1938:
- German scientists Otto Hahn and Fritz Strassmann performed experiments on uranium and discovered nuclear fission.
1939:
- Lise Meitner and Otto Frisch, Austrian and Danish physicists, published a paper explaining nuclear fission.
- Albert Einstein wrote a letter to U.S. President Franklin D. Roosevelt warning about the potential dangers of nuclear weapons.
2. Manhattan Project:
1942:
- The United States initiated the Manhattan Project, a secret research and development program for creating atomic weapons. It was led by Major General Leslie Groves and involved some of the most renowned scientists of the time.
3. Uranium and Plutonium:
- Scientists worked on enriching uranium and producing plutonium, two elements that could be used for atomic bombs.
4. Site Selection:
- Los Alamos, New Mexico, was chosen as the primary research and development site for the atomic bombs.
5. Research Teams:
- The project comprised several teams led by prominent physicists such as J. Robert Oppenheimer, Enrico Fermi, and Edward Teller.
6. Design of Atomic Devices:
- Two types of atomic bombs were pursued: Uranium-based ("Little Boy") and Plutonium-based ("Fat Man").
7. Building and Testing:
- The Oak Ridge National Laboratory in Tennessee enriched uranium, while the Hanford Nuclear Site in Washington produced plutonium.
- The Trinity Test: On July 16, 1945, the first nuclear explosion was successfully detonated in New Mexico.
8. Bombing of Hiroshima and Nagasaki:
August 6, 1945:
- The Enola Gay, a B-29 bomber, dropped the uranium bomb "Little Boy" on Hiroshima, Japan.
August 9, 1945:
- The Bockscar, another B-29, dropped the plutonium bomb "Fat Man" on Nagasaki, Japan.
9. End of World War II:
- The atomic bombings helped bring about the surrender of Japan and resulted in the end of World War II on September 2, 1945.
10. Fallout and Consequences:
- The explosions caused devastating destruction, high radiation levels, and long-term health effects on the affected populations.
11. Nuclear Arms Race:
- The atomic bombings marked the beginning of the nuclear arms race and created a heightened sense of global insecurity and fear of nuclear war.