SEGNER, Ján Andrej
* 9. 10. 1704, Bratislava, Slovakia
† 5. 10. 1777, Halle, Germany
Mathematician, physicist
After finishing the evangelical school in Bratislava S. initially studied in Gyõr and Debreczen. In 1725 Segner began studying at the University of Jena, where he studied medicine and science to 1730. In 1729 he received a medical certificate and returned to Bratislava as well as in Debrecen, where he started to work as a physician. After a year he became a professor at the University of Jena (from 1732 to 1735), in Göttingen (mathematics, physics and chemistry) and Halle (experimental physics, philosophy and mathematics from 1755 onwards).
At the University of Halle, S. dealt exclusively with teaching and scientific work in the fields of mathematics, general physics, optics, hydraulics, astronomy, medicine and botany. His research and invention of the hydraulic machines and rotating propellers importantly contributed to the development of theoretical mechanics, especially after his famous discovery of Segner-wheel or Segner turbine, which uses the same principle as Hero's Aeolipile. The device is placed in a suitable hole in the ground. The water is delivered to a top of a vertical cylinder at the bottom of which there is a rotor with specially bent pipes with nozzles. Due to the hydrostatic pressure the water is ejected from the nozzles causing the rotation of the rotor.
He was a member of scientific academies in London (1739), Berlin (1747) and St. Petersburg (1754) as well as the Royal Association of Göttingen (1751). S. became friends with mathematicians Leonard Euler in Göttingen and encouraged him with his discovery to research the foundation of the turbine theory.
