1931 (idea)

The Empire State Building is completed in May, after a 14-month building period. Standing 448 metres tall, it is the tallest building in the world until the completion of the first tower of the World Trade Center in Lower Manhattan in 1972. As of September 11, 2001 the Empire State Building is once again the highest building in New York City.
Spain becomes a republic (the so-called Second Spanish Republic) with the overthrow of King Alfonso XIII. The revolutionary committee becomes the provisional government, naming Niceto Alcala Zamora president. A new constitution is drafted.
The Mukden Incident begins Japanese occupation of Manchuria.
The planned capital of New Delhi opens in India.
Gangster Al Capone sentenced to 11 years in prison for tax evasion, although he is eventually freed in 1939 and dies in 1947.
The Scottsboro trial begins, exposing the depth of Southern racism.
"The Star Spangled Banner" by Francis Scott Key officially becomes the national anthem.
There are nearly 30,000 television sets in the United States; 9,000 of them are in New York City alone.
Double features emerge as a way for the unemployed to occupy time.
General Motors's Frigidaire makes refrigerators safe for household use.
Karl Jansky begins the science of radio astronomy as he observes interference in the form of hissing sounds coming from beyond the earth's atmosphere.
Harold Urey discovers heavy water.
An electron microscope is developed by Vladimir Zworykin and James Hillier.

U.S. Statistics
President: Herbert C. Hoover
Vice President: Charles Curtis
Population: 124,039,648
Federal spending: $3.58 billion
Consumer Price Index: 15.2
Unemployment: 16.3%

Entertainment Awards
Pulitzer Prize for Fiction: Years of Grace, Margaret Ayer Barnes
Pulitzer Prize for Drama: Alison's House, Susan Glaspell

Academy Award for Best Picture: Cimarron (RKO Radio)
Academy Award for Best Actor: Lionel Barrymore, A Free Soul
Academy Award for Best Actress: Marie Dressler, Min and Bill
Academy Award for Directing: Norman Taurog, Skippy

Nobel Prize for Literature: Erik Axel Karlfeldt (Sweden) for "The poetry of Erik Axel Karlfeldt". Interpret this how you will - it is the official motivation offered by the 1931 Nobel jury.
Nobel Prize for Chemistry: Karl Bosch and Friedrich Bergius (Germany), "in recognition of their contributions to the invention and development of chemical high pressure methods".
Nobel Prize for Physics: No Nobel prize was awarded during 1931, the prize money was allocated to the Special Fund of this prize section.
Nobel Prize for Medicine: Otto H. Warburg (Germany), for discovery of the character and mode of action of the respiratory ferment.
Nobel Peace Prize: Jane Addams and Nicholas Murray Butler(USA)