Template:Selected anniversaries/May 21: Difference between revisions

From Gnomon Chronicles
Jump to navigation Jump to search
No edit summary
No edit summary
Line 46: Line 46:
||1902: Camillo Herbert Grötzsch born ... mathematician. He was born in Döbeln and died in Halle. Grötzsch worked in graph theory. He was the discoverer and eponym of the Grötzsch graph, a triangle-free graph that requires four colors in any graph coloring, and Grötzsch's theorem, the result that every triangle-free planar graph requires at most three colors.
||1902: Camillo Herbert Grötzsch born ... mathematician. He was born in Döbeln and died in Halle. Grötzsch worked in graph theory. He was the discoverer and eponym of the Grötzsch graph, a triangle-free graph that requires four colors in any graph coloring, and Grötzsch's theorem, the result that every triangle-free planar graph requires at most three colors.


||1911: Williamina Fleming dies ... astronomer and academic.
||1911: Williamina Fleming dies ... astronomer and academic. Pic.


||1917: Thomas Christian Sneum born ... Danish pilot. He collected information about the German Freya radar that had been installed on his home island in Denmark. On the night of 21–22 June 1941 he and pilot Kjeld Pedersen made a spectacular escape from Denmark to Great Britain in a D.H. Hornet Moth. Pic: https://alchetron.com/Thomas-Sneum
||1917: Thomas Christian Sneum born ... Danish pilot. He collected information about the German Freya radar that had been installed on his home island in Denmark. On the night of 21–22 June 1941 he and pilot Kjeld Pedersen made a spectacular escape from Denmark to Great Britain in a D.H. Hornet Moth. Pic: https://alchetron.com/Thomas-Sneum


||1919: Evgraf Fedorov dies ... mathematician, crystallographer, and mineralogist.
||1919: Evgraf Fedorov dies ... mathematician, crystallographer, and mineralogist. Pic.


||1921: Sandy Douglas born ... computer scientist and academic, designed OXO.
||1921: Sandy Douglas born ... computer scientist and academic, designed OXO.

Revision as of 06:37, 15 May 2019