TIME

The Atomic Age

Black-and-white photograph of the Trinity test fireball six milliseconds after detonation, a bright dome above the desert floor, with a 100 metre scale bar.

Recorded HistoryThe Atomic Age

At 5:29 a.m. on 16 July 1945, a plutonium implosion device nicknamed the Gadget was detonated from a 100-foot tower at the Trinity site in the New Mexico desert, near Alamogordo. The Manhattan Project’s test released energy equal to about 21 kilotons of TNT, with published estimates ranging from 15 to 22.

Trinity was the first nuclear detonation, not the first use of the weapon in war. A uranium bomb was dropped on Hiroshima on 6 August 1945, and a plutonium bomb, of the same design as the Gadget, on Nagasaki three days later. The archive dates the Atomic Age to the test because it was the first time humans released nuclear energy at that scale. The bombings killed well over a hundred thousand people, and the weapons shaped the Cold War.

16 July 1945, placed on the scale of its era on a line leading toward now.

Era
Recorded History
Period
16 July 1945
Edition
1/1
Status
Reserved for a Future Release
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Background artwork

The Trinity test fireball at 6 milliseconds, 16 July 1945, Alamogordo, New Mexico. U.S. Department of Energy photograph, public domain. Trinity was the first nuclear detonation, not the bombing of Hiroshima or Nagasaki.