Louis Carl Heinrich Friedrich Paschen (22 January 1865 – 25 February 1947) was a German

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

, known for his work on electrical discharges. He is also known for the

Paschen series The emission spectrum of atomic hydrogen has been divided into a number of ''spectral series'', with wavelengths given by the Rydberg formula. These observed spectral lines are due to the electron making transitions between two energy levels in ...

, a series of hydrogen spectral lines in the infrared region that he first observed in 1908. He established the now widely used Paschen curve in his article ''"Über die zum Funkenübergang in Luft, Wasserstoff und Kohlensäure bei verschiedenen Drücken erforderliche Potentialdifferenz"''. He is known for the

Paschen-Back effect The Zeeman effect () is the splitting of a spectral line into several components in the presence of a static magnetic field. It is caused by the interaction of the magnetic field with the magnetic moment of the atomic electron associated with ...

, which is the

Zeeman effect The Zeeman effect () is the splitting of a spectral line into several components in the presence of a static magnetic field. It is caused by the interaction of the magnetic field with the magnetic moment of the atomic electron associated with ...

's becoming non-linear at high magnetic field. He helped explain the

hollow cathode effect The hollow cathode effect allows electrical conduction at a lower voltage or with more current in a cold-cathode gas-discharge lamp when the cathode is a conductive tube open at one end than a similar lamp with a flat cathode. The hollow cathode ef ...

in 1916.

Life

Paschen was born in

Schwerin Schwerin (; Mecklenburgisch-Vorpommersch dialect, Mecklenburgisch-Vorpommersch Low German: ''Swerin''; Polabian language, Polabian: ''Zwierzyn''; Latin: ''Suerina'', ''Suerinum'') is the Capital city, capital and List of cities and towns in Germ ...

Grand Duchy of Mecklenburg-Schwerin The Grand Duchy of Mecklenburg-Schwerin () was a territory in Northern Germany held by the House of Mecklenburg residing at Schwerin. It was a sovereign member state of the German Confederation and became a federated state of the North German C ...

. From 1884 to 1888 he studied at the universities 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 ...

and

Strassburg Strasbourg ( , ; ; ) is the Prefectures in France, prefecture and largest city of the Grand Est Regions of France, region of Geography of France, eastern France, in the historic region of Alsace. It is the prefecture of the Bas-Rhin Departmen ...

, after which he became an assistant at the

Academy of Münster An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the go ...

. He became a professor at the Technische Hochschule Hannover in 1893 and professor of physics at the

University of Tübingen The University of Tübingen, officially the Eberhard Karl University of Tübingen (; ), is a public research university located in the city of Tübingen, Baden-Württemberg, Germany. The University of Tübingen is one of eleven German Excellenc ...

in 1901. He served as president of the Physikalisch-Technischen Reichsanstalt from 1924–33 and an honorary professor of the University of Berlin in 1925. During the second world war he had the Chinese scientist

He Zehui Professor He Zehui or Ho Zah-wei ( zh, c=何泽慧; March 5, 1914 – June 20, 2011) was a Chinese nuclear physicist who worked with Walther Bothe in Nazi Germany during World War II and with Irène Joliot-Curie in Paris, and later helped deve ...

to stay at his house and she became like a daughter to him. With his help she was introduced to

Walther Bothe Walther Wilhelm Georg Bothe (; 8 January 1891 – 8 February 1957) was a German physicist who shared the 1954 Nobel Prize in Physics with Max Born "for the coincidence method and his discoveries made therewith". He served in the military durin ...

who led the

Kaiser Wilhelm Institute The Kaiser Wilhelm Society for the Advancement of Science () was a German scientific institution established in the German Empire in 1911. Its functions were taken over by the Max Planck Society. The Kaiser Wilhelm Society was an umbrella organi ...

in Heidelberg. Paschen taught in Berlin until his death in

Potsdam Potsdam () is the capital and largest city of the Germany, German States of Germany, state of Brandenburg. It is part of the Berlin/Brandenburg Metropolitan Region. Potsdam sits on the Havel, River Havel, a tributary of the Elbe, downstream of B ...

in 1947. He is buried at the

Stahnsdorf South-Western Cemetery The Stahnsdorf South-Western Cemetery () is a Protestant rural cemetery in Germany. Established in 1909, the cemetery is located in the municipality of Stahnsdorf in Potsdam-Mittelmark district, Berlin/Brandenburg Metropolitan Region. With a la ...

External links

References

{{DEFAULTSORT:Paschen, Friedrich 1865 births 1947 deaths Burials at Stahnsdorf South-Western Cemetery 19th-century German physicists People from Schwerin People from the Grand Duchy of Mecklenburg-Schwerin Humboldt University of Berlin alumni Academic staff of the Humboldt University of Berlin University of Strasbourg alumni Academic staff of the University of Münster Academic staff of Leibniz University Hannover Academic staff of the University of Tübingen Honorary members of the Russian Academy of Sciences (1917–1925) 20th-century German physicists

Life

See also

External links

References