Little Caesar hits theaters; it covers mafia themes inspired by Al Capone

Du Pont’s Rowland and Rohm produce Plexiglas

Dirac publishes “The Principles of Quantum Mechanics”

Robert J. Van de Graaf builds a generator capable of creating a powerful stream of subatomic particles: the Van de Graaf generator

Gandhi leads civil disobedience. In his boldest act of civil disobedience against British rule, Mahatma Gandhi led a long march to the sea to protest the salt tax. Accompanied by thousands of demonstrators, Gandhi and his followers managed to reach the Arabian Sea, where they began producing salt by evaporating seawater. 60,000 people were arrested, including Gandhi himself, but he gained greater international respect and support for his movement. Gandhi’s nonviolent methods, including vigorous hunger strikes, ultimately proved effective, and India achieved independence in 1947. In 1948, Gandhi was assassinated by a Hindu extremist. He was 78 years old.

Soviet Union. The Solovki Islands GULag, the first one, built in 1923 with three thousand prisoners, already had 50,000 inmates by 1930. But by 1928, the Solovki cancer had metastasized and spread throughout the Soviet Union, first to Karelia, and then especially to Siberia. There would eventually be over three hundred inmates, including KotLag, BelBaltLag, SevDvinLag, SolikamLag, SevUralLag, EchtLag, UchtPecLag, SevZerDorLag, and PecorLag, for a total of 253,000 hectares in Russia and 56,000 in Ukraine.

Carothers invents polymers

The Smoot-Hawley Tariff Act imposed tariffs on over 20,000 imported goods. Some economists, though controversially, believe it significantly contributed to the onset of the Great Depression. A few days earlier, over a thousand economists signed a letter to President Hoover urging him to veto it. The truth is, according to Abhijit V. Banerjee and Esther Duflo of MIT, that complete autarky would indeed make large countries like the United States poorer, but not much poorer, thanks to the large size of the economy, while also gaining stability.

Thomas Midgley and his team were searching for a non-toxic, non-flammable compound with a low boiling point that would make it suitable for refrigeration. After countless attempts, they tried chlorofluorocarbons (CFCs), which proved highly promising and highly stable, interacting with almost nothing. Dramatically, to demonstrate the non-toxicity and non-flammability of CFCs, Midgley, in a public demonstration, inhaled CFCs and blew them on a lit candle, extinguishing the flame. They seemed like the perfect gas for refrigerators, and would be used in billions of household refrigerators for decades, dramatically changing our lives for the better. By the 1970s, one million tons of CFCs were produced annually. Then, in 1974, at a meeting of the American Chemical Society in Atlanta, Sherwood Rowland and Mario Molina announced worrying results. Precisely because of the stability of the CFC molecule, they wander unperturbed in the atmosphere for decades, rising into the stratosphere and finally being broken down by solar radiation. Chlorine atoms in the stratosphere increase the rate of decomposition of the thin ozone layer that protects us from the sun’s harmful ultraviolet rays. Chlorine, moreover, acts only as a catalyst, so it then continues unperturbed to cause further ozone decomposition, undepleted, thousands of times over. The news didn’t cause much alarm until 1985, when increasing depletion of the ozone layer over Antarctica was measured, and in 1987, chlorine monoxide (ClO) was discovered: the smoking gun. In 1987, an agreement called the Montreal Protocol obliged the signatory nations to gradually reduce CFCs until they were completely eliminated. In 1995, Rowland and Molina won the Nobel Prize. The Montreal Agreement is the greatest environmental success of the 20th century, even if the CFCs released into the atmosphere (and the millions of refrigerators still in operation with CFCs – not all nations have signed) will continue to cause damage perhaps for centuries to come.

England. Sir Frank Whittle files the first patent for the jet engine for aircraft. He is only 22 years old. He dies in the United States in 1996.

Russia. Writer Varlam Shalamov is arrested. He will spend much of his life in Siberian gulags. He will die in 1982 in a mental institution, where he will be admitted by the KGB. His books will begin selling several years after the fall of the Soviet Union, in 1991.

Russell proves that the universe contains mostly hydrogen

Subrahmanian Chandrasekhar establishes the maximum limit for a white dwarf before becoming a neutron star (1.4 Solar Masses), the calculations are confirmed in 1930 by the Russian Lev Landau; the limit for a neutron star (Landau-Oppenheimer-Volkov limit) is instead 2.5 Solar Masses

Edwin Hubble from Mount Wilson, California, announces his discovery that the Universe is expanding.

Vladimir Kosma Zworykin, inventor of the iconoscope and the kinescope, began working for RCA, thus applying his inventions to cinema.

The scientific community believes it is impossible to obtain the energies necessary for the disintegration or decomposition of the atomic nucleus.

Louis De Broglie receives the Nobel Prize for theoretically predicting the existence of diffraction and interference properties in free electrons.

Pauli hypothesizes the existence of neutrinos, a by-product of the radioactive decay of the neutron

King Alexander I, successor to Peter I, following the rise of Croatian separatist movements, declared a dictatorship and coined the name Yugoslavia for the nation.

Enrico Fermi married Laura Capon. They had two children: Nella (January 31, 1931) and Giulio (February 16, 1936).

Umberto Nobile and his crew set off to fly over the North Pole in an airship; during the return journey, the cabin of the airship crashes to the ground during a storm. The eight men who remained aboard the airship and the aircraft itself are nowhere to be found; the eight who were thrown to the ground camp in a makeshift tent, three of them set off on foot towards Norway, one of whom, a Swede, dies of starvation.

Carpi earthquake measured 4.8 on the Richter scale