Electron Microscope, FM Radio, Nuclear Fission, Transistor

 Ernst Ruska built the electron microscope in 1933. Electrons have very, very tiny wavelengths. Saples must be viewed in a vacuum. He went to work for Siemens. He learned how viruses behave. They may be useful in gene therapy in the future. Ernst Ruska was born on December 25, 2906 in Heidelberg. He was born on Christmas day!

Edwin Armstrong was born in Manhattan, New York in 1890. He became interested in radio technology while he was in college. He invented the "Super Regenative" Reciever in 1922. The FM radio was patented in 1933. FM radio is less sensitive to interference. Public demonstration helped display benefits. FM gained widespread popularity in the 1960s. FM radio changed music.

Leo Szilard was born in Hungary in 1898. He demonstrated fission in 1939. The first atomic bomb was demonstrated in 1945. The Americans dropped an atomic bomb on Japan to end World War II. Hand made nuclear reactions are more controlled. It uses neutrons to produce a chain reaction. Nuclear power supplied 20% of the US electricity in 2015.

Inventors began looking for ways to replace the vacuum tube. The transistor was invented in 1947 by two American physicists John Bardeen and Walter Brattain. The Transistor was picked by a contest. It's a mini, solid-state tried tube. The transistor radios appeared by 1955. The transistor altered the course of history.