Our program featured Rick Bigelow, Commander USNR (Ret.) who, amongst other things is a nuclear engineer and patent attorney in private practice in Boalsburg and Nuangola, Pennsylvania. He offered an historical perspective of the science, the people, and the politics that led us to the Manhattan Project and the dawn of the nuclear age.
By the late 1800’s, it was the consensus among the leading lights of science and physics that all the great discoveries had been made prompting Lord Kelvin to say “There is nothing new to discover in Physics. It only remains to be measured more and more precisely.” Within a few years, quantum theory, the theory of relativity, manned flight, and discovery of the neutron and proton showed how wrong the conventional wisdom was. Work by scientists including Bohr, Einstein, and Lawrence paved the way for particle accelerators and the atom was split for the first time in 1932. Neutrons were discovered in the same year.
In 1938, German chemist Otto Hahn bombarded atoms of uranium with neutrons expecting a heavier element to be produced. Instead, he found he had produced (a) two much lighter elements such as Barium, (b) two or more neutrons and (c) a significant amount of energy. Dr. Lise Meitner and her nephew Otto Frisch helped explain the result when they concluded that the uranium atom had “fissioned” (i.e. split) into smaller atoms. Nuclear Fission had been discovered and explained. Scientists worldwide recognized the possibility of a chain reaction that would produce an enormous amount of energy, perhaps in the form of a bomb. One of these scientists was German Nobel Prize winner Werner Heizenberg who was put in charge of the German nuclear project by Hitler. Another scientist who realized this was Dr. J. Robert Oppenheimer, a Berkeley physicist.
The race to develop the bomb was underway. Urged on by a letter from Einstein, President Roosevelt did everything he could to fast-track the work. The Army established an office in Washington and another in NYC near prime contractor Stone & Webster and Columbia University. The Project became known as the Manhattan Engineering District and eventually the Manhattan Project. Col. Leslie Groves reluctantly became head of the project on Sept. 23, 1942. Oppenheimer became the technical lead to design and build the bombs.
By late December 1941, scientists were certain that a Uranium bomb would work. The problem was obtaining enough U-235. There was also optimism that a Plutonium bomb might work. The problem was producing enough Pu-239 for the bomb. There were 5 major efforts involved in the Manhattan Project: Build a facility to enrich Uranium to 90% U-235. Build a facility to produce Plutonium 239. Build a facility to prove that a nuclear chain reaction could be sustained. Build the Uranium Bomb. Build and test the Plutonium Bomb. The uranium was enriched at a plant in Oak Ridge Tennessee and the plutonium was produced in Hanford, Washington. Los Alamos New Mexico was chosen as the site where the bombs would be built.
FDR passed away in April 1945 and Germany surrendered shortly after. New President Harry Truman knew little about the Project. There was some thought to abandon the Project now that there was no longer a need to beat the Germans to the bomb. President Truman decided to allow the work to continue. Two bombs were created. The “Fat Man” plutonium-based bomb and the “Little Boy” uranium-based bomb. The Trinity Test involved the detonation of the Fat Man bomb at a site 200 miles south of Los Alamos. The successful test explosion could be heard 100 miles away.
The war in the Pacific dragged on until it reached the point where an invasion of Japan would be necessary. The War Dept estimated in July 1945 that the invasion code-named “Operation Downfall” would result in 1.7 to 4 million US casualties; 400,000 to 800,000 US KIA and 5 – 10 million Japanese dead. The decision was made to use the nuclear weapons. The Little Boy bomb was dropped on Hiroshima on August 6, 1945. Three days later, the Fat Boy bomb hit Nagasaki. The cities were leveled, and an estimated 120,000 people were dead. Thanks to intelligence gathered by spies, Russia was able to produce and test their own nuclear bomb by 1949. The Cold War had begun and would last for almost 50 years.
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