2721: Euler Diagrams

2023-01-07T03:07:17Z

Chandlerswift: Add link to Wikipedia Page for list of things Euler invented

{{comic
| number = 2721
| date = January 6, 2023
| title = Euler Diagrams
| image = euler_diagrams_2x.png
| imagesize = 370x409px
| noexpand = true
| titletext = Things Leonhard Euler created ( most of math ( overlapping circle diagrams ) a cricket bowling machine ) Things John Venn created
}}

==Explanation==
{{incomplete|Created by JOHN EULER AND LEONHARD VENN - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Cueball]] is showing an off-screen person a {{w|Venn diagram}} he made about something. The off-screen person then informs Cueball that it is in fact an {{W|Euler diagram}}, not a Venn diagram. Cueball then proceeds to complain that {{w|List of things named after Leonhard Euler|many things}} are named for {{w|Leonhard Euler}} (specifically {{w|Euler's constant}} and {{w|Euler's function}}) and and wants to call the diagram a Venn diagram to give {{w|John Venn}} more credit. His off-screen friend refuses, and mockingly states that numbers are now called "Euler letters", which is currently false.{{citation needed}} Modern {{w|Arabic numerals}} predate Euler by at least a century, and other numerals existed before that.

A Venn diagram is "a widely used diagram style that shows the logical relation between sets". It shows overlap of items in different categories (sets) by using overlapping circles (or other shapes) to stand in for categories. If an item is within a certain circle, it is in the category the circle represents. So in a Venn diagram of "animals" and "fuzzy things", cat would be in the overlap between both circles, frog would be inside only "animals", and "kiwifruit would only be in "fuzzy things". "Crystals" would be outside both circles. In a Venn diagram, all 'circles' must overlap with all other circles, even if there are no items in the overlap. This is easy enough for 2 and 3 sets, but as the number of sets increases the diagrams can get [https://www.newscientist.com/article/dn22159-logic-blooms-with-new-11-set-venn-diagram/ rather complicated], and the sets can start looking very non-circular. An Euler diagram only depicts the non-empty combinations, and therefore does not have this constraint.

[[File:Euler Diagrams title text.png|300px|thumb|right|The title text as a Venn diagram]]
The title text is an example of a "written" Venn diagram, with Leonhard Euler creating "most of math", John Venn creating a {{w|cricket}} bowling machine, and both of them having created overlapping circle diagrams.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}<br>
:[Cueball is standing in front of a whiteboard with his palms raised. The text "Venn Diagram of" is visible in large letters, with "of" on the next line and slightly smaller. Below this are two squiggly lines representing illegible text, followed by three partially overlapping circles with a number of squiggly lines in them.] 
:Friend (offscreen): Actually, that's an ''Euler'' diagram, because-
:Cueball: Come '''''onnnn.'''''
:Cueball: '''''Everything''''' is named after Euler. Euler's constant, Euler's function.
:Cueball: Can't we let John Venn have this?
:Friend (offscreen): No.
:Friend (offscreen): Also, numbers are now "Euler letters."

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Math]]
[[Category:Euler diagrams]]
[[Category:Venn diagrams]]
[[Category:Sport]]

explain xkcd - User contributions [en]

2721: Euler Diagrams