, Aristotle does not also say, as claimed above, one also gets the number of divine movers - eternal imperceptible substances - from astronomy. Rather that is the subject of metaphysics. such as whether the rule is indeed one divine unmoved mover per sphere or not. And as Aristotle concludes:

"Let this [number, 47 or 55], then, be taken as the number of the [planetary] spheres, so that the unmoveable substances and principles may also probably be taken as just so many; the assertion of necessity must be left to more powerful thinkers." Metaphysics 1074a15

Aristotle is apparently not too certain about the one-one relationship of gods to spheres.

So in conclusion the article's claim here attributed to Lloyd - that Aristotle's says one should get the exact number of spheres from astronomers - is significantly false and misleading, whether or not Lloyd has in effect been misreported.

I propose the following replacement.

'Aristotle says the exact number of spheres is to be determined by astronomical investigation. The exact number of divine unmoved movers is to be determined by metaphysics, and Aristotle assigned one unmoved mover per sphere.[25]'

But the historically important point this overlooks is that Aristotle apparently made a major historical innovation in the celestial mechanics of astronomy in respect of interconnecting all the different planets' spheres together into just one mechanical transmission model rather than a collection of separate models for each planet. His specific innovation was the introduction of 'unrolling' spheres to achieve this, but which the astronomers had not accounted. This information should be added once it has been clarified by further discussion.

So much for Lloyd being a good start on Aristotle's celestial physics ! Useful reading here in addition to Aristotle's Metaphysics is Dreyer's History of Astronomy on Eudoxus, Callippus and Aristotle, and Grant's 1996 Foundations of Modern Science in the Middle Ages p65-7, although both may be numerically mistaken in their analyses of Aristotle's spheres, as may well have been Aristotle himself. See the following discussion to come on these problems. --Logicus (talk) 17:37, 24 June 2008 (UTC)[reply]

How many spheres are there in Aristotle's model ?

The article currently gives the impression Aristotle's celestial model had " ...anywhere from 47 to 55 concentric spheres..."

But this is the number of spheres stated by many historians of science* who fail to read the logical context of Aristotle's presentation when he announces 47 or 55 planetary spheres, namely that he is discussing the number of extra spheres and unmoved movers required by the planets in addition to the stellar sphere and prime unmoved mover he has already discussed. So the stellar sphere must be added to the 47 or 55 planetary spheres to get the total number of 48 or 56 celestial spheres altogether. {*e.g. Edward Grant says "Aristotle's [cosmological] system consisted of 55 concentric celestial spheres..." on p71 of his 1977 Physical Science in the Middle Ages]

So I provisionally edit the numbers in the article.

But there are also various other problems with gleaning the number of spheres posited variously by Eudoxus, Callippus and Aristotle from Aristotle’s Metaphysics analysis. It may be that he made a counting error and the maximum number should have been 49.

Immediately here I just post a simple table, for other editors to ponder and criticise, that currently seems to me to be the most plausible account of Aristotle’s analysis, whereby the max number of spheres should have been 49 rather than his 56. But I may well have blundered somehow.

Column 1 gives the number of spheres it seems Aristotle may attribute to Eudoxus, and Column 2 for Callippus. Column 3 gives the number for Callippus when the daily stellar sphere counterpart he and Eudoxus gave to each planet's set of spheres is knocked out when the single stellar sphere does that job when Aristotle connects up all the spheres to get total transmission of the stellar rotation to reach planet's spheres. Column 4 enumerates Aristotle’s unroller spheres required when he connects up, with his final grand totals of 'actives' plus 'unrollers' in Column 5.

1 2 3 4 5

Eudoxus Kalippus Kalippus Aristotle's Aristotle minus dailies 'unrollers' Totals

Moon 3 5 4 0 4

Venus 4 5 4 4 8

Mercury 4 5 4 4 8

Sun 3 5 4 4 8

Mars 4 5 4 4 8

Jupiter 4 4 3 3 6

Saturn 4 4 3 3 6

Stellar Sph 1 1 1 0 1

27 34 27 + 22 = 49

NB To see this Table formatted properly use Edit mode

To be discussed further…

--Logicus (talk) 18:13, 24 June 2008 (UTC)[reply]


Estimating the number of spheres Aristotle required:

There are disagreements between different historians of science on their estimates of how many spheres Aristotle posited or really needed. But on the most logically coherent interpretation, to save the planetary phenomena his model only required 49 or else 41 spheres rather than his 56 or 48. In fact it seems that rather than, as some historians of science seem to suggest, his estimate of the numbers of spheres just included practically redundant spheres whilst yet saving the phenomena, instead on Aristotle's numbers the Moon must orbit the Earth 8 times per day rather than just once and Saturn twice a day, Jupiter thrice, and so forth. For it seems Aristotle forgot to eliminate Callippus's 7 separate spheres for the daily rotation of the fixed stars in each planet's independent set of spheres that are no longer required when their function is taken by the single outermost stellar sphere once it is mechanically connected to and transmits its daily rotation to all the other spheres. Thus a daily rotating sphere axially fixed within an already daily rotating sphere would produce a 12-hourly compounded revolution, and yet another daily rotating sphere an 8-hourly compounded revolution, and so forth. So it seems Aristotle's model with 56 spheres rather than 49, and hence with a daily rotating outermost stellar sphere connected to 7 further daily rotating spheres, one for each planet, would have massively contradicted the phenomena. The logical reasoning for this interpretation based on the text of Aristotle's Metaphysics and its commentaries by Dreyer 1906, Grant 1996 and Heath 1913 is as follows.

[To be continued]--Logicus (talk) 18:05, 3 July 2008 (UTC)[reply]

Is the common geocentric planetary order right ?

The article currently claims:

"In geocentric models the spheres were most commonly arranged outwards from the center in this order: the sphere of the Moon, the sphere of Mercury, the sphere of Venus, the sphere of the Sun, the sphere of Mars, the sphere of Jupiter, the sphere of Saturn, the starry firmament, and sometimes one or two additional spheres."

But is this right, rather than rather Moon, Venus, Mercury, Sun...? Although the Apian diagram shows Moon Mercury Venus, the geoheliocentric diagrams show Moon Mercury Venus Sun as it were, and I had also somehow got the impression this was the most common arrangement for the pure geocentric model. I suggest this claim at least needs a citation, so will flag it. --Logicus (talk) 17:48, 25 June 2008 (UTC)[reply]

Almagest a purely geometrical model ?

The article currently claims:

"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"

But what is the evidence that the Almagest is a non physical purely geometrical model ? It clearly talks of the spheres as though real, such as in Book 9 for example.

A citation to the Almagest itself in English translation denying the physical reality of the spheres is surely needed here, so I shall flag it.

It then claims next

"In doing so, he achieved greater mathematical detail and predictive accuracy than had been lacking in earlier spherical models of the cosmos."

But in doing what ? By extending a geometrical model to a physical model ? This needs clarifying, disambiguating.

--Logicus (talk) 18:01, 26 June 2008 (UTC)[reply]

What did Ptolemy explain or improve upon ?

The article currently claims:

"Through the use of the epicycle, eccentric, and equant, this model of compound circular motions could account for all the irregularities of a planet's apparent movements in the sky.[7][8]"

But if this means Ptolemy explained all the observed phenomena in exact detail, as it appears to mean, then it is patently false, since otherwise this would have been the end of planetary astronomy in completely perfect predictions without room for improvement.

But if "irregularities" means deviations from some rule, it is meaningless unless the rule(s) and irregularities are identified.

So what does it mean ? Is it trying to say Ptolemy explained more types of phenomena than previously had been ? But what ?

One thing the Ptolemaic model explained to some extent was variable brightness for planets such as Venus and Mars, but this is hardly an irregularity rather than a variation, and anyway such had already been explained by the epicyclical models of Heraclides, Apollonius and Hipparchus.

What is actually required here is a statement of what preceding model/astronomy Ptolemy's model improved upon and how, if indeed it did. Presumably it was the astronomy of Hipparchus he was trying to improve on, including in such important respects as increasing the Hipparchan star catalogue by hundreds(?) of stars.

However, mention of Robert Newton's 1977 thesis that Ptolemy was a massive fraudster who concocted his claimed observations from those of Hipparchus to fit his model also needs to be included. (Gingerich's 1980 apologetics 'Was Ptolemy a fraud ?' is of interest).

In the interim of a reliable statement of Ptolemy's achievement being provided, I propose the deletion of this false or meaningless claim, unless it can be acceptably clarified.

It should perhaps be noted that Gingerich's assessment of Ptolemy's astronomical achievement seems patently false:

"...for the first time in history (so far as we know) an astronomer has shown how to convert specific numerical data into the parameters of planetary models, and from the models has constructed a homogeneous set of tables...from which solar, lunar and planetary positions and eclipses can be calculated as a function of any given time." (p55 The Eye of Heaven)

But obviously the conversion of "specific numerical data into the parameters of planetary models" was already long entrenched, for example in such trivialities as the observed data of a 24 hour rotation of the fixed stars converted into the parameter of the period of revolution of a uniformly rotating sphere, or Aristarchus's conversion of data into parameters of the sizes of spheres. And publishing the predictions of a model is a publishing achievement rather than an astronomical achievement.

--Logicus (talk) 15:30, 27 June 2008 (UTC)[reply]

User Deor has restored this false or meaningless claim deleted by Logicus without justification. The fact that somebody makes this bizarre claim does not mean it should therefore be repeated in Wikipedia. But in the first instance I propose Deor should provide the actual quotation from the source supplied that actually makes this bizarre claim, to see whether it does justify it.. One often finds with Wikipedia history of science sources for claims made that they do not justify the claim made because the author has misinterpreted what they actually said. I shall delete the claim again until it is reliably justified, but which of course it cannot be essentially because it is blatantly false. --Logicus (talk) 17:35, 28 June 2008 (UTC)[reply]
User Deor uncivilly transgresses Wikipedia courtesy requirements
User Deor has yet again restored the following untenable claim first deleted by Logicus on 27 June after demonstrating it was either false or meaningless:
"Through the use of the epicycle, eccentric, and equant, this model of compound circular motions could account for all the irregularities of a planet's apparent movements in the sky.[7][8]"
without providing any justifying quotation for this claim from the justifying sources given, as courteously requested by Logicus here on 28 June in Talk as follows:
"User Deor has restored this false or meaningless claim deleted by Logicus without justification. The fact that somebody makes this bizarre claim does not mean it should therefore be repeated in Wikipedia. But in the first instance I propose Deor should provide the actual quotation from the source supplied that actually makes this bizarre claim, to see whether it does justify it.. One often finds with Wikipedia history of science sources for claims made that they do not justify the claim made because the author has misinterpreted what they actually said. I shall delete the claim again until it is reliably justified, but which of course it cannot be essentially because it is blatantly false. --Logicus (talk) 17:35, 28 June 2008 (UTC)"
Thus Deor is apparently in breach of the courtesy requirement stipulated in the second and third paragraphs of the following Wikipedia rules for Verifiability in reliable sources
" # ^ When content in Wikipedia requires direct substantiation, the established convention is to provide an inline citation to the supporting references. The rationale is that this provides the most direct means to verify whether the content is consistent with the references. Alternative conventions exist, and are acceptable when they provide clear and precise attribution for the article's assertions, but inline citations are considered "best practice" under this rationale. For more details, please consult Wikipedia:Citing_sources#How_to_cite_sources.
  1. ^ When there is dispute about whether the article text is fully supported by the given source, direct quotes from the source and any other details requested should be provided as a courtesy to substantiate the reference.
The burden of evidence lies with the editor who adds or restores material. All quotations and any material challenged or likely to be challenged should be attributed to a reliable, published source using an inline citation.[1] "
Logicus would be grateful for Deor's compliance with these courtesy requirements, especially noting that Logicus has repeatedly shown Deor's friend McCluskey's cited sources do not justify the claims he makes, whereby McCluskey stands exposed as committing Original Research and breaching NPOV in such cases. In one recent major blunder in this respect, in the Scientific Revolution article's Talk page on 18 April McCluskey tried his usual stunt of insinuating or accusing Logicus's corrections of his untenable POV handiwork breach NPOV because Logicus had pointed out Aristotle did not maintain all motion requires an external force but only violent motion, contrary to McCluskey's claim that Aristotle did according to Stillman Drake, whereupon Logicus had to quote the Stanford Encyclopedia of Philosophy on Aristotle at McCluskey before he would accept Logicus was right and he and Drake as reported were wrong. The triumvirate of Deor, McCluskey and Ragesoss would do well to study this episode as a powerful illustration of how it is they, not Logicus, who impose POVs and Original Research in Wikipedia history of science articles, whilst making insulting unjustified accusations of such against Logicus who challenges them.
Will the outcome be similar in this case ? Will Deor manage to find some textual quotation that shows some historians of science do indeed hold this manifestly mistaken view ?
--Logicus (talk) 01:01, 7 July 2008 (UTC)[reply]

Restoration of section on impetus dynamics of spheres in ‘Middle Ages’

Logicus proposes:I shall now restore the section on impetus dynamics previously deleted by user Deor without any good reason, but for which deletion Deor has provided no valid justification, but rather to the contrary a justification that entails it definitely must be included.(See above) Deor claimed "The article should deal with exactly what its title implies—the spheres, their natures, and their history in human thought — not the theories of impetus or inertia." But to explain again for Deor and the hard of understanding, the theory of impetus deals exactly with the natures of the spheres, namely whether they are animistic or mechanistic, driven by inner animate souls or by angels or by inanimate forces in their natures.

For a 'scholarly' precedent in the inclusion of discussion of the issue of impetus dynamical explanations of the motions of the celestial spheres in discussions of the medieval physics of the spheres, Deor may wish to consult that American author much favoured by McCluskey, Edward Grant, in his 1996 The Foundations of Modern Science in the Middle Ages. Discussion of Buridan’s impetus mechanics of the spheres is included in its section on the physics of the celestial region ‘The Celestial Region: The causes of celestial motion.’ on page 112.--Logicus (talk) 16:14, 27 June 2008 (UTC)[reply]

Logicus restores Deor deletion: Deor has unjustifiably deleted this restoration on the patently invalid ground it is unsourced, and with the bogus objection of no consensus on the Talk page. If such expressed consensus were required, there would be virtually no articles.--158.143.135.0 (talk) 18:02, 28 June 2008 (UTC)[reply]

Logicus's restoration is as follows:

Parisian impetus dynamics and the spheres

In the 14th century the logician and natural philosopher Jean Buridan, Rector of Paris University, subscribed to the Avicennan variant of Aristotelian impetus dynamics according to which impetus is conserved forever in the absence of any resistance to motion, rather than being evanescent and self-decaying as in the Hipparchan variant. In order to dispense with the need for positing continually moving intelligences or souls in the celestial spheres, which he pointed out are not posited by the Bible, Buridan applied the Avicennan self-conserving impetus theory to their endless rotation by extension of a terrestrial example of its application to rotary motion in the form of a rotating millwheel that continues rotating for a long time after the originally propelling hand is withdrawn, driven by the impetus impressed within it.[ref>See p112 of Edward Grant's 1996 The Foundations of Modern Science in the Middle Ages for his account of Buridan's application of impetus dynamics to celestial motion.[/ref>[ref>According to Buridan's theory impetus acts in the same direction or manner in which it was created, and thus a circularly or rotationally created impetus acts circularly thereafter.</ref> Earlier Franciscus de Marchia had given a partial impetus dynamics account of celestial motion in the form of the sphere’s angel continually impressing impetus in its sphere whereby it was moved directly by impetus and only indirectly by its moving angel.[ref>See p112 The Foundations of Modern Science in the Middle Ages Edward Grant 1996</ref>This hybrid mechanico-animistic explanation was necessitated by the fact that de Marchia only subscribed to the Hipparchan-Philoponan impetus theory in which impetus is self-dissipating rather than self-conserving, and thus would not last forever but need constant renewal even in the absence of any resistance to motion.

Buridan wrote on the impetus of the celestial spheres as follows:

"God, when He created the world, moved each of the celestial orbs as He pleased, and in moving them he impressed in them impetuses which moved them without his having to move them any more...And those impetuses which he impressed in the celestial bodies were not decreased or corrupted afterwards, because there was no inclination of the celestial bodies for other movements. Nor was there resistance which would be corruptive or repressive of that impetus."[ref>Questions on the Eight Books of the Physics of Aristotle: Book VIII Question 12 English translation in Clagett's 1959 Science of Mechanics in the Middle Ages p536</ref>

However, having discounted the possibility of any resistance due to a contrary inclination to move in any opposite direction and due to any external resistance, Buridan obviously also discounted any inherent resistance to motion in the form of an inclination to rest within the spheres themselves, such as the inertia posited by Averroes and Aquinas. And in fact contrary to that inertial variant of Aristotelian dynamics, according to Buridan "prime matter does not resist motion". But this then raises the question within Aristotelian dynamics of why the motive force of impetus does not therefore move them with infinite speed. The impetus dynamics answer seemed to be that it was a secondary kind of motive force that produced uniform motion rather than infinite speed, just as it seemed Aristotle had supposed the planets' moving souls do, or rather than uniformly accelerated motion like the primary force of gravity did by producing increasing amounts of impetus. --158.143.135.0 (talk) 18:04, 28 June 2008 (UTC)[reply]

You've sourced the material in part, but the question of relevance to this article still remains, as does, more importantly, the fact that the speculative conclusions ("obviously discounted"; "the impetus dynamics answer seemed to be") drawn in the final paragraph violate WP:OR. I suggest that you read that policy—in particular, the section WP:SYN—before attempting to readd the material. Deor (talk) 10:56, 29 June 2008 (UTC)[reply]
Logicus improvement: Deor yet again fails to explain why material on the causes of motion of the celestial spheres is not of absolutely central relevance to an article on the spheres. His claims that the last paragraph of the above text violates Wiki OR rules are also mistaken. But this may be made clearer by the following proposed improved version of the last paragraph of the above text on impetus dynamics and the spheres:
'However, having discounted the possibility of any resistance due to a contrary inclination to move in any opposite direction or due to any external resistance, in concluding their impetus was therefore not corrupted by any resistance Buridan also discounted any inherent resistance to motion in the form of an inclination to rest within the spheres themselves, such as the inertia posited by Averroes and Aquinas. For otherwise that resistance would destroy their impetus, as the anti-Duhemian historian of science Annaliese Maier maintained the Parisian impetus dynamicists were forced to conclude because of their belief in an inherent inclinatio ad quietem or inertia in all bodies. But in fact contrary to that inertial variant of Aristotelian dynamics, according to Buridan prime matter does not resist motion.[ref>See e.g. Moody's statement "What I have found in Buridan's writings...is the repeated assertion that "prime matter" does not resist motion..." in footnote 7 p32 of his essay Galileo and his precursors in Galileo Reappraised Golino (ed) University of California Press 1966</ref>But this then raised the question within Aristotelian dynamics of why the motive force of impetus does not therefore move the spheres with infinite speed. One impetus dynamics answer seemed to be that it was a secondary kind of motive force that produced uniform motion rather than infinite speed,[ref>The distinction between primary motive forces and secondary motive forces such as impetus was expressed by Oresme, for example, in his De Caelo Bk2 Qu13, which said of impetus, "it is a certain quality of the second species...; it is generated by the motor by means of motion,.." [See p552 Clagett 1959]. And in 1494 Thomas Bricot of Paris also spoke of impetus as a second quality, and as an instrument which begins motion under the influence of a principal particular agent but which continues it alone. [See p639 Clagett 1959].</ref> just as it seemed Aristotle had supposed the spheres' moving souls do, or rather than uniformly accelerated motion like the primary force of gravity did by producing constantly increasing amounts of impetus. However in his Treatise on the heavens and the world in which the heavens are moved by inanimate inherent mechanical forces, Buridan's pupil Oresme offered an alternative 'Thomist' response to this problem in that he did posit a resistance to motion inherent in the heavens (i.e. in the spheres), but which is only a resistance to acceleration beyond their natural speed, rather than to motion itself, and was thus a tendency to preserve their natural speed.[ref>"For the resistance that is in the heavens does not tend to some other motion or to rest, but only to not being moved any faster." Bk2 Ch 3 Treatise on the heavens and he world</ref>This analysis of the dynamics of the motions of the spheres seems to have been a first anticipation of Newton's conception of inertia as only resisting accelerated motion but not resisting uniform motion.' —Preceding unsigned comment added by 80.6.94.131 (talk) 18:05, 2 July 2008 (UTC)[reply]
Police Constable Deor ? Logicus says No !
Imperious User Deor has elected to set himself up as Police Constable Wikipedian who polices Wikipedia and reports breaches of what he imagines to be its rules and breaches of its rules to its administrators. Here we present Deor's latest arrogant imperious mistaken comments posted to Logicus's User Talk page for everybody to read
"[edit] Celestial spheres redux
I'm going to revert your additions and deletions once again. Repeatedly adding material that is not relevant to the article's topic and, in essence, constitutes an original synthesis of material in primary sources is disruptive and impermissible in Wikipedia. Any further disruption at this article will be brought up at Wikipedia:Administrators' noticeboard/Incidents, as you have repeatedly attempted to insert your original research and personal interpretations of historical sources into multiple articles. This is an encyclopedia that relies on information gleaned from secondary sources, not a forum for posting what appears to individuals to be "logically" inferrable from the historical record. Deor (talk) 18:31, 3 July 2008 (UTC)
Retrieved from "http://en.wikipedia.org/wiki/User_talk:Logicus" "
But on the cardinal issue here of relevance, it should be self-evident to one and all that any material on the causes of the motions of the celestial spheres, such as the theories of Buridan, is of absolutely central relevance to any article on the celestial spheres and their motions. And yet Wiki User Deor repeatedly seeks to deny this, and under repeated challenge to provide any rational justification for this unjustifiable POV, repeatedly fails to do so. Why is this ? Should User Deor be banned from meddling with Wikpeida articles because of his anti-educational tendency. [Watch this space !] Logicus
The Restoration: Logicus has courteously given Deor over three weeks to substantiate his unsubstantiated allegations that (i) the medieval impetus dynamics of the celestial spheres is not relevant to this article and (ii) Logicus's account of it constitutes Wiki Original Research. But he has done neither, in spite of Logicus having posted the text of his account on User talk:Deor with the following invitation:
"Logicus now invites Deor to either demonstrate his claim that the following text is 'in essence an original synthesis of material in primary sources' within 48 hours, or else desist from any further unagreed deletions of Logicus's contributions to the article on this topic."
Thus Logicus has added the text to the article, and trusts Deor will desist from any further deletion of it.
--Logicus (talk) 15:33, 30 July 2008 (UTC)[reply]

Logicus restores pre 4 May paragraph 2

I have restored the pre 4 May paragraph 2 because subsequent edits have introduced error and confusion. See my critical comments on the subsequent version in square brackets as follows:

"The spheres were said to surround the earth [No, not the heliocentric spheres of Copernicus --Logicus (talk) 19:22, 10 July 2009 (UTC)], which was understood to be spherical, stationary, and at the center of the universe.[Not the heliocentric spheres--Logicus (talk) 19:22, 10 July 2009 (UTC)][26] The spheres were typically in this order up from the earth: Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn, and fixed stars. Medieval Christians identified the sphere of stars with the Biblical firmament and sometimes posited an invisible layer of water above the firmament, to accord with Genesis.[26] A tenth sphere [But there were dozens of spheres, not merely ten. --Logicus (talk) 19:22, 10 July 2009 (UTC)], inhabited by angels, appeared in some accounts.[26] The order of the lower planets was not universally agreed. Because Venus and Mercury orbit closer to the sun than earth, their positions in the sky are always near the sun.[This is an unintelligible explanation of their bounded elongation--Logicus (talk) 19:22, 10 July 2009 (UTC)] The celestial sphere model doesn't explain this phenomenon [Wrong, it did explain their bounded elongation--Logicus (talk) 19:22, 10 July 2009 (UTC)], and scholars disagreed on the positions of Mercury and Venus. Plato and his followers ordered them Moon, Sun, Mercury, Venus, and then followed the standard model for the upper spheres.[27] Ptolemy placed both of them beneath the Sun and with Venus beneath Mercury, but noted others placed them both above the Sun, and some even on either side of the Sun, as Alpetragius came to do. "[reply]

Proposed change from Celestial spheres to Celestial orbs

I've been looking at the literature on this topic lately, and I've found that there appears to be a tendency, especially among historians of science, to treat this topic under the title of Celestial orbs rather than Celestial spheres. It might be worthwhile to change the title of this article; this change would also have the advantage of avoiding confusion with the modern concept of the Celestial sphere.

Before undertaking such a change (which should involve careful editing to achieve consistent terminology within the article as well), I'd like to here comments on this idea. --SteveMcCluskey (talk) 20:33, 7 September 2009 (UTC)[reply]

This seems to me an unecessary upheaval. Why not just put in a redirect for 'celestial orbs' to 'celestial spheres'? I suspect the somewhat arch terminology of historians of science would not be that of Joanna Public (-: --Logicus (talk) 18:11, 8 September 2009 (UTC)[reply]

Restoring introductory text on order of spheres.

The replacement text introduced by McCluskey on 7/09/09is both wrong about the number of spheres and thus about their order, and also loses important informational detail in the original. And the sentence about medieval Christian spherist cosmology is a detail that really belongs to the section on the middle ages.

So I propose to restore an improved version of the original text, but incorporating the Eastwood reference supplied by McCluskey. I move the medieval Christian sentence to the medieval section.

For reference McCluskey's text was as follows:

"In geocentric models the spheres were said to surround the earth, which was understood to be spherical, stationary, and at the center of the universe.[2] The spheres were typically in this order up from the earth: Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn, and fixed stars. Medieval Christians identified the sphere of stars with the Biblical firmament and sometimes posited an invisible layer of water above the firmament, to accord with Genesis.[2] A tenth sphere, inhabited by angels, appeared in some accounts.[2] The order of the lower planets was not universally agreed; Plato and his followers ordered them Moon, Sun, Mercury, Venus, and then followed the standard model for the upper spheres.[3]"

--Logicus (talk) 18:08, 9 September 2009 (UTC)[reply]

Physical spheres, not geometrical astronomy

The section on the Renaissance begins with a discussion of the Copernicus's understanding of the physical spheres and ends with their abandonment by Kepler, but the bulk of the section is concerned principally with the positional and geometrical astronomy of the planets. Indicative of this approach are two figures displaying the geoheliocentric models of Paul Wittich and Ursus, neither of which discuss three dimensional, physical planetary spheres. This material might fit better in the article on the Copernican revolution. --SteveMcCluskey (talk) 19:43, 7 October 2009 (UTC)[reply]

Newton & Lunar Orb

When Newton used the mathematical procedure described in the article to compute the force of the Moon from the center, he was not basing them on the Lunar orb. He imagined that a square circumscribes the circular path of the Moon, and on that basis computed the central force. (Westfall, Never at Rest, pp. 148-50) --SteveMcCluskey (talk) 20:08, 7 October 2009 (UTC)[reply]

The Galileo discussion is also dubious. Galileo wrote as early as 1615 to Monsignor Dini:
However, this is not to take away motions made by the stars in circles eccentric to earth or in epicycles, which are the genuine and simple assumptions of Ptolemy and the other great astronomers; it is rather to repudiate the solid, material, and distinct orbs, introduced by the builders of models to facilitate understanding by beginniers and computation by calculators; this is the only fictitious and unreal part, as God does not lack the means to make the stars move in the immense celestial space, within well-defined and definite paths, but without having them chained and forced. (Finocchiaro, The Galileo Affair, pp. 61-2)
Since Galileo speaks of epicycles, it is clear that he is using "stars" in the general sense, which includes planets. --SteveMcCluskey (talk) 20:24, 7 October 2009 (UTC)[reply]


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)[reply]

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)[reply]


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

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)[reply]
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)[reply]

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)[reply]

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)[reply]

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)[reply]
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)[reply]
I agree completely with Sławomir Biały. Very well stated. —Finell 20:17, 22 November 2009 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
  • 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)[reply]
  • 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)[reply]
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)[reply]
  • (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)[reply]
  • 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)[reply]
  • 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 215a24 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)[reply]
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)[reply]
Now answered below.
—David Wilson (talk · cont) 19:25, 28 November 2009 (UTC)[reply]
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 (249b27–250b10), 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 250a9–250a27 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)[reply]
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)[reply]
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)[reply]
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 300a24–27, 269a10–12, and Physics, 215a24ff, 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)[reply]
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)[reply]
Answered below.
—David Wilson (talk · cont) 15:10, 26 November 2009 (UTC)[reply]


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)[reply]

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

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)[reply]

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

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)[reply]

  • 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)[reply]

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)][reply]

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)[reply]

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)][reply]

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)[reply]

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)[reply]

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)][reply]

(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)][reply]

(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)][reply]

(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)][reply]

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)[reply]

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)[reply]

Towards a Summary

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

class="wikitable " 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)[reply]

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)[reply]

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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]

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)[reply]
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)[reply]
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)[reply]

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.

" ... 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;
"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."
"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)[reply]

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)[reply]

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)[reply]

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)[reply]
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)[reply]
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)[reply]
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.

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)[reply]

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)[reply]

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

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)[reply]

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

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)[reply]
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)[reply]

(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)[reply]
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)[reply]

'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)[reply]

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)[reply]
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)[reply]

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)[reply]

  1. ^ The mathematical rules of natural motion are presented in such as Physics 215a24f
  2. ^ Aristotle presents his mathematical rules for anti- gravitational 'violent' motion in Physics Bk7 Ch5. Of course the external resistance of the medium must also be added to the gravitational resistance, but Aristotle always discounts it in his analyses of violent motions, which are thereby the equivalent of violent motion in a vacuum. Thus in the ship-hauling example he considers the only resistance is the ship's weight
  3. ^ i.e. in a media void but with natural places and therefore with gravity, as opposed to a pure void without any natural places either, dubbed 'the great inane', and thus without gravity insamuch as gravity is only a tendency towards some natural place
  4. ^ See Aristotle's Physics 215a24f. The impossibility of such instantaneous motion was the refuting absurdity of the reductio ad absurdumof one of Aristotle's leading anti-atomist arguments against the possibility of motion in a void
  5. ^ Physics 690.34-691.5, as translated by Sorabji on p333 of his 2004 The Philosophy of the Commentators 200-600 AD Volume 2
  6. ^ The logic of this refutation of Aristotle's law of motion may be reconstructed as follows. The prediction of the speed of the spheres' rotations in Aristotelian celestial dynamics is given by the following logical argument [ (i) v α F/R & (ii) F > 0 & (iii) R = 0 ] entail v is infinite. These premises comprise the conjunction of Aristotle's law of motion in premise (i) with his dynamical model of celestial motion in premises (ii) & (iii). But the observation v is not infinite entails at least one premise must be false. But which one ? Philoponus decided to direct the falsifying arrow of modus tollens at the very first of the three theoretical premises of this prediction, namely Aristotle's law of motion, and replace it with his alternative law v α F - R. But logically premises (ii) or (iii) could have been rejected and replaced instead.
  7. ^ Some regard Philoponus's rejection of the core law of Aristotle's dynamics, together with the rejection of his theory of projectile motion in favour of the Hipparchan impetus theory, as the overthrow of Aristotelian dynamics tout court. See Sorabji's 1987 Philoponus and the Rejection of Aristotelian Science.
  8. ^ 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 ] entail v = ¥ was to reject its third premise R = 0 instead of its first premise as Philoponus had. It seems that nobody, even Newton, ever contemplated revising its second premise.
  9. ^ For Aquinas's innovation in extending Averroes' purely celestial inertia to the sublunar region and thus universalising inertia, see Bk4.L12.534-6 of Aquinas's Commentary on Aristotle's Physics Routledge 1963. See Duhem's analysis of this - St Thomas Aquinas and the Concept of Mass- on p378-9 of Roger Ariew's 1985 Medieval Cosmology, an extract also to be found online at <http://ftp.colloquium.co.uk/~barrett/void.html>. But Duhem notably fails to accord Averroes his originating innovatory due compared with Avempace and Aquinas, as more clearly accorded by Sorabji's 1988 Matter, Space and Motion p284. Duhem was originally refuting Mach's claim that Newton first discovered the crucial notion of inertial resistant mass in the 17th century, an error surprisingly still repeated by the self-professed Duhemian gradualist Bernard Cohen a century later in his 2002 Cambridge Companion to Newton article Newton's concepts of force and mass p59.
  10. ^ See e.g. p144 of Koyre's 1939/78 Galileo Studies. But Koyre was obviously mistaken in claiming Kepler's notion of inertia "prevented him from laying the foundations of the new dynamics", since the very notion of inherent inertial resistant mass without which forced motion would be instantaneous was in fact also fundamental in Newton's dynamics.
  11. ^ Thus Newton annotated his Definition 3 of the inherent force of inertia in his copy of the 1713 second edition of the Principia as follows: "I do not mean Kepler's force of inertia, by which bodies tend toward rest, but a force of remaining in the same state either of resting or of moving." See p404 Cohen & Whitman 1999 Principia
  12. ^ Its first millenium had seen Philoponus's 6th century innovation of net force in which those forces of resistance by which the motive force was to be divided in Aristotle's dynamics (e.g. media resistance and gravity) were rather to be subtracted, thus providing what was eventually to become the numerator F - R of the classical mechanics law, and had also seen Avicenna's 10th century terrestrial impetus dynamics innovation, which maintained that gravitational free-fall under a constant gravitational force would be dynamically endlessly accelerated, rather than only initially accelerated with a terminal speed as in the Hipparchan impetus theory, thus eventually providing uniform acceleration as the subject of the law rather than average speed.
  13. ^ The mathematical rules of natural motion are presented in such as Physics 215a24f
  14. ^ Aristotle presents his mathematical rules for anti-gravitational 'violent' motion in Physics Bk7 Ch5. Of course the external resistance of the medium must also be added to the gravitational resistance, but Aristotle always discounts it in his analyses of violent motions, which are thereby the equivalent of violent motion in a vacuum in effect. Thus in the ship-hauling example he mentions, the only resistance considered is the ship's (horizontal) weight
  15. ^ i.e. where in this case a vacuum is only a space without any medium in it, but still one with natural places and therefore with gravity, as opposed to a pure void without any natural places either, dubbed 'the great inane', i.e. the great directionless, and thus without gravity insamuch as gravity is just a tendency towards some natural place.
  16. ^ See Aristotle's Physics 215a24f. The presumed impossibility of such instantaneous motion was the refuting absurdity of the reductio ad absurdum of one of Aristotle's leading anti-atomist arguments against the possibility of motion in a void expounded in this passage.
  17. ^ In fact it seems Strato, Aristotle's second successor as head of the Lyceum, had objected that the spheres did not need movers and made all their motions natural, as Cicero put it, 'to free God from work'. See Sorabji's Matter, Space and Motion 1988 p223. This would thus avoid the consequence of the motion being infinitely fast, rather than being interminable. Unlike interminable locomotion, interminable rotation was not an oxymoron in Aristotle's physics.
  18. ^ Physics 690.34-691.5, as translated by Sorabji on p333 of his 2004 The Philosophy of the Commentators 200-600 AD Volume 2
  19. ^ Some regard Philoponus's rejection of the core law of Aristotle's dynamics, together with the rejection of his theory of projectile motion in favour of the Hipparchan impetus theory, as the overthrow of Aristotelian dynamics tout court. See Sorabji's 1987 Philoponus and the Rejection of Aristotelian Science. However, in recent years at least impetus dynamics has come to be accepted as an organic auxiliary part of the Aristotelian science of motion rather than its total overthrow as Duhem had maintained.
  20. ^ For Aquinas's innovation in extending Averroes' purely celestial inertia to the sublunar region and thus universalising inertia, see Bk4.L12.534-6 of Aquinas's Commentary on Aristotle's Physics Routledge 1963.
  21. ^ See Duhem's analysis of this development - St Thomas Aquinas and the Concept of Mass- on p378-9 of Roger Ariew's 1985 Medieval Cosmology, an extract also to be found online at <http://ftp.colloquium.co.uk/~barrett/void.html>. But Duhem notably fails to accord Averroes his originating innovatory due compared with Avempace and Aquinas, as more clearly accorded by Sorabji's 1988 Matter, Space and Motion p284. Duhem was originally refuting Mach's claim in his Science of Mechanics that Newton first discovered the crucial notion of inertial resistant mass in the 17th century, an error surprisingly still repeated by the self-professed 'Duhemian gradualist' Bernard Cohen a century later in his 2002 Cambridge Companion to Newton article Newton's concepts of force and mass p59.
  22. ^ See p423 of Ariew's 1985 Medieval Cosmology
  23. ^ p128f of Galileo's Opere VIII, see p87f of Drake's 1974 Two New Sciences translation.
  24. ^ This refutes the Kantian and Baconian experimentalist account of the origins of Newtonian physics, as distinct from celestial observation.
  25. ^ See Metaphysics 12.8, p881-884 in The Basic Works of Aristotle Richard McKeon (Ed) The Modern Library 2001
  26. ^ a b c David C. Lindberg, The beginnings of Western science. Chicago: University of Chicago Press. 1992.
  27. ^ In his De Revolutionibus Bk1.10 Copernicus claimed the empirical reason why Plato's followers put the orbits of Mercury and Venus above the sun's was that if they were sub-solar, then by the sun's reflected light they would only ever appear as hemispheres at most and would also sometimes eclipse the sun, but they do neither. (See p521 Great Books of the Western World 16 Ptolemy-Copernicus-Kepler)
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