On This Day in Science History - July 2

July 2^nd is the birthday of Hans Bethe. Hans Bethe was a German-American physicist who was awarded the 1967 Nobel Prize in Physics for describing how stars create their energy. He was in a good place to work out ideas in atomic and nuclear physics when he worked in the theoretical division of the Manhattan Project to build America's atomic bomb. He was part of the team that calculated the critical mass necessary for a chain reaction and later worked on the implosion method to start that chain reaction.

After the war, President Truman announced the hydrogen bomb project and Bethe joined the project but hoped it would prove an impossible task. His personal feelings against atomic and thermonuclear weapons showed when he joined Einstein's Emergency Committee of Atomic Scientists against nuclear testing and the arms race. He also played a role in the eventual ban on atmospheric testing and the SALT I Anti-Ballistic Missile Treaty.

Find out what else occurred on this day in science history.