Fat Man was the second bomb developed by the project. It was even more powerful than Little Boy. Detonated over Nagasaki, the bomb destroyed 44% of the Japanese city.
The Manhattan Project remains to this day a controversial subject. However, in 2015, the US Congress opened the Manhattan Project National Historical Park, made up of three units at Oak Ridge, Hanford, and Los Alamos.
Sources: (History) (History Hit)
"Development of Substitute Materials" was the original name given to the project. However, they realized early on that it would be evocative of its real purpose.
President Roosevelt took Einstein's warning seriously, and soon convened a research committee, named the Advisory Committee on Uranium. It was due to his letters that the work on the nuclear weapons started in the US.
The Gadget was a test version of the implosion system used in the Fat Man. This bomb was more robust than Little Boy and made from plutonium.
Little Boy was the code name for the bomb made of uranium–235. This was the type of bomb that exploded in Hiroshima, Japan, claiming 265,000 lives.
The project was named Manhattan because that's the home of Columbia University. This is where much of the theoretical research took place.
Albert Einstein sent letters to President Franklin D. Roosevelt making him aware of the possibility of nuclear chain reactions, which could lead to the atomic bombs. He also warned about how Germany might work on a nuclear bomb project.
But even with many employees, not more than a few dozen people knew the full extent of the Manhattan Project. Only about 1,000 of them were aware that it involved atoms.
Building plants and producing the fissionable materials took more than 90% of the total expenditure. Less than 10% was for the development and production of the weapons.
Because the workforce employed was so huge, a special intelligence corps was set up to handle the security issues. Just like screening tests, lie detection tests also became normal practice.
Although they were allies during the war, the US didn't trust the Soviets. However, it was revealed after the war that some of the top scientists, including George Koval and Klaus Fuchs (pictured), were spying for the Soviets.
There were strict warnings about disclosing the secrets of the project. Punishments included prison sentences of up to 10 years or a US$10,000 fine.
Set up in 1943, the Los Alamos Laboratory was the project’s most significant research center. It was led by American research director J. Robert Oppenheimer.
The first detonation of a nuclear weapon took place on July 16, 1945. Code named the Trinity Test, it took place in the Jornada del Muerto desert in New Mexico.
The Manhattan Project grew big, and employed more than 130,000 people. It cost almost US$22 billion in today's money.
The name was inspired by the poetry of John Donne, whom Oppenheimer was reading at the time. The 25-kiloton blast created a 40,000-ft (12-km) high mushroom cloud.
But while Einstein did warn the US about possible nuclear weapons, he was not actually part of the Manhattan Project. This is because he didn't get the security clearance required from the US Army Intelligence office. On top of that, they didn't allow scientists working on the project to consult with him.
And while Germany had been the first country to discover nuclear fission and begin research in 1939, the research lacked state support. This was due to the discrimination against Jews, which made many prominent scientists leave the country.
The project was top secret because the US was worried enemy nations would learn about nuclear technology and weapons.
To ensure the safety of employees at the lab sites, detectors were used to check the amount of radiation. Nose swabs were also required to detect the inhalation of plutonium dust.
"Tickling the dragon’s tail" was the experiment performed in which two scientists, Harry Daghlian and Louis Slotin, died because of acute radiation. Slotin is pictured wearing sunglasses, and Daghlian is seated in the back.
While the project had mostly male employees, there were still some female scientists involved, notably Leona Woods (pictured) and Maria Goeppert-Mayer. Also, hundreds of women were employed as secretaries and tasked with doing massive calculations by hand.
After the deaths, workers began referring to the plutonium mass as "the demon core." Manual manipulation became forbidden. The core was later used to create the bomb tested at Bikini Atoll.
The latter years of World War II were marked by an international race in search of a super weapon that would instantly destroy the opposing side. And while Germany produced a variety of weapons that were advanced technological innovations, the US cracked the secret of the atomic bomb through the Manhattan Project. The research project took place between 1942 and 1945, culminating in the only use of atomic weapons in warfare, which resulted in the defeat of Japan. The research was led by a number of leading scientists, many of them refugees from war-torn Europe, as well as the American military.
Want to discover more about the controversial project? Then read through this informative gallery.
Uncovering details of the Manhattan Project
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The latter years of World War II were marked by an international race in search of a super weapon that would instantly destroy the opposing side. And while Germany produced a variety of weapons that were advanced technological innovations, the US cracked the secret of the atomic bomb through the Manhattan Project. The research project took place between 1942 and 1945, culminating in the only use of atomic weapons in warfare, which resulted in the defeat of Japan. The research was led by a number of leading scientists, many of them refugees from war-torn Europe, as well as the American military.
Want to discover more about the controversial project? Then read through this informative gallery.