Arabic numerals
Development of numerical zero
Euclidean geometry.
Archimedes principle (and his various inventions)
Various religious turning points: Xtianity/its schisms, Islam/its schism.
Gunpowder.
Magna Carta.
Accession of Scottish kings to the English throne.
The dropping of the great seal of England in the Thames by an ousted king.
Newton/Leibnitz on calculus.
Newton's law of gravity.
French revolution
Darwin's theory of evolution
USA
Invention of the concentration camp by England during the Boer war.
Maxwell/Faraday/wireless transmission of signals.
Saint-Victor/Becquerel/Curie - radioactivity
Internal combustion engine/motor car.
WW1
Russian revolution
The Irish revolution 1922
Female suffrage
Chinese revolution
Baird/TV
Fleming/Penicillin
Steel strung guitar.
Beauchamp/Rickenbacker invention of electric guitar.
WW2
The Pill
Leo Fender/Jim Burns/Jim Marshall
Hiroshima and Nagasaki
Chernobyl
Fukushima

Oh, and from about 300BCE to date - various abolitions of slavery.