Portal:History of science/Selected anniversaries/September 5
- 1667 - Birth of Giovanni Gerolamo Saccheri, Italian mathematician (d. 1733)
- 1725 - Birth of Jean-Étienne Montucla, French mathematician (d. 1799)
- 1787 - Birth of François Sulpice Beudant, French mineralogist and geologist (d. 1850)
- 1792 - Birth of Pierre-Armand Dufrénoy, French geologist and mineralogist (d. 1857)
- 1901 - Death of Ignacij Klemenčič, Slovenian physicist (b. 1853)
- 1906 - Death of Ludwig Boltzmann, Austrian physicist (b. 1844)
- 1917 - Death of Marian Smoluchowski, Polish physicist (b. 1872)
- 1948 - Death of Richard C. Tolman, American mathematical physicist (b. 1881)
- 2002 - Death of David Todd Wilkinson, American astronomer, author of the first study of the Cosmic microwave background radiation (b. 1935)