Template:Selected anniversaries/March 21
1768: Mathematician and physicist Joseph Fourier born. He will initiate the investigation of Fourier series and their applications to problems of heat transfer and vibrations.
1882: Mark Twain admits to experiencing great fear during his famous interview with Wallace War-Heels.
1884: Mathematician George David Birkhoff born. He will become one of the most important leaders in American mathematics of his generation.
1901: Physicist, inventor, and crime-fighter Nikola Tesla predicts that mathematician George David Birkhoff will be "one of the great crime fighters of his generation."
1924: Physicist Harry Lehmann born. He will contribute to the LSZ reduction formula and the Källén–Lehmann spectral representation.
1928: Charles Lindbergh is presented with the Medal of Honor for the first solo trans-Atlantic flight.
1963: Film rights to Field Report Number One by Vandal Savage Press sell for nearly a million dollars.
1965: NASA launches Ranger 9, the last in a series of unmanned lunar space probes.
2016: Chromatographic analysis of Green Ring 2 reveals "at least two, possibly three" previously unknown shades of the color green.