The hydrogen bomb (mankind's most destructive weapon - also known as the H-Bomb or thermonuclear bomb) works on the principle of nuclear fusion, where isotopes of hydrogen (namely Deuterium and tritium) combine or fuse under extremely high temperatures to form helium. Hydrogen atoms are "ideal candidates" here for their very light nuclei that carry very weak positive charges serve well in the process of fusion. The conversion of mass into energy in the hydrogen bomb is actually an application of Albert Einstein's famous formula E = mc2. As mentioned before, Hydrogen nuclei fuse only under extremely high temperatures, accordingly, the hydrogen bomb requires tremendous heat in order to detonate. Such heat is attained by the explosion of an atomic bomb, i.e: it takes an atomic bomb just to initiate the process of fusion. One can now imagine the great explosive - and destructive - power of this bomb. "A thermonuclear explosion produces blast, light, heat and varying amounts of fallout." The blast produces concussive force in the form of a shock wave that radiates at supersonic speeds to destroy buildings several miles away from the point of the explosion. The light emitted is so intense that it can cause permanent blindness to those who gaze at it from a distance of dozens of miles. The heat, along with the light, may ignite an entire firestorm. The radioactive fallout lasts for long intervals, contaminating air, water and soil. "The explosive power of hydrogen bombs is frequently expressed in megatons, each unit of which equals the explosive force of 1,000,000 tons of TNT." Facts: "Edward Teller and other American scientists developed the first hydrogen bomb, which was tested at Enewetak atoll on Nov. 1, 1952. The U.S.S.R. first tested a hydrogen bomb on Aug. 12, 1953, followed by the United Kingdom in May 1957, China (1967), and France (1968). During the late 1980s there were some 40,000 thermonuclear devices stored in the arsenals of the world's nuclear armed nations. This number declined during the 1990s. The massive destructive threat of these weapons has been a principle concern of the world's populace and of its statesman since the 1950s."