Trinity Test at 80: American Nuclear Society CEO Craig Piercy reflects on the Manhattan Project

July 16, 2025, 7:02AMANS NewsCraig Piercy

By Craig H. Piercy, CEO and Executive Director of the American Nuclear Society

Eighty years ago today, at exactly 5:29:45 a.m. local time* on July 16, 1945, the United States Army detonated the world’s first nuclear bomb in the Jornada del Muerto desert of southern New Mexico. The searing flash and thunderous shockwave marked the culmination of the Manhattan Project, a secret, three-year national effort to harness nuclear fission and hasten the end of the Second World War.

The Trinity Test, overseen by Manhattan Project director Major General Leslie Groves and Los Alamos Laboratory director Dr. J. Robert Oppenheimer, was the final act of that race to build the atomic bomb. Hoisted atop a 100-foot steel tower, the plutonium implosion device, known as the Gadget, unleashed a blast equal to 21,000 tons of TNT and temperatures hotter than the center of the sun.

From ten miles away, observers wearing darkened welder goggles looked on in stunned silence. “We knew the world would not be the same,” recalled Oppenheimer.

CP-1 at 80: The legacy of CP-1—and the scientist who created its neutron activity detector

December 8, 2022, 3:00PMNuclear News
A replica of the chianti bottle signed by many of those present on December 2, 1942, alongside the image of a document signed 20 years later by most of those present (Photo: ANL); a portion of a photo of CP-1 scientists taken on December 2, 1946 (Photo: ANL); January 1993 Nuclear News coverage of CP-1 50th anniversary commemorations during the 1992 ANS Winter Meeting.

Nuclear Newswire is back with the final #ThrowbackThursday post honoring the 80th anniversary of Chicago Pile-1 with offerings from past issues of Nuclear News. On November 17, we took a look at the lead-up to the first controlled nuclear chain reaction and on December 1, the events of December 2, 1942, the day a self-sustaining nuclear fission reaction was created and controlled inside a pile of graphite and uranium assembled on a squash court at the University of Chicago’s Stagg Field.