The Manhattan Project: Race to the Atomic Bomb · 2 Aug 2026 · 13 min

Chain Reaction: The Day Nuclear Fire Was First Unleashed

On December 2, 1942, Enrico Fermi triggered the world's first controlled nuclear chain reaction beneath a Chicago squash court — and the atomic bomb became inevitable. This episode follows the fear, secrecy, and physics that drove the Manhattan Project from Einstein's letter to the moment the chain reaction wouldn't stop.

The Manhattan Project: Race to the Atomic Bomb
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Chain Reaction: The Day Nuclear Fire Was First Unleashed

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What's covered

The Question Nobody Could Answer

Here's what they didn't know on the morning of December second, nineteen forty-two. They didn't know if it would work.

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How Fear Built the Bomb

To understand December second, you have to go back three years. To a letter.

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Building the Invisible City

By nineteen forty-two, the project had a name, a budget, and a general. General Leslie Groves was not a scientist.

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Fermi's Moment

But before Los Alamos could build a bomb, someone had to prove the underlying physics actually worked at scale. That was Fermi's job.

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The Plutonium Problem

Proving a chain reaction was one thing. Building a weapon was something else entirely.

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Trinity

By July of nineteen forty-five, the implosion device was ready to test. Oppenheimer named it the Gadget.

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Hiroshima, Nagasaki, and What Came After

Three weeks later, on August sixth, nineteen forty-five, the uranium bomb known as Little Boy was dropped on Hiroshima. Approximately one hundred thousand people died.

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