Editing 1900 (section)

=== October ===
{{Main|October 1900}}
* [[October 9]] – The [[Cook Islands]] become a territory of the United Kingdom.
* [[October 19]] – [[Max Planck]] first states [[Planck's law]] of [[black-body radiation]] to a meeting of the [[German Physical Society]] in Berlin, marking the birth of modern [[quantum mechanics]].<ref>{{cite book|last=Gamow|first=Max|title=Thirty Years that Shook Physics|publisher=Dover Publications|isbn=978-0486248950|year=1985}}</ref> He restates it on December 14.
* [[October 24]] – [[1900 United Kingdom general election]]: voting concludes with the [[Unionist government, 1895–1905|Unionist]]s led by the [[Robert Gascoyne-Cecil, 3rd Marquess of Salisbury|Marquess of Salisbury]] re-elected.
* [[October 25]] – The United Kingdom annexes the [[South African Republic|Transvaal]].