Talk:Celestial spheres

Spheres and orbs
I was recently reading Pierre Duhem's Le Système du Monde, vol. 2, p. 123, where he presents the following text from Alhazen (in French translation of a Latin translation of the original Arabic): "Les sphères des trois planètes supérieures... sont absolument semblables entre elles, et par le nombre des orbes que les composent...."

Perhaps Duhem's use of these two different synonyms suggests a way out of our problem of counting spheres. Why not consider the planets' spheres as made up of numerous consitutuent orbs. Such a terminological distinction would limit the number of spheres to the seven planetary spheres, the stellar sphere, and the other spheres mentioned in the introductory section, in more "popular" discussions and illustrations, and elsewhere. Each planet would then have its constituent orbs resulting in the different totals found for Eudoxus, Callipus, Aristotle, Ptolemy, etc. Alternatively, we could consider the planets' orbs to be made up of constituent spheres; the main point is to establish consistent use of these two synonyms within the article.

I'm considering running through the article to work for consistency on this terminology, which would make a complicated system clearer to a reader. I'd like comments before I take the effort involved. --SteveMcCluskey (talk) 19:49, 29 December 2009 (UTC)


 * We would need a reliable secondary source to support an interpretation, or re-interpretation, of this sort. I also doubt that orb and sphere have different meanings in the context of pre-modern astronomy. The two words exist because orb derives from French via Latin, while sphere derives from Greek. Dictionaries have a definition for both words as meaning what the article calls the celestial spheres. In the title of Copernicus's main work, orbium is usually translated as "spheres", but sometime as "orbs".—Finell 04:26, 30 December 2009 (UTC)


 * Of course, you're right. I was just hoping for a consistent way to use these synonyms to achieve simple rhetorical clarity in the article.  If it won't work, we'll just have to struggle with something like "total orbs" or "concentric spheres" (the latter used by Grant) and "component spheres", "constituent spheres", or even "eccentric spheres" for the parts that make up the whole.  Perhaps your copy-editors eye could see a way through this.--SteveMcCluskey (talk) 13:48, 30 December 2009 (UTC)


 * The terms' meanings and the concepts that they represent were not used consistently by each author or in each period. It became a patchwork of "fixes" to "save the appearances" (i.e., to explain the planets' observed positions while clinging desperately to the ancient ideal that celestial motions must be perfect circles). Statements about the physical makeup or properties of the spheres themselves (that is, other than the orbits, which had to conform to observations) were entirely products of philosopher-astrologer-astronomers' imaginations. Subsequent scholars (our secondary sources) have tried to make out a neat, consistent system from the mess, and they (unsurprisingly) each use their own terminology in doing so. (This is just my own unpublished, unpublishable, unreliable take on this. You and others are much better-read about this subject than I am.) One way out may be to take the best modern encyclopedic treatment of the subject (I don't know which one that would be) and use its terminology consistently.—Finell 18:08, 30 December 2009 (UTC)


 * The reduction of astronomy to "Saving the appearances" was advocated by some ancient philosophers (Simplicius was apparently the first) and more recently by physicist / philosopher / historian Pierre Duhem. That's pretty much what I learned in grad school and until recently this approach dominated the historical study of ancient astronomy.  However, recent investigations have found increasing evidence that ancient and medieval astronomers had strong commitments to the reality of their models.  It was more than a patchwork of fixes.
 * On a related matter, in the past few days I came across a number of recent articles on the celestial spheres and reviews of a recent two volume study by Michel-Pierre Lerner, Le monde des sphères: Tome 1, Genèse et triomphe d'une représentation cosmique; Tome 2, La fin du cosmos classique. When we add to that Grant's Planets, Stars and Orbs, which is cited frequently here, it seems that there's been a lot of historical work on this topic in the last decade or so.
 * I think you're right on the issue of terminology; there doesn't seem to be a historically legitimate way to make it neat. Most historical and modern writers use spheres and orbs pretty indiscriminately as synonyms.  --SteveMcCluskey (talk) 03:30, 31 December 2009 (UTC)


 * I did not mean to imply that pre-modern astronomers did not believe in the physical reality of their models, or that they thought that "saving the appearances" employed artificial means. They believed that perfect circles must be real on philosophical grounds, and therefore invented devices (epicycles and equants) to retain perfect circles while "saving the appearances" (i.e., conforming to observations). Copernicus appears to have believed in his model, yet he wrote of the importance of "saving the appearances". Even Kepler, the last great astronomer who was also an astrologer, also tried unsuccessfully to make a model based on the traditional concentric spheres that fit improved observations (i.e., that "saved the appearances"), and also tried some other mysticism-based arrangements, until he went modern, discarded the historical and mystical baggage, and worked out his three laws. Kepler is the bridge from the Middle Ages to the Age of Enlightenment, with big assists from Galileo and Newton.—Finell 06:15, 31 December 2009 (UTC)

Dab page in hatnote
There are other possibilities that readers who search for "Celestial spheres" might actually be looking for in addition to Celestial sphere. They might be looking for any number of Sky objects such as Celestial objects, Celestial bodies and Astronomical objects. In addition, they might actually want to peruse the article on the Celestial coordinate system, and for all we know, readers might even be thinking about the Celestial kingdom. As editors, we are not mind readers and can never truly anticipate what readers might be looking for. But we can work toward making things less confusing for readers, and to make what they might be looking for as available to them as possible. And that is the sole purpose of the dab page.

The hatnote could be shortened if other editors agree that it is too long. We might try something like this:

or perhaps even:

&mdash; Paine ( Ellsworth's   Climax )  16:49, 25 June 2010 (UTC)

RE: a reproduction of Peter Apian's Celestial Spheres diagram
Hello,

I recreated Apian's Celestial Spheres diagram and. It clears up the original a bit and makes the text and various divisions more distinct. Any interest in adding it to the page? — Preceding unsigned comment added by Cipozy (talk • contribs) 01:55, 1 October 2015 (UTC)


 * Thanks for creating a nice modern interpretation of the Apianus diagram, which must have involved a lot of work. However, for a historical article like this, I think the original woodcut is more appropriate. --SteveMcCluskey (talk) 18:25, 1 October 2015 (UTC)


 * Alright, I thought that might be the case. I'll only leave it on Wikimedia then. --Cipozy (talk) 15:13, 4 October 2015 (UTC)

External links modified (January 2018)
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Chinese astronomy
The celestial sphere model mentioned in that article links here, but here I find no mention of it. It'd be nice if somone could rectify that omission and make Wikipedia less culturally biased. Thank you! 2A02:8109:1040:1724:B116:3D31:32C9:411B (talk) 15:23, 21 December 2018 (UTC)
 * Good point; parallels to the Greek model of celestial spheres in other cultures should be included in this article. However, Chinese cosmological models have not been as extensively studied as Greek models and it is hard to find good documentation on them. The discussion of the Chinese Celestial Sphere Cosmology, associated with the Hun Tian school, cites an article by Joseph Needham and Colin Ronan in Hetherington's Encyclopedia of Cosmology (1993). That article's discussion of this cosmology is really quite sketchy, pointing  out similarities to Greek models, and hinting at possible influence. Geoffrey Lloyd suggests (Adversaries and Authorities, (1996), pp. 162-3) that Chinese cosmologies were "closely tied to observational techniques … and they are better considered not so much as cosmological theories, as rather ways of doing astronomy." Lloyd never addresses possible Greek influences on Chinese cosmological models, and seems to treat the Chinese model as an independent development.
 * Further investigation into the published sources is called for before the Chinese Celestial Sphere Cosmology can find a place in this article. Please feel free to dig into the literature and make additions. --SteveMcCluskey (talk) 21:56, 21 December 2018 (UTC)