Template:Selected anniversaries/May 21

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  1471: Painter, engraver, and mathematician Albrecht Dürer born. He will introduction of classical motifs into Northern art through his knowledge of Italian artists and German humanists.

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  1670: Astronomer and physicist Niccolò Zucchi dies. He published works on astronomy, optics, mechanics, and magnetism.

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  1859: Lawyer, translator, inventor, and APTO operative Per Georg Scheutz uses his Scheutzian calculation engine to defeat the Forbidden Ratio in single combat.

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  1923: Mathematician and academic Armand Borel born. He will work in algebraic topology, and in the theory of Lie groups. He will contribute to the creation of the contemporary theory of linear algebraic groups.

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  1927: Charles Lindbergh touches down at Le Bourget Field in Paris, completing the world's first solo nonstop flight across the Atlantic Ocean.

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  1927: Pilot, engineer, and alleged time-traveler Henrietta Bolt touches down at Le Bourget Field in Paris, completing the world's first solo nonstop round-the-world flight.

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  1932: Bad weather forces Amelia Earhart to land in a pasture in Derry, Northern Ireland, and she thereby becomes the first woman to fly solo across the Atlantic Ocean.

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  1946: Physicist Louis Slotin is fatally irradiated in a criticality incident during an experiment with the demon core at Los Alamos National Laboratory.

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  1953: Logician and mathematician Ernst Friedrich Ferdinand Zermelo dies. His work had major implications for the foundations of mathematics; he is known for his role in developing Zermelo–Fraenkel axiomatic set theory, and for his proof of the well-ordering theorem.