Today in History—July 16: The Day the End of the World Began

At 5:29 am on this day in 1945, the first atomic bomb exploded in the New Mexican desert.

The test, conducted at the Alamogordo air base, was the culmination of the Manhattan Project, the classified American effort to build an atom bomb—before Nazi Germany could do the same.

The Manhattan Project is forever associated with J. Robert Oppenheimer and his fellow physicists working in isolation at Los Alamos, New Mexico. But an estimated 485,000 people—one in every 250 Americans—actually worked on the bomb over the course of the project, many without knowing what they were helping to build.

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Many of them worked on the construction of the facilities at Oak Ridge, Tennessee, where three different uranium enrichment plants were built, or at the Hanford Works in Benton county, Washington, where the plutonium was made that was used in the first atom bomb.

Test sites in California, Colorado, New Mexico, and Texas were considered. The final test site was chosen to be far enough from Los Alamos, so the explosion would not be connected with the goings-on at the laboratory there, but close enough that scientists and engineers could easily travel to the site.

Oppenheimer named the test of the first bomb “Trinity.” He later wrote, “Why I chose the name is not clear,” but that the poems of John Donne—with their themes of death and resurrection—were then on his mind. One of Donne’s best-known sonnets contains the famous line, “Batter my heart, three-person’d God.”

The Trinity test, with a bomb known as the “Gadget,” was conducted 100 feet in the air. The bomb exploded with the energy of between 15 and 20 thousand tons of TNT and exceeded the expectations of its builders. U.S. Pres. Harry S. Truman, who was meeting with Winston Churchill and Joseph Stalin at the Potsdam Conference, was immediately informed of the success.

Within weeks, atomic bombs were dropped on the Japanese cities of Hiroshima and Nagasaki, killing tens of thousands.

The atomic age had begun. The world would never be the same.

Famous Birthdays

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Ida B. Wells-Barnett

1911: Ginger Rogers—American actress and dancer