The first nuclear bomb was known as the “Trinity” bomb and was detonated on July 16, 1945, as part of the Manhattan Project, a top-secret research program to develop atomic weapons during World War II. The bomb was designed and built by a team of scientists led by physicist J. Robert Oppenheimer.
The Trinity bomb was a plutonium implosion-type bomb, which means it relied on the compression of a subcritical mass of plutonium by conventional explosives to achieve a critical mass and initiate a nuclear chain reaction. The bomb was about 13 feet (4 meters) long and weighed around 4.5 tons.
The Trinity bomb was detonated at a test site in Alamogordo, New Mexico, in the United States. The test was successful and produced an explosion with a yield of around 20 kilotons of TNT. The explosion generated a bright flash, a powerful shockwave, and a mushroom cloud that reached heights of over 40,000 feet (12,000 meters).
The Trinity test was a critical step in the development of nuclear weapons and marked the first time that a nuclear chain reaction had been achieved in a weapon. The success of the test led to the development of more advanced nuclear weapons, including the bombs that were later dropped on the Japanese cities of Hiroshima and Nagasaki in August of 1945, which resulted in the deaths of around 200,000 people.