How It Works

The Manhattan Project



1. Cost
The project cost $20 billion and was the first ever development of uranium and plutonium bombs. In Einstein’s and Szilárd’s letter they urged American President Franklin D. Roosevelt to create a weapon before the Axis powers had the chance. Check out the actual letter Einstein sent to the US Government here.

2. Headquarters
Facilities were built in Oak Ridge, Tennessee, Hanfod and Washington. The locations were deliberately far apart to lessen the chances of enemy espionage. The project took less than four years to complete and was ready for Hiroshima and Nagasaki after successful tests were carried in New Mexico.

3. The science behind the bomb
The isotopes used in the bomb were uranium-235 and plutonium-239. The bomb works by splitting the nucleus of an atom to create a fission chain reaction which releases the explosive energy.

4. Little Boy
The project produced four bombs. The most famous two were ‘Little Boy’ which was dropped on Hiroshima and ‘Fat Man’ which was used on Nagasaki. The first was a uranium based bomb while the second was plutonium.

5. The best of the best
The amount of scientists and physicists working on the project wasn’t limited to just Einstein and Szilárd. Other big names in science were Robert Oppenheimer, David Bohm, Eugene Wigner, Otto Frisch, Rudolf Peierls, Felix Bloch, Niels Bohr, Emilio Segre, James Franck, Enrico Fermi, Klaus Fuchs and Edward Teller.

The bomb 'Little Boy' which landed on Hiroshima
The bomb ‘Little Boy’ which landed on Hiroshima
The bomb 'Fat Man' which landed on Nagasaki
The bomb ‘Fat Man’ which landed on Nagasaki