Template:Selected anniversaries/April 20

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  1653: Oliver Cromwell dissolves the Rump Parliament.

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  1902: Pierre and Marie Curie refine radium chloride.

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  1918: Physicist and academic Karl Ferdinand Braun dies. Braun contributed significantly to the development of radio and television technology, sharing the 1909 Nobel Prize in Physics with Guglielmo Marconi "for their contributions to the development of wireless telegraphy".

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  1932: Mathematician Giuseppe Peano dies. He did pioneering work in mathematical logic and set theory.

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  1933: Art critic and alleged time-traveller The Eel is caught in the act of cracking a safe.

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  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.

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  1961: Failure of the Bay of Pigs Invasion of US-backed Cuban exiles against Cuba.

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  1962: Traces of Clandestiphrine residue are detected at the Bay of Pigs, raising questions about CIA involvement with transdimensional drugs.