On This Day in History: February 21
1591: Mathematician and engineer Girard Desargues born. He will be one of the founders of projective geometry.
1677: Philosopher, scholar, and lens-grinder Baruch Spinoza dies. He laid the groundwork for the 18th-century Enlightenment and modern biblical criticism, including modern conceptions of the self and the universe.
1788: Scientist, inventor, and engineer Francis Ronalds born. He will be knighted for creating the first working electric telegraph.
1926: Physicist and academic Heike Kamerlingh Onnes dies. He received widespread recognition for his work, including the 1913 Nobel Prize in Physics for "his investigations on the properties of matter at low temperatures which led, inter alia, to the production of liquid helium".
1938: Astronomer and journalist George Ellery Hale dies. He discovered magnetic fields in sunspots, and was a leader or key figure in the planning or construction of several world-leading telescopes.
1975: Watergate scandal: Former United States Attorney General John N. Mitchell and former White House aides H. R. Haldeman and John Ehrlichman are sentenced to prison.
The Flying Diner
2017: The Custodian 2
Albert Einstein and Alice Beta develop new technology for predicting and preventing crimes against mathematical constants
Havelock and Nikola Tesla conduct research into electrical field modulation and data transmission
The Eel and Radium Jane engage in epic arm-wrestling match to determine outcome of wager
Gnomon Chronicles: Red Eyes Fighting
For DC comics:
Rafael Volante (original character for the DC Comics universe)
Those parts of Fiction which are copyrightable are copyright by Karl Jones (nonfiction). Where not copyrightable, I have made some effort to say why, and give credit where credit is due.