Atomic bomb blasts in hiroshima and nagasaki


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Atomic bomb blasts in hiroshima and nagasaki

  2. 2. ATOMIC BOMB BLASTING OF HIROSHIMA AND NAGASAKI:NUCLEAR ENERGY BECOMES BLASPHEMYThe second world war ended up with the deadly bomb blasts of Hiroshima and Nagasaki in theyear of 1945.The allied forces of great Britain, China and USA devastated the Japanesehomeland by dropping two atomic bombs named as little boy and fat man respectively onHiroshima on the 6thand Nagasaki on the 9thof August. The first one was made throughfission of Uranium-235 and the other was from Plutonium-239.Why this attack????U.S. and British researchers were investigating the feasibility of nuclear weapon since 1939.Since1941, when the Japanese attacked Pearl Harbor, the forces of the United States and her allies hadbeen at war with Japan. In August 1942, the United States launched the Manhattan Project toproduce an atomic bomb. In September 1944, the decision was made to use the new weaponagainst Japan. On July 16, 1945, the United States successfully carried out the worlds firstnuclear weapon test in the desert of New Mexico, a mere three weeks before the weapon wasdropped on Hiroshima. By May 1945, Germany had surrendered and the tide of the war hadturned in the favor of the Allied Forces. In 1945 July an ultimatum was brought to Japan from theU.S.A force which included Japan’s unconditional surrender. But Japanese emperor Hirohitorejected to surrender to the allied force and the U.S.A. military force got that opportunity forwhich they were awaiting. Making an issue by Japan’s not to be bowed down they mercilesslyblasted bombs on Japan. By this they achieve dtwo goals of testing their nuclear weapon andalso to step against Japan.Choosing area: Between 10 and 11 May 1945, a committee made for Japan bomb attack of theallied force came up with a list of cities most potentially suitable as targets of atomic attacks. Thecommittee eventually arrived at the recommendation of four targets: Kyoto, Hiroshima,Yokohama, and Kokura. Hiroshima was chosen as the first target due to its military and industrialvalues.Night before attack in Hiroshima: From the evening of August 5, 1945, to the early morning ofAugust 6, sirens and air-raid warnings were sounded frequently. City residents passed a fitfulnight. On the morning of August 6, the alarms finally stopped, the all-clear siren sounded, andthat morning began like any other. August 6, 1945, in Hiroshima a single bomb burned into theground. An entire city was instantly destroyed beyond recognition. Nagasaki suffered the samefate as Hiroshima in August 9, 3 days after Hiroshima attack. A single bomb was dropped onHiroshima at 8.15 a.m. in 6thAugust and at 11.02 a.m. in 9thAugust on Nagasaki another one.These bombs were launched from B-29 bomber.Atomic bombs used in these two attacks
  3. 3. In Hiroshima attack ‘little boy’ and in Nagasaki attack ‘fat man’ were used. These were producedfrom the research under Manhattan project. On August 6, 1945, a B-29 plane, the "Enola Gay"piloted by Paul W. Tibbets, dropped a uranium atomic bomb, code named "Little Boy" onHiroshima, JapansFigure : bomb blasted out in Hiroshima, August 6th, 1945seventh largest city. The observation B-29 dropped instruments attached to three parachutes andat 11:02 a.m. the other plane released the atomic bomb. It was the bomb attack on Nagasaki in 9thApril,1945.Atomic bomb is so much destructive that within just a second it can devastate a hugearea, can be cause of death of million billion people and it was actually happened. The worldtestified the dangers of nuclear weapon misdeeds for the first time and obviously this was terrific.Here is the description of that 1 second of blasting atomic bomb in Hiroshima: Temperature atburst point reaches several million degrees F within one-millionth of a second followingdetonation. All bomb material becomes ionized gas & gamma rays. It was before the explosionand in 0.0001 millisecond.• 0.1 second: Bomb explodes and fireball forms. In addition to heat and force,radiation was 3% of total energy, of which gamma rays & neutrons damaged living organisms,soil and ground structures.
  4. 4. Figure: little boy (Uranium bomb) Figure: fat man (Plutonium bomb)• 0.15 second: Shock wave expands rapidly, heating air to luminous condition. Fireballvisible for following 10 seconds.• 0.2 second: Thermal energy, especially infrared wave-lengths, causes most of thermalburns to humans.• 1.0second: Fireball reaches maximum diameter of 200-300 metersMechanism of making atomic bomb:Atomic bomb’s main specialty is this that it is made from fission chain reaction that can not bestopped and therefore this is undoubtedly much more powerful than the ordinary powerful bombseven. Mainly radioactive metals are used to make this type of bomb. Even these bombs can bederived from Hydrogen using fusion reaction. These are called the Hydrogen bomb. But atomicbombs are mainly created from the binding energy of fission reaction.Bombs attacking over Japan were atomic bombs. ‘Little boy’ was created from Uraniumisotope’s (U-235) and ‘Fat man’ was created from Plutonium isotope’s (Pu-239) fissionreactions. The main mechanism of these reactions are like this:A neutron strikes over the big Uranium isotope and then the Uranium gets divided into two smallatomic masses. From a big mass 239 it took forms of two little masses and also two littlecompounds and so here creates ultimately a lot of energy. Among the energy there exists 3neutrons and gama and alfa radioactive rays. These three neutrons again strike over threedifferent Uranium atoms. And this reaction keeps going in a chain form again and again. So auncrediable amount of energy forms and this is the main thing for the atomic bomb.Here is this reaction in an image form:Fission reaction to make atomic bombHere the yellow sphere is neutron, light blue one is Barium and dark blue one is Krypton.Uranium is marked as red sphere. Here also binding energy is shown.
  5. 5. Destruction: Some victims were vaporized instantly, many survivors were horribly disfigured,and death from radiation was uncertain—it might not claim its victims for days, weeks, months,or even years.The initial death count in Hiroshima, set at 42,000–93,000, was based solely on the disposal ofbodies, and was thus much too low. Later surveys covered body counts, missing persons, andneighborhood surveys. A similar survey by officials in Nagasaki set its death toll at 60,000–70,000. (Its plutonium bomb was more powerful, but its destructive range was limited bysurrounding hills and mountains).Over 90% of persons within 500 meters (1,600 ft.) of groundzero in both cities died. Most persons close to ground zero who received high radiation dosagesdied immediately. The cumulative death rates (%) in both cities rose dramatically during the firsttwo weeks and leveled off in subsequent weeks.• First two weeks: mainly burns from rays and flames, and wounds (trauma) from blast andfalling structures.3rd week through 8th week: symptoms of damages by radioactive rays,e.g., loss of hair, anemia, loss of white cells, bleeding, diarrhea. Approximately 10% ofcases in this group were fatal.• 3rd and 4th months: “some improvement” in burn, trauma, and even radiation injuries.But then came “secondary injuries” of disfiguration, severe scar formations, bloodabnormalities, sterility (both sexes), and psychosomatic disorders.Even now, after over half a century later, many aftereffects remain: leukemia, A-bomb cataracts,and cancers of thyroid, breast, lungs, salivary glands, birth defects, including mental retardation,and fears of birth defects in their children, plus, of course, the disfiguring scars.Radiation injury penetrates deeply into human body and injures cells. Persons who sufferedthermal burns within 1.0 to 2.0 kilometers of ground zero suffered serious flame and contactburns in addition to moderate flash burns. In a cataract the ocular lens becomes opaque. Thiscondition appeared a few years after the atomic bombings; the first was found in 1948 inHiroshima; and the next, the following year in Nagasaki.Leukemia is a malignant tumor or cancer of the blood cells, with an excessive overgrowth ofyoung white cells. By 1975 a total of 1,838 cases were diagnosed as leukemia in Hiroshima andNagasaki.
  6. 6. Figure: chronicle and acute leukemia affected from 1945 to 1975 in Hiroshima; adapted from Ohkita,1976Of these, 512 were exposed within 10 km from ground zero. Incidence peaked in 1951-52 in bothcities.Thyroid, breast and lung cancer were the most common and acute cancers among the affectedand these had been reported out among 1945 to 1975 in a drastic number and even in their nexttwo or more generations as a result of radioactivity.Chromosome changes was also acute . The number of chromosomes is constant in humans’ bodyand this is referred to be 26 in a normal state. But as an aftereffect of radiation of those bombblasts, many people borne after 1945 in Japan possessed chromosome more or less than normalnumbers.Microcephaly , one of the most pathetic aftereffects of the atomic bombings, especially whenaccompanied by mental retardation. A-bomb included effects of spontaneous abortions,stillbirths, congenital malformations, and more. These bomb attacks fatally destroyed many abuildings. Many buildings were structurally collapsed, many were burnt, many blasted. Of theseschool buildings, arm forced and military centers, industries, offices , factories were included .As Nagasaki was in mountain area it faced fewer damages than Hiroshima faced. As a result itwas easy to collect data about its damages. According to an approximate statistic there were50000 buildings in Nagasaki before the devastating attack and after this attack there remained30413 undamaged.Figure: destructed industry Figure: destroyed residential areaThe damage to man-made structures caused by the bombs was due to two distinct causes: first theblast, or pressure wave, emanating from the center of the explosion, and, second, the fires whichwere caused either by the heat of the explosion itself or by the collapse of buildings containingstoves, electrical fixtures, or any other equipment which might produce what is known as asecondary fire, and subsequent spread of these fires. The blast produced by the atomic bomb hasalready beenstated to be approximately equivalent to that of 20,000 tons of T.N.T. Given this figure, one maycalculate the expected peak pressures in the air, at various distances from the center of theexplosion, which occurred following detonation of the bomb. The peak pressures which werecalculated before the bombs were dropped agreed very closely with those which were actuallyexperienced in the cities
  7. 7. during the attack as computed by Allied experts.Restraints on recoveryFormally termed the Press Code, officially issued by the Occupation GHQ on September 19,1945, it prohibited the publication of all reports and studies of A-bomb damages, includingmedical and scientific studies of all injuries and losses suffered by A-bomb victims in bothHiroshima and Nagasaki. Thus the A-bombed citizens struggled with ignorance of the manymedical and social aspects.ResultAfter these bomb blasts that happened what had to be happened, for which the most powerfulnation attacked over the weak one; Japan surrendered to the allied force on 15thAugust. This wasalso the end of Second World War. There was also an outcome of this barbarous act and this wasthe threat to any country weak in position or does not belonging nuclear weapon in properquantity.ConclusionMany a lives were sacrifices to Hiroshima Nagasaki bomb attacks. If a question arises that wasthese attacks justifiable, considering both ethically and logically. Some will answer against usingof nuclear weapon drastically over civil population. The other opinion about it will be of the viewthat in total war, as carried on in Japan, there was no difference between civilians and soldiers,and that the bomb itself was an effective force tending to end the bloodshed, warning Japan tosurrender and thus avoid total destruction.