Little Boy was an atomic weapon which was detonated over the Japanese city of Hiroshima on August Sixth, 1945, marking the first time a nuclear weapon was used in wartime. The bombing of Hiroshima was followed three days later by the bombing of Nagasaki, which led the Japanese to surrender, ending the conflict of the Second World War. The bombings of Hiroshima and Nagasaki have become extremely controversial in retrospect, as some people believe that they were unnecessary, while others believe that the bombings were justified.
Like Fat Man, the bomb dropped on Nagasaki, Little Boy was developed through the offices of the Manhattan Project, a top-secret project in the Second World War which was dedicated to finding the secret of the atom bomb before the Germans did. Little Boy was a uranium bomb, the first of its kind, and the detonation of Little Boy was the second man-made nuclear explosion in history.
The bomb was dropped from the Enola Gay, a B-29 Superfortress named after the pilot's mother. At 1,980 feet (580 meters), the bomb detonated, using a gun-type detonation system which basically shot a uranium rod onto a spike to trigger a nuclear reaction. Within seconds, a cloud of superheated gases had formed over the city, followed by an intense pressure wave.
Little Boy was actually somewhat weaker bomb than Fat Man, with an estimated force of around 15 kilotons of TNT, but it was far more devastating, thanks to the fact that Hiroshima was on a relatively flat plain, allowing the explosion to disperse widely. An estimated 66,000 people died as an immediate result of the explosion; many of them were so completely incinerated that the only signs of their presence were eerie shadows on buildings and roadways.
In the weeks and months following, many more victims of the bomb died as a result of injuries sustained in the explosion and subsequent fires. Survivors of the bomb also experienced a variety of health problems as a result of their exposure to the radiation caused by the bomb, with around 60,000 people dying as a result of the bomb in the decades following.
The use of nuclear weapons in wartime was unprecedented before Little Boy exploded over Hiroshima on that August morning, and almost immediately, it triggered a global discussion. As follow-up studies on the long-term effects of the bomb continued, many critics became much more outspoken, including critics drawn from the ranks of the scientists who built the bomb. Some people felt that such weapons were so devastating that they should never be used in wartime again, while others felt that nuclear weapons had a legitimate place in military arsenals.
Whether or not one agrees that the atom bomb should have been dropped on Hiroshima, it certainly radically changed the face of warfare. Research into nuclear weapons continues even today, and most modern nuclear bombs are far more powerful than Little Boy and Fat Man.