The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.
The result was: promoted by MeegsC (talk) 10:10, 23 March 2021 (UTC)
... that the common depiction of the Borromean rings as three linked but pairwise-unlinked circles (pictured) is an impossible object, because they cannot actually be circular? Sources: Aigner, Martin; Ziegler, Günter M. (2018), "Chapter 15: The Borromean Rings Don't Exist", Proofs from THE BOOK (6th ed.), Springer, pp. 99–106; Freedman, Michael H.; Skora, Richard (1987), "Strange actions of groups on spheres", Journal of Differential Geometry, 25: 75–98, doi:10.4310/jdg/1214440725; Lindström, Bernt; Zetterström, Hans-Olov (1991), "Borromean circles are impossible", American Mathematical Monthly, 98 (4): 340–341; Tverberg, Helge (2010), "On Borromean rings", The Mathematical Scientist, 35 (1): 57–60. The Aigner/Ziegler and Zetterström sources are paywalled but Freedman/Skora and Tverberg are both open, albeit probably unreadable to nonmathematicians.
Nice, interesting hook with illustration. Well referenced article. Good to go. EchetusXe 15:47, 18 March 2021 (UTC)