Ludolph van Ceulen (28 January 1540–31 December 1610) was a German mathematician. Born in Hildesheim, Germany, like many Germans during the Catholic Inquisitions, he emigrated to the Netherlands.

He moved to Delft to teach fencing and mathematics. In 1594 he opened a fencing school in Leiden. In 1600 he was appointed the first professor of mathematics at the University of Leiden. He died in Leiden.

Calculating π

Ludolph van Ceulen spent a major part of his life calculating the numerical value of the mathematical constant π, using essentially the same methods as those employed by Archimedes some two thousand years earlier. He published a 20-decimal value in his 1596 book Van den Circkel ("On the Circle"), later expanding this to 35 decimals. After his death, the "Ludolphine number",

3.14159265358979323846264338327950288...,

was engraved on his tombstone in Leiden. The tombstone was later lost but was restored in 2000.

External links

• Oomes, R. M. Th. E.; Tersteeg, J. J. T. M.; Top, J. "The epitaph of Ludolph van Ceulen." Nieuw Arch. Wiskd. (5) 1 (2000), no. 2. online in Dutch.
• MacTutor biography of van Ceulen

1540 births | 1610 deaths | German mathematicians | Dutch mathematicians | 16th century mathematicians | 17th century mathematicians | pi

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