Johann Andreas Segner
| Born |
October 9, 1704 Pressburg (Bratislava), Kingdom of Hungary |
|---|---|
| Died |
October 5, 1777 (aged 72) Halle, Duchy of Magdeburg |
Johann Segner (Johann Andreas von Segner, Ján Andrej Segner, János András Segner, Iohannes Andreas de Segner) was a 18th-century physicist, physician, astronomer, botanist, mathematician and inventor. One of the best-known scientists of his age, Segner was a member of the St Petersburg Academy of Sciences, the Berlin Academy and the Royal Society in London.
Early life
Segner was born in 1704 in Pressburg, then capital of Kingdom of Hungary (today Bratislava, Slovakia). His ancestors came to Pressburg from Styria by the 18th century.
Studies
Segner attended school at Pressburg's Lyceum where he showed special talents for medicine and mathematics. He also attended school in Győr and, while it is not completely certain, it does seem highly probable that he spent the year 1724 at the College in Debrecen.
In 1725 he went to Germany and entered the University of Jena, studying medicine there. While he was an undergraduate he published essays on a wide variety of topics including mathematics, philosophy, physics, astronomy, chemistry, and medicine. He qualified as a medical doctor in 1729 and, in the following year, he was employed as a doctor by the authorities in Debrecen, taking up his new post in November 1730. He did not find being a doctor of medicine to his liking and, after spending eighteen months in the job at Debrecen, he returned to the academic world returning to the University of Jena to take a Master's Degree. His studies at Jena were so successful that he was soon offered a post at the university.
Teaching
He had the great distinction of becoming the first professor of mathematics at Göttingen taking up the chair in 1735. Segner's was therefore the first to fill what was to become one of the foremost chairs of mathematics in the world. In 1743 Segner was put in charge of the construction of the university observatory which was finished in 1751.
He left Göttingen in 1755 and, with Euler's assistance, became professor in Halle where he lectured on mathematics, physics and medicine. He continued to write good textbooks and in Halle, as in Göttingen, established an observatory.
Inventions
Segner was the first scientist to use the reactive force of water. While at Göttingen he discovered that every solid body has three axes of symmetry. He used Daniel Bernoulli's theoretical work on the 'reaction effect' to produce a horizontal waterwheel using the same principle which drives one type of modern lawn sprinkler.
In 1751 Segner introduced the concept of the surface tension of liquids and made an unsuccessful attempt to give a mathematical description of capillary action. Other work which he undertook included the theory of spinning tops. His publications include Elements of Arithmetic and Geometry and Nature of Liquid Surfaces.
Segner also produced the first proof of Descartes' rule of signs. Historians of science remember him as the father of the water turbine.
Death
He died in 1777 in Halle, Duchy of Magdeburg.
Legacy
According to Mathematics Genealogy Project, as of February 2013, he has over 66 thousand academic descendants, out of the total 170 thousand mathematicians in the database.
The lunar crater Segner is named after him, as is asteroid 28878 Segner.
