The Atomic Bomb

"The search for a revolutionary weapon was one of the most immediate and persistent outcomes of the industrialisation of war in the mid-nineteenth century, and both a logical and an inevitable extension of the revolution in war which preceded it." (Keegan p. 578)

Einstein and Szilard in Germany, from Einstein pictures

Origins - 1933-39

Sept. 12, 1933 - Leo Szilard's inspiration on a London street corner

1933 emigres join 1918 Hungarian emigres who fled the White Terror of Nicholas Horthy:

Dec. 1938 - Hahn and Strassmann fission experiment

Bohr in Germany, with Einstein, Frank, Rabi, from Einstein pictures

1939 - research by Joliet in Paris (their cyclotron went to Germany), Fermi in Italy, Bohr in Copenhagen, Abelson and Lawrence in U.S.

Aug. 15 - Szilard/Einstein letter written

Sept. 1 - Poland invaded

Sept. 15 - Werner Heisenberg led German bomb project at Kaiser Wilhelm Institute

Oct. 11 - Alexander Sachs gives FDR his own summary of the Einstein letter

Oct. 21 - Advisory Committee on Uraniun under Lyman Briggs of Bureau of Standards

Research - Phase 1 - 1940

M. Stanley Livingston (L) and Ernest O. Lawrence in front of 27-inch cyclotron at the old Radiation Laboratory at the University of California, Berkeley, 1934 (NWDNS-434-RF-25(1) ) from NAIL

June 27 - National Defense Research Council under Vannevar Bush of MIT (engineer)

Oct. - Radiation Lab at MIT under Edwin McMillan of Berkeley


Feb. 23 - Seaborg transmutes plutonium

Mar. 17 - Lawrence convinced Alfred Loomis (Stimsons 1st cousin) and Arthur Compton to fund plutonium

Enrico Fermi, Italian-American physicist, received the 1938 Nobel Prize in physics for identifying new elements and discovering nuclear reactions by his method of nuclear irradiation and bombardment. He was born in Rome, Italy, on September 29, 1901, and died in Chicago, Illinois, on November 28, 1954 1943-1949 (NWDNS-434-OR-7(24)) from NAIL

June 1 - Office of Scientific Research and Development under V. Bush

July 15 - British MAUD report recommended low-yield U-235 bombs by 1943

Oct. 9 - FDR gave Bush full approval - Top Policy Group formed

Dec. 6 - decision to expand individual projects (funding at $1,200,000):

Dec. 7 - Pearl Harbor

Dec. 18 - S-1 Committee replaced NDRC individual projects

Development - Phase 2 - 1942

May 23 - decision for parallel development within Manhattan Project

June - J. Roberrt Oppenheimer group at Berkeley worked on weapon design

Major General Leslie R. Groves, in charge of the Manhattan Project, 1942 (NWDNS-208-PU-83S(2) ) from NAIL

Sept. 17 - Gen. Leslie Groves, builder of the Pentagon, to head Manhattan Project construction:

Sept. 21 - 1st test flight of B-29 - 1600 already ordered; in one year, deliveries begin from Boeings Wichita plant; 3763 delivered by August 1945 at total cost of $3B.

B-29 construction
B-29 Enola Gay after strike at Hiroshima, entering hard-stand, 08/06/1945 (NWDNS-77-BT-91) from NAIL
B-29 construction

Dec. 2 - Fermi's Met Lab CP-1 pile at Chicago went critical for 4+ minutes - produced neutrons


Feb. 16 - Vemork heavy water plant destroyed in Norway

April - Gen. Kenneth Wolfe put in charge of B-29 project by Hap Arnold; independent, strategic

Dr. J. Robert Oppenheimer, atomic physicist and head of the Manhattan Project. ca1944 (NWDNS-434-OR-7(44) ) from NAIL

April - Oppenheimer's group moved to Los Alamos

May 25 - Oppenheimer to Fermi: "I should recommend delay if that is possible. In this connection I think that we should not attempt a plan unless we can poison food sufficient to kill half a million men, since there is no doubt that the actual number affected will, because of non-uniform distribution, be much smaller than this."

May 27 - Operation Gomorrah authorized for Hamburg

July 28 - first firestorm at Hamburg

Aug. 16 - 330 Allied aircraft bomb Peenemunde island in the Baltic

Oct. 6 - Niels Bohr fled to England with Heisenbergs German pile drawing

Nov. 16 - Vemork bombed

Nov. 29 - first B-29 is modified

Dec. - Emilio Segre reduces gun bomb to 2' x 6' - now called Little Boy

Little Boy uranium bomb on trailer cradle in pit, bomb bay door in upper right-hand corner, 08/1945 (NWDNS-77-BT-115) from NAIL
Fat Man plutonium bomb being placed on trailer cradle in front of Assembly Building #2, 08/1945 (NWDNS-77-BT-187) from NAIL

Production - Phase 3 - 1944

Jan. - British Tube Alloys group to Los Alamos:

Bohr, Felix Frankfurter seek openness: "We are in a completely new situation that cannot be resolved by war...It appeared to me that the very necessity of a concerted effort to forestall such ominous threats to civilization would offer quite unique opportunities to bridge international divergencies."

Mar. 3 - B-29 drops first "pumpkin"

April 15 - "Battle of Kansas" settles on modification centers rather than 30,000 design changes

June 15 - 1st B-29 mission from China - 47 of 92 return - map

June 15 - Saipan

July 24 - Tinian

Sept. 19 - Hyde Park agreement after 2nd Quebec

Sept. 26 - Hanford B-pile goes critical

Oct. 12 - 1st B-29 from Kansas lands on Saipan

Nov. 24 - first B-29 raid on Tokyo aircraft plant

1945 - Defeat of Japan


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