What do you know about the Manhattan Project?

In the early morning hours of August 6, 1945, the United States of America detonated a nuclear weapon over the Japanese city of Hiroshima. The explosion destroyed nearly the entire city, killing an estimated 70,000 people instantly, and injuring tens of thousands more. Three days later, on August 9, the U.S. conducted a second nuclear strike, this time on the city of Nagasaki. The death toll from that attack is estimated to have been between 40,000 and 80,000 people.

In the years since the United States’ decision to use nuclear weapons against Japan, the legacy of the Manhattan Project – the scientific and engineering undertaking that produced the world’s first atomic bombs – has been intensely debated. Was the use of nuclear weapons against Japan justified? Could the United States have avoided using them? What lessons should be learned from the experience of the Manhattan Project?

The use of nuclear weapons against Japan remains one of the most controversial decisions in American history. In the years since 1945, historians and other scholars have engaged in intense debate over whether the use of nuclear weapons was justified. Some argue that the use of nuclear weapons was necessary to save lives and bring about a swift end to the war. Others contend that the use of nuclear weapons was morally wrong and that America could have avoided using them if it had been willing to make certain concessions to the Japanese government.

The Manhattan Project was a massive undertaking involving tens of thousands of people and costing billions of dollars. It was also a top-secret operation, with few people outside those directly involved even aware of its existence. In the months and years leading up to the use of nuclear weapons, the project’s scientists and engineers worked feverishly to design and build the world’s first atomic bombs.

The Manhattan Project was born out of a genuine fear that Nazi Germany was developing its own nuclear weapons and might use them against the United States or its allies. In 1939, Albert Einstein wrote to President Franklin Roosevelt warning that Germany might be close to developing an atomic bomb and urged the United States to begin its own research into nuclear weapons.

In this now-famous letter to President Roosevelt warning of the potential development of "extremely powerful bombs of a new type." Roosevelt responded by creating the Advisory Committee on Uranium, which began funding research into what would become the Manhattan Project-the effort to create the world's first atomic weapon.

The goal of the project was to develop a nuclear weapon before Germany could.

The Manhattan Project would ultimately end up involving over 100,000 people, including some of the world’s most renowned scientists, such as Enrico Fermi, Robert Oppenheimer, Edward Teller, and Leo Szilard. The project was headquartered at a secret location in Los Alamos, New Mexico, and involved research facilities in a number of other states, including Tennessee, Washington, and Illinois.

Over the course of several years, the scientists and engineers working on the Manhattan Project made incredible progress in designing and building atomic bombs. In July 1945, after successful test detonations at sites in New Mexico and in the Pacific Ocean, U.S. officials decided to move forward with using nuclear weapons against Japan.

The decision to use nuclear weapons against Japan, as written before, was not an easy one. In early August 1945, President Harry Truman – who had taken office less than five months earlier after Roosevelt’s death – met with his advisors to discuss the potential use of nuclear weapons. Truman was told by some of his advisors that using nuclear weapons might be necessary to prevent a lengthy and costly invasion of Japan. He was also told that if nuclear weapons were not used, it was estimated that hundreds of thousands – possibly even millions – of American soldiers would be killed in an invasion.

After much deliberation, Truman decided to authorize the use of nuclear weapons against Japan. On August 6, 1945, the United States dropped a nuclear bomb on the city of Hiroshima. Three days later, another bomb was dropped on Nagasaki. On August 15, 1945, Japan announced its surrender, effectively ending World War II.

Though it is impossible to know exactly how many people died as a result of the atomic bombs dropped on Japan, it is estimated that at least 129,000 people were killed outright in Hiroshima and 74,000 in Nagasaki. Tens of thousands more died in ensuing years from injuries and radiation exposure. The devastation wrought by the bombs led to calls for international control of nuclear weapons and an end to their use. These efforts eventually led to the creation of the Nuclear Non-Proliferation Treaty in 1968.

While the Manhattan Project is most commonly associated with the creation of atomic weapons, it also played a significant role in developing nuclear power for peaceful purposes. The first nuclear reactor was built at Oak Ridge, Tennessee as part of the Manhattan Project, and reactors built as part of the project went on to power both submarines and aircraft carriers. After the war, many scientists involved in the Manhattan Project continued their work on nuclear energy at U.S. Department of Energy labs like Argonne National Laboratory near Chicago.

HERE A SHORT VIDEO ABOUT THE MANHATTAN PROJECT: