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 caus ...
, 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 prize ...
, 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 prize ...
'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 (; Mecklenburgisch dialect, Mecklenburgian Low German: ''Swerin''; Latin: ''Suerina'', ''Suerinum'') is the Capital city, capital and List of cities and towns in Germany, second-largest city of the northeastern States of Germany, German ...
,
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 Hous ...
. 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 constitue ...
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 Eur ...
, after which he became an assistant at the
Academy of Münster
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary education, secondary or tertiary education, tertiary higher education, higher learning (and generally also research or honorary membershi ...
. 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-Wü ...
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 (; 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 B ...
in 1947.
[ ]
See also
*
Paschen notation
*
Townsend discharge
The Townsend discharge or Townsend avalanche is a gas ionisation process where free electrons are accelerated by an electric field, collide with gas molecules, and consequently free additional electrons. Those electrons are in turn accelerated and ...
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