The Dropping of the Atomic Bomb:
Hiroshima (August 6, 1945) and Nagasaki (August 9, 1945)
In late May 1945, a committee of military officers and Manhattan Project scientists chose Kokura Arsenal, Hiroshima, Niigata and Kyoto as potential targets for the atomic bombs. They believed that attacks on these cities, none of which had been bombed before, would have a profound psychological effect on the Japanese. Kyoto was later removed from the list because of its cultural and historical significance, and Nagasaki was added in its place.
With the capture of Iwo Jima and Okinawa, the distance from US troops and Japan closed greatly. Thousands of lives were lost in the occupation of Iwo Jima and Okinawa. President Truman feared that an invasion on Japan would cost thousands more lives. This fear sparked the decision to drop the Atomic Bomb. The first bomb was dropped on Hiroshima. Hiroshima was hit first because it held no American POW's and was an important communications center for the Japanese military. The B-29 Superfortress dubbed "Enola Gay" after the pilot's mother, was the first plane to drop the Atomic bomb. Pilot Col. Paul Tibbets brought the plane up to an altitude of 31,000 feet then released "Little Boy". The Enola Gaybanked sharply and accelerated, getting 11.5 miles away from the site before the bomb exploded. The B-29 'Enola Gay' Returns
The 'Enola Gay' lands safely after delivering its earth shattering paylod.

"There was the mushroom growing up, and we watched it blossom. And down below it, the thing reminded me more of a boiling pot of tar than any other description I can give it. It was black and boiling underneath with a steam haze on top of it. And, of course, we had seen the city when we went in, and there was nothing to see when we came back. It was covered by this boiling, black-looking mess."--Col. Paul Tibbets.

Mushroom Cloud over Hiroshima
Hiroshima after the blast.
Hiroshima after the dropping of the atomic bomb. 		The immediate vacinity around the bomb was vaporized. Everything within a 4.4 square mile area around the detonation was burned. Out of the 300,000 inhabitants of Hiroshima over 100,000 people were killed, with about 70,000 or more wounded. The Japanese refused to surrender. A second Atomic bomb was dropped on the city of Nagasaki, by Major Charles Sweeney in his B-29 "Bockscar". However Nagasaki was no the intended target, Sweeney was meant to take out the Kokura Arsenal.  First a fuel pump went out, and then Kokura was obscured by clouds, thus Sweeney moved to the secondary target.  Nagasaki was home to Mitsubishi Stell and Arms Works.  It too, was covered in clouds, but then for one moment the clouds opened up and "Fat Man" could be dropped. 40,000 people were killed and around 40,000 injured from the blast.



Japan Finally Surrenders
(September 2, 1945)

Although the surrender was an unconditional one signed on the United States battleship Missouri there was still conflict in Japan as to if they should surrender. After the bomb on Hiroshima, President Truman of America, warned that another such bomb would be dropped if Japan did not surrender within 24 hours. The Japanese Council of six was split three to three as to surrender or continue the war effort.  After the second bomb things change and the war council was replaced by a new Cabinet, which went to the Emperor and persuaded him to call an imperial conference. At this conference the Emperor emotionally gave his opinion that Japan should surrender to the United States.  Thus on September 2, 1945 to Japanese officials in full formal wear and top hats strode on to the deck of the battle ship Missouri and signed the unconditional surrender.  The Allied powers were represented by General Douglas MacArthur, who said, "when everywhere can walk upright in the sunlight.", referring to the new era of peace. Afterwards MacArthur would personally take control of Japan and rebuild it with American backing.

The Development of the Bombs

When the idea of these bombs were first being developed it was planned that each atomic bomb would be the equivalent of 2,000 B-29's with there maximum load of 10,000 pounds of bombs.  The first atomic bomb tested at Trinity on July 16, 1945 proved that the U.S. was in possession of the most destructive weapon ever devised by man. The bomb was powered by the splitting of all the nuclei in several kilograms of plutonium. A sphere of plutonium the size of a baseball produced an explosion equal to 15,000 to 20,000 tons of TNT. When the bomb exploded at Trinity at 5:30 a.m., it vaporized the tower and turned asphalt around the base of the tower to green sand. Suddenly the sky was brighter than several suns. Seconds after the explosion came a huge blast that sent withering heat across the desert.
A massive orange and yellow cloud in the shape of a mushroom surged and billowed upward reaching into the sub-stratosphere up to an elevation of 41,000 feet. A soldier 10,000 feet away was knocked off his feet by the force of the shock wave. The flash of light was seen more than ten miles away, and a soldier five miles away was temporarily blinded. The explosion was heard 50 miles away.

Uranium Bomb: Little Boy

    The uranium bomb detonated over Hiroshima was a fairly simple design, as far as nuclear weapons are concerned.  It was also relatively low yeild for a nuclear device.  It was designed with two pieces of uranium, one in the shape of a large cup, the second a cylindrical slug, when the two pieces were brought together they would reach critical mass and create a chain reaction.  The cylidrical slug would be fired into the 'cup' through a gun barrel and yield 20,000 tons of dynamite worth of explosives.  The scientists which built Little Boy were so confident it would work they did not even test the method prior to Hiroshima.
 

Plutonium Bomb: Fat Man

    This type of bomb could potentially yield more explosive power with less material, the only problem was that the 'gun' method used in Uranium would cause plutonium to detonate prematurely.  Thus an implosion trigger was created.   What this did, was take a ball of plutonium, not quite to critical mass, then surround it with synchronous explosives that would cause the ball to implode and reach critical mass.