Karl Hermann Knoblauch (; 11 April 1820 – 30 June 1895) was a German physicist. He is most notable for his studies of radiant heat. He was one of the six founding members of the

Deutsche Physikalische Gesellschaft The German Physical Society (German: , DPG) is the oldest organisation of physicists. As of 2022, the DPG's worldwide membership is cited as 52,220, making it one of the largest national physics societies in the world. The DPG's membership peaked ...

at Berlin on 14 January 1845. Knoblauch's father was a well-to-do silk fabrics manufacturer in Berlin. Despite pressure from his father to enter the family business, Knoblauch in his early 20s opted to study mathematics and science at the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

. There he became one of the star students in the laboratory of Gustav Magnus. Knoblauch's doctorate, completed in Berlin in 1847, described valuable experiments that established some of the optical properties of

radiant heat Thermal radiation is electromagnetic radiation emitted by the thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. The emission of energy arises from a combination of electro ...

(a.k.a. infrared radiation). In an article describing these experiments Knoblauch wrote that experimental facts are "the only permanent things in science", while abstract models are "transitory" and should be treated with caution and kept separate from the facts, a view that Magnus maintained also. As a researcher and teacher at the

University of Marburg The Philipps University of Marburg () is a public research university located in Marburg, Germany. It was founded in 1527 by Philip I, Landgrave of Hesse, which makes it one of Germany's oldest universities and the oldest still operating Prote ...

, 1849–53, he produced valuable experimental demonstrations about the nature of

diamagnetism Diamagnetism is the property of materials that are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnet ...

. Knoblauch's student and collaborator on the diamagnetism work was

John Tyndall John Tyndall (; 2 August 1820 – 4 December 1893) was an Irish physicist. His scientific fame arose in the 1850s from his study of diamagnetism. Later he made discoveries in the realms of infrared radiation and the physical properties of air ...

. Tyndall and Knoblauch maintained a correspondence on and off over the next 25 years. Knoblauch moved to 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 ...

in 1853, and remained there for the rest of his career. During his first few years at Halle he did not publish anything. Later his publications were still not as frequent as they had been before moving to Halle. In his Halle years, apart from science teaching and research, he also gave his time to various administrative functions in German science including being president for 17 years of the German Academy of Sciences. He was also the rector (chief administrative officer) of the University of Halle for a while. His wife Elisabeth (1827–1855) died on September 12 due to complications from childbirth of their son

Johannes Johannes is a Medieval Latin form of the personal name that usually appears as " John" in English language contexts. It is a variant of the Greek and Classical Latin variants (Ιωάννης, '' Ioannes''), itself derived from the Hebrew name '' Y ...

, who was born on August 27.

References

''Some of the above information has been taken from the German language Wikipedia article Hermann Knoblauch'' *

External links

* * {{DEFAULTSORT:Knoblauch, Karl Hermann 1820 births 1895 deaths 19th-century German physicists German experimental physicists Politicians from Berlin Scientists from the Province of Brandenburg Prussian politicians Humboldt University of Berlin alumni Academic staff of the University of Bonn Academic staff of the Martin Luther University of Halle-Wittenberg Academic staff of the University of Marburg Members of the Prussian House of Lords Presidents of the German National Academy of Sciences Leopoldina Scientists from Berlin Physicists from the Kingdom of Prussia

See also

References

External links