1930
Schrödinger views electrons as continuous clouds and introduces "wave mechanics" as a mathematical model of the atom.
--------------------------------------------------------------------------------
1931
Albert Einstein urges all scientists to refuse military work.
Harold C. Urey of the United States and associates discover deuterium (heavy hydrogen) which is present (0.014%) in all natural hydrogen compounds including water.
John D. Crockcroft of Great Britain develops high-voltage apparatus for atomic transmutation.
--------------------------------------------------------------------------------
1932
James Chadwick proves the existence of neutrons, using alpha particles striking a beryllium foil. He determines their mass by measuring the recoil tracks of known atoms of the rarified gas in his cloud chamber.
John Cockcroft and E. T. S. Walton of Great Britain split the atom on a linear accelerator built at
Ernest Rutherford’s Cavendish Laboratory at Cambridge University. Their experiment proves Albert Einstein’s theory of relativity.
Leo Szilard reads H.G. Wells' novel, The World Set Free, in which Wells prophesizes an atomic war in which the major cities of the world are destroyed (See Related Links on top right for on-line version of the book.)
August 2
American experimentalist Carl Anderson discovers a new particle the "positron." It is an electron with a positive instead of negative charge.
--------------------------------------------------------------------------------
1933
January 30
Adolph Hitler becomes Chancellor of Germany.
March 23
Following the Reichstag fire and subsequent suspension of constitutional liberties, Reichstag voluntarily gives over its powers to Hitler's cabinet.
April 7
Third Reich promulgates its first anti-Jewish ordinance.
September 12
Leo Szilard, a Hungarian physicist who took refuge in London from Nazi Germany, reads about a speech in which Lord Rutherford ridiculed the idea of using the transformation of atoms as a source of power. Szilard realizes that, “if we could find an element which is split by neutrons, and which would emit two neutrons when it absorbs one neutron, such an element could sustain a nuclear chain reaction.”
--------------------------------------------------------------------------------
1934
Frederic and Irene Joliot-Curie of France discover artificial radioactivity, i.e. the radioactivity of atoms produced in transmutation experiments.
Enrico Fermi of Italy irradiates uranium with neutrons. He believes he has produced the first transuranic element, but unknowingly achieves the world’s first nuclear fission.
June 28 and July 4
Leo Szilard files for patent amendments for "the liberation of nuclear energy for power production and other purposes through nuclear 'transmutation.' " He proposes a "chain reaction" for the first time.
--------------------------------------------------------------------------------
1935
April 9
Leo Szilard files patent amendment identifiying uranium and bromine as "examples for elements from which neutrons can liberate multiple neutrons.
The development of atomic bomb boosted the level of understanding in terms of physics and chemistry of that particular time period. Physicists started to realize that stable nuclei can be converted to unstable nuclei. Through such process, they discovered that heavy nuclei can undergo nuclear fission. While testing, they added a neutron to an isotope of Uranium 235. This resulted Uranium 235 to become unstable and break down into Barium and Krypton, releasing two to three more neutrons. The breakdown of Uranium 235 is called “fission”. When the released neutrons attach to other isotopes of Uranium 235, this can result in a chain reaction of fission. For every generation of fission, the amount of fission is doubled, and this resulted in an extreme outburst of energy. The amount of energy released by this process is related to Einstein’s famous equation “E=mc^2” (Wolf).
Physicists found out that among the pieces of a split atom were newly produced neutrons. These might encounter other uranium nuclei, cause them to split, and start a chain reaction. If the chain reaction was limited to a moderate pace, a new source of energy could be the result. The chain reaction could release energy rapidly and with explosive force. Leo Szilard, Eugene Wigner, and Edward Teller, Hungarian-born physicists, were frightened by the possibility that Germany might produce an atomic bomb.
Development of the Hydrogen Bomb In the world, there is little thing called power. Many countries want to have great power, few get it. Powers gave the Soviet Union and the U.S. the ability to dominate in wars. In the 1950’s during the Cold War these two countries had a race to see who could create the most powerful weapon the world has ever seen, the Hydrogen Bomb. Edward Teller, an atomic physicist, and Stanislaw Marcin Ulam, a mathematician, "who together developed the Teller-Ulam design in 1951" for the Hydrogen Bomb (Teller-Ulam Design).
His data he from his experiments led to the discovery of the physical electron in an atom by J.J. Thomson at Cambridge around 1898, and was H.A. Lorentz’s baseline for his formal theory on the existence of the electron. In his Nobel Lecture in 1902 Lorentz would go on to acknowledge and credit Stoney for his contributions to his study. His discoveries changed the way others looked at the atomic structure. He received an honorary Doctorate of Science (D.Sc.) from the University of Dublin in June 1902 just 9 years before he died at the age of eighty-five. The lasting impact of his work is acknowledged even today because he aided in the advancement of the atomic theory by providing a new piece to the incomplete atomic
physics. The work of Ernest Rutherford, H. G. J. Moseley, and Niels Bohr on atomic
Early Soviet nuclear physics in the 1920s and 1930s enjoyed success in many fields. David Holloway states, “In spite of the difficulties it faced, Soviet nuclear physics reached a high standard in the 1930s.” 1 Physicists such as Abram Ioffe, who studied under Röntgen, Igor Kurchatov, Kirill Sinel’nikov, and others were prominent and capable scientists who advocated and build many of the institutions in the new Soviet Union to support scientific research. Ioffe’s Physicotechnical Institute was one of these institutes. The Soviets did not actually lack from talented and intelligent physicists in the early years of scientific research...
Enrico Fermi (1901-1954) succeeded in splitting the uranium atom and the Nobel Committee later awarded him the 1938 prize for physics. At Columbia University in New York, Fermi realized that if neutrons are emitted in the fissioning of uranium then the emitted neutrons might proceed to split other uranium atoms, setting in motion a chain reaction that would release enormous amounts of energy.(1) Fermi had succeeded in taking one of the first steps to making an atomic bomb.
It was Italian-born physicist and Nobel winner Enrico Fermi, and his colleagues at the University of Chicago who were responsible for this success (“Nuclear”).
The atomic bomb1 is the most destructive weapon known to mankind. A bomb of this nature is capable of obliterating anything up to four square miles and anything reaching outside that area receives very extreme damage. Albert Einstein was the man who had convinced the United States to research the Atomic Bomb.
After the United States developed the atomic at the end of World War II, interest in nuclear technology increased exponentially. People soon realized that nuclear technology could be used for electricity, as another alternative to fossil fuels. Today, nuclear power has its place in the world, but there is still a lot of controversy over the use of nuclear energy. Things such as the containment of radiation and few nuclear power plant accidents have given nuclear power a bad image. However, nuclear power is a reliable source of energy because it has no carbon emissions, energy is available at any time, little fuel is needed for a lot of energy, and as time goes on, it is becoming safer and safer.
Uranium, a radioactive element, was first mined in the western United States in 1871 by Dr. Richard Pierce, who shipped 200 pounds of pitchblende to London from the Central City Mining District. This element is sorta boring but I found something interesting, they used it to make an an atomic bomb in the Cold War. In 1898 Pierre and Marie Curie and G. Bemont isolated the "miracle element" radium from pitchblende. That same year, uranium, vanadium and radium were found to exist in carnotite, a mineral containing colorful red and yellow ores that had been used as body paint by early Navajo and Ute Indians on the Colorado Plateau. The discovery triggered a small prospecting boom in southeastern Utah, and radium mines in Grand and San Juan counties became a major source of ore for the Curies. It was not the Curies but a British team working in Canada which was the first to understand that the presence of polonium and radium in pitchblende was not due to simple geological and mineral reasons, but that these elements were directly linked to uranium by a process of natural radioactive transmutation. The theory of radioactive transformation of elements was brilliantly enlarge in1901 by the New Zealand physicist Ernest Rutherford and the English chemist Frederick Soddy at McGill University in Montreal. At dusk on the evening of November 8, 1895, Wilhelm Rontgen, professor of physics at the University of Wurzburg in Germany, noticed a cathode tube that a sheet of paper come distance away. He put his hand between the tube and the paper, he saw the image of the bones in his hand on the paper.
The next big step in the discovery of the atom was the scientific test that proved the existence of the atom. After the discovery of the atom we had the discovery of subatomic particles. With the discovery of the subatomic particles came the research, which came from experiments that were made to find out more about the subatomic particles. This research is how we uncovered that most of the weight of an atom is from its nucleus. With the gold foil experiment, tested by Ernest Rutherford, he discovered the existence of the positively charged nucleus. He proved this when the experiment was happening, a small fraction of the photons th...
Democritus, Dalton, Thompson, Millikan, and Rutherford, were few of the scientists who contributed to the development of the modern atomic theory. Each one of them developed a certain experiment to prove and demonstrate its way of seeing these tiny particles. They tested and proved each other’s theories, in order to create the modern atomic theory. During this investigation, the previous scientists will be researched and explained, with the purpose of understanding how did these theories overlap and improve.
...t with the quantum theory (“Niels Bohr.” Concordia). Without Bohr’s father and Ernest Rutherford, Bohr would not have accomplished all that he had done.
Scientists from earlier times helped influence the discoveries that lead to the development of atomic energy. In the late 1800’s, Dalton created the Atomic Theory which explains atoms, elements and compounds (Henderson 1). This was important to the study of and understanding of atoms to future scientists. The Atomic Theory was a list of scientific laws regarding atoms and their potential abilities. Roentagen, used Dalton’s findings and discovered x-rays which could pass through solid objects (Henderson 1). Although he did not discover radiation from the x-rays, he did help lay the foundations for electromagnetic waves. Shortly after Roentagen’s findings, J.J. Thompson discovered the electron which was responsible for defining the atom’s characteristics (Henderson 2). The electron helped scientists uncover why an atom responds to reactions the way it does and how it received its “personality”. Dalton’s, Roentagen’s and Thompson’s findings helped guide other scientists to discovering the uses of atomic energy and reactions. Such applications were discovered in the early 1900’s by using Einstein’s equation, which stated that if a chain reaction occurred, cheap, reliable energy could b...