The world's first nuclear explosion occurred on July 16, , when a plutonium implosion device was tested at a site located miles south of Los Alamos, New Mexico, on the barren plains of the Alamogordo Bombing Range, known as the Jornada del Muerto. Inspired by the poetry of John Donne, J. Robert Oppenheimer code-named the test "Trinity. Seconds after the explosion came an enormous blast, sending searing heat across the desert and knocking observers to the ground.
He arrived in a country that was then at the forefront of nuclear physics. He reasoned that if you could find an atom that was split by neutrons and in the process emitted two or more neutrons, then a mass of this element would emit vast amounts of energy in a self-sustaining chain reaction. Szilard pursued the idea with little success. When they analysed the debris they were stunned to find traces of the much lighter element barium.
As luck would have it, Hahn and Strassman were opponents of the regime. Hahn wrote to the Austrian chemist Lise Meitner, who had worked with him in Berlin until she fled to Sweden after the Nazis occupied Vienna in Meitner wrote back explaining that the uranium nucleus was splitting into two roughly equal parts. The next piece of the puzzle came when Italian physicist Enrico Fermi, who had fled Fascism and was working at Columbia University in New York, discovered that uranium fission released the secondary neutrons that were needed to make the chain reaction happen.
Szilard soon joined Fermi in New York. Some countries wanted the option of developing their own nuclear weapons arsenal and never signed the NPT. India was the first country outside of the NPT to test a nuclear weapon in Pakistan has a known nuclear weapons program. Israel is widely believed to possess nuclear weapons, though has never officially confirmed or denied the existence of a nuclear weapons program. South Sudan is not known or believed to possess nuclear weapons.
North Korea initially signed the NPT treaty, but announced its withdrawal from the agreement in Since , North Korea has openly tested nuclear weapons, drawing sanctions from various nations and international bodies.
North Korea tested two long-range intercontinental ballistic missiles in —one reportedly capable of reaching the United States mainland. In September , North Korea claimed it had tested a hydrogen bomb that could fit on top an intercontinental ballistic missile. Iran, while a signatory of the NPT, has said it has the capability to initiate production of nuclear weapons at short notice. International Atomic Energy Agency.
The Development and Proliferation of Nuclear Weapons. But if you see something that doesn't look right, click here to contact us! Subscribe for fascinating stories connecting the past to the present. The explosion immediately killed an estimated 80, people; tens of thousands more would later die of radiation The instability created in Europe by the First World War set the stage for another international conflict—World War II—which broke out two decades later and would prove even more devastating.
Rising to power in an economically and politically unstable Germany, Adolf Soon after arriving at the Potsdam Conference in July , U. President Harry S. On July 24, eight days Tsutomu Yamaguchi was preparing to leave Hiroshima when the atomic bomb fell. The gaseous diffusion process employed a porous barrier through which uranium hexaflouride gas would be pumped; the lighter molecules of U would pass through more readily than the heavier ones of U and could be collected via a chemical process.
Construction by the contractor experienced no unusual difficulties, but a nationwide shortage of copper for the massive magnets for the electromagnetic system had to be solved by using silver, which came from the U. Treasury Depository in huge quantities. By October the system was ready for testing. However, it soon became apparent that the magnets were plagued by numerous electrical shorts, caused by faulty design and manufacture. All of the 48 magnets had to be rebuilt. Finally the system was ready for operation in January Thousands of diffusion tanks for the gaseous-diffusion process would be required.
Selection of a suitable barrier material was a difficult problem, causing a dispute among adherents of competing approaches. Groves finally decided to submit the matter to a British-American committee, who ratified a decision that he had already made to use a new but superior design that would further delay production. The date of Groves' decision was in early January In early Oak Ridge began shipping weapon-grade U to Los Alamos, where weapon development was taking place.
In early Groves had selected Hanford, Washington, as the site for plutonium production. The selection of Hanford over Oak Ridge was based on the former's remote location, which militated against disastrous results if a nuclear accident occurred.
Major design, recruiting, and construction problems existed, but the principal buildings were ready for installation of the first nuclear pile by February Plutonium production in quantity began in December The next major problem, which surfaced in late , was the establishment of a laboratory for work on bomb design. General Groves favored Robert Oppenheimer as the director, although Army counterintelligence objected because of Oppenheimer's former friends who had been Communist Party members.
Groves was able to convince Vannevar Bush, the head of the Office of Scientific Research and Development, that no one else could be a better choice. The site was on the grounds of a boys' school located on a rugged mesa thirty-five miles northwest of Santa Fe. Manning and construction started in early The remoteness of the site made recruiting of qualified personnel difficult, but Oppenheimer was able to appeal to most candidates' patriotism. There were two possible approaches to bomb design.
The first was to achieve a critical mass and the resulting nuclear explosion by very rapidly joining two sub-critical halves and initiating a neutron source. This approach was called the "gun type" since the system used a tube in which the two halves were fired toward each other.
The other, newer approach used a ball called core of fissionable material surrounded by a number of lenses of explosive which when detonated squeezed the ball into a critical mass. The neutron initiator was located in the center of the core.
This approach was called the implosion method. The gun-type was considered the more reliable; the implosion method required simultaneous detonation of the lenses and was relatively risky.
In early the Army Air Forces started its program to develop a delivery capability using the B aircraft. The B was the logical choice in view of its long range, superior high-altitude performance, and ability to carry an atomic bomb that was expected to weigh to 10, pounds. In August seventeen Bs entered a modification program at the Glenn L. Martin plant in Omaha, Nebraska, to apply the lessons learned at Muroc. That month the decision was made to train a special group to deliver the first atomic bombs; and a squadron then based at Fairmont, Nebraska, in training for assignment to Europe, was selected to form the nucleus of the new organization, which was designated the th Composite Group.
Tibbetts to command the th. Tibbets was highly qualified for the position. An intensive training program for the th took place, designed specifically to prepare the crews for a high altitude release of the bomb, including an escape maneuver that would avoid the shock wave that could damage or destroy the aircraft.
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