The Manhattan Project: A Secret Research and Engineering Project in the Second World War

During the second world war, the United States government carried out a top-secret research and engineering project known as the Manhattan Project. This project was responsible for the development of the world's first nuclear weapons. After receiving a letter from Albert Einstein, winner of the Nobel Prize in Physics, in October of 1939, President Franklin D. Roosevelt established a committee under his administration with the mission of investigating the feasibility of creating a nuclear weapon. In the letter that he sent to the president, Albert Einstein expressed his concern that Nazi Germany was most likely already working on the development of a nuclear weapon.

The Beginning of the Manhattan Project: The Race to Develop the Atomic Bomb

At the beginning of 1939, members of the international scientific community learned that German physicists had mastered the techniques necessary to split an atom of uranium. Concerns quickly arose regarding the likelihood that Nazi scientists will make use of that energy in order to develop a bomb that is capable of unimaginable devastation.

Scientists Albert Einstein and Enrico Fermi, who both escaped persecution at the hands of the Nazis and Fascist Italy, respectively, were now residing in the United States. They were all in agreement that the President needed to be made aware of the threats posed by the Axis powers having access to nuclear technology. In March, Fermi made the trip to Washington, DC, to voice his concerns to various government officials there. But only a select few shared his unease.

Later on in that year, Albert Einstein penned a letter to President Franklin D. Roosevelt in which he strongly recommended that an atomic research program be established. Roosevelt did not believe that such a project was necessary or useful, but he did agree that it should be carried out gradually. Late in the year 1941, the endeavor by the United States of America to design and construct an atomic bomb was given a code name: the Manhattan Project.

Trinity: The First Nuclear Explosion

An experiment with the implosion bomb, which had been given the code name Trinity by Oppenheimer in reference to a poem written by John Donne, was carried out on July 16, 1945. The device went off at 5:29 in the morning, releasing an amount of energy that was roughly equivalent to 20 kilotons of TNT. Trinitite is the name given to the mildly radioactive light green glass that was created when silica-rich desert sand melted and transformed into a new substance. It carved out a hole in the desert that was five feet deep and thirty feet wide. At the time of the explosion, the surrounding mountains were illuminated "brighter than daytime" for one to two seconds, and the heat was reported as "being as hot as an oven" at the base camp.

Leadership and Vision: Key Factors in the Success of the Manhattan Project

The Manhattan Project was helped tremendously by the presence of an unusually high number of exceptionally bright, experienced, and capable leaders. Their tremendous energy and fearless spirit allowed the project to move forward in spite of the overwhelming likelihood that it would fail. A few of these outstanding leaders were General Leslie Groves of the Army Corps of Engineers, physicists J. Robert Oppenheimer and Enrico Fermi, DuPont's Crawford Greenewalt and Kellogg's Percival Keith, MIT's Vannevar Bush, Harvard's James B. Conant, and Berkeley's Ernest O. Lawrence. Other leaders included Crawford Greenewalt of DuPont and Percival Keith of Kellogg.

Separating Uranium Isotopes: The Challenges of the Manhattan Project

Uranium-235, which is the essential fissionable component of the hypothetical bomb, cannot be separated from its natural companion, which is the significantly more abundant uranium-238. Instead, the atoms of these two uranium isotopes must be physically separated from each other in order to accomplish this task. The electromagnetic process, which was developed at the University of California, Berkeley, under the direction of Ernest Orlando Lawrence. Both of these processes, but especially the diffusion method, required enormous, complicated facilities as well as enormous amounts of electric power in order to produce even minute amounts of uranium-235 that had been separated from the rest of the uranium.

The Manhattan Project: Developing the Fat Man and Little Boy Atomic Bombs

The Fat Man and Little Boy atomic bombs were both products of the Manhattan Project, which was responsible for their development. The more complicated of the two was Fat Man, which was the bomb that was dropped on Nagasaki. A bulbous bomb measuring 10 feet in height and containing a sphere made of the metal plutonium 239, it was surrounded by blocks of high explosives that were intended to produce an implosion that was extremely precise and symmetrical. The scientists working on the plutonium bomb design at Los Alamos decided to schedule the Trinity test because they did not have complete faith in the design.

Hiroshima: The First Atomic Bomb Attack in History

The first atomic bomb ever used as a weapon of war was detonated at 8:15 in the morning of August 6, 1945, in the city of Hiroshima, which was located in Japan. The city was completely destroyed. The bomb, which was codenamed "Little Boy," was released from the B29 bomber "Enola Gay" of the United States Army Air Force and detonated approximately 1,800 feet above the city. The bomb, which detonated with the force of approximately 12.5 kilotons of TNT, reduced an area of the city center equal in size to 5 square miles to ashes and was responsible for the deaths of an estimated 120,000 people in the first four days after the explosion.

The Second Atomic Bomb Attack: Nagasaki

The explosion caused many people to be instantly vaporized, and others died later as a result of the burns and radiation that they received. Three days later, on the morning of August 9th, a second aircraft belonging to the United States took off from the airbase located on the island of Tinian, which is located in the Pacific Ocean. "Fat Man" was the codename given to the nuclear bomb that it carried. During the Trinity test, a more sophisticated type of bomb based on plutonium and designed to implode had been put through its paces.

The city of Kokura was the primary objective of the attack. However, because of a thick layer of clouds, the crew of the airplane decided to change their target to Nagasaki, which was the secondary objective. The yield of the bomb was approximately 21 kilotons, and it exploded at an altitude of approximately 500 meters. The Radiation Effects Research Foundation has estimated that the number of immediate deaths could range anywhere from 60,000 to 80,000 people.

Aftermath of the Atomic Bombings: The Atomic Bomb Casualty Commission's Studies on Hiroshima and Nagasaki

In the weeks that followed the bombings and the surrender of Japan, Hiroshima and Nagasaki became the focus of in-depth research carried out by scientists from the United States. The Atomic Bomb Casualty Commission was established so that research can be conducted into how victims were affected by radioactive contamination. Its findings, including the substantial amount of film and photo material taken at the time, were kept secret for decades after it was completed.