Thursday, April 24, 2014

U is for Uranium

U is for Uranium
The students of the U.S. History class at Cedar Ridge Academy Private International Therapeutic Boarding School were given the assignment to write a post on the letter U, their teacher thinking that they would do “United States”.  However, as a teacher continually learns—these boys and girls can surprise us.  They came up with uranium all on their own.  Here is what they learned.

Uranium is a radioactive metal used as the energy source in nuclear power plants and nuclear bombs. The reason it is used is that it has immense energy stored in its nucleus, which can break apart and release this energy. This process of splitting the nucleus is called Fission. This is done by striking the nucleus with a neutron. A U-235 nucleus splits readily when it is struck by a neutron into two or more fragments. This releases energy and two or more neutrons. These neutrons can then cause other U-235 nuclei to break apart releasing more neutrons repeating the process continuously. This self-sustaining process of fission events is called a chain reaction. U-238 nuclei, in most cases, will absorb the nuclei that hit them. When scientists discovered the ability to cause a chain reaction they discovered that a tremendous amount of energy was released. Albert Einstein created the theory that shows matter can be transformed into energy and that energy and matter are related by the equation E= mc^2. This says that energy (E) into which a given amount of matter can change into equals the mass (m) of that matter multiplied by the speed of light squared (c^2). This theory was created in 1905. Scientists determined using this formula that one pound of Uranium would release as much energy as 8,000 tons of TNT. This realization determined that Uranium could be used to make a powerful bomb.

The United States took these discoveries and put them to use in the making of the first working nuclear weapons. The weapons were two nuclear bombs each made using different technologies. A subcritical mass is a mass unable to sustain itself while undergoing a chain reaction. This subcritical mass must be triggered into a chain reaction in order to achieve a nuclear explosion. A fission weapon uses one of two methods to create a critical mass, which is a minimum amount of fissionable material. The first way is the gun-type method. This is where two subcritical pieces of material are placed into a device similar to the barrel of a gun. One piece is at one end of the barrel and the other is near the opposite end with a conventional, or non-nuclear, explosive behind it. When triggered, the conventional explosive propels the first into the second at very high speed. The result is a combining of mass causing a chain reaction. This is the cause of the explosion. The second method is the implosion method. In this method, a subcritical mass is made into a supercritical mass by compressing it into a smaller volume. This mass is in the center of a weapon, surrounded by conventional explosives. When triggered, the conventional explosives go of simultaneously, compressing the subcritical mass into a very high density supercritical mass. A self-sustaining chain reaction occurs, causing the explosion. There are also Thermonuclear and other types of nuclear bombs, but none have been used.

Leo Szilard was a renown physicist who learned the Germans had split the Uranium atom. He alerted the famous scientist Albert Einstein, who in turn notified Franklin D. Roosevelt. FDR approved the Manhattan Project, which was spear headed by General Leslie R. Groves. Once the team learned the British had started developing a bomb, Roosevelt approved the creation of an American bomb. Szilard and Enrico Fermi were the scientist responsible for major advances, and under J. Robert Oppenheimer, they tested the first bomb in Los Alamos, New Mexico in 1945. President Harry Truman was the president who, during his term, approved the drop of the atomic bomb on Japan.

The bomb known as "Little Boy"
that was dropped on Hiroshima
Two uranium bombs were dropped on Japan at the end of WWII. Little Boy, the smaller of the two bombs, fell on the city of Hiroshima at 8:15 AM on August 6, 1945. Fat Man, over twice the size of its partner, hit Nagasaki three days later on August 9. In the case of both explosions, ground zero and the surrounding area was decimated and both cities were left in a state of utter ruin. The combined death toll was around 83,000 victims, a significant number of whom were captured forced laborers and American prisoners of war. WWII ended with the Japanese surrender on August 15, 1945, just six days after the bombing of Nagasaki.

Harry Truman will go down in history as a man that mercilessly killed hundreds of thousands of innocent civilians. “The most terrible weapon ever known.” says Was it really necessary? Most Americans think of Truman as a hero. The decision to drop the bobs was undoubtedly difficult. Japan had broken international peace, and their allies, the Germans, had committed crimes that will never be forgotten. Some may think the bombing was a harsh punishment, but it is comparable to how the Japanese treated their war adversaries.

Before the bombs were dropped, the US offered Japan an unconditional surrender. The Japanese military command rejected this offer. The times were dire, and the US officials had heard that the uranium atom had been split, making the event of atomic war inevitable. The “good guys” had to assert dominance before things really got out of control.

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