Template:Selected anniversaries/August 23
1638: René Descartes, in a letter to Marin Mersenne, proposed his folium (x-cubed + y-cubed = 2axy) as a test case to challenge Pierre de Fermat's differentiation techniques. To Descartes' embarrassment, Fermat's method worked.
1829: Mathematician and historian Moritz Cantor born. He will write Vorlesungen über Geschichte der Mathematik, which traces the history of mathematics up to 1799.
1946: Signed first edition of Alice and Niles Dancing sells for ten thousand dollars in charity auction to benefit victims of crimes against mathematical constants.
1966: Lunar Orbiter 1 takes the first photograph of Earth from orbit around the Moon.
1999: Sensors on the Mir spacecraft detect patterns of electricity which reveal existence of a vast electrical intelligence in the Earth's ionosphere, now known as AESOP.
1999: Biochemist and crystallographer John Kendrew dies. He shared the 1962 Nobel Prize for chemistry with Max Perutz for determining the atomic structures of proteins using X-ray crystallography.
2011: Pond At Dawn voted Picture of the Day by the citizens of New Minneapolis, Canada.
2017: Reality TV show Dennis Paulson of Mars wins Pulitzer Prize for Most Innovative Programming.