Partial Nuclear Test Ban Treaty

Edward Teller proposed a 10,000-megaton bomb in 1954. The physics allowed it — the delivery problem killed it.

Three credible sources, three different numbers — and the gap isn't new explosions. It's what each one decided to count.

From Sedan's 104-kiloton crater to a plan for 520 bombs in the Negev — how the atomic age tried to become civil engineering.

In 1962, the US detonated a 1.4-megaton warhead 400 km above the Pacific. The sky turned green for 90 minutes.

In 1961, the Soviets dropped the largest bomb ever built — a weapon with no military purpose, designed to be seen.