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Assessing the Decision to Build and Use the Atomic Bomb Col. Paul W. Tibbets, Jr., pilot of the Enola Gay, the plane that dropped the atomic bomb on Hiroshima, waves from his cockpit before takeoff.

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Assessing the Decision to Build and Use the Atomic Bomb. Col. Paul W. Tibbets, Jr., pilot of the Enola Gay , the plane that dropped the atomic bomb on Hiroshima, waves from his cockpit before takeoff. Albert Einstein. Whether to Build an Atomic Bomb. - PowerPoint PPT Presentation

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Page 1: Assessing the Decision to Build and Use the Atomic Bomb

Assessing the Decision to Build and Use the Atomic Bomb

Col. Paul W. Tibbets, Jr., pilot of the Enola Gay, the plane that dropped the atomic bomb on Hiroshima, waves from his cockpit before takeoff.

Page 2: Assessing the Decision to Build and Use the Atomic Bomb

Albert Einstein

Page 3: Assessing the Decision to Build and Use the Atomic Bomb

Whether to Build an Atomic BombIn August 1939, FDR received a letter from Albert Einstein. He alerted FDR

that Germany might be building an atomic bomb. When Einstein wrote

this letter to Roosevelt, the US was not yet at war with Germany. However,

FDR took interest in the developments described in the letter. The bomb

would not only be the most powerful weapon on earth, it would transform warfare by making it possible to kill

more people with less effort.

Page 4: Assessing the Decision to Build and Use the Atomic Bomb

In the 18 months following Einstein’s letter, members of the Roosevelt administration debated what action should be taken to

counter the German threat. Some officials wondered how serious the threat really

was. In addition, not all scientists agreed with Einstein. In fact, two Nobel Prize-

winning nuclear physicists, Enrico Fermi and Niels Bohr, believed that the

construction of an atomic bomb was a practical improbability.

Page 5: Assessing the Decision to Build and Use the Atomic Bomb

Critical Thinking Question 1

You are an advisor to President Roosevelt. Which of the

following do you advise the president to do? Explain why.

Page 6: Assessing the Decision to Build and Use the Atomic Bomb

A: Ignore scientific developments and do not

build an atomic bomb; concentrate U.S. efforts on

building conventional weapons, such as faster

planes and more powerful tanks.

Page 7: Assessing the Decision to Build and Use the Atomic Bomb

B: Vigorously pursue the construction of an atomic bomb because the United

States is in a race against the Germans.

Page 8: Assessing the Decision to Build and Use the Atomic Bomb

C: Postpone the development of an atomic bomb and send

spies into Germany to determine the accuracy of

Einstein’s letter.

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D: Do not develop the bomb. Instead, monitor the

construction of new German weapon facilities and then send American bombers to

destroy them.

Page 10: Assessing the Decision to Build and Use the Atomic Bomb

E: Denounce the development of atomic bombs as immoral.

Only evil could come from their development.

Page 11: Assessing the Decision to Build and Use the Atomic Bomb

Question 1: Actual Decision• 1939 – FDR supported bomb research;

discovered a bomb could be built in two years

• Manhattan Project – code name for top secret project – Led by Robert Oppenheimer – 100,000 people involved – cost $2 billion – Fermi and Bohr major players in development

• No formal agreement; just understood that any weapon developed would be used to end war quickly

Page 12: Assessing the Decision to Build and Use the Atomic Bomb

J. Robert Oppenheimer

Page 13: Assessing the Decision to Build and Use the Atomic Bomb

How the Bomb WorkedA sphere of U-235 is made around the neutron

generator and a small bullet of U-235 is removed. The bullet is placed at the one end of a long tube with

explosives behind it, while the sphere is placed at the other end. A barometric-pressure sensor determines

the appropriate altitude for detonation and triggers the following sequence of events:

1.The explosives fire and propel the bullet down the barrel.

2.The bullet strikes the sphere and generator, initiating the fission reaction.

3.The fission reaction begins. 4.The bomb explodes.

Simulation: How the “Little Boy” bomb workedhttp://people.howstuffworks.com/nuclear-bomb5.htm

Page 14: Assessing the Decision to Build and Use the Atomic Bomb

How the Bomb Worked, Con’t.Scientists recognized that compressing the

subcritical masses together into a sphere might be a good way to make a supercritical mass. There were problems with this idea. But the

Manhattan Project team solved the problems. When the bomb was detonated, this is what

happened: 1. The explosives fired, creating a shock wave. 2. The shock wave compressed the core. 3. The fission reaction began. 4. The bomb exploded.

Simulation: How the “Fat Man” bomb workedhttp://people.howstuffworks.com/nuclear-bomb6.htm

Page 15: Assessing the Decision to Build and Use the Atomic Bomb

Workers with the Manhattan Engineer District gently carry the plutonium core for the world's first atomic bomb into the

McDonald Ranch house for assembly, July 12, 1945

Page 16: Assessing the Decision to Build and Use the Atomic Bomb

A member of the Manhattan Project's Special Engineering

Detachment holds the assembled plutonium core for the world's

first atomic bomb in a special shock-

absorbing case on July 12, 1945. The core was

about the size of an orange and weighed

13.5 pounds.

Page 17: Assessing the Decision to Build and Use the Atomic Bomb

Physicists Norris Bradbury and Boyce McDaniel stand at the top of a 100 foot tower after helping to assemble the world's first atomic bomb on July 15, 1945, one day before the Trinity test.

The device was nicknamed the "Gadget."

Page 18: Assessing the Decision to Build and Use the Atomic Bomb

Photo of Trinity test site - Ten seconds after detonation

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Oppenheimer and Leslie Groves inspect the tower.

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Facts about the Bomb’s Test• Before dawn – July 16, 1945 – “gadget”

tested• Fireball so bright – blind girl saw flash• Cloud rose eight miles into the sky• Force so strong windows shattered in

buildings 125 miles away• Crater left in Earth was 1,200-foot-wide• People were told an ammunition dump

exploded• The sand directly under the tower got so

hot that it turned to glass

Page 21: Assessing the Decision to Build and Use the Atomic Bomb

More Facts about the Bomb’s Test• The explosion was equal to 20,000 tons of

TNT• Half mile from the blast: everything was either

vaporized or burned beyond recognition• One Mile from the blast: all buildings above

ground were destroyed• Two miles: structures collapsed and rivers

flowed the wrong way • Three miles away: buildings sustained severe

fire and wind damage, people would have suffered second and third degree burns, if they were lucky

Page 22: Assessing the Decision to Build and Use the Atomic Bomb

Revelation 6:12

And I beheld when he had opened the sixth seal, and, lo, there was a

great earthquake; and the sun became black as sackcloth of hair, and the moon became as

blood.

Page 23: Assessing the Decision to Build and Use the Atomic Bomb

Harry S. Truman

Vice-president Harry S. Truman taking the oath of office after the death of FDR. Not until nearly two weeks after he was sworn in was he told about

the existence of the atomic bomb.

Page 24: Assessing the Decision to Build and Use the Atomic Bomb

Whether to Drop an Atomic BombVice President Harry S. Truman became

president after Roosevelt unexpectedly died in April 1945. While attending an Allied

conference in Potsdam, Germany, three months later, Truman received a telegram

stating that the test of the atomic bomb had been successful. By this time in the war,

Germany had been utterly defeated. However, Japan had vowed to fight on, despite the Allies’

demand at Potsdam for an unconditional surrender. The Japanese felt that an

unconditional surrender would jeopardize the position of their emperor, whom they

considered divine (Godlike).

Page 25: Assessing the Decision to Build and Use the Atomic Bomb

In addition, the Japanese viewed surrender as dishonorable. They fought with fanatic

resistance and believed it was more honorable to commit suicide than to surrender to enemy forces. In this vein, Japanese kamikaze pilots strapped themselves into planes loaded with explosives and crashed them into American naval vessels. They managed to destroy 53 ships and damage 158 others. The US had

hoped to end the Pacific War by invading the home islands of Japan. However, in the face of

Japanese fanaticism, Truman was deeply concerned that such an invasion would cost

tens of thousands of American lives.

Page 26: Assessing the Decision to Build and Use the Atomic Bomb

In light of this concern, some of Truman’s advisors recommended that he end the war quickly by dropping a bomb without warning

on a large Japanese city. The undersecretary of the navy, Ralph Bard, disagreed and told Truman that dropping the bomb without a

specific warning would jeopardize “the position of the US as a great humanitarian

nation.” A group of scientists from the bomb project suggested that the US drop the bomb in a remote, unpopulated location to show the

bomb’s power and convince Japan to surrender.

Page 27: Assessing the Decision to Build and Use the Atomic Bomb

Critical Thinking Question 2

You are a close advisor to President Truman. Which of the

following do you advise the president to do? Explain why.

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A: Without warning, drop an atomic bomb on a Japanese

city as soon as possible.

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B: Drop the bomb on an unpopulated area to

demonstrate its destructive capabilities.

Page 30: Assessing the Decision to Build and Use the Atomic Bomb

C: Warn the Japanese that the United States possesses

atomic weapons and is willing to use them if they don’t

surrender in a specified time. If they don’t surrender, then

drop the bomb.

Page 31: Assessing the Decision to Build and Use the Atomic Bomb

D: Reject the use of atomic weapons, and continue the

naval blockade and conventional bombing. If the measures do not produce a Japanese surrender, invade

Japan.

Page 32: Assessing the Decision to Build and Use the Atomic Bomb

E: Reject the use of atomic weapons and negotiate an

end to World War II, allowing the Japanese to surrender

with their emperor as a part of the postwar government.

Page 33: Assessing the Decision to Build and Use the Atomic Bomb

Question 2: Actual Decision• August 6, 1945 – Enola Gay dropped bomb

on Hiroshima; 100,000 people killed

• August 9, 1945 – bomb dropped on Nagasaki; 70,000 people killed

• Japan surrendered 5 days later

• Truman defended his decision by saying it saved the lives of thousands of American soldiers

Page 34: Assessing the Decision to Build and Use the Atomic Bomb

Leaflets dropped on cities in Japan - c. August 6, 1945TO THE JAPANESE PEOPLE:America asks that you take immediate heed of what we say on this

leaflet.We are in possession of the most destructive explosive ever devised

by man. A single one of our newly developed atomic bombs is actually the equivalent in explosive power to what 2000 of our giant B-29s can carry on a single mission. This awful fact is one for you to ponder and we solemnly assure you it is grimly accurate.

We have just begun to use this weapon against your homeland. If you still have any doubt, make inquiry as to what happened to Hiroshima when just one atomic bomb fell on that city.

Before using this bomb to destroy every resource of the military by which they are prolonging this useless war, we ask that you now petition the Emperor to end the war. Our president has outlined for you the thirteen consequences of an honorable surrender. We urge that you accept these consequences and begin the work of building a new, better and peace-loving Japan.

You should take steps now to cease military resistance. Otherwise, we shall resolutely employ this bomb and all our other superior weapons to promptly and forcefully end the war.

EVACUATE YOUR CITIES.

Page 35: Assessing the Decision to Build and Use the Atomic Bomb

ATTENTION JAPANESE PEOPLE. EVACUATE YOUR CITIES.Because your military leaders have rejected the thirteen part surrender

declaration, two momentous events have occurred in the last few days. The Soviet Union, because of this rejection on the part of the military has

notified your Ambassador Sato that it has declared war on your nation. Thus, all powerful countries of the world are now at war with you.

Also, because of your leaders' refusal to accept the surrender declaration that would enable Japan to honorably end this useless war, we have employed our atomic bomb.

A single one of our newly developed atomic bombs is actually the equivalent in explosive power to what 2000 of our giant B-29s could have carried on a single mission. Radio Tokyo has told you that with the first use of this weapon of total destruction, Hiroshima was virtually destroyed.

Before we use this bomb again and again to destroy every resource of the military by which they are prolonging this useless war, petition the emperor now to end the war. Our president has outlined for you the thirteen consequences of an honorable surrender. We urge that you accept these consequences and begin the work of building a new, better, and peace-loving Japan.

Act at once or we shall resolutely employ this bomb and all our other superior weapons to promptly and forcefully end the war.

EVACUATE YOUR CITIES.

Page 36: Assessing the Decision to Build and Use the Atomic Bomb

Hiroshima, August 6, 1945

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Nagasaki, August 9, 1945

Page 38: Assessing the Decision to Build and Use the Atomic Bomb

Facts about the Bomb in Japan• Temperature at the center of blast – 100

million degrees

• People at the center vaporized – remains left shadows on pavement and walls

• Skin was seen peeling and hanging off of bodies

• Many died of radiation poisoning – lost their hair, vomited blood, then died

Page 39: Assessing the Decision to Build and Use the Atomic Bomb

Whether Truman Made the Right DecisionImmediately following the dropping of the two atomic bombs on Japan, the majority of Americans felt the right

decision had been made. Surveys conducted by Fortune magazine in the fall of 1945 revealed that over 50% of Americans believed that the US “should have used the two bombs on cities just as we did.” Another

22.7% felt the US “should have quickly used many more before Japan had the chance to surrender.” American soldiers also supported Truman’s decision. One young

soldier stated: “When the bombs were dropped and news began to circulate that the invasion would not take place after all, that we would not be obliged to run up the beaches near Tokyo assault-firing while being mortared

and shelled…we cried with relief and joy. We were going to live. We were going to grow up to adulthood

after all.”

Page 40: Assessing the Decision to Build and Use the Atomic Bomb

Many officials in the top ranks of the military and government supported Truman’s decision to

drop the atomic bombs. However, others expressed doubts. Admiral William D. Leahy

stated: “It is my opinion that the use of the barbarous weapon was of no material

assistance in our war against Japan. The Japanese were all ready defeated and ready to

surrender because of the effective sea blockade and the successful bombing with

conventional weapons. My own feeling was that being the first to use the bomb, we adopted an ethical standard common to the barbarians

of the Dark Ages.”

Page 41: Assessing the Decision to Build and Use the Atomic Bomb

Dwight D. Eisenhower, a general with enormous prestige, expressed the hope that the US would

never have to use such a weapon against an enemy again because he disliked seeing the

country “initiate the use of anything so horrible and destructive.” Some historians have severely criticized Truman’s decision. They argue that the

Japanese were all ready defeated in August 1945, and that the atomic bombs were used primarily as a warning to the Soviet Union.

Although they were allies during WWII, the US and the USSR had very different visions for the

postwar world.

Page 42: Assessing the Decision to Build and Use the Atomic Bomb

Historians critical of Truman’s decision argue that he authorized the use of the atomic bombs mainly to scare the Soviets out of Eastern

Europe and to keep them from gaining more territory in Asia. To these historians, the citizens of Hiroshima and Nagasaki were

sacrificed in a high-stakes poker game between two superpowers. They also argue that the

postwar nuclear arms race can be traced back to the fear and mistrust created by Truman’s decision. Other historians counter that the

military pressures Truman was under at the end of WWII played a much more important role in

his decision than the threat of Soviet aggression.

Page 43: Assessing the Decision to Build and Use the Atomic Bomb

Critical Thinking Question 3

Truman’s decision to use atomic weapons against Japan is one of

the most controversial in history. In retrospect, do you think Truman

made the right decision in authorizing the use of atomic

weapons? Explain why.

Page 44: Assessing the Decision to Build and Use the Atomic Bomb

A: Truman did not make the right decision when he

authorized the use of atomic weapons.

Page 45: Assessing the Decision to Build and Use the Atomic Bomb

B: Truman made the right decision when he authorized the use of atomic weapons.

Page 46: Assessing the Decision to Build and Use the Atomic Bomb

Question 3: The Debate Continues

• Truman defended his decision to his death.

• J. Robert Oppenheimer, the lead scientist of the Manhattan Project, said: “I am death, the destroyer of worlds.”

• Albert Einstein regretted ever writing FDR.

• By 1990 – approximately 100,000 nuclear weapons in existence

Page 47: Assessing the Decision to Build and Use the Atomic Bomb

“Fat Man” and “Little Boy”

Page 48: Assessing the Decision to Build and Use the Atomic Bomb

Located just under the hypocenter, only the dome-shaped framework and part of the outer wall remained. It

has come to be called "the A-bomb Dome."

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August 6. 1945. This is one of six photographs recording the disaster of Hiroshima.

Page 50: Assessing the Decision to Build and Use the Atomic Bomb

The cause of keloids is not clear yet, but it is considered to be caused by a combination of

powerful heat rays and radiation.

Page 51: Assessing the Decision to Build and Use the Atomic Bomb

The dark portion of the pattern of the clothing was imprinted on the skin by the powerful heat rays.

Page 52: Assessing the Decision to Build and Use the Atomic Bomb

A person sat down on the steps facing the direction of the hypocenter, possibly waiting for the bank to open. By a flash of

the heat rays, that person was incinerated on the stone steps.

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A woman who was exposed to the A-bomb less than 2 kilometers from the hypocenter, judging by the

extent of the burns on her entire back.

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Close to the hypocenter, victims were burned to death in their last gesture grasping at the air or trying

to escape.

Page 55: Assessing the Decision to Build and Use the Atomic Bomb

This boy had thermal burns on more than one-third of his body. He miraculously recovered.

Page 56: Assessing the Decision to Build and Use the Atomic Bomb

A child crying from the pain of having a gauze dressing changed. He suffered third-degree burns that exposed

the bone.

Page 57: Assessing the Decision to Build and Use the Atomic Bomb

A view of Nagasaki after the explosion

Page 58: Assessing the Decision to Build and Use the Atomic Bomb

A shadow made by the heat rays. This place is about 800 meters from the hypocenter. The unshielded asphalt surface was scorched, and the surface shielded by the handrail is a

whitish shadow.

Page 59: Assessing the Decision to Build and Use the Atomic Bomb

This boy was burned to death with his hands placed on his chest, leaving an impression of agony.

Page 60: Assessing the Decision to Build and Use the Atomic Bomb

Critical Thinking Question 3

Truman’s decision to use atomic weapons against Japan is one of

the most controversial in history. In retrospect, do you think Truman

made the right decision in authorizing the use of atomic

weapons? Explain why.

Page 61: Assessing the Decision to Build and Use the Atomic Bomb

A: Truman did not make the right decision when he

authorized the use of atomic weapons.

Page 62: Assessing the Decision to Build and Use the Atomic Bomb

B: Truman made the right decision when he authorized the use of atomic weapons.