This notebook records an experiment of the Manhattan Project, the all-out, but highly secret, effort of the Federal Government to build an atomic bomb during World War II. Recorded here is the world's first controlled, self-sustaining nuclear chain reaction, achieved on December 2, 1942.
Eight months after the United States entered World War II, the Federal Government
launched the Manhattan Project, an all-out, but highly secret, effort to build
an atomic bomb—and to build one before the Germans did. The task was to
translate the vast energy released by atomic fission into a weapon of unprecedented
power. On December 2, 1942, a group of distinguished physicists, working under
top-secret conditions in an unpretentious laboratory at the University of Chicago,
took a crucial step towards this goal: they created the world’s first
controlled, self-sustaining nuclear chain reaction. Nobel prize-winning physicist
Enrico Fermi directed the experiment.
Fermi directed the construction of a pile of graphite and uranium bricks and
wooden timbers, assembled in the precise arrangement necessary to start and
stop a nuclear chain reaction. Cadmium rods inserted into the pile regulated
the nuclear reaction to prevent it from “burning” itself out of
control. Had it not been controlled, the experiment could have released a catastrophic
amount of energy, wreaking havoc in the middle of the densely populated city
of Chicago.
“We’re cooking!” was the exuberant reaction recorded when
the experiment succeeded. (The data shown on these notebook pages is the record
of the nuclear reactor’s response to the movement of the control rods.)
(Information excerpted from Stacey Bredhoff, American Originals [Seattle:
University of Washington Press, 2001], pp. 94–95.)
