Nuclear+Weapons

Nuclear weapons are explosive devices that get their destructive power from the transformation of matter into energy. They are many times more powerful than all conventional bombs, and are classified alongside chemical and biological weapons as weapons of mass destruction (WMD or WMDs). Since the first weapon was created in 1945, many people have speculated that their extensive use in war could end human civilization as we know it. The nations of the world have long sought ways to limit the spread of nuclear weapons and to reduce the chances of their use in war.

Hiroshima and the Effects of Nuclear Weapons
Fission bombs were first developed by the United States during World War II. America dropped two such bombs on the Japanese cities of Hiroshima and Nagasaki in 1945, completely destroying those cities and bringing about Japan’s surrender and the end of that war. President Harry S. Truman’s decision to use the weapons remains debated to this day. The large mushroom-shaped cloud created by a nuclear weapon blast is a familiar image to many. The other effects of nuclear weapons are known not only from numerous tests the United States and other nations have conducted, but also from what happened to Hiroshima and Nagasaki. These include immediate blast effects, thermal energy and radiation, initial nuclear radiation, and residual nuclear radiation. The immediate blast effect of the Hiroshima bomb was equivalent to about twelve thousand tons of the explosive TNT. It created a fireball of hot gas that vaporized what it touched, and a blast wave, or shock wave, of rapidly moving compressed air that flattened buildings. The combination obliterated five square miles of the city. The initial blast also created intense thermal radiation—infrared radiation that caused eye injuries and skin burns and ignited flammable mat

erials. An estimated eighty thousand Japanese people immediately perished from the blast effects or initial heat radiation from the Hiroshima bomb. In addition to immediate blast effects, nuclear weapons can create deadly radiation including gamma rays. Initial nuclear radiation is what is created in the first minute of a nuclear blast. Nuclear radiation can damage the cells of humans and other living creatures, resulting in radiation sickness and, in some cases, death. In Hiroshima, an additional sixty-thousand Japanese died by the end of 1945 from radiation sickness. Many who survived were later found to have a greater probability of getting cancer. Residual radiation is created later than one minute after the initial blast. It consists mainly of subatomic particles that strike dust and dirt fragments, making them radioactive. Such radioactive dust, called fallout, can spread hundreds of miles through the air before falling back to earth. During the 1950s and 1960s, nuclear-bomb tests carried out by the United States and other nations created fallout that may have caused thousands of cancer deaths, according to some estimates. Some scientists have theorized that if a war happened in which hundreds of nuclear bombs exploded, the smoke they would create through fires could prevent sunlight from reaching the earth’s surface, leading to cold weather, failing harvests and worldwide famine. This scenario has been dubbed nuclear winter.