Overview. Section 1 Overview

Transcription

1 Overview Section 1 Overview In just one second on August 6, 1945, the world was changed forever. Since 1942, a secret U.S. weapons program, called the Manhattan Project, had been at work on two revolutionary bombs of such intense heat and explosive force that they would reduce the two target cities Hiroshima and Nagasaki to vast scorched wastelands. But it was the bombs radioactivity, which remained deadly long after the debris settled and the smoke cleared, that changed our world forever. The Hiroshima bomb was exploded at a height of 580 meters (1,870 ft.) for maximum effect. The bomb s explosive force immediately impacted the earth directly below (ground zero), spread swiftly out to surrounding hills, and then rebounded back into the city. A housetop weathervane later found pointing toward the city center testified starkly to the rebounding force. I don t believe anyone ever expected to see a sight quite like that. Where we had seen a clear city two minutes before, we could no longer see the city at all. Enola Gay co-pilot Bob Lewis, postwar interview. The energy release of the Hiroshima bomb was the equivalent of 12.5 kilotons of TNT. At burst point, the temperature reached several million degrees Centigrade. This heat was 35% of the bomb s total energy release. Hiroshima s resident-plus-temporarily present population at that time, is estimated at 340, ,000. *Panorama view of bombed-out Hiroshima, August 6, 1945 (HIMAT) Then a tremendous flash of light cut across the sky. It seemed like a massive sheet of sunlight. Rev. Kiyoshi Tanimoto, in John Hersey s Hiroshima. 1

2 The Nagasaki bomb was exploded at a height of 503 meters (1,540 ft.) above a densely populated valley just north of the city s center. Here, too, the explosive force and heat instantly impacted ground zero, swept out to the hills and back. Its destructive heat and force exceeded that of Hiroshima. The combined resident-plustemporarily present population total for Nagasaki on the bombing date is estimated at 260, ,000. *Scene of bombed-out Nagasaki, August 9, 1945 (HIMAT) There was a blinding white flash of light, and the next moment BOOM! CRACK! A huge impact like a gigantic blow smote down our bodies, our heads, our hospitals. Dr. Tatsuichiro Akizuki, Franciscan Tuberculosis Hospital, Nagasaki The initial burst of both bombs took only an unspeakable second, and their explosive energy was fully spent in about 10 seconds, though the destructive effects were overpowering for days and weeks, and lingering damages to human bodies persisted for years. Especially serious was the radioactive fallout that ranged over each city and many miles beyond. Radioactive elements (isotopes), besides direct damage to external tissues, were taken into human bodies by inhalation. The radioactivity also contaminated food and water supplies, thus affecting the people s blood and vital organs, as well as compounding injuries caused by burns, blast, and falling structures. 2

3 Section 2 The unspeakable second s explosive sequence: 0.0 second: Temperature at burst point reaches several million degrees F within one-millionth of a second following detonation. All bomb material becomes ionized gas & gamma rays. 0.1 second: Bomb explodes and fireball forms. In addition to heat and blast force, radiation was 3% of total energy, of which gamma rays & neutrons damaged living organisms, soil and ground structures second: Shock wave expands rapidly, heating air to luminous condition. Fireball visible for following 10 seconds. 0.2 second: Thermal energy, especially infrared wave-lengths, causes most of thermal burns to humans. 1.0 second: Fireball reaches maximum diameter of meters. Blast (50% of energy) is now complete. Overpressure at hypocenter (or ground zero, directly below the burst point) in Hiroshima reaches an estimated tons per square meter, and moves through the air and across the ground at the approximate speed of sound. Maximum pressure at Nagasaki s hypocenter may have been as high as 10 tons per square meter. Recent research has found that in the initial non-instant" (0.0 sec.) a powerful neutron burst struck a milewide area directly below burst point before the bomb casing exploded. This pre-explosion burst was caused by the initial impact of the uranium bullet with the core of uranium 235. This finding resolved a long-perplexing question of a young man near ground zero who died (Sept. 3) with symptoms of severe internal bleeding but no surface burns. *Hiroshima victim of pre-explosion neutron blast (HPMM) Suddenly there was a brilliant flash, like a photographer s magnesium flash. Then came a blast with a deafening bang, and I felt as though I had been kicked in the guts... The world was all black. F.J. Johnson. Australian prisoner of war, Nagasaki. 3

4 Physical Devastation The Hiroshima bomb was exploded over the city center, which was crowded with large public buildings and countless wood-frame residences and shops. Beneath the huge column of smoke that arose from the explosion, tens of thousands were already dead or dying. As fires raced out of control, destruction of wooden structures and reinforced concrete buildings alike was virtually complete within 2 km (1.2 mi.) of ground zero. *Atomic cloud rises over Hiroshima; photo taken from the B-29 Enola Gay about 30 seconds after the A-bomb exploded. (HIMAT) In Nagasaki, the more powerful bomb destroyed an estimated 12,000 buildings by blast and burning. Virtually nothing was left standing of the valley s homes, schools and factories. Worshippers in shrines, temples, and churches perished as they prayed. In both cities, fires generated by the explosions intense heat, and fed by broken gas and electrical lines, raged out of control. Fire stations and equipment had been destroyed, fire fighters were dead or injured, and water pipes were ruptured. Many corpses were found at places where there was some water rivers, old wells, fire-safety cisterns, ponds, and the like. People who did not die instantly had, it appears, exerted themselves to the limit just to find some water. Marina Transport Rescue Team member, Hiroshima. Hiroshima s gigantic firestorm leveled 13 square kilometers (5 sq. mi.), destroying some 92% of the city s structures. Nagasaki s firestorm, hemmed in by the valley, consumed some 22.7% of the entire city s structures. The bodies of many people who were close to ground zero in the two cities were shattered by blast or burned beyond recognition in the firestorms. Houses and trees were leveled as far as the eye could see, and fires began breaking out in the ruins. At the roadside I saw the corpse of a man who had been leading a horse cart,still on his feet, with his hair standing on end like wire. The river was filled with the dead and half-dead; burned children were screaming, Mommy! Mommy! and mothers searched for their children, calling their names in faltering vcoices. Ms. Hide Kurokawa, Nagasaki. 4

5 Last Modified on 12/2005 Copyright 2005 AtomicBombMuseum.org 5

6 Section 3 Coping with Chaos Human losses in both cities were staggering. Government officials, military and police personnel, hospital and medical professionals were mostly among the victims, and thus unable to help others. Through the two cities debrisfilled streets streamed near-naked, bleeding and burned survivors seeking relief and rest. Surviving doctors and nurses (no more than 10% of pre-bombing totals) set up make-shift relief stations, but bedding, essential medical supplies, and trained personnel were in desperately short supply. *Relief station by police station at Miyuki Bridge in Hiroshima shortly after the explosion (HIMAT) Indeed, there were hopelessly few to rescue. The biggest immediate task was the recovery and disposal of tens of thousands of corpses. Those who had died immediately were buried under rubble; those who had survived minutes or even hours were piled deep on bridges and along river banks, or just left to float down the rubble-ridden rivers. Later, corpses were piled high for burning. Flocks of scavenging crows accentuated the eerie scene. 6

7 7

8 *Hand-drawn scenes of corpse disposal in Hiroshima (HIMAT) 8

9 I threw myself into a frantic search for m family, casting about in the still-hot rubble. Before long, the tips of my shoes were burned so that my toes stuck out, an my hands became swollen with blisters. Looking along the road, near a neighbor s house, I found a charred copse that seemed to be my wife. The dead baby on her back I took to be our one-year-old daughter Takako. However, I never was able to Find our eight-year-old son Tateki, or our elder daughter Makiko. Tsuneo Tomimatsu, Nagasaki. Earlier in the morning, before the bombings, families had dispersed as fathers went to work places, children left for school, and mothers remained at home or went shopping while a grandparent stayed at home. Now, survivors still able to walk searched frantically for family members among the disfigured or dead in the smoldering ruins. Few recognizable buildings remained, and records for identifying and finding persons in schools, offices, hospitals, and so on were now only ashes. And few public servants survived to help. Family contact and cohesion, not just buildings, were woefully shattered. Second only to the massive loss of human lives and the crippling internal and external injuries was the near-total loss of social institutions needed to succor and restore the people s lives. Hospitals, schools, transport facilities, police and fire departments, water and sewage agencies, and not least, reliable news agencies, were all destroyed, their employees dead or dispersed. *Policeman writing casualty certificates for victims at a Hiroshima streetcar stop about 2 p.m. on August 6. (HPMM) As citizens gradually recovered, they naturally began thinking of how to avoid such a horrible fate ever happening again, to anyone. This concern fueled personal efforts to record individual testimonies of the bombings, and on a larger public level, a fervent desire to develop means for peace education at home and on a global scale. I thought she was dead, but finally found he alive. I hoped that she could at least duie at home, so I borrowed a cart from a neighbor to take her home to Kuba. I had brought her up since she was two years old, after her 9

10 father died. I took her to the Red Cross Hospital. She was so pitiful, burned on the left side of her body, face and arm. I still cry to think of it. Mrs. Kohide Matsuda, Hiroshima 10