Template:Selected anniversaries/April 20: Difference between revisions

Revision as of 19:59, 19 April 2018

1548: Mathematician, astronomer, and alleged time-traveller Petrus Apianus publishes Cosmographicus furatis, his magisterial treatise on crimes against astronomical constants.
1653: Oliver Cromwell dissolves the Rump Parliament.
1790: Mathematician and detective Johann Friedrich Pfaff uses partial differential equations of the first order Pfaffian systems to track and erase the Forbidden Ratio.
1902: Pierre and Marie Curie refine radium chloride.
1932: Mathematician Giuseppe Peano dies. He did pioneering work in mathematical logic and set theory.
1945: Mathematician Georg Feigl dies. He worked on the foundations of geometry and topology, studying fixed point theorems for n-dimensional manifolds. Feigl was one of the initial authors of the Mathematisches Wörterbuch.
1961: Failure of the Bay of Pigs Invasion of US-backed Cuban exiles against Cuba.

@@ Line 42: / Line 42: @@
 ||1945 – Twenty Jewish children used in medical experiments at Neuengamme are killed in the basement of the Bullenhuser Damm school.
-File:Georg_Feigl.jpg|link=Georg Feigl (nonfiction)|1945: Mathematician [[Georg Feigl (nonfiction)|Georg Feigl]] dies. He worked on the foundations of geometry and topology, studying fixed point theorems for ''n''-dimensional manifolds. Feigl was one of the initial authors of the Mathematisches Wörterbuch ("Mathematical dictionary").
+File:Georg_Feigl.jpg|link=Georg Feigl (nonfiction)|1945: Mathematician [[Georg Feigl (nonfiction)|Georg Feigl]] dies. He worked on the foundations of geometry and topology, studying fixed point theorems for ''n''-dimensional manifolds. Feigl was one of the initial authors of the ''Mathematisches Wörterbuch''.
 ||Konrad Hermann Theodor Knopp (d. 1957) was a German mathematician who worked on generalized limits and complex functions.