Assessing the Decision to Build and Use the Atomic Bomb

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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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Albert Einstein
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Whether to Build an Atomic Bomb

• In 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.

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• In the 18 months following Einsteins 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.

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Critical Thinking Question 1

• You are an advisor to President Roosevelt. Which
  of the following do you advise the president to
  do? Explain why.

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• 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.

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• B Vigorously pursue the construction of an
  atomic bomb because the United States is in a
  race against the Germans.

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• C Postpone the development of an atomic bomb and
  send spies into Germany to determine the accuracy
  of Einsteins 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.

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• E Denounce the development of atomic bombs as
  immoral. Only evil could come from their
  development.

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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

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J. Robert Oppenheimer
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How the Bomb Worked

• A 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
• The explosives fire and propel the bullet down
  the barrel.
• The bullet strikes the sphere and generator,
  initiating the fission reaction.
• The fission reaction begins.
• The bomb explodes.

Simulation How the Little Boy bomb worked
http//people.howstuffworks.com/nuclear-bomb5.htm
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How the Bomb Worked, Cont.

• 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 worked
http//people.howstuffworks.com/nuclear-bomb6.htm
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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
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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.
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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."
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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 Bombs 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

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More Facts about the Bombs 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
  

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Revelation 612

• 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.

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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.
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Whether to Drop an Atomic Bomb

• Vice 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).

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• 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.

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• In light of this concern, some of Trumans
  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 bombs power and convince Japan to
  surrender.

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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.

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• C Warn the Japanese that the United States
  possesses atomic weapons and is willing to use
  them if they dont surrender in a specified time.
  If they dont surrender, then drop the bomb.

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• 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.

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• 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.

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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

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• Leaflets dropped on cities in Japan - c. August
  6, 1945
• TO 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.

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• 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.

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Hiroshima, August 6, 1945
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Nagasaki, August 9, 1945
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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

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Whether Truman Made the Right Decision

• Immediately 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 Trumans 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
  shelledwe cried with relief and joy. We were
  going to live. We were going to grow up to
  adulthood after all.

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• Many officials in the top ranks of the military
  and government supported Trumans 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.

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• 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 Trumans 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.

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• Historians critical of Trumans 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 Trumans 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.

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Critical Thinking Question 3

• Trumans 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.

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• A Truman did not make the right decision when he
  authorized the use of atomic weapons.

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

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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

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Fat Man and Little Boy
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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.
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The cause of keloids is not clear yet, but it is
considered to be caused by a combination of
powerful heat rays and radiation.
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The dark portion of the pattern of the clothing
was imprinted on the skin by the powerful heat
rays.
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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.
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This boy had thermal burns on more than one-third
of his body. He miraculously recovered.
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A child crying from the pain of having a gauze
dressing changed. He suffered third-degree burns
that exposed the bone.
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A view of Nagasaki after the explosion
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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.
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This boy was burned to death with his hands
placed on his chest, leaving an impression of
agony.
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Critical Thinking Question 3

• Trumans 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.

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• A Truman did not make the right decision when he
  authorized the use of atomic weapons.

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

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Nuclear Testing After WWII