Heinrich Heesch (June 25, 1906 – July 26, 1995) was a German

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

. He was born in

Kiel Kiel () is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 246,243 (2021). Kiel lies approximately north of Hamburg. Due to its geographic location in the southeast of the Jutland ...

and died in

Hanover Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German state of Lower Saxony. Its 535,932 (2021) inhabitants make it the 13th-largest city in Germany as well as the fourth-largest city in Northern Germany ...

. In

Göttingen Göttingen (, , ; nds, Chöttingen) is a university city in Lower Saxony, central Germany, the capital of the eponymous district. The River Leine runs through it. At the end of 2019, the population was 118,911. General information The ori ...

he worked on

Group theory In abstract algebra, group theory studies the algebraic structures known as group (mathematics), groups. The concept of a group is central to abstract algebra: other well-known algebraic structures, such as ring (mathematics), rings, field ...

. In 1933 Heesch witnessed the

National Socialist 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 ...

purges of university staff. Not willing to become a member of the National Socialist organization of university teachers as required, he resigned from his university position in 1935 and worked privately at his parents' home in Kiel until 1948. During this time he did research on tilings. In 1955 Heesch began teaching at Leibniz University Hannover and worked on

graph theory In mathematics, graph theory is the study of ''graphs'', which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of '' vertices'' (also called ''nodes'' or ''points'') which are conn ...

. In this period Heesch did pioneering work in developing methods for a computer-aided proof of the then unproved four color theorem. In particular, he was the first to investigate the notion of "discharging", which turned out to be a fundamental ingredient of the eventual computer-aided proof by

Kenneth Appel Kenneth Ira Appel (October 8, 1932 – April 19, 2013) was an American mathematician who in 1976, with colleague Wolfgang Haken at the University of Illinois at Urbana–Champaign, solved one of the most famous problems in mathematics, the fou ...

and

Wolfgang Haken Wolfgang Haken (June 21, 1928 – October 2, 2022) was a German American mathematician who specialized in topology, in particular 3-manifolds. Biography Haken was born in Berlin, Germany. His father was Werner Haken, a physicist who had Max ...

. Between 1967 and 1971, Heesch made several visits to the United States, where bigger and faster computers were available, working with Haken at University of Illinois at Urbana-Champaign and with Karl Durre and Yoshio Shimamoto at

Brookhaven National Laboratory Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratory located in Upton, Long Island, and was formally established in 1947 at the site of Camp Upton, a former U.S. Army base and Japanese internment c ...

. During the crucial phase of his project, the German national research fund DFG cancelled financial support. After the 1977 success of Appel and Haken, Heesch worked on refining and shortening their proof, even after his retirement.

Works

* Heinrich Heesch, ''Untersuchungen zum Vierfarbenproblem'', Bibliographisches Institut, Mannheim 1969 * Bigalke, Hans-Günther (Hrsg.). ''Heinrich Heesch, Gesammelte Abhandlungen'', Bad Salzdetfurth 1986.

Literature on Heinrich Heesch's work

* Bigalke, Hans-Günther. ''Heinrich Heesch, Kristallgeometrie, Parkettierungen, Vierfarbenforschung'', Basel 1988.

External links

* http://www.ifg.uni-kiel.de/eckenundkanten/hk-02_de.html Biography (in German) {{DEFAULTSORT:Heesch, Heinrich 1906 births 1995 deaths 20th-century German mathematicians Scientists from Kiel People from the Province of Schleswig-Holstein University of Göttingen faculty University of Hanover faculty

Works

Literature on Heinrich Heesch's work

See also

External links