Wednesday, 3 December 2014

Hiroshima And Nagasaki


Nagasaki is the capital and the largest city of Nagasaki prefecture on the island of Kyushu in Japan. Hiroshima is the capital of Hiroshima prefecture, and the largest city in the Chukugo region of western Honshu, the largest island of Japan. In August 1945, during the final stage of the Second World War, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki. The two bombings, which killed at least 129,000 people, remain the only use of nuclear weapons for warfare in human history.
Why the Americans attacked Hiroshima and Nagasaki?
The attack on Pearl Harbour was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbour, Hawaii, on the morning of December 7, 1941 . After the attack on Pearl Harbour the Americans decided to take revenge from Japan by attacking the two cities Hiroshima and Nagasaki.
Why Americans did attacked Hiroshima first?
Hiroshima was chosen as the primary target since it had remained largely untouched by bombing raids, and the bomb's effects could be clearly measured. While President Truman had hoped for a purely military target, some advisers believed that bombing an urban area might break the fighting will of the Japanese people. Hiroshima was a major port and a military headquarters, and therefore a strategic target. A uranium gun-type atomic bomb Little Boy was dropped on Hiroshima on August 6, 1945.
Attack on Nagasaki:
At 11:02 am on August 9th, 1945, an all-Christian bomber crew dropped a plutonium bomb, on Nagasaki, Japan. That bomb was the second and last atomic weapon that had as its target a civilian city.
Designs of the Two Bombs:
The Manhattan Project produced two different types of atomic bombs, code-named Fat Man and Little Boy. Fat Man, which was dropped on Nagasaki, was the more complex of the two. A bulbous, 10-ft. bomb containing a sphere of the metal plutonium 239, it was surrounded by blocks of high explosives that were designed to produce a highly accurate and symmetrical implosion. This would compress the plutonium sphere to a critical density and set off a nuclear chain-reaction. Scientists at Les Alamos were not entirely confident in the in the plutonium bomb design, so they scheduled the Trinity test.The Little Boy type of bomb, which was dropped on Hiroshima, had a much simpler design than the Fat Man model that had been tested at Trinity. Little Boy triggered a nuclear explosion, rather than implosion, by firing one piece of uranium 235 into another. When enough U235 is brought together, the resulting fission chain reaction can produce a nuclear explosion. But the critical mass must be assembled very rapidly; otherwise, the heat released at the start of the reaction will blow the fuel apart before most of it is consumed. To prevent this inefficient pre-detonation, the uranium bomb uses a gun to fire one piece of U235 down the barrel into another. The bomb’s gun-barrel shape was believed to be unquestionably reliable and had never been tested. In fact, testing was out of the question since producing Little Boy had used all of the purified U235 produced to date; therefore, no other bomb like it has ever been built. Detonated by a mechanism that resembled a cannon, Little Boy had a muzzle or target that was a hollowed-out sub critical mass of uranium. The cannon ball was another supercritical mass of uranium, which fit perfectly into the hollow of the target as a plug. The plug was propelled down the cannon barrel by several thousand pounds of high explosive. When it hit, the combination of compression and increased mass pushed the uranium to the supercritical level and the bomb went off
Einstein’s role in creating the nuclear bomb:
The physicist Albert Einstein did not directly participate in the invention of the atomic bomb. But as we shall see, he was instrumental in facilitating its development .In 1905, as part of his Special Theory of Relativity, he made the intriguing point that a large amount of energy could be released from a small amount of matter. This was expressed by the equation E=mc2 (energy = mass times the speed of light squared). The atomic bomb would clearly illustrate this principle. But bombs were not what Einstein had in mind when he published this equation. Indeed, he considered himself to be a pacifist. In 1929, he publicly declared that if a war broke out he would "unconditionally refuse to do war service, direct or indirect... regardless of how the cause of the war should be judged.” As Einstein was a Jew he had a deal with America that he would invent a nuclear bomb and in return the Americans had to provide land to the Jews. But it was also committed that the nuclear bomb would never be used as it is the most destructive weapon.
End of the War:

In the end of the World War II the Japanese surrender as the Japanese prime minister once said in his interview that I have seen deaths with unbearable pains. 



1 comment: