Ludolphian number
English
![](Images/wiktionary/Ceulen_-_De_circulo_%2526_adscriptis_liber%252C_1619_-_BEIC_175795.jpg.webp)
Van Ceulen's De Circulo & Adscriptis Liber
Etymology
From Ludolph van Ceulen, a German mathematician who improved on previous approximations of pi.
Noun
Ludolphian number (uncountable)
- (mathematics, chiefly historical) Synonym of pi, particularly the 35-decimal approximation discovered by Ludolph van Ceulen
- 1992 March 2, Richard Preston, The New Yorker, "The Mountains of Pi":
- Pi... came to be called the Ludolphian number, after Ludolph van Ceulen, a German mathematician who approximated it to thirty-five decimal places... a calculation that took Ludolph most of his life to accomplish, and gave him such satisfaction that he had the digits engraved on his tombstone... the stone vanished, possibly to be turned into a sidewalk slab. Somewhere in Leiden, people may be walking over Ludolph's digits.
- 1992 March 2, Richard Preston, The New Yorker, "The Mountains of Pi":