Johann Andreas von Segner (, , , ; October 9, 1704 – October 5, 1777) was a Hungarian scientist of German descent. He was born in the

Kingdom of Hungary The Kingdom of Hungary was a monarchy in Central Europe that existed for nearly a millennium, from 1000 to 1946 and was a key part of the Habsburg monarchy from 1526-1918. The Principality of Hungary emerged as a Christian kingdom upon the Coro ...

, in the former Hungarian capital city of Pozsony, or Pressburg (today

Bratislava Bratislava (German: ''Pressburg'', Hungarian: ''Pozsony'') is the Capital city, capital and largest city of the Slovakia, Slovak Republic and the fourth largest of all List of cities and towns on the river Danube, cities on the river Danube. ...

Early life and education

Johann Segner was born to Johann Michael von Segner and his wife Christine von Segner (née Fischer) on probably the 10 October 1704. Other sources mention also the 4 or the 9 October. His father was a tax clerk. His paternal ancestors came from

Styria Styria ( ; ; ; ) is an Austrian Federal states of Austria, state in the southeast of the country. With an area of approximately , Styria is Austria's second largest state, after Lower Austria. It is bordered to the south by Slovenia, and cloc ...

to Pressburg in the

; by the 18th century. In 1596 the family was granted nobility for their military accomplishments by

Rudolph II Rudolf II (18 July 1552 – 20 January 1612) was Holy Roman Emperor (1576–1612), King of Hungary and Kingdom of Croatia (Habsburg), Croatia (as Rudolf I, 1572–1608), King of Bohemia (1575–1608/1611) and Archduke of Austria (1576–16 ...

. He studied at Pressburg and

Debrecen Debrecen ( ; ; ; ) is Hungary's cities of Hungary, second-largest city, after Budapest, the regional centre of the Northern Great Plain Regions of Hungary, region and the seat of Hajdú-Bihar County. A city with county rights, it was the large ...

. In April 1725, Segner began studying at the

University of Jena The University of Jena, officially the Friedrich Schiller University Jena (, abbreviated FSU, shortened form ''Uni Jena''), is a public research university located in Jena, Thuringia, Germany. The university was established in 1558 and is cou ...

. Under the guidance of Georg Erhard Hamberger, Segner developed an evidence for the cartesian rule of signs. In his third year at Jena, he began to teach other students in mathematics. During his stay in Jena, he was supported by Hermann Friedrich Teichmeyer, who lectured at the faculty of medicine.Kleinert, Andreas; Steiner, Thomas (2018). p.234 In October 1729, he graduated under Simon Paul Hirscher from the faculty of medicine. Following he returned to Pressburg where he worked as a medic until December 1731. Following he worked temporarily as the city

physician A physician, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the Medical education, study, Med ...

in Debrecen until early 1732. In 1732 he returned to Jena where he requested a degree from the faculty of philosophy and also the possibility to give lectures in the faculty of philosophy. He graduated in May 1732 he began to lecture in 1733. In September the same year he was nominated a professor in the faculty of philosophy where he soon lectured the metaphysics of Christian Wolff.

University of Göttingen

The University in Göttingen was established after a visit by George II to

Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...

in 1732.Kleinert, Andreas; Steiner, Thomas (2018). p.235 After Hamberger was denied his resignation from the University of Jena, he suggested von Segner instead. 1735 Segner became the professor of mathematics and physics at the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

. As in January 1736 the professor for medicine died, he also lectured in the faculty of medicine.

University of Halle

After Christian Wolff died, the Prussian King Friedrich II requested from the mathematician

Leonhard Euler Leonhard Euler ( ; ; ; 15 April 170718 September 1783) was a Swiss polymath who was active as a mathematician, physicist, astronomer, logician, geographer, and engineer. He founded the studies of graph theory and topology and made influential ...

advice on who could be succeed Wolff at the

University of Halle Martin Luther University Halle-Wittenberg (), also referred to as MLU, is a public research university in the cities of Halle and Wittenberg. It is the largest and oldest university in the German state of Saxony-Anhalt. MLU offers German and i ...

.Kleinert, Andreas; Steiner, Thomas (2018). pp.244–245 Euler suggested

Daniel Bernoulli Daniel Bernoulli ( ; ; – 27 March 1782) was a Swiss people, Swiss-France, French mathematician and physicist and was one of the many prominent mathematicians in the Bernoulli family from Basel. He is particularly remembered for his applicati ...

who did not accept. Then Euler suggested von Segner, who requested the recognition of his Hungarian title and an extraordinary treatment at the university in return of his acceptance. In 1755 he became a professor at Halle, where he divided the lectures in mathematics and physics with Johann Joachim Lange. In Halle he also established an observatory. Von Segner died on the 5 October 1777.Kleinert, Andreas; Steiner, Thomas (2018). p.254

Connections

One of the best-known scientists of his age, Segner was a member of the academies of

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

, and

Saint Petersburg Saint Petersburg, formerly known as Petrograd and later Leningrad, is the List of cities and towns in Russia by population, second-largest city in Russia after Moscow. It is situated on the Neva, River Neva, at the head of the Gulf of Finland ...

. According to

Mathematics Genealogy Project The Mathematics Genealogy Project (MGP) is a web-based database for the academic genealogy of mathematicians.. it contained information on 300,152 mathematical scientists who contributed to research-level mathematics. For a typical mathematicia ...

, as of February 2013, he has over 66 thousand academic descendants, out of the total 170 thousand mathematicians in the database.

Contributions

He was the first scientist to use the reactive force of water and constructed the first water-jet, the Segner wheel, which resembles one type of modern

lawn sprinkler An irrigation sprinkler (also known as a water sprinkler or simply a sprinkler) is a device used to irrigate (water) agricultural crops, lawns, landscapes, golf courses, and other areas. They are also used for cooling and for the control of airb ...

. Segner, also produced the first proof of

Descartes' rule of signs In mathematics, Descartes' rule of signs, described by René Descartes in his ''La Géométrie'', counts the roots of a polynomial by examining sign changes in its coefficients. The number of positive real roots is at most the number of sign chang ...

. Historians of science remember him as the father of the

water turbine A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, t ...

. The lunar crater Segner is named after him, as is asteroid 28878 Segner.

Personal life

In 1732, he married Carolina Sophia, the daughter of Hermann Friedrich Teichmeier. They had three children of which two reached adulthood.

References

Works in modern edition

* Johann Andreas Segner, ''Specimen logicae universaliter demonstratae'' (1740) edited with an introduction by Mirella Capozzi, Bologna: CLUEB, 1990.

External links

* {{DEFAULTSORT:Segner, Johann Andreas 1704 births 1777 deaths Scientists from Bratislava 18th-century Hungarian mathematicians 18th-century Hungarian physicists Fellows of the Royal Society University of Jena alumni Academic staff of the University of Jena Academic staff of the University of Göttingen Academic staff of the University of Halle Members of the Prussian Academy of Sciences Hungarian people of Austrian descent Emigrants from the Kingdom of Hungary (pre-1805) Immigrants to the Holy Roman Empire