Brief Chronology of the German
- Dec. 22 Otto Hahn sends paper to Lise Meitner containing
experimental results that are interpreted by Meitner and
nephew Otto Frisch as nuclear fission.
- Jan. 6 Hahn and assistant Fritz Strassmann publish their
- Jan. 26 Niels Bohr, informed by Frisch, announces the
discovery in Washington, D.C.
- Feb. 11 Meitner and Frisch publish a theoretical
interpretation of the Hahn-Strassmann results as nuclear
- June-July Heisenberg visits the United States.
- Aug. 2 Einstein signs letter to President Roosevelt
alerting him to the possibility of a bomb and urging
- Sept. 1 Bohr and John Wheeler publish a comprehensive
theory of nuclear fission.
- Sept. 3 War breaks out in Europe.
- Sept. 16 The German Army Weapons Bureau assembles
scientists to begin fission research.
- Oct. 5 The Weapons Bureau takes control of the
Kaiser-Wilhelm Institute for Physics in Berlin-Dahlem.
- Dec. 6 Heisenberg submits to the Weapons Bureau the first
part of a two-part comprehensive report on the prospects and
methods for exploiting nuclear fission.
- Feb. 29 Heisenberg submits the second part of his report
to the Weapons Bureau.
- May 3 German troops occupy Norway, seizing the world's
only heavy-water production plant at Vemork.
- May 19 Frisch and Rudolf Peierls submit a memorandum to
the British government estimating the critical mass of 235 U
needed for an atomic bomb and urging a bomb research
- June 15 Using the Berkeley cyclotron, Philip Abelson and
Edwin McMillan demonstrate that neutrons captured by 238U
lead to the creation of elements 93 and 94, neptunium and
- July 17 C. F. von Weizsäcker suggests to the Weapons
Bureau that neptunium bred in a reactor can be used as the
explosive material in a fission bomb.
- Jan. 20 Walther Bothe and Peter Jensen report results on
neutron absorption in graphite indicating, mistakenly, that
graphite cannot be used as a moderator.
- Mar. 28 American physicists confirm that plutonium is
fissionable, thus usable for a bomb.
- June 22 Germany invades the Soviet Union. August Fritz
Houtermans reports to German authorities the possibility of
using plutonium in a bomb.
- Dec. 5 In the wake of total mobilization Erich Schumann,
head of research in the Army Weapons Bureau, orders a review
of all research projects.
- Dec. 6 The Manhattan Project to build the bomb is
- Dec. 7 Japan attacks Pearl Harbor; America enters the
- February The Army Weapons Bureau decides to withdraw
almost entirely from fission research and relinquishes the
Kaiser-Wilhelm Institute for Physics.
- Feb. 26 Heisenberg, Hahn, and other scientists deliver a
lecture series on nuclear research to the Reich Education
Ministry in Berlin, gaining ministry backing for the project
under the Reich Research Council.
- April The first neutron multiplication is obtained in a
Leipzig test reactor.
- [June 4] Heisenberg reports on fission research to Albert
Speer, Germany's Minister for Armaments and War Production,
and other senior officials.
- June 9 Hitler issues a decree, placing the Reich Research
Council under Goring and Speer.
- July 1 Heisenberg becomes acting head of the Kaiser-
Wilhelm Institute for Physics, Germany's main reactor
research laboratory, and lays plans for the construction of a
working reactor containing heavy water and uranium metal
- July Kurt Diebner, supported by the Weapons Bureau,
begins reactor construction using the alternative design of
metal cubes suspended in heavy water, achieving positive
neutron multiplication over the following year.
- Nov. 5 Construction of a uranium isotope separation plant
begins at Oak Ridge, Tennessee.
- Dec. 2 Enrico Fermi and collaborators in Chicago achieve
the first self-sustained chain reaction in a pile consisting
of uranium spheres embedded in graphite bricks.
- January Planning begins for construction of reactors at
Hanford, Washington to breed plutonium for a bomb.
- May 6 Heisenberg, Hahn, and other scientists deliver
lectures on fission research before Göring's German Academy
of Aerodynamical Research.
- Autumn Berlin research institutes begin moving to
southern Germany for safety against Allied bombing raids. The
Kaiser- Wilhelm Institute for Physics is split between Berlin
and the neighboring southern towns of Hechingen and
- [Jan. 1] Walther Gerlach is appointed "plenipotentiary"
of all fission research sponsored by the Reich Research
- June 6 D-Day invasion of Europe.
- August The Alsos Mission, an American science
intelligence unit, arrives Europe.
- November The Alsos Mission determines that no German atom
- January Gerlach orders the remainder of the Heisenberg
and Diebner teams to move south.
- March The Heisenberg team in Haigerloch begins war time
Germany's last attempt to achieve a critical reactor.
- Apr. 23 The Alsos Mission captures scientists and
equipment in Hechingen, Haigerloch, and nearby
- May 1-3 The Alsos Mission captures Diebner and Gerlach in
Munich and Heisenberg in German-held Bavaria.
- May 7-8 Germany surrenders.
- July 3 Ten of the captive German scientists are flown
from Belgium to England and interned at Farm Hall.
- July 16 The first atomic bomb, fueled by plutonium, is
detonated in the New Mexico desert.
- July 17 Truman, Stalin, and Attlee meet at Potsdam near
Berlin to discuss the future of Germany and the former Axis
and Axis-occupied nations.
- Aug. 6 A uranium fission bomb destroys Hiroshima.
- Aug. 9 A plutonium fission bomb destroys Nagasaki.
- Jan. 3 The ten captive German scientists are returned to
Germany and released under Allied supervision within the
British zone of occupation.
File translated from TEX
by TTH, version 2.77.
On 18 Oct 2000, 22:35.