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The School of Athens in this article the image is identified as zoroaster, but now it is used here for hipparchus. Which is it? (talk) 07:15, 19 September 2013 (UTC)

Star Catalogue[edit]


I like your re-write of the section on Hipparchos' star catalogue. About 3 years ago I had an edit war with XJamRastaFire, and I got bogged down before re-writing that section, which thusfar has been mostly X's rather confused text. Maybe stress the point that Ptolemy adapted and extended H's catalogue, so superseded it, which is why H's original work has not been preserved. It was on P's, not H's catalogue that later islamic astronomers built. Note that in his commentary on Aratos, H lists polar distances of stars, which are equivalent to declination: he appears to have used mixed aequatorial and ecliptic coordinates; P later used ecliptic coordinates exclusively; I don't understand the remark about a "real" coordinate system. Also he is famous for having made a celestial globe. Do you have a reference for Pliny's mention of a nova? Tom Peters 16:49, 3 June 2006 (UTC)

Thanks. For basic factchecking of Pliny's mention of the nova (which was already in the text), I went to James Evans' survey (it's on p. 247); the source is Natural History II.95. I have no idea, either, what is meant by the "real" system, so I was slightly conservative in editing. Ptolemy's star catalogue is a contentious subject. I won't write up anything on it until I have a chance to review the R. R. Newton debate, which might be a while. This article still needs a lot of work before it's useful as an encyclopedia article for a general audience. It seems like it was trying to include everything ever written about Hipparchus. Maestlin 20:42, 5 June 2006 (UTC)
Not much is known about H. anyway, but a few years ago I did read up on him, and because the Wikipedia article was very poor I started writing, and kept writing, and writing... He did in fact have a very fruitful career, and we know the titles of 13 books. I think it is valuable to not just mention his studies and results, but also describe his methods because it shows how people back then approached phenomena that everyone can still see and wonder about today. As for the controversy on Ptolemy's star catalogue: that is a very hairy subject in which a minority group has a very vocal position. Anyway it involves Ptolemy rather than Hipparchos so better not rake up the mirk too much here. Tom Peters 23:14, 8 June 2006 (UTC)

Solar and lunar theory[edit]

Does anyone checking this page know the rationalization for separate sections on "motion of the moon" and "orbit of the moon" (and ditto for sun)? "Orbit" is anachronistic in this context. I am unsure what the editor was trying to distinguish. Maestlin 00:37, 28 March 2006 (UTC)

I originally made that distinction: "motion" refers to period lengths and ratio's babylonian style; "orbit" refers to geometry, which is Greek and in which Hipparchus made his most innovative contributions. Tom Peters 15:40, 17 July 2006

So "orbit of the moon" is something like "lunar theory" then? Maestlin 17:52, 20 July 2006 (UTC)

Well, "lunar theory" if I'm not mistaken nowadays refers to the dynamical description of the motion of the Moon under influence of the gravitational (and other) forces of th Earth, Sun, and planets. The ancients had no such concepts. The Hellenistic scientists treated the motion from a geometric or even mechanical model; the Babylonians apparently didn't care about mechanics but only about events and positions, which could be predicted with simple period relations and arithemetic. Tom Peters 01:26, 22 July 2006 (UTC)

The word "theory" is used somewhat differently in the history of premodern astronomy. It's fairly common to write of the solar, lunar, and planetary theories of Ptolemy and Copernicus, for instance. I have in mind accomplished specialists like O. Neugebauer and N. Swerdlow, not astrophysicists attempting to understand predecessors in familiar terms. Let me ask in another way: By "Orbit of the Sun" you meant that Hipparchus explains the solar phenomena with an eccentric, with such-and-such eccentricity, apsidal line, and tropical year? Maestlin 18:42, 25 July 2006 (UTC)

Well, yes: Hipparchus distinguishes himself from the Babylonians who only worked with a numerical model of the observable phenomena; and from his Greek predecessors who would draw a qualitative geometric model but never fitted the numerical details to observations. Hipparchus seems to have been the first to create models - theories if you like - that were both qualitative and quantitative valid (i.e. that they described, explained, and predicted the observable phenomena). So "lunar theory" in the classical sense would not be an alternative title for my "orbit", but could refer to the merge of the two sections of motion and orbit, if you believe that they should be merged. I have them separated because they come from two separate traditions, can be treated separately, and I don't want to make very long sections. Tom Peters 07:34, 26 July 2006 (UTC)

I'm not 100% sure I follow your reasoning. I brought this matter up in the first place because I am looking for ways to improve Wikipedia's coverage of Hipparchus more useful to general readers; I doubt whether the current version serves their interests. I understand the desire to preserve information that has already been entered into Wikipedia, even though I personally find the sections on planetary motions to be opaque. Maybe the best solution is to set up a separate article on this subject, and write a summary for this oversize page. Maestlin 19:13, 26 July 2006 (UTC)

briefly: as you see, "motion" refers to period lengths. Babylonians used period relations to predict recurrence of events, and most of the values that Hipparchus and Ptolemy used seem to have come from there. "orbit" deals with the typically Greek geometrical models. Before Hipparchus, they would treat planetary motions qualitatively and explain it by excentrics or an epicycle: without however determining the excentricity or size of the orbits from observations, i.e. in a quantitative way.
Anyway, I agree that the article is long: but in what way is it not useful to general readers? My intent has been to collect here what is known about Hipparchus, which is not much, and explain the concepts and put it into context. Wikipedia is not limited by constraints of printing costs and book sizes, so I see no reason not to be comprehensive. The first few paragraphs treat Hipparchus briefly for the casual reader. Tom Peters 11:24, 28 July 2006 (UTC)

Why do I think the article is not useful to the general reader? The reason actually is that it does not say enough about Hipparchus. For instance, the section on the sun and moon IMO doesn't sufficiently explain his synthesis of Babylonian and Greek methods, his inability to create models for the five planets, his reported critique of Greek colleagues for creating inadequate models, or his influence on Ptolemy and possibly Indian astronomy. The article is strong on numbers and method, but still poor in context and in striking a happy medium. It's already pushing the upper limits of article size, and if any more information is added, it will definitely be too long. I'm not worried about saving bytes; I'm concerned about the psychological problems with reading and editing a very long article on a computer screen. Maestlin 18:55, 28 July 2006 (UTC)

Oh well: I guess this is because little is actually known about Hipparchus and his sources and influence (except on Ptolemy), and what we know is derived from references and congruences in (much) later sources. I collected various papers from the past 4 decades, mostly listed under the Literature, and what is in the article is what they tell. I left out the geometrical proofs that they reconstructed. In fact this article contains more info than those on similar lemmata e.g. Ptolemy. Considering the length: I think that what you started, i.e. splicing the sections to their own articles and covering them briefly in the main article, is a valid approach. BTW I think Hipparchus was not inable to create models for the planets, but that he just never got to it. Tom Peters 23:12, 30 July 2006 (UTC)

I've been looking over the history of this article and I think I understand better how it came to be. "Inable" and "never got to it" are probably the same thing in this case. We know he did some work on planetary theories thanks to Almagest IX.2, which combines factual reporting and speculation on Hipparchus' chains of reasoning. Some of the other articles could use more information on the maths, like Ptolemy; actually a fuller discussion of Hipparchus' solar and lunar work could take up some of the slack. Looks like I won't get to it for a while though. Maybe for a long while, since I'll be moving and won't have the ready access to an academic library I've been enjoying. This article has a lot of good points and I just can't do it justice right now. Maestlin 19:25, 1 August 2006 (UTC)

Elaborations on precession[edit]

Someone has added quite some text about precession, and I have several issues with that.

First, it is not accurate. Ptolemy did not confirm Hipparchus' results: his value is significantly different, and he under-estimated the rate of precession; Hipparchus' value was closer to reality. Also the false theory of trepidation of the aequinoxes was invented to match accurate medieval observations to the older but false observations handed down from Ptolemy.

Second, I consider this not NPOV. Ptolemy's star catalogue is highly controversial, and he has even been accused of fraud. So the presentation that he was in line with H. and with later astronomers is misleading.

Third, I find these elaborations out of place: the article, which is already too long, should concentrate on Hipparchus. I can agree that the relation to and differences with Ptolemy would merit attention here: but leave out what happened in the rest of the world before and after his time. That really should be moved to an article about precession proper.

Finally, be very critical about even older cultures knowing about precession. Especially tales about the Egyptians are highly misleading. Anyway, Hipparchus would know nothing about them.

Tom Peters 12:50, 1 March 2006 (UTC)

IMO the useful information about precession should be salvaged and put into a slightly more general article on history of precession, or some such. Even though he is the standard discoverer, Hipparchus' role is not really enough to warrant a separate article, but one that compared him with Ptolemy, added trepidation, etc., could be worthwhile. Likewise, there should be an article about Babylonian influence on Greek astronomy in general, not limited just to Hipparchus. Oh yes, I just started an article on Greek astronomy which might be another place to dump some information. Maestlin 04:33, 14 March 2006 (UTC)
  • I have begun an article on the Discovery of precession by copy-and-pasting from Hipparchus. I decided it would take a lot of heavy editing and rewriting to make it more readable (to me, anyway) and less presentist. I have also set up the article so that it accomodates statements about older cultures knowing precession without affecting the Hipparchus content. Any feedback or contributions would be welcome. If anyone looks at it right now, the unmodified text is between a couple of screeen-wide lines. Once the new article has been hammered into shape, there will be something worthwhile to summarize for this one in place of the current text. Maestlin 02:25, 25 March 2006 (UTC)

The Farnese Atlas[edit]

I have added the following text to this article: "In 2005, it was reported [1] that information from Hipparchus' long lost star catalog may have been preserved in stone as part of the sculpture The Farnese Atlas." I also created the article at The Farnese Atlas. Johntex 18:43, 18 Jan 2005 (UTC)

On Jan 12 I also added information on this: It is symptomatic of the issues with this article that this wasn't more obvious. The article really needs work. A thought that may have already been suggested: maybe we could have a summary page, with a link to the content of the current article for those who want more background and details. Hipparchus background and details anyone? -- Mmm 02:10, Jan 19, 2005 (UTC)
Oops. Sorry about that, Mmm. I guess I did not read the article carefully enough. I like how you have incorporated the information. I do agree the article could use some clean-up. As far as I know, it is not customary to have a "summary" page, the summary is supposed to be the introductory paragraph. However, I have seen temporary pages created to allow for more easy editing when big changes are needed. I am not able to committ to helping on this one right now. I have a lot going at the moment, and I am no expert on this topic. However, I will try to stop by and see if there is a way I can lend a hand if I get the time. Best, Johntex 03:20, 19 Jan 2005 (UTC)


What I had in mind is not really a summary, but more of a concise, readable overview without delving into so much background information and detail. There is a wealth of good stuff in the current article, but it seems a bit bulky and it could really use some wordsmithing, editing, and organizing (as has been pointed out by others). Further, I see that placeholders have been put in for even more detail and content. My thought was that it might be easier to move the current article to a new page, replace the current page with something more concise, and put many links to the original article for those that want to delve deeper. Maybe the sections could be something like this:

  • Brief biography, overview of life & contributions
  • Historical context, influences on him
  • Observations
  • Writings
  • Legacy, his influences on others

I'm sure others can come up with a better outine, but you get the basic idea. I think a few paragraphs on each section would probably give the average encyclopedia user the sort of information they are looking for. As examples to compare, the articles for Plato and Socrates seem about the right length. Like you, I don't feel I have the time or background to really take this on at this point, but I don't mind making the suggestion for someone else! :-) -- Mmm 07:29, Jan 19, 2005 (UTC)

I've largely completed a separate article that supercedes the Distance/Parallax subsection of this article. I've placed a link to the new article in that section, and I've attempted to incorporate as much of the information on this page into it as I possibly could. Barring any objections, I'm going to reduce the nine paragraphs in that section on this page to one, since the information is all redundant now. I suggest this as a model of how the Hipparchus page might be fixed. It would be much more manageable if these subsections were forked off into their own articles. --Dantheox 08:41, 25 December 2005 (UTC)

Rename the article?[edit]

Wouldn't it be better to rename the article Hipparchus of Nicaea? This is the name with which he is more commonly remembered in modern texts. Aldux 21:41, 11 November 2005 (UTC)

I strongly disagree. He should remain as Hipparchus because the astronomer is what readers generally have in mind. Google has Hipparchus with 174,000 hits, whereas "Hipparchus of Nicaea" has only 669 hits and "Hipparchus of Rhodes" has only 602 hits. Analysis of the first few "Hipparchus" Google pages shows that the astronomer is indeed what those pages almost always discuss. These numbers also indicate that moving this page from Hipparchus to Hipparchus (astronomer) was wrong. It was also never discussed on this page. Thus I also disagree with your recent move of Hipparchus (disambiguation) to Hipparchus. — Joe Kress 06:47, 14 November 2005 (UTC)
If a majority is against moving Hipparchus (astronomer) to Hipparchus of Nicaea I won't insist. But as to the second point I have to note that Hipparchus was before only a redirect that pointed to Hipparchus (disambiguation), and I honestly thought it would be more logical the other way around. As for the change of the article name from Hipparchus to Hipparchus (astronomer), it was done quite a long time ago, 13 March 2005, and never appears to have generated protest until now. Aldux 17:51, 14 November 2005 (UTC)
I moved the article from Hipparchus (astronomer) to Hipparchus. All other possible meanings can't compete with the ancient father of astronomy. In fact, all the links to Hipparchus (which was a disambig page, remember) meant the astronomer. Moving Hipparchus to Hipparchus (astronomer) was a very bad idea, but it's all fixed now. Maurog 12:36, 25 June 2007 (UTC)
While there were many historical persons with the name Hipparchus - the Hipparchus who discovered precession is THE Hipparchus and stands above the rest (historically speaking). Terry Macro (talk) 00:15, 29 May 2013 (UTC)
The relevant policies here are WP:PRIMARYTOPIC, WP:ENGLISH WP:COMMON name, and WP:TERSE. In short, Hipparchus is always going to point to this guy as THE Hipparchus; it's not in any sense uncommon for him to be referenced simply as Hipparchus; and, given those two points, there's no good reason to force everyone to type more letters to link to or get to this article. — LlywelynII 11:21, 14 March 2015 (UTC)

which contributions to astrology[edit]

The most recent edit drew this line to my attention: "Astrology developed in the Greco-Roman world during the Hellenistic period, borrowing many elements from Babylonian astronomy; some historians have suggested that Hipparchus played a key role in this."

I believe the recent edit was to word the paragraph in such a way to indicate there is no evidence that Hipparchus himself was an astrologer. That's fine. But I think it should be more specific about what unique astronomical elements Hipparchus contributed to the development of astrology. What about his astronomy was unique from Babylonian astronomy? One thing attributed to Hipparchus that was useful to astrology was the division of the zodiac into 12 signs of equal degrees (30 each). Any other contributions? Zeusnoos 14:10, 17 July 2006 (UTC)"

I made the last edit, and I would be totally happy if you could substantiate additional claims. I don't know whether he was the first to use 12 zoodiacal signs of 30 deg; I did read he was the first to use a circle of 360 deg. His unique contribution was that he was the first to derive quantitative parameters for the abstract geometrical models that the Greek had developed to qualitatively explain the motion of the Sun and Moon. So for the first time it was possible to compute an ephemeris based on a geometrical model, instead of using the phenomenological Babylonian period relations. Before him, no-one could reliably predict a solar eclipse. But apparently he never got to apply his method to the planets, so his influence on astrological computation must have been limited. Tom Peters 15:51, 17 July 2006 (UTC)

Chord table and Pi[edit]

According to the present article:

For his chord table Hipparchus must have used a better approximation for π than the one from Archimedes of between 3 + 1/7 and 3 + 10/71; perhaps he had the one later used by Ptolemy: 3;8:30 (sexagesimal) (Almagest VI.7); but it is not known if he computed an improved value himself.

The article chord seems to imply that what Hipparchus actually approximated (implicitly or explicitly) was the reciprocal, 1/π, as 0;19:6 sexagesimal. This could be compatible with the above: 1/(3;8:30) = 0;19:5.8889 ; true 1/π= 0;19:5.9156 . But 7/22 = 0;19:5.4545 and 71/223 = 0;19:6.188, so equally he could simply have picked the only whole number of seconds in that range. Jheald 01:35, 10 October 2007 (UTC)

First heliocentric system??[edit]

I'm pretty sure Aristarchus is believed to have been the first to propose heliocentrism, actually.. See wikipedia entry on Aristarchus or heliocentrism. Also confirmed by Science and Technology in World History by McClellan and Dorn (pg 82-83), second edition. —Preceding unsigned comment added by (talk) 01:45, 19 October 2010 (UTC)

The article does not say that Hipparchus was the first to propose heliocentrism, but the first to calculate it, which is not the same thing. However, no source is given even for that statement. — Joe Kress (talk) 03:39, 19 October 2010 (UTC)

Only such tablet[edit]

The text now says " ...only such tablet ...dated...". The observations of the Babylonians probably extended for centuries or millenia before the date of the known dated tablet. —Preceding unsigned comment added by (talk) 11:12, 15 April 2011 (UTC)

The Babylonian observations might go back to Sumerian times, 3,500 B. C. —Preceding unsigned comment added by (talk) 12:34, 15 April 2011 (UTC)

Value for Apogee[edit]

I find the value for the Apogee in Hipparchus time to be about 70 from vernal equinox. If correct I think this deserves a mention. However I can't find a reliable source for this, can anyone help. Sceptic1954 (talk) 17:15, 4 January 2013 (UTC)

Did Hipparchus believe that stars move and eventually perish?[edit]

I came across this.

Hipparchus anticipated that the stars come into being, slowly move during the course of centuries, and eventually perish, it was he who first catalogued the positions and magnitudes of the stars to detect such changes. Euclid produced a textbook on geometry from which humans learned for twenty-three centuries"3. Such astounding wisdom backed up by studious thinking and experimentation could have launched the world into the modern era. But it didn't. [2]

  1. Is the website reliable enough so this can go into the article?
  2. Does anyone know of other websites with the same information?

Proxima Centauri (talk) 09:02, 20 February 2014 (UTC)

No. No. Vexen is not reliable. He or she makes no attempt to prove his or her assertions about Hipparchus. — Preceding unsigned comment added by (talk) 14:22, 12 January 2015 (UTC)
Vexen Crabtree describes himself as a Satanist. — Preceding unsigned comment added by (talk) 14:26, 12 January 2015 (UTC)


This edit established the page's usage as BC/AD. Kindly maintain it consistently pending a new consensus to the contrary. — LlywelynII 11:06, 14 March 2015 (UTC)

Date of Discovery of Precession[edit]

Hipparchus is generally recognized as discoverer of the precession of the equinoxes in 127 bc.[39] I don't think the source is particularly painstaking and it doesn't sit readily with the entry at "The lunar eclipses he observed, for instance, took place on April 21, 146 BC, and March 21, 135 BC (Toomer 1984, p. 135 n. 14)." Maybe someone has a better source. (talk) 15:26, 27 October 2015 (UTC)

Although I found another ref to agree with this the article is now contradictory. It says he began work on his star catlaogue in the mid 130s and then says "His interest in the fixed stars may have been inspired by...his discovery of precession, according to Ptolemy, who says that Hipparchus could not reconcile his data with earlier observations made by Timocharis and Aristillus." which would place this earlier. (talk) 16:33, 27 October 2015 (UTC)

That's not Hipparchus[edit]

It's Zoroaster-- (talk) 03:33, 9 May 2016 (UTC)

Hipparchus isn't even mentioned at The School of Athens. I believe this image fails WP:PORTRAIT and will remove it. —David Eppstein (talk) 04:36, 9 May 2016 (UTC)