The Manhattan Project The Making of an Atomic Bomb
Dec 14, 2015
The Setting (1930’s – 1940’s)
•World War II was happening and many important Jewish scientists were fleeing to the USA to work▫Einstein (Princeton), Rutherford (Harvard),
Szilard (Brown), and others•Einstein had published his famous E =
mc2
•Work had been done with fission (splitting an atom), but most of the work was done in Germany .
The Idea – July 1939
•The first to believe that atomic bomb could be made were Leo Szilard and two other Hungarians
•Attempted to contact FDR, but unsuccessful.
•Met with Einstein▫Einstein wrote a letter to FDR
The Chicago Test – December 1941•Had to determine if sustainable nuclear
reaction was possible.▫$6000 Grant
•Performed at the University of Chicago▫Italian named Enrico Fermi in charge.
•“Homemade” Nuclear Reactor▫500 Tons of Granite Bricks
•First self sustaining nuclear reaction ever!
The Manhattan Project – Sept. 1942
•General Groves put in charge.▫Career military man who knew very little
about science.•Groves selected scientists from around
the US▫J Robert Oppenheimer – Head Researcher
Young Scientist from Cal Questionable background Brilliant, but had never stuck with anything
long enough to win a Nobel Prize.
Site Y – November 1942
•Requirements▫Not near a border or large city▫Decent transportation and moderate
climate▫Adequate water and electrical supply.
•Los Alamos, NM chosen▫Construction began immediately▫Locals told it was going to be an “electric
rocket” facility.
The Recruitment – Winter 1942• Oppenheimer tried to attract the best scientists in
the world to Los Alamos. (40+)▫Bohr - Model of the atom (Nobel Prize, 1922)▫Feynman – Quantum Electronics (Nobel Prize, 1965)▫Von Neumann – Mathematician▫Szilard – Physicist ▫Fermi – Developed 1st Reactor (Nobel Prize, 1938)▫Chadwick – Discovered Neutron (Nobel Prize, 1935)▫Rutherford – Discovered Nucleus (Nobel Prize,
1924)▫Teller – Later developed the H Bomb (Nobel Prize,
1955)
The Plan
•Make three bombs▫One uranium bomb▫Two plutonium bombs – 1 practice/1 real
•Uranium Bomb▫Could be set off by colliding two masses of
uranium.•Plutonium Bomb
▫To unstable to be collided▫Had to develop a new strategy
The Other Sites
•Oak Ridge, TN▫Purified Uranium
•Richland, WA▫Made and Purified Plutonium
•Both sites had multiple problems in the construction and were far behind schedule in the early years of the project▫Worried that there wouldn’t be enough fuel
for the bombs.
The Germans •Heisenberg
▫Only major scientists who stayed in Germany to help Nazis.
•US had a spy follow him throughout the war•Attempted to contact Bohr
▫Bohr met him and was given “secret” information.
•After the war found out that Germany was years behind the US in the development of an atomic bomb.
The Trinity Site – July 1945
•Selected a site to test the plutonium bomb. Near Sante Fe.
•Test Bomb▫Plutonium bomb – Called Gadget
•Two observation bunkers▫20 miles and 5.7 miles away
•Performed prior to Truman’s meeting with Stalin and Churchill.▫Success gave new president Truman more
clout.
The Test Results
•Deemed a complete success▫Flash seen in 3 states – Very colorful▫Mushroom cloud was about 38,000 ft in the
air. ▫Everything within a 1 mile radius
annihilated. ▫Heat at the center of the explosion was
estimated to be the same temperature as the sun. Fused sand into green-grey glass.
•Locals told that it was a test of rockets and pyrotechnics.
The Spies• The Rosenbergs – Convicted in 1949
▫Convicted of sharing the ideas for the new plutonium bomb with Germans.
▫Sentenced to Death• Klaus Fuchs – Convicted 1954
▫Pass on very valuable information to East Germany
▫British Citizen – Tried in England. • Ted Hall
▫Never actually convicted▫Admitted it late in life