Ludolphn.
/ˈluːdɒlf/ Ludolph's number: the number π (see pi n.1).
ΘΚΠ
the world > relative properties > number > mathematical number or quantity > [noun] > infinitesimal > pi
pi1706
Ludolph's number1894
1887 Encycl. Brit. XXII. 434/2 In Germany the ‘Ludolphische Zahl’ is still a common name for the ratio.]
1894 F. Cajori Hist. Math. 154 The value of π is therefore often named ‘Ludolph's number’.
1959 Webster's Biogr. Dict. at Ceulen Ludolph van... Known for computations of the value of π (Ludolphian, or Ludolph's number).
Derivatives
Luˈdolphian adj.
ΘΚΠ
the world > relative properties > number > mathematical number or quantity > [adjective] > prime > irrational
irrational1551
surd1551
radical1557
irradicala1690
ineffable1702
Ludolphian1886
1886 G. S. Carr Synopsis Elem. Results Math. II. Index 901/1 Ludolphian number.
1905 Westm. Gaz. 14 Oct. 3/1 The history of the search for this ratio, the Ludolphian number..is practically the early history of mathematics itself.
1953 H. Eves Introd. Hist. Math. iv. 92 Ludolph van Ceulen of Germany computed π to 35 decimal places by the classical method, using polygons having 262 sides. He spent a large part of his life on this task and his achievement was considered so extraordinary that the number was engraved on his tombstone, and to this day is frequently referred to in Germany as ‘the Ludolphian number’.
This entry has not yet been fully updated (first published 1976; most recently modified version published online March 2018).
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n.1886