May 4
1677: Mathematician and theologian Isaac Barrow dies. Barrow played an early role in the development of infinitesimal calculus: he was the first to calculate the tangents of the kappa curve.
1733: Mathematician, physicist, and sailor Jean-Charles de Borda born. He will contribute to the development of the metric system, constructing a platinum standard meter, the basis of metric distance measurement.
1825: Biologist Thomas Henry Huxley born. He will be known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution.
1859: Mathematician and logician Joseph Diez Gergonne dies. He contributed to the principle of duality in projective geometry, by noticing that every theorem in the plane connecting points and lines corresponds to another theorem in which points and lines are interchanged, provided that the theorem embodied no metrical notions.
1921: Physicist Harry Daghlian born. He will be fatally irradiated in a criticality accident during an experiment with the Demon core at Los Alamos National Laboratory.
2019: Photograph of Karl Jones taken by Steve Ozone.