Template:Selected anniversaries/May 21
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.
1670: Astronomer and physicist Niccolò Zucchi dies. He published works on astronomy, optics, mechanics, and magnetism.
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.
1932: Bad weather forces aviator Amelia Earhart to land in a pasture in Derry, Northern Ireland, after flying solo across the Atlantic Ocean.
1946: Physicist Louis Slotin is fatally irradiated in a criticality incident during an experiment with the demon core at Los Alamos National Laboratory.