Ludolph van Ceulen was a German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 / Dutch mathematician

Mathematician

A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

 from Hildesheim

Hildesheim

Hildesheim is a city in Lower Saxony, Germany. It is located in the district of Hildesheim, about 30 km southeast of Hanover on the banks of the Innerste river, which is a small tributary of the Leine river...

. He emigrated to the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

.

Ceulen moved to Delft

Delft

Delft is a city and municipality in the province of South Holland , the Netherlands. It is located between Rotterdam and The Hague....

 to teach fencing and mathematics

Mathematics

Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

. In 1594 he opened a fencing school in Leiden. In 1600 he was appointed the first professor of mathematics at Leiden University

Leiden University

Leiden University , located in the city of Leiden, is the oldest university in the Netherlands. The university was founded in 1575 by William, Prince of Orange, leader of the Dutch Revolt in the Eighty Years' War. The royal Dutch House of Orange-Nassau and Leiden University still have a close...

. 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

Pi

' is a mathematical constant that is the ratio of any circle's circumference to its diameter. is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve , which makes it one of the most important mathematical constants...

, using essentially the same methods as those employed by Archimedes

Archimedes

Archimedes of Syracuse was a Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and an...

 some seventeen hundred 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

Pi

' is a mathematical constant that is the ratio of any circle's circumference to its diameter. is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve , which makes it one of the most important mathematical constants...

",

3.14159265358979323846264338327950288...,

was engraved on his tombstone

Headstone

A headstone, tombstone, or gravestone is a marker, usually stone, that is placed over a grave. In most cases they have the deceased's name, date of birth, and date of death inscribed on them, along with a personal message, or prayer.- Use :...

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
• MacTutor biography of van Ceulen
• Ludolph van Ceulen (1540-1610)