Mathwar/Personlist/Borsuk Karol
Karol Borsuk
Karol Borsuk (* May 8th 1905 in Warsaw, † January 24th 1982 in Warsaw) Borsuk introduced the theory of absolute retracts (ARs) and absolute neighborhood retracts (ANRs), and the cohomotopy groups, later called Borsuk-Spanier cohomotopy groups. He also founded the so called Shape theory. He has constructed various beautiful examples of topological spaces, e.g. an acyclic, 3-dimensional continuum which admits a fixed point free homeomorphism onto itself; also 2-dimensional, contractible polyhedra which have no free edge. His topological and geometric conjectures and themes stimulated research for more than half a century.
Life
During the Nazi occupation Borsuk tried to keep the University of Warsaw functioning in the way that Kuratowski describes in the quote above. However, he was unable to do this without being found out by the Nazis and he was imprisoned for this "crime". Borsuk, however, escaped and was able to survive by remaining in hiding throughout the rest of the war.