Template:Selected anniversaries/June 30
1660: Mathematician William Oughtred dies. He invented the slide rule in 1622.
1770: Astronomer Charles Messier is elected to the French Academy of Sciences.
1907: Spike in crimes against mathematical constants blamed on upcoming Tunguska event.
1905: Albert Einstein sends the article "On the Electrodynamics of Moving Bodies", in which he introduces special relativity, for publication in Annalen der Physik.
1908: The Tunguska event occurs in remote Siberia.
1956: The Tunguska Event Preservation Society launches fundraiser to simulate the 1927 Tunguska expedition.
1963: Physicist and educator Nikolay Basov publishes his theory of quantum gnomo-electronics; his ideas quickly find application in the detection and prevention of crimes against physical constants.