Because of their shapes. Fat Man used plutonium. A sphere of plutonium was surrounded by conventional explosives which were designed to send the force of their explosion inward to crush the sphere into a smaller shape (thus higher density) in order to trigger the nuclear reaction. Thus the bomb had a very rounded shape to it, suggestive of a fat man. In contrast the other bomb, which used uranium, had the nuclear reaction triggered by firing a small slug of uraniun down a track into a larger mass of the same element. Thus that bomb looked long and slender by comparison and so picked up the moniker Little Boy in contrast. Michael Montagne
It was a terrible act, but understand that the citizens of Japan were ready to stand on the beaches with swords, pitchforks and any available weapons, allowing thousands more Allied troop casualties on order to protect their emperor (The Japanese people viewed the emperor as a god and would worship him and fight to the death for him). The two bombs ended the war and resulted in the unconditional surrender of Japanese forces.
Remember that the United States Government sent out letters to the Japanese civilians at Hiroshima and Nagasaki warning of a possible atomic threat but the Japanese government intercepted these and did not hand them out to the civilians.
They needed code names for them.
To end the war.
Little Boy was employed at Hiroshima and Fat Man at Nagasaki.
"Little Boy" was dropped on Hiroshima and "Fat Man" was dropped on Nagasaki .
'Little Boy' was dropped upon Hiroshima whereas 'Fat Man' was dropped upon the Japanese city of Nagasaki .
Fat Man and Little Boy
The atomic bomb that was dropped on Hiroshima was named "Little Boy." The atomic bomb that was dropped on Nagasaki was named "Fat Man."
Little Boy was dropped on Hiroshima Fat Man was dropped on Nagasaki
Little Boy was employed at Hiroshima and Fat Man at Nagasaki.
"Little Boy" was dropped on Hiroshima and "Fat Man" was dropped on Nagasaki .
Fat man and little boy.
The planes were both B29 Superfortress'; the Enola Gay (Hiroshima) and Bock's Car (Nagasaki).
Little boy was dropped over Hiroshima and fat boy was dropped over Nagasaki.
'Little Boy' was dropped upon Hiroshima whereas 'Fat Man' was dropped upon the Japanese city of Nagasaki .
They were called Little Boy and Fat man. (see related question link below)
'Little Boy' (Hiroshima) 'Fat Man' (Nagasaki)
Hiroshima and Nagasaki Japan.
Fat Man and Little Boy
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