Births on July 20

Ian P. Howard, English-Canadian psychologist and academic (d. 2013)

Ian Porteus Howard (July 20, 1927 – June 1, 2013) was a Canadian psychologist and researcher in visual perception at York University in Toronto.

10 Jan

Metropolis (1927 film)
Fritz Lang's futuristic film Metropolis is released in Germany.
23 Feb

Uncertainty principle
German theoretical physicist Werner Heisenberg writes a letter to fellow physicist Wolfgang Pauli, in which he describes his uncertainty principle for the first time.
5 May

Virginia Woolf
To the Lighthouse by Virginia Woolf is first published.
27 May

Ford Model T
The Ford Motor Company ceases manufacture of the Ford Model T and begins to retool plants to make the Ford Model A.
26 Jun

Coney Island
The Cyclone roller coaster opens on Coney Island.