Talk:Hipparchus/Archive 1

message: 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)
thread_title:  Reorg 

message: 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)
replies: text: 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)

text: * 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)
thread_title:  Elaborations on precession 

message: Maestlin,
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)
replies: text: 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)
replies: text: 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)
thread_title:  Star Catalogue 

message: 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)
replies: text: 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)
thread_title:  which contributions to astrology 

message: 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)
thread_title:  Chord table and Pi 

message: 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 142.104.112.22 (talk) 01:45, 19 October 2010 (UTC)
replies: text: 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)
thread_title:  First heliocentric system??