Portal:History of science/Selected anniversaries/September 18
- 1752 - Birth of Adrien-Marie Legendre, French mathematician (d. 1833)
- 1783 - Death of Leonhard Euler, Swiss mathematician (b. 1707)
- 1819 - Birth of Léon Foucault, French physicist (d. 1868)
- 1891 - Death of William Ferrel, American mathematician (b. 1817)
- 1896 - Death of Hippolyte Fizeau, French physicist (b. 1819)
- 1907 - Birth of Edwin McMillan, Nobel laureate (d. 1991)
- 1959 - Vanguard 3 is launched into Earth orbit
- 1967 - Death of John Cockcroft, British physicist, Nobel Prize laureate (b. 1897)
- 1977 - Death of Paul Bernays, Swiss mathematician (b. 1888)
- 1984 - Joe Kittinger completes the first solo balloon crossing of the Atlantic