After months of preliminary work, the scientists at the University of Chicago's new Metallurgical Laboratory were ready to run their first experiment. The experiment did not involve metallurgy.
In fact, there were no metallurgists in the Metallurgical Laboratory. The name was a screen to disguise a key part of America's vast effort to beat Nazi Germany in the race to build an atomic bomb.An early hurdle in that race was to prove that a nuclear chain reaction could be turned on and off, something that had never been done.
That was the dangerous job of the 43 physicists who crowded into a freezing squash court beneath the stands of Stagg Field, where the first nuclear reactor had been built.
Considering the sophisticated science involved and the risk of conducting such an experiment in a city neighborhood, the materials that the scientists used in building "Chicago Pile No. 1" were laughable.
Spheres of a uranium compound were placed between layers of solid graphite bricks, which were held together by a wooden frame. The chief researcher, Italian refugee and Nobel Prize winner Enrico Fermi, relied upon a 6-inch slide rule.
Most incredible of all, three young physicists stood by at the top of the pile. In case the reaction started to run out of control, they were to pour a cadmium solution over the pile and hope for the best.
Throughout the day, a control rod was withdrawn from the reactor a few inches at a time. Shortly after 3:30 p.m., a measuring device finally traced a steep line on a piece of graph paper. "The pile has gone critical," Fermi said, signifying that the reaction had figuratively caught fire. With that laconic announcement, the Atomic Age was born.
From that beginning grew not only the atomic bombs that destroyed Hiroshima and Nagasaki but also peaceful uses of nuclear power, such as nuclear medicine and nuclear power. The early reactor work at the University of Chicago led to the establishment of the Argonne National Laboratory in a forest preserve southwest of the city. Fermi, who died of cancer in 1954, was commemorated in the 1960s when another national laboratory, Fermilab, was built in the Chicago area.
In 1995, Fermilab scientists announced they had discovered what is believed to be the last remaining piece of the subatomic jigsaw puzzle, the long-elusive "top" quark.