# Talk:Leonhard Euler

Page contents not supported in other languages.
Leonhard Euler is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so.
This article appeared on Wikipedia's Main Page as Today's featured article on November 11, 2006.
Article milestones
DateProcessResult
July 5, 2006Featured article candidateNot promoted
October 7, 2006Featured article candidatePromoted
September 4, 2021Featured article reviewKept
Facts from this article were featured on Wikipedia's Main Page in the "On this day..." column on April 15, 2007, April 15, 2017, and April 15, 2022.
Current status: Featured article

## Expressions That May Lead to Confusion

Section 2.1 Mathematical notation, line 3: He also introduced ... the letter e for the base of the natural logarithm (now also known as Euler's number)

Section 2.5 ... describing numerous applications of ... Euler numbers

It is hard to distinguish between Euler's number and Euler number. Although there are seperate pages devoted to the two concepts, this may still lead to confusion for beginners and those who use English as a foreign language. Shouldn't there be "see also" links behind both expressions?

-- User:Dale Zhong 14:59, 7 July 2007 (GMT+0800)

## Square root of -1 in lead

The third paragraph of the lead states: "Euler is credited for popularizing ... the letter i to express the imaginary unit sqrt(-1)"

Would this not be more accurately re-worded to something along the lines of "popularizing ... the letter i, the imaginary unit whose square is -1"? Ediniast (talk) 06:44, 19 March 2023 (UTC)

He popularized THE USE OF the letter i for this mathematical purpose. Saying that "he popularized the letter i" without including the "to denote" part that our lead currently includes makes no sense because it was already a popular letter in the orthography of many languages. And saying "the letter i, the imaginary unit..." also makes no sense: a letter is a notation for a mathematical value, not the value itself. And it is the notation that we are crediting him for popularizing, not its value. —David Eppstein (talk) 06:49, 19 March 2023 (UTC)
I wasn't entirely clear, I apologize I meant "Euler is credited for popularizing ... the letter i, the imaginary unit whose square is -1" and got lazy writing it out, my comment was more on the nature of i being defined as a number whose square is negative one, rather than i being equal to negative one. Ediniast (talk) 06:55, 19 March 2023 (UTC)
"The imaginary unit ${\displaystyle {\sqrt {-1}}}$" is a correct description of ${\displaystyle i}$. It is an imaginary unit, and among the two imaginary units is the one identified by the principal branch of the complex square root function, the branch denoted by the square root notation. "The imaginary unit whose square is -1" is an ambiguous and inaccurate description of ${\displaystyle i}$. There are two imaginary units whose square is –1, so the use of the definite article is not justified. —David Eppstein (talk) 07:25, 19 March 2023 (UTC)

## Pronunciation of name

The correct pronunciation is shown in phonetic symbols (IPA) and in an English approximation. The two do not appear to match. This is also true in the footnote, which explains how not to pronounce the name. I believe that the English approximations of the correct and incorrect pronunciations have been switched. Cctimar (talk) 19:29, 17 April 2023 (UTC)

There was some vandalism to this part of the article today. Maybe you saw it in its vandalized state. —David Eppstein (talk) 20:33, 17 April 2023 (UTC)

## Inaccurate reference

In Leonhard Euler#Personal philosophy and religious beliefs is mentioned that Euler also labelled Wolff's ideas as "heathen and atheistic", with reference to Calinger 1996, pp. 153–154. However, in the mentioned article we read, instead, that Euler knew well that pietists and conservative theologians had labelled Wolff’s rational, mathematical philosophy as ‘‘heathen and atheistic’’ from the 1720s, and not that it was not Euler himself who labelled thus Wolff's ideas. I propose this reference to be removed or corrected. (The other one is accurate.) AresPi (talk) 13:30, 6 June 2023 (UTC)

@David_Eppstein Doing the talk page thing, lest I draw cries of "Edit War"! The summary for your recent revert reads:

"They are collected in X" means that they can all be found as a collection in X". "They are being collected in X" means that at the present time someone is putting together a collection of them. The first is true; the second is false.

However, the Opera Omnia Leonhard Euler is not yet complete (at least as of September 2022, according to the article). Hence, the sentence in question ending in "will consist of 81 quarto volumes" (emphasis added). So the latter is true (as someone is ostensibly still, at this present time, putting together the collection), and the former is false (until the collection is complete).

That is, unless the final publication (Volume IVA/9) has been released since September 2022. If it has been, you should update the end of the sentence and also the article for the Opera Omnia itself, rather than reverting the change.

Unless you have further objections, I'll reinstate @Toddcs's edit after some arbitrary wait. Reil (talk) 04:20, 27 October 2023 (UTC)

Ok, with this justification, I think it's ok to reinstate the edit. But Toddcs's claim that the original was ungrammatical was incorrect. It is grammatical, it just means something different. —David Eppstein (talk) 05:22, 27 October 2023 (UTC)
@david_eppstein Thank you for all that, especially for analyzing my change itself, in order to understand my intent, which you did perfectly.
When I labeled my change as a grammar fix, I was giving the original writer the benefit of the doubt, that they knew the difference between "are collected" and "are being collected," but had only taken a shortcut in expressing it.
Thanks again for analyzing my change, instead of simply relying on its annotation alone. And for essentially concurring, it seems, in my underlying observation. Toddcs (talk) 17:43, 27 October 2023 (UTC)

## Hollow Earth

How is his most important work not mentioned here??? 79.106.203.40 (talk) 09:03, 9 March 2024 (UTC)