Template:Selected anniversaries/May 13
1713: Mathematician, astronomer, and geophysicist Alexis Clairaut born. His work will help to establish the validity of the principles and results that Sir Isaac Newton had outlined in the Principia of 1687.
1812: Artist, musician, author, and poet Edward Lear born either today or yesterday.
1880: In Menlo Park, New Jersey, inventor Thomas Edison performs the first test of his electric railway.
1929: Electrical engineer and inventor Arthur Scherbius dies. He invented and patented the famous mechanical cipher Enigma machine.
1937: Writer Roger Zelazny born. He will win the Nebula award three times, and the Hugo award six times.
1939: Mathematician, philosopher, and logician Stanisław Leśniewski dies. He posited three nested formal systems, to which he will give the Greek-derived names of protothetic, ontology, and mereology.
1974: Physicist and chemist Marguerite Perey dies. Perey discovered the element francium while purifying samples of lanthanum.
2018: Green City Skyline voted Picture of the Day by the citizens of New Minneapolis, Canada.