Bartholomaeus Pitiscus (also ''Barthélemy'' or ''Bartholomeo''; August 24, 1561 – August 24, 1613) was a 16th-century German trigonometrist,

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

and

theologian Theology is the study of religious belief from a religious perspective, with a focus on the nature of divinity. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of ...

who first coined the word ''

trigonometry Trigonometry () is a branch of mathematics concerned with relationships between angles and side lengths of triangles. In particular, the trigonometric functions relate the angles of a right triangle with ratios of its side lengths. The fiel ...

''.

Biography

Pitiscus was born to poor parents in Grünberg (now Zielona Góra, Poland), then part of the Duchy of Glogau/Głogów, one of the

Habsburg The House of Habsburg (; ), also known as the House of Austria, was one of the most powerful dynasties in the history of Europe and Western civilization. They were best known for their inbreeding and for ruling vast realms throughout Europe d ...

-ruled Duchies of Silesia. He studied theology in

Zerbst Zerbst () is a List of cities and towns in Germany, town in the district of Anhalt-Bitterfeld, in Saxony-Anhalt, Germany. Until an administrative reform in 2007, Zerbst was the capital of the former Anhalt-Zerbst district. Geography Zerbst is sit ...

and

Heidelberg Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

. A

Calvinist Reformed Christianity, also called Calvinism, is a major branch of Protestantism that began during the 16th-century Protestant Reformation. In the modern day, it is largely represented by the Continental Reformed Protestantism, Continenta ...

, he was appointed to teach the ten-year-old Frederick IV, Elector Palatine of the Rhine, by Frederick's Calvinist uncle

Johann Casimir of Simmern John Casimir, Count Palatine of Simmern ( German: ''Johann Casimir von Pfalz-Simmern'') (7 March 1543 – Brockhaus Geschichte Second Edition) was a German prince and a younger son of Frederick III, Elector Palatine. A firm Calvinist, he was a l ...

, as Frederick's father had died in 1583. Pitiscus was subsequently appointed court chaplain at Breslau (Wrocław) and court preacher to Frederick. Pitiscus supported Frederick's subsequent measures against the

Roman Catholic Church The Catholic Church (), also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.27 to 1.41 billion baptized Catholics Catholic Church by country, worldwid ...

. Pitiscus died in

. The lunar crater Pitiscus is named after him. The classical scholar Samuel Pitiscus (1637–1727) was his nephew.

Mathematics

Pitiscus achieved fame with his influential work, ''Trigonometria: sive de solutione triangulorum tractatus brevis et perspicuus'' (Trigonometry: A short and clear treatise on the solution of triangles) which was printed as an appendix to work of

Abraham Scultetus Abraham Scultetus (24 August 1566 – 24 October 1625) was a German professor of theology, and the court preacher for the Prince-elector, Elector of the Palatinate Frederick V, Elector Palatine, Frederick V. Biography Early life Abraham wa ...

''Sphæricorum libri tres methodice conscripti & utilibus scholiis expositi.'' This introduced the word ''trigonometry'' to the English and French languages, translations into which had appeared in 1614 and 1619, respectively. It consists of five books on plane and

spherical trigonometry Spherical trigonometry is the branch of spherical geometry that deals with the metrical relationships between the edge (geometry), sides and angles of spherical triangles, traditionally expressed using trigonometric functions. On the sphere, ge ...

. A standalone edition called ''Trigonometriæ sive de dimensione triangulorum libri quinque'' (Five books on trigonometry or the dimensions of triangles) was published in 1608 which included trigonometric tables with another, improved, edition being published in 1612. Pitiscus also published '' Thesaurus mathematicus'' (1613) in which he improved the trigonometric tables of Georg Joachim Rheticus for whom he had previously helped publish an improved version of ''Opus palatinum de triangulis'' in 1607.Reconstruction of Pitiscus' tables

The Decimal Point

Pitiscus is often credited with inventing the

decimal point FIle:Decimal separators.svg, alt=Four types of separating decimals: a) 1,234.56. b) 1.234,56. c) 1'234,56. d) ١٬٢٣٤٫٥٦., Both a comma and a full stop (or period) are generally accepted decimal separators for international use. The apost ...

, the symbol separating integers from decimal fractions. These are claimed to first appear in his 1608 edition of ''Trigonometria'' in the added trigonometric tables and can also be found in the 1612 edition. However, others argue that the use of the '.' symbol only constitute a way of grouping numbers and that the mixed use of decimal points and fractions as well as multiple decimal points do not correspond to current use. Similar usage of the symbol is found in ''Thesaurus mathematicus.'' The decimal place was later used in its modern context by

John Napier John Napier of Merchiston ( ; Latinisation of names, Latinized as Ioannes Neper; 1 February 1550 – 4 April 1617), nicknamed Marvellous Merchiston, was a Scottish landowner known as a mathematician, physicist, and astronomer. He was the 8 ...

in '' Mirifici Logarithmorum Canonis Descriptio.''

Works

* * ''Thesaurus mathematicus.'' 1613

Notes

References

* S. Gottwald, H.-J. Ilgauds, K.-H. Schlote (Hrsg.): ''Lexikon bedeutender Mathematiker''. Verlag Harri Thun, Frankfurt a. M. 1990

External links

* *

Allgemeine Deutsche Biographie (ADB; ) is one of the most important and comprehensive biographical reference works in the German language. It was published by the Historical Commission of the Bavarian Academy of Sciences between 1875 and 1912 in 56 volumes, printed in Lei ...

:de:s:ADB:Pitiscus, Bartholomaeus {{DEFAULTSORT:Pitiscus, Bartholomaeus 1561 births 1613 deaths 16th-century German astronomers 16th-century German mathematicians 17th-century German mathematicians German Calvinist and Reformed ministers People from Zielona Góra 16th-century German writers 16th-century German male writers 17th-century German writers 17th-century German male writers People from the Habsburg monarchy