Gerhard Thomsen (23 June 1899 – 4 January 1934) was a German mathematician, probably best known for his work in various branches of

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

Life

Thomsen was born on 23 June 1899 in

Hamburg (male), (female) en, Hamburger(s), Hamburgian(s) , timezone1 = Central (CET) , utc_offset1 = +1 , timezone1_DST = Central (CEST) , utc_offset1_DST = +2 , postal ...

. His father, Georg Thomsen, was a physician. Thomsen grew up in Hamburg and attended the Johanneum ( gymnasium/highschool) from 1908 to 1917. After completing school he served in the army during the last year of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. In 1919 he became of the first students at the newly founded

University of Hamburg The University of Hamburg (german: link=no, Universität Hamburg, also referred to as UHH) is a public research university in Hamburg, Germany. It was founded on 28 March 1919 by combining the previous General Lecture System ('' Allgemeines Vor ...

majoring in

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

and

natural science Natural science is one of the branches of science concerned with the description, understanding and prediction of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and repeatab ...

. Aside from a temporary interlude Thomsen studied in Hamburg until 1923. He received a certification to teach at highschools the fall of 1922 and finally his

PhD PHD or PhD may refer to: * Doctor of Philosophy (PhD), an academic qualification Entertainment * '' PhD: Phantasy Degree'', a Korean comic series * ''Piled Higher and Deeper'', a web comic * Ph.D. (band), a 1980s British group ** Ph.D. (Ph.D. albu ...

in the summer of the following year. After he worked shortly as an assistant at the

Karlsruhe Institute of Technology The Karlsruhe Institute of Technology (KIT; german: Karlsruher Institut für Technologie) is a public research university in Karlsruhe, Germany. The institute is a national research center of the Helmholtz Association. KIT was created in 2009 w ...

before returning to Hamburg in a similar capacity in the spring of 1925. While working on his

habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including a ...

thesis Thomsen spend one year in Rome on

Rockefeller grant Rockefeller is a German surname, originally given to people from the village of Rockenfeld near Neuwied in the Rhineland and commonly referring to subjects associated with the Rockefeller family. It may refer to: People with the name Rockefeller fa ...

to study with

Levi-Civita Tullio Levi-Civita, (, ; 29 March 1873 – 29 December 1941) was an Italian mathematician, most famous for his work on absolute differential calculus (tensor calculus) and its applications to the theory of relativity, but who also made significa ...

. He received his habilitation in Hamburg in 1928 and started a position as a tenured professor at the

University of Rostock The University of Rostock (german: link=no, Universität Rostock) is a public university located in Rostock, Mecklenburg-Vorpommern, Germany. Founded in 1419, it is the third-oldest university in Germany. It is the oldest university in continen ...

in the fall of 1929. On 11 November 1933 Thomsen gave an inflammatory talk entitled "Über die Gefahr der Zurückdrängung der exakten Naturwissenschaften an Schulen und Hochschulen" (''On the danger of marginalizing the exact sciences in schools and universities''), that received a large amount of publicity in academic circles. While the talk seemed supportive of some aims of the

Nazis Nazism ( ; german: Nazismus), the common name in English for National Socialism (german: Nationalsozialismus, ), is the far-right totalitarian political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in Na ...

, it also directly attacked their suppression of education in the sciences. This caused him to be investigated by the

Gestapo The (), abbreviated Gestapo (; ), was the official secret police of Nazi Germany and in German-occupied Europe. The force was created by Hermann Göring in 1933 by combining the various political police agencies of Prussia into one organi ...

. Thomsen was killed by a train on a railroad track in Rostock on 4 January 1934. It is assumed that he committed suicide possibly triggered by the Gestapo investigation.

Work

In Hamburg Thomsen assisted

Wilhelm Blaschke Wilhelm Johann Eugen Blaschke (13 September 1885 – 17 March 1962) was an Austrian mathematician working in the fields of differential and integral geometry. Education and career Blaschke was the son of mathematician Josef Blaschke, who taught ...

to apply

Felix Klein Christian Felix Klein (; 25 April 1849 – 22 June 1925) was a German mathematician and mathematics educator, known for his work with group theory, complex analysis, non-Euclidean geometry, and on the associations between geometry and group ...

Erlangen Program In mathematics, the Erlangen program is a method of characterizing geometries based on group theory and projective geometry. It was published by Felix Klein in 1872 as ''Vergleichende Betrachtungen über neuere geometrische Forschungen.'' It is nam ...

differential geometry Differential geometry is a mathematical discipline that studies the geometry of smooth shapes and smooth spaces, otherwise known as smooth manifolds. It uses the techniques of differential calculus, integral calculus, linear algebra and multili ...

. He also edited and organized Blaschke's lectures on differential geometry for publication as a series of three books. Thomsen wrote 22 papers on various topics in geometry and furthermore a few papers on theoretical physics as well. The latter were mostly written in Italian rather than in German. Thomsen also wrote a book on the foundations of elementary geometry. In elementary geometry

Thomsen's theorem Thomsen's theorem, named after Gerhard Thomsen, is a theorem in elementary geometry. It shows that a certain path constructed by line segments being parallel to the edges of a triangle always ends up at its starting point. Consider an arbitrary ...

is named after him.

Notes

James T. Smith: ''Methods of Geometry''. Wiley, 2011, , p
291
Max Pinl: ''Kollegen in schwerer Zeit''. Jahresbericht DMV, Volume 73, 1972, p
205–206
(German) ''Satz von Thomsen'' In: ''Schülerduden – Mathematik II''. Bibliographisches Institut & F.A. Brockhaus, 2004, , pp. 358–359 (German) {{DEFAULTSORT:Thomsen, Gerhard 1899 births 1934 deaths 20th-century German mathematicians Geometers Mathematical analysts 1934 suicides Suicides by train Suicides in Germany