Fat Man

Definition

Fat Man was the codename for the type of nuclear weapon detonated over Nagasaki, Japan on August 9, 1945. It was the second and last atomic bomb used in warfare, following the bombing of Hiroshima three days earlier with the 'Little Boy' bomb. The Fat Man device was a plutonium implosion-type nuclear weapon, significantly more powerful than the uranium-based Little Boy.

5 Must Know Facts For Your Next Test

1. The Fat Man bomb weighed nearly 10,000 pounds and had a yield of approximately 21 kilotons of TNT, making it significantly more powerful than the Little Boy bomb used on Hiroshima.
2. The Fat Man device was detonated over the city of Nagasaki, killing an estimated 70,000 people instantly and causing widespread destruction.
3. The development of the Fat Man bomb was a key accomplishment of the Manhattan Project, the secret U.S. government program that produced the first nuclear weapons.
4. The Fat Man design was based on the plutonium implosion method, which used a spherical arrangement of chemical explosives to compress a plutonium core and initiate a nuclear chain reaction.
5. The decision to use the Fat Man bomb on Nagasaki came after the bombing of Hiroshima, as the U.S. sought to demonstrate the full destructive power of its nuclear arsenal and compel Japan's surrender.

Review Questions

• Explain the key technological differences between the Fat Man and Little Boy atomic bombs used in World War II.
  • The key technological difference between the Fat Man and Little Boy bombs was the method of detonation. The Fat Man was a plutonium implosion-type weapon, which used a spherical arrangement of chemical explosives to compress a plutonium core and initiate a nuclear chain reaction. In contrast, the Little Boy bomb used a uranium-based design that relied on a gun-type mechanism to bring two subcritical masses of uranium together. The Fat Man's plutonium implosion design allowed for a significantly more powerful explosive yield compared to the Little Boy bomb.
• Describe the role of the Manhattan Project in the development of the Fat Man bomb.
  • The Fat Man bomb was a product of the top-secret Manhattan Project, the U.S. government program established during World War II to research and develop the first nuclear weapons. The Manhattan Project brought together the world's leading scientists and engineers to tackle the technical challenges of creating a functional atomic bomb. The plutonium implosion design used in the Fat Man was a major scientific and engineering achievement that resulted from the collaborative efforts of the Manhattan Project team. The successful detonation of the Fat Man over Nagasaki in 1945 represented a critical milestone in the project's mission to produce a nuclear weapon capable of ending the war.
• Analyze the strategic and political implications of the United States' decision to use the Fat Man bomb against Japan.
  • The decision to use the Fat Man bomb against Nagasaki, following the bombing of Hiroshima with the Little Boy, was a strategic and political calculation by the U.S. government. Militarily, the Fat Man's significantly greater explosive yield compared to the Little Boy demonstrated the full destructive power of the U.S. nuclear arsenal, which the U.S. hoped would compel Japan's surrender and end the war. Politically, the use of the Fat Man bomb, along with the earlier Hiroshima bombing, solidified the United States' status as the world's first and only nuclear power at the time, giving it immense leverage in the emerging post-war global order. The devastating effects of the Fat Man bomb also ushered in the nuclear age, raising profound ethical and humanitarian questions about the use of such weapons of mass destruction.

Related terms

Atomic Bomb: A nuclear weapon that derives its explosive force from the rapid release of nuclear energy through the fission of heavy atomic nuclei, such as uranium or plutonium.

Plutonium Implosion: A method of detonating a nuclear weapon by using chemical explosives to compress a sphere of plutonium, increasing its density and triggering a nuclear chain reaction.

Manhattan Project:

The top-secret research and development program during World War II that produced the first nuclear weapons, including the Fat Man and Little Boy bombs.