75 years after Trinity, the 1st atomic weapons test

The test on July 16, 1945, resulted from the Manhattan Project.

This is an Inside Science story.

The Manhattan Project's massive effort to build the first atomic bomb led to the Trinity test on July 16, 1945.

The project had consumed huge amounts of resources and, in building weapons of unprecedented potency, gave godlike power to flawed humans. It also inspired innovations and actions that continue to cascade through science and culture in ways both predictable and surprising.

In the decades that followed, scientists deployed the Manhattan Project's facilities to advance research across a wide range of disciplines, brought their messages directly to the public more often, saw the New Mexico desert location of the first bomb test become a tourist site -- and much, much more.

The power of the atom is undeniable and in many ways unfathomable. The stories, videos and graphics collected here commemorate the 75th anniversary of Trinity and present a snapshot of how deeply the influence of the Manhattan Project has permeated science and culture.

While we can't possibly capture the full extent of the project's history and legacy, in the timeline and stories below we present elements of it that we found inspiring, surprising, or illuminating. As Manhattan Project physicist Joan Hinton told historian and physicist Ruth Howes, when the sound of the explosion reached those she had gathered with, "We suddenly started talking out loud and felt exposed to the whole world."

  • 1942 -- The first large plutonium reactor at Hanford shut down shortly after researchers tried to fire it up. Physicist Chien-Shiung Wu, nicknamed "the queen of nuclear research," traced the problem to Xe-135.
  • July 16, 1945 -- The first atomic weapons test, codenamed Trinity, took place at 5:29 a.m., outside Socorro, New Mexico. The site was later designated a National Historic Landmark.
  • November 1945 -- The first issue of Bulletin of the Atomic Scientists was published. In the subsequent decades, the publication has addressed the potential for many types of human-made disasters.
  • September 1953 -- After much of the radioactivity had subsided, the first Trinity Site open house was held. The McDonald ranch house, where the core of the weapon was assembled, was restored in 1984 by the National Park Service.
  • 1954 -- The Atomic Fireball candy was invented by the Ferrara Pan Candy Company. This is just one way that atomic-themed concepts entered pop culture.
  • March 1959 -- The American Weekly published a feature by author Pearl S. Buck that recounts a discussion between Manhattan Project scientists J. Robert Oppenheimer and Arthur Compton about the possibility that an atomic bomb could ignite the atmosphere.
  • October 1961 -- Melvin Calvin was awarded the Nobel Prize in Chemistry "for his research on the carbon dioxide assimilation in plants." The work relied, in part, on radioactive carbon-14 produced in a Manhattan Project reactor.
  • 1996 -- The Comprehensive Test Ban Treaty, which aimed to ban all nuclear explosions, opened for signatures from nations.
  • Inside Science is an editorially independent nonprofit print, electronic and video journalism news service owned and operated by the American Institute of Physics.