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 an ...

, 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 effect of splitting of a spectral line into several components in the presence of a static magnetic field. It is named after the Dutch physicist Pieter Zeeman, who discovered it in 1896 and received a Nobel pri ...

, which is the

Zeeman effect The Zeeman effect (; ) is the effect of splitting of a spectral line into several components in the presence of a static magnetic field. It is named after the Dutch physicist Pieter Zeeman, who discovered it in 1896 and received a Nobel pr ...

'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 e ...

in 1916.

Life

Paschen was born in

Schwerin Schwerin (; Mecklenburgian Low German: ''Swerin''; Latin: ''Suerina'', ''Suerinum'') is the capital and second-largest city of the northeastern German state of Mecklenburg-Vorpommern as well as of the region of Mecklenburg, after Rostock. It ...

Mecklenburg-Schwerin The Duchy of Mecklenburg-Schwerin was a duchy in northern Germany created in 1701, when Frederick William and Adolphus Frederick II divided the Duchy of Mecklenburg between Schwerin and Strelitz. Ruled by the successors of the Nikloting Hou ...

. From 1884 to 1888 he studied at the universities of

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitu ...

and

Strassburg Strasbourg (, , ; german: Straßburg ; gsw, label= Bas Rhin Alsatian, Strossburi , gsw, label= Haut Rhin Alsatian, Strossburig ) is the prefecture and largest city of the Grand Est region of eastern France and the official seat of the E ...

, after which he became an assistant at the

Academy of Münster An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosop ...

. He became a professor at the Technical Academy of Hannover in 1893 and professor of physics at the

University of Tübingen The University of Tübingen, officially the Eberhard Karl University of Tübingen (german: Eberhard Karls Universität Tübingen; la, Universitas Eberhardina Carolina), is a public research university located in the city of Tübingen, Baden-W� ...

in 1901. He served as president of the

Physikalisch-Technischen Reichsanstalt The Physikalisch-Technische Bundesanstalt (PTB) is the national metrology institute of the Federal Republic of Germany, with scientific and technical service tasks. It is a higher federal authority and a public-law institution directly under f ...

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 (; March 5, 1914 – June 20, 2011) was a Chinese nuclear physicist who worked to develop and exploit nuclear physics in Germany and China. Early life and education He Zehui was born in Suzhou in 1914. She att ...

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 nuclear physicist, who shared the Nobel Prize in Physics in 1954 with Max Born. In 1913, he joined the newly created Laboratory for Radioactivity at the Reich Physi ...

who led the

Kaiser Wilhelm Institute The Kaiser Wilhelm Society for the Advancement of Science (German: ''Kaiser-Wilhelm-Gesellschaft zur Förderung der Wissenschaften'') was a German scientific institution established in the German Empire in 1911. Its functions were taken over by ...

in Heidelberg. Paschen taught in Berlin until his death in

Potsdam Potsdam () is the capital and, with around 183,000 inhabitants, largest city of the German state of Brandenburg. It is part of the Berlin/Brandenburg Metropolitan Region. Potsdam sits on the River Havel, a tributary of the Elbe, downstream of ...

in 1947.

References

{{DEFAULTSORT:Paschen, Friedrich 1865 births 1947 deaths 19th-century German physicists People from Schwerin People from the Grand Duchy of Mecklenburg-Schwerin Humboldt University of Berlin alumni Humboldt University of Berlin faculty University of Strasbourg alumni University of Münster faculty University of Hanover faculty University of Tübingen faculty Honorary Members of the USSR Academy of Sciences 20th-century German physicists

Life

See also

References