The Bomb Called "Little Boy"
Through self-sustaining nuclear
fission (chain reaction), an atomic bomb emits a huge amount of
energy instantaneously.
The atomic bomb dropped on Hiroshima was a gun-barrel bomb. The uranium
was divided into two pieces, both less than a critical
mass and placed at either end of a cylinder. When one piece was
fired into the other, critical mass was achieved.
Though the bomb was long and thin in shape, it grew shorter over
the course of the project. Hence, the final bomb was called "Little
Boy."
●"Little Boy," the Atomic Bomb Dropped
on Hiroshima