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.

• 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.

Fire

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 15 year-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

• • 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

• • • • • • • • • • • 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

• • • • • • • • 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

• • • • • • • • • • • • • • 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

Truman Library http://www.pcf.city.hiroshima.jp/peacesite/indexE.html

Primary documents from the 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

bomb Article by David Hansen on the decision to drop the http://sun.menloschool.org/~sportman/ethics/project/topics/hiroshima/index.html

pro and con of the bombing of Hiroshima and Nagasaki Student website that outlines the http://wgordon.web.wesleyan.edu/papers/hiroshim.htm

a masters student at Wesleyan University Argument against the dropping of the bomb by Bill Gordon, 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

http://www.nuclearfiles.org/ Links to A-Bomb sites 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