1920's Science and Technology | Important Events in Science and Technology, 1920

1920

In February, physicist William D. Harkins posits the existence of the neutron, a subatomic particle with a neutral charge and a mass equal to that of a proton. In 1932, British physicist James Chadwick will discover the neutron.
In March, physicist Otto Stern announces that electrons have a spin expressible in either whole numbers (bosons) or half numbers (fermions).
In July, American inventor Earl Charles Hanson invents the first hearing aid using vacuum tubes. It is marketed in 1921 as the Vactuphone.
In November, John Thompson, a retired U.S. Army officer, receives a patent for his machine gun, later nicknamed the "tommy gun."
On November 2, Station KDKA in Pittsburgh transmits the first regular licensed radio broadcast.
On December 13, at the Mount Wilson Observatory in California, physicist Albert Michelson uses a stellar interferometer to calculate the diameter of the...