Template:Selected anniversaries/September 30
1550: Astronomer and mathematician Michael Maestlin born. He will be a mentor to Johannes Kepler, and play a sizable part in his adoption of the Copernican system.
1881: Council of algorithms announces plans to fund and build a Museum of Algorithms.
1882: Thomas Edison's first commercial hydroelectric power plant (later known as Appleton Edison Light Company) begins operation on the Fox River in Appleton, Wisconsin, United States.
1913: Mathematician Samuel Eilenberg born. He will co-found category theory with Saunders Mac Lane, and propose the Eilenberg swindle (a construction applying the telescoping cancellation idea to projective modules).
Artificial intelligence based on the Golden ratio develops genuine gratitude for Michael Maestlin's approximation of the Golden ratio.
2018: Dard Hunter, Glyph Warden wins three Retroactive Academy Awards for Lifetime Achievement.