Development & Use of the Development & Use of the Atomic Bomb during WWIIAtomic Bomb during WWII

Why build a bomb?Why build a bomb?

Albert Einstein wrote to President Albert Einstein wrote to President Franklin D. Roosevelt on August 2, 1939. Franklin D. Roosevelt on August 2, 1939.

Einstein and several other scientists Einstein and several other scientists explained that Nazi Germany was explained that Nazi Germany was working on a way to purify uranium-235, working on a way to purify uranium-235, which could be used to build an atomic which could be used to build an atomic bomb. bomb.

The Manhattan Project began shortly The Manhattan Project began shortly after this letter. after this letter.

Portion of the letter from Albert Einstein to President RooseveltAugust 2, 1939

http://www.fdrlibrary.marist.edu/index.html

The Manhattan ProjectThe Manhattan Project

Goal: begin research that would Goal: begin research that would produce a viable atomic bomb. produce a viable atomic bomb.

Project Chief: Brigadier General L. Project Chief: Brigadier General L. Groves Groves

Head Physicist: J.R. Oppenheimer, Head Physicist: J.R. Oppenheimer, oversaw the entire project from start oversaw the entire project from start to finish. to finish.

More than $2 billion was spent during More than $2 billion was spent during the project. the project.

Manhattan Project Cont.Manhattan Project Cont.

In 1942, Enrico Fermi produced the In 1942, Enrico Fermi produced the first controlled chain reaction in a first controlled chain reaction in a laboratory at the University of laboratory at the University of Chicago. Scientists worked to design Chicago. Scientists worked to design a bomb that could store the raw a bomb that could store the raw materials and trigger a much more materials and trigger a much more powerful chain reaction on demand.powerful chain reaction on demand.

Portion of a Memo to the Secretary of War Portion of a Memo to the Secretary of War From V. Bush and J. B. ConantFrom V. Bush and J. B. Conant

September 30, 1944September 30, 1944

The TestThe Test

““The Gadget” (code-name for the The Gadget” (code-name for the bomb) was tested on July 16, 1945 in bomb) was tested on July 16, 1945 in the desert of New Mexico at 5:30 in the desert of New Mexico at 5:30 in the morning. the morning.

J.R. Oppenheimer was thrilled with J.R. Oppenheimer was thrilled with the success of the bomb, but at the the success of the bomb, but at the same time concerned about the same time concerned about the threat it posed for mankind. threat it posed for mankind.

The Test Cont.The Test Cont. After the blast Oppenheimer is After the blast Oppenheimer is

remembered to have quoted a remembered to have quoted a portion of the Bhagavad Gita. “I am portion of the Bhagavad Gita. “I am become Death,” he said, “the become Death,” he said, “the destroyer of the worlds.” destroyer of the worlds.”

After viewing the test several of the After viewing the test several of the participants signed petitions against participants signed petitions against dropping the bomb. It was dropping the bomb. It was suggested that it be held in control suggested that it be held in control by the international community.by the international community.

Dropping the bombDropping the bomb

The atomic bomb has only been used The atomic bomb has only been used twice in warfare. twice in warfare.

The first bomb was dropped on The first bomb was dropped on Hiroshima August 6, 1945. It was a Hiroshima August 6, 1945. It was a uranium bomb nicknamed “Little uranium bomb nicknamed “Little Boy”, even though it weighed over Boy”, even though it weighed over four and half tons. four and half tons.

The bomb was dropped from the Enola The bomb was dropped from the Enola Gay. It killed 66,000 people instantly. Gay. It killed 66,000 people instantly.

This shows the "Little Boy" weapon in the pit ready for loading into the bomb bay of Enola Gay. (Photo from U.S. National Archives, RG 77-BT)

A nuclear weapon of the "Little Boy" type, the uranium gun-type detonated over Hiroshima. It is 28 inches in diameter and 120 inches long. "Little Boy" weighed about 9,000 pounds and had a yield approximating 15,000 tons of high explosives. (Copy from U.S. National Archives, RG 77-AEC)

The mushroom cloud billowing up 20,000 feet over Hiroshima on the morning of August 6, 1945 (Photo from U.S. National Archives, RG 77-AEC)

Dropping the bomb cont.Dropping the bomb cont.

The second bomb was dropped on The second bomb was dropped on August 9, 1945 on Nagasaki. August 9, 1945 on Nagasaki.

It was a Plutonium bomb nicknamed It was a Plutonium bomb nicknamed “Fat Man”. “Fat Man”.

It missed its target by over a mile It missed its target by over a mile and a half, but still leveled nearly and a half, but still leveled nearly half the city. half the city.

The polar cap of The polar cap of the "Fat Man" the "Fat Man" weapon being weapon being sprayed with sprayed with plastic spray plastic spray paint in front paint in front of Assembly of Assembly Building Building Number 2. Number 2. (Photo from (Photo from U.S. National U.S. National Archives, RG Archives, RG 77-BT) 77-BT)

The mushroom cloud over Nagasaki shortly after the bombing on August 9. (Photo from U.S. NationalArchives, RG 77-AEC)

After the BombAfter the Bomb

The dropping of the bomb itself was The dropping of the bomb itself was not the only thing that killed people. not the only thing that killed people.

The rain that falls after an atomic The rain that falls after an atomic detonation is full of radioactive detonation is full of radioactive particles. particles.

Many survivors of Hiroshima and Many survivors of Hiroshima and Nagasaki succumbed to radiation Nagasaki succumbed to radiation poisoning. poisoning.

After the Bomb cont.After the Bomb cont.

Survivors of the blast have had Survivors of the blast have had lasting implications.lasting implications.

Leukemia is commonly passed on to Leukemia is commonly passed on to the offspring of survivors. the offspring of survivors.

QuestionsQuestions

Were atomic strikes necessary Were atomic strikes necessary primarily to avert an invasion of Japan primarily to avert an invasion of Japan in November 1945? in November 1945?

Did Truman authorize the use of atomic Did Truman authorize the use of atomic bombs for diplomatic-political reasons-- bombs for diplomatic-political reasons-- to intimidate the Soviets--or was his to intimidate the Soviets--or was his major goal to force Japan to surrender major goal to force Japan to surrender and bring the war to an early end? and bring the war to an early end?

Questions Cont.Questions Cont.

Were there alternatives to the use of the Were there alternatives to the use of the weapons? If there were, what were they weapons? If there were, what were they and how plausible are they in retrospect? and how plausible are they in retrospect? Why were alternatives not pursued? Why were alternatives not pursued?

How greatly did the atomic bombings How greatly did the atomic bombings affect the Japanese decision to affect the Japanese decision to surrender?surrender?

Was the dropping of the atomic bombs Was the dropping of the atomic bombs morally justifiable? morally justifiable?

SourcesSources

http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB162/index.htm

America: Pathways to the Present, America: Pathways to the Present, Prentice HallPrentice Hall

http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB162/index.htm

http://www.loc.gov/index.html?http://www.loc.gov/index.html?gclid=CIrKuOifg4kCFQ2uSAod7irfAAgclid=CIrKuOifg4kCFQ2uSAod7irfAA