PHY 180B: Nuclear Weapons & Society —
From Trinity to Tehran
Chronology
(2/14/11)
| 1803 | John Dalton of Britain proposes chemical atomic theory. |
| 1855 - 65 | The cathode-ray tube (Crookes' Tube) is invented and perfected. |
| 1895 | Wilhelm Conrad Röntgen of Germany discovers X-rays. |
| 1896 - 98 | Antoine Henri Becquerel and Pierre and Marie Curie of France discover natural radioactivity. |
| 1897 | J.J. Thomson of Britain discovers the electron. |
| 1899 | Ernest Rutherford of Britain discovers alpha and beta rays in his study of radium. |
| 1900 | Frederick Soddy of Britain is the first to identify and describe isotopes. |
| 1902 | Rutherford and Soddy publish the theory of radioactive decay. |
| 1905 | Einstein publishes the special theory of relativity. (E = mc2). |
| 1911 | Rutherford discovers the nucleus of the atom. |
| 1913 | Niels Bohr of Denmark combines nuclear and quantum theory to create a new theory of atomic structure. |
| 1914 | H.G. Wells publishes The World Set Free and describes "atomic bombs." |
| 1915 | Einstein publishes the general theory of relativity. |
| 1919 | Rutherford discovers the proton by artificially transmuting an element:a + 14N → 17O + p |
| 1929 | Ernest O. Lawrence of the United States develops the concept of the cyclotron to increase the speed of protons hurled at atomic nuclei. John Cockroft and E.T.S. Walton develop the first linear accelerator for accelerating protons to study atomic transmutations. |
| 1931 | E.O. Lawrence builds his first cyclotron. Robert J. Van de Graff develops the electrostatic generator. |
| 1932 | James Chadwick of Britain discovers the neutron:a + 9Be → 12C + n |
| 1933 | Leo Szilard is the first to realize that "a chain reaction might be set up if an element could be found that would emit two neutrons when it swallowed one neutron." Frédéric and Irène Joliot-Curie of France discover artificial radioactivity. |
| 1934 | Enrico Fermi of Italy is the first to achieve nuclear fission in an experiment, but he does not realize his achievement. |
| 1938 | Otto Hahn and Fritz Strassmann of Germany discover the process of fission in uranium. |
| 1939 | Publication of Hahn's results excites physicists around the world, who begin to conduct experiments in fission. Alarmed by the possibility of a uranium bomb, Albert Einstein writes to colleagues, who forward the letter to US President Franklin D. Roosevelt. Roosevelt responds by creating a committee to look into the military applications of atomic research. World War II begins when Germany invades Poland on September 1. |
| 1940 | Scientists in the United Kingdom secretly encourage a British atomic bomb project. Using the cyclotron, scientists Philip Abelson and Edwin McMillan at the University of California, Berkeley, bombard uranium-238 to create "elements 93 and 94." (???) |
| 1941 | Scientist Glenn T. Seaborg discovers plutonium, and determine that it is fissionable -- in fact, it is more fissionable than uranium-235.. The British MAUD Project determines that it is possible to make an atomic bomb with uranium-235. The United States enters the war. |
| 1942 | The United States creates the top secret Manhattan Project to develop an atomic bomb. An experimental reactor "pile" at the University of Chicago generates the first self-sustaining nuclear reaction. |
| 1943 | The Manhattan Project establishes a top-secret city and laboratory at Los Alamos, New Mexico, to design and build the atomic bomb. Other secret facilities are built to create weapons-grade plutonium. |
| 1944 | German attempts to create an atomic bomb begin to lag. The race to develop the first atomic weapon is effectively over. |
| 1945 | FDR dies of cerebral hemorrhage on April 12; Truman becomes President. End of war in Europe, May 7. Intense fire-bombing destroys nearly all Japanese cities; in March, 100,000 die in Toyko. Tokyo is firebombed again in May, this time resulting in 83,000 deaths. The first atomic bomb is successfully tested at Trinity Site, New Mexico, on July 16. The second bomb is dropped on Hiroshima, Japan, on August 6. On August 8, Russian informs Japan that it is declaring war on Japan. A third bomb, which devastates Nagasaki, is dropped on August 9. Japan surrenders on August 14. The Japanese sign articles of surrender aboard the U.S.S. Missouri on September 2, 1945, and World War II officially ends. |
The origin of this Chronology appears in Nuclear Dawn by James P. Delgado. Portions have been paraphrased, and substantial material has been added from other sources.