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Arthur WangMatthew SchaefferPatrick FaheyPeriod 3THE MANHATTAN PROJECT

Why it Startedand the Einstein LettersThe Americans feared that Germany would be attempting to build a nuclear weapon, leading to the rush to build one faster than Germany could. This was described in 4 letters by Einstein to FDR.First Letter: describes the potential of uranium as a source for immense energy. Notes that Germany stopped all sale of uranium in Czechoslovakia (occupied by Nazis). Einstein believes that such an early action may condemn the Allies to a uranium-powered bomb.Second Letter: mentions the son of German Undersecretary of State, C. F. von Weizscker was collaborating with a group of chemists working with uranium at the Kaiser Wilhelm Institute of Chemistry. Also describes how interest in uranium has intensified since the start of the war. The Kaiser Wilhelm Institute of Physics appears to be working with the Institute of Chemistry on a project of great secrecy, it states.

Third Letter: Not much can be taken from the letter except that Einstein believes that the urgency of the situation is greater than ever before.

Fourth Letter: Introduces Dr. L. Szilrd who understands the potential power of uranium and is greatly disturbed by its possible effects.

Security

A large amount of spies from Germany and Japan recognized rumors of the Project, but no one ever succeeded in obtaining informationThe Soviet Union was more successful with thousands of spies in the US and UK, but no US or UK spies in MoscowMany physicists (not necessarily tied to the project) were part of the Communist Party of the United States of America (CPUSA)Some of the physicists leaked info to the USSR, but nothing more than rumorsThe threat was imminent and Soviets gave the code name ENORMOZ (enormous)

Security of the project was so tight not even most of US knew anything more than rumors Several communist spies worked at Los Alamos, including David Greenglass who was transferred there as part of the Special Engineering Detachment He leaked information on the project to his sister and his brother-in-law, Ethel Greenglass and Julius Rosenberg 1950 - Klaus Fuchs admitted to being a spy, leading the FBI to his handler, Harry Gold, who then led the FBI to Julius Rosenberg

General Leslie Groves was placed in charge of the Manhattan Engineer Project in September 1942. He was placed in charge of all the phases: scientific, production, security and planning. He was ranked Temporary Brigadier General.

General Leslie GrovesScientists Who Were Involved1945 - 40 laboratories and factories and approximately 200,000 workersAlbert Einstein, Enrico Fermi, Richard Feynman, J. Robert Oppenheimer, and Harold Urey

Albert Einstein: Wrote the letter describing Germanys attempts at purifying U-235, which could then be used to create an atomic bomb

Enrico Fermi: placed in charge of the Manhattan Project at the University of Chicago in 1942. His team developed the first atomic pile and produced the first nuclear chain reaction

Richard Feynman: received a Ph.D. from Princeton University in 1942, and in his theses applied the Principle of Stationery Action to problems of quantum mechanics- At Princeton, Robert W. Wilson encouraged Feynman to participate in the Project Robert Wilson: youngest group leader at Los Alamos, worked closely with Oppenheimer and Fermi, and was known for his brilliance, enthusiasm, and get-it-done resourcefulness

J. Robert Oppenheimer: scientific director of the project, considered the father of the atomic bomb, overlooked the Trinity test, his second child was born at the site in Los Alamos.

Harold Urey: in spite of pacifism, directed isotope separation studies

UraniumAtomic # - 92Atomic Symbol- UAtomic Mass - ~238Melting Point - 1135CBoiling Point - 4131CFirst isolated from the mineral pitchblende in 1841 by PeligotMore abundant than mercury and silverHeavy silvery-white metal that is pyrophoric (highly flammable) when finely divided16 isotopes- all radioactive- most commonly used: U-238, U-235, U-234Natural occurring uranium contains about 99.283% U-238, 0.711% U-235, 0.005% U-234Nuclear fission of U-235 used in bombs and explosives including Little Boy

5Plutonium

AN- 94AS- PuAM- 244MP- 640CBP- 3228CPu-238- produced in 1940 by Seaborg, McMillan, Kennedy, and WahlPu-239 is used in nuclear reactors/reactionsComplete detonation of a kg of plutonium = 20,000 tons of chemical explosive

Fat ManWas the atomic bomb dropped over Nagasaki, Japan at about 1,800 ft above ground level10,200 pounds, 10.6 ft long, 5 ft diameterThe blast was equal to that of 42 million sticks of dynamite Was an implosion type weapon with a plutonium core Thought to be named after Winston Churchill 39,000 people were killed on impact and 25,000 others were injured

Little BoyWas the atomic bomb dropped over Hiroshima Japan Got its explosive power from the nuclear fission of Uranium 235Its power was between 13-18 kilotons of dynamite140,000 people were killed

Trinity TestLittle Boy was never fully tested, only Fat Man wasThe trinity test site was at the Alamorgodo Bombing Range 210 miles south of Los AlamosThree observation bunkers were built 10,000 yards awayThe bomb (known as the gadget vaporized the tower and turned the asphalt around the base of the tower to green sand.The blast knocked people even 5 miles away off their feetThe bomb was over twice as powerful as the makers expected it to be

Decision to use the BombsWas originally going to be dropped on Germany, and when Germany surrendered the only other major resistance to end the war was JapanTruman told Japan about the bomb and asked them to surrender, Japan refusedIt was decided that the bomb should be dropped because the death toll would be less than if the war continued (for Americans and Japanese)On August 3, 1945 Little Boy was dropped, despite all the devastation Japan still refused to surrenderThen three days later Fat Man was dropped, and finally Japan surrendered

THE ENDArthur WangMatthew SchaefferPatrick FaheyPeriod 3