Template:Selected anniversaries/April 3
1693: Carpenter and clockmaker John Harrison born. He will invent a marine chronometer, a long-sought-after device for solving the problem of calculating longitude while at sea.
1827: Physicist, musician, and academic Ernst Chladni dies. He has been called both the father of acoustics and the father of meteoritics.
1841: Inventor and crime-fighter Charles Grafton Page publishes new class of Gnomon algorithm functions which detect and prevent crimes against mathematical constants.
1907: Cryptanalyst and mathematician Solomon Kullback born. Krullback will begin his career with the US Army's Signal Intelligence Service (SIS) in the 1930s; when the National Security Agency (NSA) is formed in 1952, Rowlett will become chief of cryptanalysis, overseeing the research and development of computerized cryptanalysis.
1908: Chemist, physicist, and APTO field engineer William Crookes uses the famous Crookes tube to defeat the criminal mathematical function Killer Poke in single combat.
1995: Mathematician and checkers player Marion Tinsley dies. Tinsley was "to checkers what Leonardo da Vinci was to science, what Michelangelo was to art and what Beethoven was to music."
1998: Mathematician and academic Mary Cartwright dies. She did pioneering work in chaos theory.
1999: Sensors on the Mir spacecraft detect patterns of electricity which reveal existence of a vast artificial intelligence in the Earth's ionosphere.
2017: Signed first edition of Crimson Blossom spontaneously develop and previously unknown shade of red after exposure to Cherenkov radiation during a high-energy literature experiment.