Template:Selected anniversaries/December 9
1571: Mathematician and astronomer Adriaan Metius born. He will manufacture precision astronomical instruments, and published treatises on the astrolabe and on surveying.
1718: Monk, cosmographer, and cartographer Vincenzo Coronelli dies. He gained fame for his atlases and globes; some of the globes are very large and highly detailed.
1814: Physician Golding Bird born. He will pioneer the medical use of electricity.
1868: The first traffic lights are installed, outside the Palace of Westminster in London. Resembling railway signals, they use semaphore arms and are illuminated at night by red and green gas lamps.
1868: Chemist Fritz Haber born. He will receive the Nobel Prize in Chemistry in 1918 for his invention of the Haber–Bosch process, a method used in industry to synthesize ammonia from nitrogen gas and hydrogen gas.
1883: Mathematician, theorist, and academic Nikolai Luzin born. He will contribute to descriptive set theory and aspects of mathematical analysis with strong connections to point-set topology.
1901: Aurora researcher and Gnomon algorithm theorist Kristian Birkeland uses his experimental Terrella to prove, in a high-profile APTO court case, that rogue mathematician Anarchimedes guilty of planning and attempting to execute crimes against the ionosphere.
1905: Screenwriter and novelist Dalton Trumbo born.
1906: Computer scientist and Admiral Grace Hopper born. She will pioneer computer programming techniques, inventing one of the first compilers, and popularizing machine-independent programming languages (leading to the development of COBOL).
1917: Mathematician and philosopher Georg Cantor publishes new theory of sets derived from Gnomon algorithm functions. Colleagues hail it as "a magisterial contribution to science and art of detecting and preventing crimes against mathematical constants."
2018: Green Tangle 2 voted Picture of the Day by the citizens of New Minneapolis, Canada.