January 13 - The first Mickey Mouse comic strip is published in the New York Mirror

February 13 - Greta Garbo's first talkie (Anna Christie) opens; she asks for a shot of whisky

Feb. 18 - While studying photographs taken in January, Clyde Tombaugh discovers Pluto.

The same day, Elm Farm Ollie becomes the first cow to fly in an airplane and also the first cow to be milked in an airplane.

March 12 - Mohandas Gandhi sets off to a 248-mile protest march towards the sea with 78 followers to protest the British monopoly on salt - more will join them during the Salt March that ends on April 6
   
March 31 - The Motion Pictures Production Code is instituted, imposing strict guidelines on the treatment of sex, crime, religion and violence in motion pictures for the next forty years
 
April 6 - Hostess Twinkies are invented.
 
April 28 - The first night game in organized baseball history takes place in Independence, Kansas.
 
May 6 - The Great Salmas Earthquake in Iran; 7.3 on the Richter Scale and killed 4,000 people.
 
May 15 - Aboard a Boeing tri-motor, Ellen Church becomes the first airline stewardess (the flight was from Oakland, California to Chicago, Illinois).
 
May 24 - Amy Johnson lands in Darwin, Australia becoming the first woman to fly solo from England to Australia (she left on May 5 for the 11,000 mile flight).
 
June 17 - U.S. President Herbert Hoover signs the Smoot-Hawley Tariff Act into law.

June 17 - Bonus Army: Around a thousand World War I veterans mass at the United States Capitol as the U.S. Senate considers a bill that would give them certain benefits.
 
July 5 - The Seventh Lambeth Conference of Anglican Christian bishops opens. This conference approved the use of artificial birth control in limited circumstances, marking a controversial turning point in Christian views on contraception.
 
July 13 - The first Football World Cup starts
 
July 31 - The radio mystery program The Shadow airs for the first time.
 
August 9 - Betty Boop premiers in the animated film Dizzy Dishes.

August 16 - Rafael Leónidas Trujillo takes over in the Dominican Republic until 1961.

August 27 - Military junta takes over in Peru.

September 6 - José Félix Uriburu makes a successful military coup, overthrowing Hipólito Yrigoyen, President of Argentina

Freud publishes 'Civilization and discontent'

September 8 - 3M begins marketing Scotch transparent tape.
 
September 14 - National socialists win 107 seats in German parliament - 18.3% of all the votes makes them second largest party
 
An earthquake in the Izu Peninsula of Japan kills 223 people and destroys 650 buildings

October 24 - Brazil Revolution of 1930 by Getúlio Dornelles Vargas
 
December 2 - Great Depression: US President Herbert Hoover goes before Congress and asks for a US$150 million public works program to help generate jobs and stimulate the economy.
 
December 19 - Merapi volcano erupts - 1300 dead.
 
December 24 - In London, Harry Grindell Matthews demonstrates his device to project pictures to the clouds.
 
December 29 - Sir Muhammad Iqbal's presidential address in Allahabad introduces the Two-Nation Theory and outlines a vision for the creation of Pakistan.


Science News

Jake paralysis outbreak occurs in United States.
 
(Jake paralysis was neuropathy caused by drinking a Jamaican ginger extract (commonly called “jake”) diluted with an industrial chemical known as triorthocresyl phosphate (TCP or TOCP).
 
Jake had been legally sold for medicinal purposes since the Civil War. Because it was about 70% alcohol, it was widely used during prohibition in the U.S. (1920-1933) as a means of legally consuming alcohol. (Contrary to common belief, the consumption of alcohol was legal during prohibition; it was the production, distribution and sale of alcoholic beverages that was prohibited.)
 
However, in 1930, the manufacturer of jake decided to water down the product with the cheap, tasteless, water-soluble TCP. The highly toxic result (one of the uses of TCP was as a pesticide) was that an estimated 50,000 people in the US were temporarily or permanently paralyzed.
 
The paralysis was called commonly jake foot or jake leg because the neuropathy caused victims to walk in a distinctive manner. The muscles that permit a person to raise the toes were paralyzed, so victims had to raise their feet high so as not to drag their feet. As they stepped, their toes would come down first followed by a jarring “thud” sound caused by the drop of the heels.))
 
Subrahmanyan Chandrasekhar provides a theory for the existence of white dwarf stars and determines that a white dwarf can exist only if its mass is less than 1.44 times that of the Sun. This comes to be known as Chandrasekhar's limit. Arthur Eddington had earlier predicted white dwarf stars, but will disagree with Chandrasekhar on the details in a notable scientific argument of the 1930s, with Chandrasekhar generally seen as the winner.
 
Swiss-American astronomer Robert Julius Trumpler shows the existence of diffuse interstellar dust by studying its dimming effect on star clusters. As one consequence of the dust, the size of the Milky Way Galaxy is about three-fifths as big as previous estimates, which assumed that observed dimming was caused by distance.
 
Bernard Ferdinand Lyot builds the coronagraph, a special telescope in which a baffle stops the light from the solar disk and allows observation of the corona.
 
Bruno Benedetto Rossi, Italian-American physicist points out that cosmic rays should be deflected by Earth's magnetic field -- to the east if positive and to the west if negative. Studies show the deflection to the east, establishing that most cosmic rays are positive.

Russian-German optician Bernhard Voldemar Schmidt invents the corrector for a combined camera and telescope, producing a device that allows very wide-angle views with little distortion. The Schmidt telescope comes to dominate astronomy because it is free from coma, an aberration.
 
John Howard Northrup crystallizes the enzyme pepsin, an important step toward understanding the chemical nature of encimes
 
Arne Wilhelm Tiselius introduces electrophoresis, a method for separating proteins in suspension using electric currents.
 
Albert Szent-Györgyi succeeds in isolating vitamin C from capsicum (peppers).
 
Photoflash light bulbs are introduced for use in photography.
 
Construction starts on the Empire State Building in New York; it will be finished in 1931.
 
The Postum Company begins marketing frozen foods for the first time.
 
Waldo L. Semon of the B.F. Goodrich Company invents polyvinyl chloride. I. G. Farbenindustrie in Germany develops polystyrene.
 
Bernardo Alberto Houssay, Argentinean physiologist demonstrates that the pituitary gland produces a hormone that has the opposite effect from insulin, demonstrating the complexity of the endocrine system.

The lambda point of helium, where liquid helium changes from one form (helium 1) to another (helium 2) is discovered.
 
As I Lay Dying. Faulkner's most experimentally daring novel, written over a six-week period when Faulkner was working the night shift at a powerhouse, is a multivocal stream-of-consciousness account of the poor white Bundren family's journey to bury their mother, Addie, in her native town, Jefferson, Mississippi. The book combines horror, comedy, and a profound meditation on the nature of being.