Download Hiroshima and Nagasaki The Effects of the Atomic Bomb and the

Hiroshima and Nagasaki
The Effects of the Atomic
Bomb and the Debate
Note: This PowerPoint is largely
based upon exhibits found at the
Hiroshima Peace Memorial
Manhattan Project
• Code name for the secret US
program to develop a nuclear
bomb during WWII
• The idea came from Albert
Einstein’s 1939 letter to FDR in
which he suggested that an
atomic bomb could be built
• In 1942, Enrico Fermi, a
physicist, successfully
controlled the first nuclear
reaction in his reactor.
The Manhattan Project
• Based in Los Alamos, New Mexico
• Led by nuclear physicist Robert
Oppenheimer
• By July 1945, the team had developed 3
bombs
• The first was tested successfully over the
New Mexico desert on July 6, 1945
The Decision to Drop
Nazi Germany surrendered
unconditionally at 2:41 a.m.,
May 7, ending World War II in
Europe. At midnight May 8, the
guns stopped firing. The
Pacific war with Japan, who
was Germany's ally,
continued.
U. S. President Harry S.
Truman, English Prime
Minister Winston Churchill,
and Soviet Premier Joseph
Stalin met in Potsdam,
Germany between July 17 and
August 2, 1945, to discuss
strategies to end the war in the
Pacific.
Bombing of Japan
• The atomic bomb
named "Little Boy"
was dropped on
Hiroshima at 8:15 the
morning of August 6,
1945.
• “Fat Man” was
dropped on Nagasaki
three days later on
August 9, 1945.
10 ft long
28 in diameter
The Little Boy
Enola Gay & “Little Boy”
“Little Boy” was the first nuclear
weapon used in warfare. It
exploded approximately 1,800 feet
over Hiroshima, Japan, on the
morning of August 6, 1945, with a
force equal to 20,000 tons of TNT.
Immediate deaths were between
70,000 to 130,000.
“Little Boy” was dropped from a
Boeing B-29 bomber piloted by
U.S. Army Air Force Col. Paul W.
Tibbets. Tibbets had named the
plane Enola Gay after his mother
the night before the atomic attack.
After being released, it took about a minute for
Little Boy to reach the point of explosion. Little
Boy exploded at approximately 8:15 a.m. (Japan
Standard Time) when it reached an altitude of
2,000 ft above the building that is today called
the "A-Bomb Dome."
The July 24, 1995 issue of Newsweek writes:
"A bright light filled the plane," wrote Lt.
Col. Paul Tibbets, the pilot of the Enola
Gay, the B-29 that dropped the first
atomic bomb. "We turned back to look
at Hiroshima. The city was hidden by
that awful cloud...boiling up,
mushrooming." For a moment, no one
spoke. Then everyone was talking.
"Look at that! Look at that! Look at
that!" exclaimed the co-pilot, Robert
Lewis, pounding on Tibbets's shoulder.
Lewis said he could taste atomic
fission; it tasted like lead. Then he
turned away to write in his journal. "My
God," he asked himself, "what have we
done?"
(special report, "Hiroshima: August 6, 1945")
Dropping the Bomb
Hiroshima Blast
• The bomb briefly flashed at a height of 580 meters and
then erupted into an enormous fireball like the sun. More
than a million degrees Celsius at its center, the fireball
reached a maximum diameter of 280 meters in one
second. Surface temperatures near the hypocenter rose
to 3,000-4,000℃. Fierce heat rays and radiation burst out
in every direction, expanding the air around the fireball
and creating a super-high-pressure blast.
• The atomic explosion created a super-high pressure at
the epicenter of several hundred thousand atmospheres.
The surrounding air expanded enormously, creating a
tremendous blast.
Blast
• All wooden houses were destroyed within a
radius of two kilometers from the hypocenter.
Even ferro-concrete structures were crushed by
the power of the blast. Windows were smashed
at a distance of sixteen kilometers.
The Blast Pressure
• The wind velocity on
the ground beneath
the explosion center
was 980 miles/hr,
which is five times
stronger than the
wind generated by
strong hurricanes.
Fire
• When the atomic bomb
detonated, houses at or
near the hypocenter
ignited all at once.
Flames leapt up quickly
throughout the city.
For the next 3 days, the
city burned. Within a
radius of two kilometers,
all combustible material
was burned and the
thousands of people
trapped under collapsed
buildings were burned to
death.
Heat
• Within 0.3 seconds of detonation,
the fireball high in the air grew
to a diameter of more than 200 meters.
The temperature on the surface was 7,000
degrees C.
• The heat rays released by that fireball
devastated the people and things below.
Hiroshima- A Survivor’s Story
Four years after arriving in Japan, only 15year-old Mitsuo and his mother still live in
Hiroshima. His eldest brother, Toshio, is in the
Japanese merchant marines.
It's a bright, clear day. Mitsuo leaves his house
around 7:30 a.m. and walks to work. He gets
there about 8 a.m. He and his friends gather
outside, waiting for their supervisor to give
today's pep talk.
Mitsuo's mother leaves for work. Every day,
she takes the same streetcar. But today she
realizes she has forgotten some papers. She
runs back into the house to get them. Mitsuo's
mother misses her usual streetcar, and has to
wait for the next one.
It's nearly 8:15 a.m. American B-29 bombers
appear overhead. The sirens wail, but Mitsuo
and his co-workers ignore them, as usual. The
planes are headed in the direction of Tokyo.
Then, for the first time ever, Mitsuo sees the
planes reappear over Hiroshima. They're in
position now. Looking in the sky, Mitsuo sees
an object. In the instant it takes for the bomb to
drop, he feels no fear, only curiosity about this
thing that glistens in the sun.
Click on the speaker to hear the radio
report to the nation on the bombing of
Hiroshima.
Although the bomb Little Boy was ready
for use on August 2, 1945, bad weather
delayed dropping it over Japan. At 8:15 on
the morning of August 6, 1945, a large
portion of the city of Hiroshima was
destroyed when Little Boy was dropped.
Of a population of 256,000, more than
70,000 people died immediately.
Approximately half of the city had been
levelled.
Hiroshima
• The final death toll
is believed to be
around 140,000,
mostly civilians.
• The clothes of the
victims were burned
by the heat.
Bloodstained and in
tatters, the survivors
fled the devastated
city.
The picture above shows the devastating effect that the “Little Boy” bomb had
on just one small part of the city.
Damage to Buildings
• Eighty-five percent of
Hiroshima's buildings
were within three
kilometers of where the
atomic bomb exploded
over the heart of the city.
The damage extended to
virtually the entire city,
with 90 percent of all
buildings burned or
destroyed beyond repair.
Comparing Effects of the Bomb to
the 2011 Earthquake/Tsunami
in Japan
Pocket Watch
• 1,600m from the hypocenter
• Kengo Nikawa (then 59) was
exposed to the bomb crossing
the Kan-on Bridge by bike
going from his home to his
assigned building demolition
site in the center of the city. He
suffered major burns on his
right shoulder, back, and head
and took refuge in Kochi-mura
Saiki-gun. He died on August
22. Kengo was never without
this precious watch given him
by his son, Kazuo.
A survivor described the damage to people:
The appearance of people was . . . well, they all
had skin blackened by burns. . . . They had no hair
because their hair was burned, and at a glance
you couldn't tell whether you were looking at them
from in front or in back. . . . They held their arms
bent [forward] like this . . . and their skin - not only
on their hands, but on their faces and bodies too hung down. . . . If there had been only one or two
such people . . . perhaps I would not have had
such a strong impression. But wherever I walked I
met these people. . . . Many of them died along the
road - I can still picture them in my mind -- like
walking ghosts.
Acute Effects
• The most common acute
disorders were epilation;
symptoms of damage to
mucous membranes including
diarrhea, dysentery, melena
and bleeding from gums; and
impeded blood-forming
functions.
• The acute effects had largely
subsided by the end of
December, approximately five
months after the bombing.
Hair combed off of head in
3 strokes of a brush
Radiation
• The defining characteristic of
an atomic bomb
that distinguishes it from any
conventional bomb is radiation.
• Those exposed within about
1000 meters of the hypocenter
received life-threatening
doses, and most died within a
few days.
• Decades later, that radiation
was still producing harmful
aftereffects. Leukemia and
other cancers appeared over
the course of 2 to 20 years,
and radiation effects still
threaten the health of the
survivors.
Black Rain
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Soon after the explosion, a giant
mushroom cloud billowed upward,
carrying dirt, dust, and other
debris high into the air. After the
explosion, soot generated by the
conflagration was carried by hot
air high into the sky. This dust and
soot became radioactive, mixed
with water vapor in the air, then
fell back to earth in what came to
be called “black rain.”
The black rain contained
radioactive material. Fish died and
floated to the surface in the ponds
and rivers where this rain fell.
Many of the people who drank
from wells in areas where the
black rain fell suffered from
diarrhea for three months.
Keloids
• Scars left by
exposure to heat and
radiation erupted 2-3
years after the blast.
Burn Victims
Cataracts
• The patient was exposed
820m from the
hypocenter and had white
cloudiness in both eyes.
The dark area in the
center of this photo is the
cloudiness caused by an
A-bomb cataract.
• Cataracts occurred
several months to several
years after exposure.
Leukemia and Cancer
• Leukemia is cancer of the blood. The white blood cells
multiply wildly without fully maturing. Red blood cells and
platelets are reduced, leading to anemia. The white
blood cells increase in number but lose normal
functioning, which lowers resistance to infection. The
incidence of leukemia was greatest 7 to 8 years after the
bombing. The younger the survivor was at the time of
exposure, the earlier was the onset of leukemia.
• Cancers began to increase about 1960. Some cancers
for which a correspondence has been confirmed
between distance from the incidence are: myeloma,
ovarian cancer, urinary tract cancer, breast cancer, colon
cancer, lung cancer, esophageal cancer, stomach
cancer.
Birth Defects
• Radiation harmed fetuses in various ways.
– Some were stillborn.
– Some children were born without obvious problems but had
higher mortality rates, even those who lived past infancy.
– Development tended to be slower than that of other children.
– Some were born with abnormally small heads, a condition known
as microcephaly.
– Those who were exposed close to the hypocenter in early
pregnancy were likely to display microcephaly accompanied by
severe mental retardation that renders them unable to manage
everyday life without assistance.
Human Shadow Etched in Stone
• A person sitting on the bank
steps waiting for it to open was
exposed to the flash from the
atomic bomb explosion.
Receiving the rays directly
from the front, the victim
undoubtedly died on the spot
from massive burns. The
surface of the surrounding
stone steps was turned whitish
by the intense heat rays. The
place where the person was
sitting remained dark like a
shadow.
Pictures
Relief
• The atomic bomb
instantaneously destroyed the
Prefectural government offices,
City Hall, the police stations,
and all government buildings.
• The next day, the Army Marine
Headquarters (commonly
known as the Akatsuki Corps),
which sustained only slight
damage, took the lead in
establishing the Hiroshima
Security Regiment
Headquarters.
• The military, the government,
and the people united to carry
out relief activities, often with
little understanding of the
effects of radiation.
War Orphans and Discrimination
• Thousands of war orphans were created by the
bomb.
• Survivors of the bomb were victims of
discrimination after the war. Known as
Hibakusha, they found it difficult to find spouses
to marry, get into good schools and colleges,
and get hired for decent jobs. Listen at
http://www.atomicarchive.com/Docs/Hibakusha_i
ndex.shtml
Jimmy Carter in Hiroshima
• This memorial must
be a constant and
permanent reminder
for all people to work
for peace and better
understanding.
The Dalai Lama
As humans, we all have the
duty to eliminate, from this
earth, weapons with
destructive capacity beyond
expression and conception.
Please, every one of you, use
all of your power to accomplish
this duty.
A Tibetan Shakya Bhikshu
(Signature)
March 30, 1995
Poems and Testimonials
The following verse is from "Flower of Summer" (Natsu no Hana), a
collection of short stories by Tamiki Hara (1905-1951), writer and A-bomb
survivor.
This is a human being?
Look how the atom bomb changed it.
Flesh swells fearfully.
All men and women take one shape.
The voice that trickles from swollen lips on the festering, charred-black face
whispers the thin words,
"Please help me."
This, this is a human being.
This is the face of a human being.
Sadako and the Thousand Cranes
• Sadako was a young,
Japanese girl who was 2 years
old when the bomb struck
Hiroshima. At 11 years old,
she developed Leukemia. In
an effort to influence the gods
to help her survive, she folded
1,000 paper cranes. She died
at 12 years old.
• Sadako represents all of the
children who died in
Hiroshima, and the paper
crane has become an
international symbol of peace.
Hiroshima Today
J. Robert Oppenheimer,
Director of the Manhattan Project
“We knew the world would
not be the same. A few
people laughed, a few
people cried, most people
were silent. I remembered
the line from the Hindu
scripture, the Bhagavad-Gita.
Vishnu is trying to persuade
the Prince that he should do
his duty and to impress him
takes on his multi-armed
form and says, ‘Now, I am
become Death, the destroyer
of worlds.’ I suppose we all
felt that one way or another.”
Arguments for Dropping the Bomb
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Save (1,000,000?) American and Japanese lives. Japanese resisted US forces by
use of Kamikaze pilots in Okinawa and fighting without surrender at Iwo Jima and
other battles. They didn’t surrender after the fire bombing of major cities.
No worse than fire bombing those cities.
End the war quickly. The US was tired after 4 years of war. Germany had already
surrendered in May, 1945. Japan resisted an unconditional surrender.
End the war before the Soviets join the Pacific war. The USSR had promised to join
the war in August 1945.
Demonstrate US power to the world. Convince the world that these weapons should
be abolished.
Racism. US policy makers expressed racist attitudes toward Japanese
Revenge. Truman suggested after the war that he wanted to exact revenge for Pearl
Harbor.
Large resources went into the development of the atomic bomb, and there was a
desire to use it and test it.
As an unelected President, Truman was controlled by his close advisors who favored
using the bomb.
Scientists and policy makers didn’t fully appreciate effects of the bomb.
With only 2 bombs, it would have been wasteful to detonate one as a demonstration.
It might even be embarrassing if it didn’t go off.
Arguments Against Dropping the Bomb
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Moral failure for being the only country to use an atomic bomb in war. The
attack struck mainly civilians who outnumbered military personnel 6:1.
When Truman announced the attack, he falsely claimed that Hiroshima was
“a military base.”
Japan was ready to surrender anyway. It was blockaded. Its navy and air
force was destroyed. It’s overseas possessions were confiscated.
The US needlessly insisted upon an unconditional surrender, since Japan
was willing to surrender if it could retain the Emperor.
A demonstration of US power would have been sufficient
US moral authority, nationally and internationally, was weakened.
Contributed to mistrust held by the USSR and prompted a dangerous arms
race.
There was no need for the second bomb on Nagasaki.
There were many prominent military personnel against dropping the bomb,
like Eisenhower, under-Secretary of the Navy, Ralph Bard, Army Chief of
Staff General George C. Marshall, and Admiral Chester W. Nimitz,
Commander in Chief of the Pacific Fleet.
Websites and Sources
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http://www.colorado.edu/AmStudies/lewis/2010/atomic.htm
http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/bomb.htm ;
http://www.trumanlibrary.org/whistlestop/study_collections/bomb/small/small.htm Primary documents from the
Truman Library http://www.pcf.city.hiroshima.jp/peacesite/indexE.html Hiroshima Peace Memorial Museum:
http://www1.city.nagasaki.nagasaki.jp/na-bomb/museum/museume01.html Nagasaki Atomic Bomb Museum:
http://hnn.us/articles/190.html The trial of Harry Truman
http://www.dannen.com/decision/index.html Full text documents on the dropping of the atomic bomb
http://www.vw.cc.va.us/vwhansd/HIS122/Hiroshima.html Article by David Hansen on the decision to drop the
bomb
http://sun.menloschool.org/~sportman/ethics/project/topics/hiroshima/index.html Student website that outlines the
pro and con of the bombing of Hiroshima and Nagasaki
http://wgordon.web.wesleyan.edu/papers/hiroshim.htm Argument against the dropping of the bomb by Bill Gordon,
a masters student at Wesleyan University
http://encarta.msn.com/encyclopedia_761557001_4/Harry_Truman.html Encarta entry on Harry Truman
http://www.csi.ad.jp/ABOMB/index.html The A-Bomb www museum
http://www.grolier.com/wwii/wwii_mainpage.html Links to WWII sites
http://www.japan-guide.com/e/e2125.html Links to A-Bomb sites
http://www.nuclearfiles.org/ Documents and sites from The Nuclear Age Peace Foundation.
http://www.doug-long.com/marshall.htm General George Marshall's argument for dropping the bomb