Friedrich Ernst Dorn

Friedrich Ernst Dorn
Friedrich Ernst Dorn
Born	(1848-07-27)27 July 1848 Guttstadt (Dobre Miasto), Province of Prussia
Died	16 December 1916(1916-12-16) (aged 68) Halle, Province of Saxony, Germany
Nationality	German
Fields	Physics
Institutions	Halle University
Alma mater	University of Königsberg
Known for	Radon

Friedrich Ernst Dorn (27 July 1848 – 16 December 1916) was a German physicist who was the first to discover that a radioactive substance, later named radon, is emitted from radium.

Dorn was born in Guttstadt (Dobre Miasto), Province of Prussia (nowadays Warmia in Poland), and died in Halle, Province of Saxony. He was educated at Königsberg and went on to teach at the university level. In 1885, at Halle University, Dorn took over the position of personal ordinarius professor for theoretical physics from Anton Oberbeck. Since Dorn was already an ordinarius professor, he was allowed to assume the title so as to not appear as having been demoted. In 1895, Dorn succeeded Hermann Knoblauch at Halle as the ordinarius professor for experimental physics and director of the physics institute. Dorn’s previous duties were assumed by Carl Schmidt, who had been a Privatdozent and was called as an extraordinarius professor for theoretical physics.

In 1900, Dorn published a paper in which he described experiments that repeated and extended some earlier work on thorium by Ernest Rutherford. Dorn verified Rutherford's observation that a radioactive material was emitted by thorium, and discovered that a similar emission arose from the element radium. Additional work by Rutherford and Soddy showed that the same emission came from both thorium and radium, that it was a gas, and that it was actually a new element.