D.R Bhagat
Since the last many centuries many weapons are being used in the war. There is gradual improvement in them in respect of their models and efficiency. The 20th century gave the world the most sophisticated and the most dreadful weapon known as the Atom bomb. An atom bomb or a nuclear bomb is an explosive device which derives its destructive force from nuclear reactions. There are two forms of nuclear bombs, atom bomb and hydrogen bomb.
The processes involved in their manufacturing are fission and fusion. These are nuclear reactions. A nuclear reaction in which a heavy atomic nucleus of a fissile material is made to split into two equal nuclei called the fission . The fission is triggered by the absorption of a neutron by nucleus of the fissile material like uranium235 and plutonium239. If the fissile material is present in sufficient amount, fission can occur spontaneously giving rise to chain reactions. Fusion process is the reverse of fission. In this process two nuclei of lighter atoms join to form a nucleus of heavier atom. As both the lighter nuclei are positively charged, they repel each other. The nuclei are made to collide on very high speed or the reaction occurs at extremely high temperature of the order of millions of degrees Celsius. In both these processes, exceptionally large and uncontrolled amount of energy is released. The total mass of the products formed is always less than the total mass of the reactants. It means that some mass has been lost in the process which is converted into energy in accordance with the Einstein’s famous formula E= mc2, where E is the energy, m the mass and c is the velocity of light. Since velocity of light is very high i.e. 3 lac Km per second, the amount of energy released is many billions times the amount of mass destroyed. The fission process is used for making the atom bomb and fusion process is used for manufacturing the hydrogen bomb.
The hydrogen bomb is thousands times powerful than the atom bomb. The fusion process is also going on continuously in our sun by fusing hydrogen atoms to form helium which is the source of energy of the sun.
The process of making the bomb was started just before the onset of the second world war.. The nuclear fission was discovered in 1939 and shortly after that Nazi Germany started its advances towards nuclear fission in uranium. Britain and France also joined the race. Einstein in USA was not aware of these advances in nuclear arms research. He came to know about this only when he met three migrant scientists from Hungry namely Szilard, Wigner and Teller who were also the victims of Hitler persecution. Einstein who had not thought in depth about the practical feasibility of his formula E=mc2, now became confident that nuclear weapon can be materialised in short period. He also wrote a letter to president Roosevelt about the progress of development of nuclear weapons in Germany, Britain and France and also about their devastating effects. President Roosevelt died shortly after that. His successor president Truman also decided to make advances for the development of the nuclear bomb. The Manhattan project was launched in which a group of top scientists putting up in America namely Robbert Oppenheimer, Enrico Fermi, Edward Teller, John Von and Feynman was assigned the job of manufacturing of atom bomb. They were successful in producing the atom bomb in July 1945 making use of fission process using uranium and plutonium as fissile materials. Thus Oppenheimer came to be known as the father of the atom bomb. The total expenditure incurred on the project was to the tune of 2 billion dollars. The bomb was tested on 16th July 1945. It liberated energy equal to 20000 TNT. The first hydrogen bomb tested in 1954 liberated energy equal to 100million of TNT. In the world war Germany had already accepted defeat in May 1945. On July 26 USA along with UK and China asked Japan to surrender but the Government ignored it. It was decided to use atom bomb on Japan and the cities selected were Hiroshima and Nagasaki. The first one nicknamed as Little Boy and was dropped on Hiroshima on 6th August 1945 . Japan did not surrender immediately. The other bomb nicknamed as Fatman was dropped on Nagasaki on 9th August. About 2 lac people died with flash burns, radiation sickness and other injuries. Japan finally announced surrender on 15th August 1945 and instrument of surrender was signed on 2nd Sept. 1945 thus ending the world war second which claimed total six crore human lives. At present 8 countries are having nuclear weapons. They are USA, Russia, UK, France, China, Pakistan, India, and North Korea. Only two atom bombs have been used so far in warfare. We should pray that mankind should not witness any more disastrous atom bomb falling on any area of the world and atomic energy should be used for useful purposes only.