Talk:Gersonides

A Talmudist?
I know of know actual evidence that Ralbag was a talmudist and will be removing this claim from the opening paragraph until it can be substantiated. I know that later authorities claimed him to be a Talmudist, but this has little support (and is likely out of a desire that popular parshanim also be famous in the talmud world, which Rashi was, but Ibn Ezra, Ralbag, etc, were not). jnothman talk 00:55, 26 October 2007 (UTC)

Gershon or Gershom?
It would appear that the name could be more correctly spelled with an "n", as in fact the name "Gersonides" suggests. 132.70.50.117 (talk) 13:15, 25 January 2009 (UTC)

Louis Jacobs is certainly not the founder of Conservative Judaism!!! —Preceding unsigned comment added by 24.231.102.196 (talk) 16:27, 30 September 2009 (UTC)

Louis Jacobs
I removed the sentence that suggested that Orthodox theologians might disagree with the interpretation of Jacobs. First, speculation seemed to me improper. If someone has disagreed with Jacobs, they should be cited. Further, if there really is a difference of opinion, the grounds on which the two camps disagree (the relative passage in Gersonides) might have to be adduced. As I'm relatively new here, I'd love to see feedback on whether I did well here or not, and also whether or not, in the absence of cited debate, the qualifier "LJ argued" should be there or not... but it seemed to me wrong to include this hypothetical, as well as extraneous information about Jacobs (some of which is dubious, too), especially info. that implies he's got a bias without arguing it...Summortus (talk) 18:42, 17 June 2010 (UTC)

Jacob's staff quote
This quote has been marked as needing a citation since April 2009. This quote appears verabatim in a Daily Medieval blog from July 2012, as Rabbi Levi's own description, citing Book of the Wars of the Lord - Rabbi Levi's main work.

In that case, this must be a quote from Bernard Goldstein's The Astronomy of Levi ben Gerson (1288-1344), which apparently consists of a translation of the otherwise unpublished astronomical portion (Book 5, Part 1) of the Wars of the Lord. I cannot find the quote by searching Google Books' snippet-view version of the book. Does anyone have a hard copy? (The relevant quote would be in chapters 4–11, which are said by various sources to describe the Jacob's staff.)

הסרפד (Hasirpad) [formerly Ratz...bo] 06:30, 30 November 2012 (UTC)
 * Forgot to update: with the help of volunteers at WP:REX, I checked sections of the Wars of the Lord, but the quotation is not there. הסרפד  (call me Hasirpad) 01:28, 6 February 2014 (UTC)

Estimation of stellar distances
Moved from article:


 * You state that Gersonides calculated that the stars were 10 billion times farther away from Earth than what Ptolemy claimed, i.e. in the order of 100 light years. This should be about 100,000 light years (107,055 to be more precise).


 * As the mean radius is about 6,370 km this works out to 127,323,954 km. Gersonides however took it to be more than 159 x 1012. So Gersonides works out to 1.012830 exp19 km. As a light year is 9.4608exp13 km it works out to 107,550 light years, which is indeed very close to 10 billion times as far as Ptolemy's distance.

as it seems more of a discussion point --Rumping (talk) 02:27, 23 December 2012 (UTC)


 * I haven't read the primary source, but as I happened to read this Wikipedia article, I noticed more or less the same discrepancy. I looked at what Yuval Ne'eman wrote (because the Wikipedia article cites it), but he doesn't seem to have it right.
 * The only distance to an extraterrestrial object that we can be pretty sure was known at Gersonides's time was the one to the Moon. But it was also known that the Sun is much farther away than the Moon (or at least the lunar distance estimates were usually based on that); Aristarchos of Samos estimated the ratio of the distances to be something on the order of 20 (which was far too low). As the celestial sphere of the fixed stars was thought to be outside the Sun and the planets, and assuming the value of 20 for the ratio of solar and lunar distance, the celestial sphere would have been assumed to be at least 7 million km away. If the factor of 100,000 (as stated in the article and by Ne'eman) is correct, that means that the distance estimate by Gersonides would be 70 quadrillion km, a bit more than 7000 lightyears. Even if we assume that other astronomers thought the celestial sphere to be almost as close as the Moon, then by the factor 100,000 Gersonides's estimate would still have been at about 400 lightyears, and I would feel uncomfortable calling that "of the order of 100 light-years" (on an order-of-magntitude (i.e. logarithmic) scale it's already closer to "of the order of 1,000 light-years").
 * Icek~enwiki (talk) 18:59, 26 July 2017 (UTC)

A summation theorem
A simple summation formula is mentioned in a guide on "reading mathematics" and attributed to Gersonides. I could only find a blog post proving the theorem, but unfortunately nothing more substantial. Is this formula usually attributed to Gersonides in lectures or textbooks (in the anglosphere)? Is it worth mentioning it in the wiki article here? Leonry (talk) 10:20, 29 May 2022 (UTC)