In 1942 scientists built the world’s 1st nuclear reactor under a college stadium!

15 May 2026 · 1 min

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In this narrated video, Dan Novaes recounts the 1942 Chicago Pile-1 experiment, the world’s first controlled nuclear chain reaction. Conducted in a squash court beneath the University of Chicago’s Stagg Field stadium, Enrico Fermi and his team assembled graphite blocks and uranium, manually stacking layers and gradually withdrawing control rods. As the reaction progressed, instruments recorded rising radiation and a faint blue Cherenkov glow, indicating particles moving faster than light in the medium. The reaction sustained itself for a few minutes before being shut down, proving that a man‑made, stable nuclear chain reaction was possible. Novaes emphasizes the experiment’s simplicity—no concrete dome or heavy shielding—and its profound impact, laying the groundwork for both civilian nuclear power and nuclear weapons.

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In 1942, scientists turned on a machine, and it began to glow blue. This was Chicago Pile-1, the world's first nuclear reactor, built under a stadium at the University of Chicago. No concrete dome, no heavy shielding, just graphite blocks, uranium, and a group of physicists led by Enrico Fermi. Their goal was simple: create a controlled nuclear chain reaction, something never done before. They stacked layers by hand, carefully measuring each step. Then they began, slowly removing control rods, letting the reaction grow. Instruments started to rise, radiation increased, energy built up. Then it happened. The reaction sustained itself. For the first time in history, a man-made nuclear chain reaction. Stable, controlled, and real. Witnesses described a faint blue glow, Cherenkov radiation, a sign that particles were moving faster than light in that medium. Not faster than light in space, but still something extraordinary. They had unlocked nuclear energy right there in a squash court. The experiment lasted only minutes, then they shut it down. But that moment changed everything. It proved nuclear power was possible, and it opened the door to both energy generation and nuclear weapons. All from a quiet experiment under a stadium where no one expected it.