What happened on 14 December?

14 events from the Ever-When timeline, ranked by how much they mattered.

1. 1900 Planck's quantum hypothesis Max Planck proposes that energy is quantised, founding quantum theory - one of the two pillars of modern physics alongside relativity.
2. 1911 Amundsen reaches the South Pole Norwegian expedition is first to the geographic South Pole; beats Scott by 34 days.
3. 1918 Sinn Féin sweeps the 1918 election In the first election of the peace, Sinn Féin takes 73 of Ireland's 105 seats on a pledge to abstain from Westminster and declare a republic — obliterating the old Home Rule party.
4. 1986 The sarcophagus seals Reactor 4 In seven months, under lethal radiation fields, 400,000 cubic metres of concrete and 7,000 tonnes of steel entomb the burnt-out reactor — built by crane operators working from lead
5. 1941 Burma Campaign Long Japanese-British-Indian-Chinese-American struggle in Burma; Kohima and Imphal turned the tide.
6. 1992 Protect Ya Neck (Wu-Tang Clan) Self-released debut showcasing eight Staten Island MCs and RZA's grimy production.
7. 1995 Dayton Agreement US-brokered accords end the Bosnian War and divide Bosnia into two entities within a single state.
8. 1546 Born: Tycho Brahe Danish astronomer whose meticulous observations made Kepler's laws possible.
9. 2012 Sandy Hook shooting A gunman kills 20 children and 6 staff at a Connecticut elementary school, intensifying America's gun-control debate.
10. 1861 Death of Prince Albert Victoria's husband dies of typhoid; Queen withdraws into seclusion for years; reshapes the monarchy.
11. 1972 Apollo 17 leaves the Moon Gene Cernan lifts off from the Taurus-Littrow valley as the last human being to stand on the Moon — a distinction that has now held for over half a century. The plaque left behind
12. 1895 Born: George VI Reluctant king who steadied the British monarchy through the war years.
13. 1918 Puccini's Gianni Schicchi The comic final panel of Il trittico, premiered at the Met in New York: a Florentine rogue forges a dead man's will, and his daughter sings 'O mio babbino caro'.
14. 1961 Presidential Commission on the Status of Women Kennedy names Eleanor Roosevelt to chair a commission on women's inequality; its 1963 report on pay, hiring and legal rights helps spark the women's movement.