The Atomic Bomb

In 1939, the World War II started. Axis countries; Italy, Germany, and Japan, and Allied countries; the USA, Great Britain, and France etc had been fighting with each other until 1945. In 1943, Italy surrendered, and on May in 1945, Germany surrendered. And Japan was the last country which surrendered to the Allied countries. Two atomic bombs ended the World War II with a lot of victims. That was the biggest bombers of the war.

On Aug in 1945, atomic bombs were felled on the city of Hiroshima and Nagasaki. The difference of those two atomic bombs is what chemicals were used. Uranium 235 was used for the bomb against Hiroshima and Plutonium 239 was used against Nagasaki.
August 6, 1945 “Little Boy” dropped on the city of Hiroshima. It is the nick name given to the atomic bomb. It was in the morning, “Little Boy” was dropped from the Enola Gay, which is one of the B-29 airplanes that flew over Hiroshima on that day. After being released, it took about a minute for “Little Boy” to reach the point of explosion. Little Boy exploded at approximately 8:15 am when it reached an altitude of 6,000m above, the building that is today called the “A- Bomb Dorm”.
As for “Little Boy”, a nuclear fission reaction was caused explosively. Uranium wedge and Uranium target hit each other and generated an enormous amount of energy in terms of air pressure and heat. In addition to this, it generated a significant amount of radiation (Gamma ray and neutrons) that subsequently caused distractive human injuries. Distribution of energy released by the atomic bomb is like this. The energy of it is almost same as 15 kg of TNT gunpowder. Half of the energy generated Bomb blast, 35% of that produced heat, and 15% of that released radiation. The strong wind generated by the bomb destroyed most of the houses. And the wind bumped against a mountain and turned back. So, it gave more damage to the city. The wind influenced 3,200m radius at least. The speed of the wind was so fast; 400m per one second that is about 5 times as Typhoon. Many things melted because of heat produced by the atomic bomb. The heat reached 7,000 Celsius at the hypocenter.The radiation generated by the atomic bomb caused long-term problems to people who affected. Many people died within the first few month and many more in subsequent years because of radiation exposure. Some people had genetic problems which sometimes resulted in having malformed babies or being unable to have children. It is believed that the total number of people who have died due to the bomb is estimated to be 200,000 in Hiroshima.

Just three days after, the bomb was dropped to Hiroshima, the second atomic bomb called “Fat Man” was dropped to Nagasaki. The height was 3.2m and the diameter was 1.5 m and the weight was 4.5 t. That was significantly larger than that of “Little Boy” but the damage was slighter than Hiroshima because of the geographic structure of the city. It is estimated that approximately 70,000 people died by the end of the year because of the bombing.


I think we have to consider about those awful history. That is the reason why we learn history in school. These days, people all over the world are focusing on the North Korea. Because the country is insisting that they finally had nuclear power. Now, it is possible to send bombs from America to Japan within 10~15 minutes. The rate of direct hit is almost 100%. North Korea is a neighborhood country. Imagine if North Korea lunched the atomic bomb…. what is going to happen?? I think it is very serious problem. So let’s think about the Issue seriously not to repeat same sad history in our future. http://kids.s24.xrea.com/heiwa/sonota/negai/index.htm