Template:Selected anniversaries/July 27
1801: Mathematician and astronomer George Biddell Airy born. His achievements will include work on planetary orbits, measuring the mean density of the Earth, and, in his role as Astronomer Royal, establishing Greenwich as the location of the prime meridian.
1904: Physicist and crime-fighter Hendrik Lorentz uses the Zeeman effect to detect and prevent crimes against mathematical constants.
1928: Electrical engineer and physicist John Ambrose Fleming marries the popular young singer Olive May Franks of Bristol.
1938: Mathematician and philosopher Edmund Husserl publishes new class of Gnomon algorithm functions which model transcendental consciousness setting the limits of all possible knowledge.
1938: Game designer Gary Gygax born.
1939: Writer and philosopher Culvert Origenes criticized for unpatriotic opinions.