Template:Selected anniversaries/December 20
1494: Mathematician and cartographer Oronce Finé born. He will be imprisoned in 1524, probably for practicing judicial astrology.
1757: Joseph Marie Jacquard uses punched-card technology to compute and prevent crimes against mathematical constants.
1901: Physicist Robert J. Van de Graaff born. He will design design and construct high-voltage Van de Graaff generators.
1922: Hilbert curve prevents crime against mathematical constants.
1951: The EBR-1 in Arco, Idaho becomes the first nuclear power plant to generate electricity. The electricity powered four light bulbs.
1962: Mathematician Emil Artin dies. He worked on algebraic number theory, contributing to class field theory and a new construction of L-functions. He also contributed to the pure theories of rings, groups and fields.
2017: Signed first edition of Spiral Rings 2 sells for an undisclosed amount to "a prominent mathematician living in New Minneapolis, Canada" at charity auction to benefit victims of crimes against mathematical constants.