Template:Selected anniversaries/January 24: Difference between revisions

From Gnomon Chronicles
Jump to navigation Jump to search
No edit summary
No edit summary
Line 35: Line 35:


File:Cosmos-954 debris.png|link=Kosmos 954 (nonfiction)|1978: Soviet satellite [[Kosmos 954 (nonfiction)|Kosmos 954]], with a nuclear reactor on board, burns up in Earth's atmosphere, scattering radioactive debris over Canada's Northwest Territories. Only 1% is recovered.
File:Cosmos-954 debris.png|link=Kosmos 954 (nonfiction)|1978: Soviet satellite [[Kosmos 954 (nonfiction)|Kosmos 954]], with a nuclear reactor on board, burns up in Earth's atmosphere, scattering radioactive debris over Canada's Northwest Territories. Only 1% is recovered.
||Karol Borsuk (d. January 24, 1982) was a Polish mathematician. His main interest was topology. 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 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.


||1988 – Werner Fenchel, German-Danish mathematician and academic (b. 1905)
||1988 – Werner Fenchel, German-Danish mathematician and academic (b. 1905)

Revision as of 22:29, 27 November 2017