Atomic Bomb Timeline

This timeline is being assembled collaboratively by the students in Making the Bomb, a course being taught at the College of the Atlantic, spring term, 1999.

This page is a work in progress

1700-1800

1704 Isaac Newton: modeled the atom using billiard balls.
1789 Martin Heinrich Klaproth extracted a grayish metallic material from a sample of Joachimsthal pitchblend and named it Uranium.

1800-1900

1873 James Clerk Maxwell: introduced the electro magnetic field around atoms.
1885 Balmer: the Balmer series was introduced, light was shot through hydrogen and the light spectrum that came from it was studied.
1887 Heinrich Hertz: discovered electric waves (radio).
1890 Rydberg: found a more consistent bomber series, led to Rydberg constant.
1895 William Roentgen: discovered x-rays.
1896 Henry Becquerel: finds radioactivity.
1897 J.J. Thompson: discovered electrons using cathode rays, showed that glowing matter wasn't light waves.
1899 E. Rutherford: publishes discoveries on radiation, including alpha and beta particles.

1900

Planck's quantized radiation formula. Plank discovers that certain particles can only vibrate at certain energies, this led to Planks constant.
(Through 1903): Rutherford and Soddy work on spontaneous decay and radioactivity, half lives and the amount of energy released.

1901

1902

1903

1904

1905

Otto Hahn: went to work with Rutherford and helped him discover that alpha rays were charged hydrogen atoms.
Einstein shows that light sometimes behaves as if it consists not of waves but of particles.

1906

Otto Hahn moved from Montreal to Berlin to work with Emil Fischer (and organic chemist), leaving Ernest Rutherford behind.

1907

1908

1909

1910

1911

Adolf von Harnack was the first president of Kaiser Wilhelm Society.
Bohr: suggest that the atom is stationary.

1912

Bohr discovers that radioactive particles come form the nucleus, also elements are given exact place on the periodic table.
May 25: Germans bomb (with planes) a civilian town. "Strategic Bombing" begins.
October 23: Kaiser Wilhelm II dedicates first two Kaiser Wilhelm institute: one for chemistry, one for physics, in Dahlem, southwest of Berlin.

1913

Bohr found a correlation between orbiting electrons and spectral lines.
May: Mosley and C.G. Darwin start using crystals and spectroscopes and discover that they work very well. Mosley's results eventually backed up Bohr's quantized electron orbits.

1914

August: Weismann discovers BY, and anaerobic organism that decomposes starch while trying to develop a process for making synthetic rubber. Because a side product was acetone (used for making artillery propellant) the military became interested.

1915

April 22: Battle of Ypres. Germans use Chlorine gas.

1916

1917

May 25: In the town of Folkestone on the Southeastern coast of England, German Gotha bombers (biplanes) strategically bomb england for the first time. Began first effective and sustained campaign of strategic civilian bombardment.
June 13: German squadron flew against London and caused the most numerous civilian casualties of the war.
July: Germany introduces mustard gas into WWI.

1918

Ernest Rutherford moved to Cavendish to take over for J.J. Thomson.
Oppenheimer tried to work with Rutherford, but was turned down.
October: Hungarian Revolution, calls for Hungarian independence.

1919

March 21: republic of Hungary turns into Hungarian Soviet Republic.
Fall: White terror of the Horthy regime begins in Hungary. Anti-Semitism drives many Jews into exile.

1920

1921

James Chadwick was Rutherford's assistant director of research.
J.J. Thompson still worked at Cavendish and let Oppenheimer in to work with him.
January 18: Bohr opens his Institute for theoretical Physics in Copenhagen.

1922

Bohr predicts that when element 72 is found it will be similar to Zirconium. This linked chemistry to physics.
Bohr wins the Nobel prize and become a Danish national hero.
December: George deHevesy and Dirk Coster discovered element 72 which was chemically almost identical to Zirconium.
Early summer: Arnold Sommerfeld brought Werner Heisenberg with him to hear Bohr lecture in Gottingen.
Summer: Oppenheimer first encountered area of Los Alamos.

1923

1924

Easter: Heisenberg went to Copenhagen and hiked with Bohr.

1925

May: Heisenberg goes to Heligoland for two weeks and develops quantum mechanics.
June: Heisenberg, Max Born, and Pascal Jordan refine quantum mechanics.

1926

Ed Teller left Hungary at age 17 to go to the Technical Institute at Karshurle.
Erwin Schroedinger shows that matter at the atomic level behaves as if it consists of waves.
Bohr and Schroedinger attempt to reconcile dualism of atom.
Oppenheimer moved to Gottingen
Wigner, Heisenberg, Pauli, Fermi, Franck, all present in Gottingen along with Courant, Weyl, von Neumann, and Teller.

1927

Benito Mussolini's government convenes international physics congress at Como, Italy.
February: Bohr goes to Norway to ski. Heisenberg continued to work attempting to calculate the trajectory of electron in cloud chamber, realized it was hopeless.
February: Heisenberg concludes "that on the extremely small scale of the atom, there must be inherent limits to how precisely events could be known." This is the uncertainty principle.
September: At Como, Bohr proposes that particles and waves are merely words and can be accepted side by side to describe the atom.
September: Einstein refused to attend Como and support fascism.
October: Solvay conference in Brussels attended by Einstein, Bohr, Planck, Marie Curie, Lorentz, Born, Ehrenfest, Schroedinger, Pauli, Heisenberg.
October: At Solvay conference Einstein refused to accept that determinism at atomic level was impossible, claiming that "God does not throw dice.
October: Bohr disagrees with Einstein. Bohr responds, "Nor is it our business to prescribe to God how He should run the world."

1928

1929

Oppenheimer published 16 papers between 1926 and 1929.
Oppenheimer accepts join positions at Caltech and Berkeley.

1930

1931

1932

Irene Curie succeeds her famous, but sadly mortally ill, mother Marie as director of the Radium Institute in Paris.
August 2: Carl Anderson, working with a carefully prepared cloud chamber at the California Institute of Technology, discovers a positively charged electron, the "positron." This was the first indication that the universe consists not only of matter but of antimatter as well.

1933

Fermi, Segre, Corbino, Amaldi, et al. open a well funded, richly staffed physics research center in Rome, complete with a "well-made" cloud chamber and a nearby radium source (as well as wooden and marble tables), to begin intensive study of the atomic nucleus.
October: Solvay Conference in Brussels, Belgium. For the first time, this prestigious congregation was devoted purely to the consideration of nuclear physics. Attendance at this affair was the excuse the Soviet physicist George Gamow used to affect his defection.

1934

Fermi and his "Boys" test artificial transmutation in a vast array of elements. Observing the behavior of bombarded Uranium, they note that one of its decay products is an unknown substance with a 13 minute half life. In the their following publication they suggest the "possibility that the atomic number of the element may be greater than 92."
January 15: Irene Curie and her husband Frederic Joliot publish a report in the Comptes Rendus describing that in the course of experimentation with alpha particles to find the elusive neutron, they discover how to make matter radioactive by artificial means. "These experiments," they write, "give the first chemical proof of artificial transmutation" (they win the Nobel Prize in Chemistry for the work the following year).
March 12: Leo Szilard, in London, files the first of several patent applications relating to nuclear energy. By the end of the 1935, the lot of them would be merged into one complete specification: "Improvements in or Relating to the Transmutation of Chemical Elements." Without a bit of laboratory experimentation, Szilard was already acting on his idea of nuclear chain reaction, with applications from power production to, with a correct "critical mass" of chain-reacting substance, "explosion."
July 4: Marie Sklodowska Curie dies.
September: Ida Noddack publishes "On element 93," in it proposing "when heavy nuclei are bombarded by neutrons, it is conceivable that the nucleus breaks into several large fragments, which would of course be isotopes of known elements but would not be neighbors." This highly insightful piece of work would largely go ignored.

1935

Noticing a disparity in results of the same experiment on tables of wood and tables of marble, Amaldi and the Boys find that slowing neutrons gives nuclei more time to effect their "capture;" Segre would subsequently the highly effective neutron-slowing powers of paraffin.
Szilard begins searching for funds for his chain reaction research.
Szilard requests for the British War Office to hold and keep secret his patents for nuclear chain reactions. Not until February 1936, and with the prodding of Frederick Lindemann, does the Admiralty accept the patent for safe-keeping.

1936

Civil war begins in Spain.
January 27: Bohr, arguing for radical theoretical change, introduces a model for a multi-particle atomic nucleus closely packed and bound by the short range strong force. The following year, he publishes another proposal explaining the usefulness of mathematically modeling the nucleus as one would a drop of liquid.

1937

October 20: Ernest Rutherford dies.

1938

March: Hitler invades Austria
May: Hitler visits Mussolini in Rome
July 14: Manifesto della Razza -- "Jews do not belong to the -- Italian race."
Summer: Maurice Goldhaber emigrates to U.S.
August: Bohr speaks at International Congress of Anthropologic and Ethnographic Sciences in Helsingor, Zealand.
September 1: Anti-Semitic laws passed in Italy

1939

Late January: Szilard asks Fermi to keep the possibility of producting a chain reaction secret.
February 5: Bohr draws 3 graphs that explain fission for Thorium, U238, and U235, showing that any neutron (fast or slow) will fission U235.
February 7: Bohr sends a paper on this off to The Physical Review.
Late February: Joliot beging to identify secondary neutrons from fission.
Early March: Szilard gets radium to conduct his own experiments to see if neutrons are emitted in the fission process, and he finds that they are.
March 14: Hitler orders the Foreign Minister of Czechoslovakia to Berlin and threatens to bomb Prague unless the Czechs surrender to Germany
March 16: Czechoslovakia becomes a German protectorate
March 16: Wigner, Szilard, Fermi and Pegram meet and Wigner says that they should talk to the U.S. government about their discoveries
March 17: Fermi meets twith Admiral Stanford C. Hooper from the U.S. Navy to tell him about the possibility of the liberation of atomic energy leading to powerful explosives that could have military use.
March 17: Fermi, Teller, and Szilard discussed whether or not to keep Physical Review papers secret. The decide not to publish.
March 18: Joliot, VonHalban, and Kowarski published paper on secondary neutron in Water.
April 22: Joliot, VonHalban, and Kowarski publish second paper in Nature on secondary neutron; Uranium would most probably chain-react.
April 29: Secret conference in Berlin leading to research program, ban on Uranium exports, provisions for supplies of radium.
April 29: Public debate in in Washington on Physics.
June: Columbia team sends paper "Neutron production and absorption in Uranium" to Physical Review.
July 16: Wigner and Szilard meet with Einstein to discussion contacting FDR.
July: Szilard meets Alexander Sachs and discusses having Sachs approach FRD about fission.
July 30: Teller and Szilard visit Einstein for letter to FDR.
September 1: Germany invades Poland at 4:45 am. WWII starts.
September 3: Britain and France enter WWII.
Fermi and Anderson set up a new project involving measuring neutron production in a tank of liquid. Working with Szilard, they found neutron activity about 10% higher with Uranium oxide than without it.
Fermi and Anderson leave to pursue other things
Szilard comes up with the idea to use graphite as a moderator, rather than water.
Through correspondence with Fermi, the idea of using graphite becomes steadily more plausible.
After the success of the graphite experiment, Szilard, with help from Einstein, wrote up a letter to the government about the possibilities of fission (and also about the dangers of it).
September 16: Conference in Berlin. Physicists learn that German intelligence had discovered the beginning of Uranium research.
September 29: Premier Eduardo Daladier, Mussolini, Hitler, and Chamberlain met in Munich and decide to evacuate Sudentenland.
October 21. Briggs, Sachs, Szilard, Wigner, Teller, Roberts, Adamson, and Hoover meet to discuss war and physics. Chain reaction experiments get funding.
November 7: 17 year old Polish Jewish student attempts the assassination of Ernst Vom Rath, the third secretary of the German embassy in Paris.
November 9: Vom Rath dies leading to Anti-Semitic riot leaving at least 100 people dead. Work begins in USSR toward making an atomic bomb.

1940

1941

1941: Abelson's thermal diffusion column is developed as a cheap way to make uranium hexaflouride

1942

April 19: Glen Seaborg arrives in Chicago
August 20: Seaborg isolates Plutonium
September 17: Leslie Richard Groves take over Manhattan Project
October 15: Oppenheimer becomes director of Manhattan Project
December 20: Fermi, Szilard finish pile CP-1
Winter: Heavy water factory Vermark first attempted sabotage against.

1943

January: Abelson's report is released it states that uranium can be enriched with in a single thermal diffusion column.
February 2: Germans surrender at Stalingrad.
March 15: Scientist move to Los Alamos
May 27: Work began at Los Alamos-Fire bombing of Hamburg
Summer: Batches of plutonium nitrate began arriving at Los Almos
June 14: Oppenheimer met with Communist ex-love Jean Tatlock.
August 13: First drops of prototype atom bomb 14/23 scale model.
Sept. 17: First shots fired from an uranium gun.
November: Pilot scale reactor at Oak Ridge goes critical.
November: Abelson id authorized by the Navy to build his 300 column plant.
Winter: Bohr came to United States.
December: Frisch comes to America and becomes a British citizen
Teller and Bohr go to Los Alamos.
December 24: the first radio station broadcast to the Hill.

1944

January: Jean Tatlock committs suicide.
January: Kistiakowsky comes to Los Alamos
February: Installation of B Pile. February: Sinking of the Hydro.
March: Planning began for full scale test of implosion bomb. Oppenheimer code named it Trinity.
May 1: Oppenheimer seeks to replace Teller with Peirls
June 6: D-Day
August 1: Tinian secured by America, Mass suicide on Saipan.
September 26: The largeset atomic pile assembled. The first plutonium production reactor is operating.
December 7: Oppenheimer has second child.

1945

[Making the Bomb] [Dave] [College of the Atlantic]