The Creation of the Atomic Bomb

FROM THE LECTURE SERIES: Turning Points in Modern History

By Vejas Liulevicius, Ph.D., University of Tennessee

A number of advances in mankind’s knowledge about the power of the atom started to cascade in the 1930s, at a time when international peril was over the entire world. Over the decades, the atomic bomb was perfected and finally used in war.

A simple diagram showing nuclear fission of Uranium 235.
Fermi’s successful creation of a self-sustaining nuclear fission reaction in 1942 set the stage for atomic energy, which went on to become a massive research area later. (Image: Grasko/Shutterstock)

The political situation of the entire world seemed rife with dictatorships at the time when the atomic bomb was at the center-stage of science and technology. 

The Abundance of Dictatorships

During the 1930s, Hitler’s power was on the rise in Nazi Germany, Fascist Italy was ruled over by Benito Mussolini, and Stalin presided over the Soviet Union. More than a hundred noted scientists emigrated to Britain or the United States from Germany and Italy in this decade alone. This brain drain would prove decisive to the way history turned out to be the way it did: Albert Einstein from Germany, Enrico Fermi from Italy, and Leo Szilard, Eugene Wigner, and Edward Teller from Hungary, all emigrated to the United States in this decade.

Around the end of this decade, however, Hitler’s Germany seemed to have the clear lead in the world of physics. 

Learn more about the Scientific Revolution.

Experiments in Nuclear Fission

In 1938, German physicists split the atom while conducting experiments in nuclear fission. News of this advance came as a scare to refugee scientists. Leo Szilard, on hearing the news of what the Germans had suddenly accomplished, felt that H.G. Wells’ prediction of the atomic bomb was becoming a reality, and the power released from nuclear fission could really be used to produce bombs.

The brilliant Italian scientist, Enrico Fermi, shared these concerns. 

Fermi had come to the United States to teach at Columbia in 1939, shortly after winning his Nobel Prize, disgusted by the anti-semitic practices in Fascist Italy, especially since his wife was Jewish.

He tried to warn officials in Washington of these advances, but no heed was paid to him. Later, Szilard, Teller, and Wigner sent a special letter to President Roosevelt through Albert Einstein, who, already a famous scientist, signed that he would not build the bomb. 

In reality, however, it was this letter, dated August 2, 1939, that really launched the building of the bomb. It warned that “extremely powerful bombs of a new type” might be constructed as a result of the newest research. This letter showed American officials the urgency of this situation—What if someone else built a bomb before them?

The United States approved its first research project in 1940, with a budget of $6,000. 

The United States Jumps on the Atomic Train

In 1941, Roosevelt founded the Office of Scientific Research and Development to mobilize science for total war. 

This mobilization resulted in the so-called Manhattan Project, which got its codename from the early work done at Columbia University in Manhattan. It was General Leslie Groves who was put in charge of the project by Robert Oppenheimer for the research effort.

The project ended up costing over two billion dollars, the largest national undertaking before the space missions. It gathered an ever-expanding group of scientists and engineers, who would often work only knowing their part of the larger project. Some indeed only found out what they’d been working on when they heard about the bombing of Hiroshima on the radio.

Learn more about the Manhattan Project.

Problems With the Manhattan Project

A lot of culture clashes arose between the military and the scientists. General Groves briefed his staff as such: “Your job won’t be easy. At great expense, we have gathered the largest collection of crackpots ever seen.” He was referring to the collection of scientists gathered for this task. 

Lt. Gen. Leslie Groves Jr., who led the Manhattan Project for the creation of the atomic bomb.
Lt. Gen. Leslie Groves was in charge of the Manhattan Project, and he had a hard time getting his troops to work together with the scientists on the project. (Image: Department of Energy/Public domain)

This had become an international venture, in collaboration with Britain and Canada. Many of the scientists, in fact, were descendants from Europe. 

A popular joke at the time was that whenever Enrico Fermi, the Italian, left the room, the other physicists breathed a sigh of relief and lapsed back into their common native language, Hungarian.

The moral implications of creating a weapon of mass destruction weighed on the team from the beginning. Most agreed that the Nazis should not be allowed to build the first bomb and that the United States having a bomb too may serve as a deterrent for Nazi Germany using their weapons.

This is a transcript from the video series Turning Points in Modern History. Watch it now, on The Great Courses Plus.

The Race for Mass Destruction

The race for the atomic bomb continued at breakneck speed, and while penicillin was mass-produced as a healing invention, research continued for the creation of this superweapon.

The race took off with the creation and control of a chain reaction, as was done in December 1942 in Chicago. This first nuclear reactor was codenamed CP1 for ‘Chicago Pile #1’. This pile, of almost 400 tons of graphite bricks, uranium, and control rods, was assembled secretly, literally shrouded from view by a grey balloon stretched around the project. The balloon was provided by Goodyear, who did not know what it was for.

In December, the project was finally ready to take off. There was a lot of tension, and no one could be sure that the reaction would not run out of control, ensuing in an explosion in one of the largest cities of the world. The procedure was not equipped with any shield or cooling system. Instead, a technician with an ax stood ready to cut a rope that would insert one more control rod. In addition, workers stood by with buckets of cadmium and salt to throw onto the pile if it went out of control, as a last resort. 

The bottle of Chianti purchased by Wigner to celebrate Fermi's team's success, which the team later signed.
There was great concern regarding the reactor, but Fermi’s team managed to create a self-sustaining reaction, a huge feat that they then celebrated with a bottle of Chianti. (Image: ENERGY.GOV/Public domain)

Once Fermi started the process, the pile began to operate, building to criticality over the hours. Then, amidst the tension of this historic moment, Fermi called for a lunch break. But then the experiment resumed, and by 3:25 p.m., Fermi and his team had been successful. They celebrated with a bottle of Chianti, which was later signed by members of the team.

It was Dean Arthur Compton, of the University of Chicago, who had to report the victory to their military superiors. But since no code had been arranged in advance, Compton was forced to improvise on the phone, and his words were: “The Italian navigator has landed in the New World.” 

His words were a telling link to history, to the encounter of Columbus with the Americas.

Learn more about Columbus’s interaction with the Americas.

Common Questions About the Creation of the Atomic Bomb

Q: What was the political scenario of the world at the time when the atomic bomb was being created?

The political scenario of the world had a large part to play in the events that led to the creation of the atomic bomb. During the 1930s, Hitler’s power was on the rise in Nazi Germany, Fascist Italy was ruled over by Benito Mussolini, and Stalin presided over the Soviet Union. As a result, many scientists emigrated to Britain or the United States from Germany and Italy in this decade and played significant roles in the creation of the atomic bomb. Albert Einstein from Germany and Enrico Fermi from Italy were just two of the noted scientists who emigrated to the United States.

Q: Why were scientists appalled at the progress of nuclear fission in the 1930s?

In 1938, German physicists were able to split the atom while conducting experiments in nuclear fission. This sudden advancement scared scientists, who suddenly saw H.G. Well’s scary prediction of an atomic bomb becoming a reality. Scientists like Fermi tried to warn officials in Washington of this development, but no heed was paid to them. Later, Szilard, Teller, and Wigner, in a letter sent to Roosevelt via Albert Einstein, declared their reluctance to build a bomb.

Q: What was the Manhattan Project?

In 1941, Roosevelt decided to mobilize science for war efforts and founded the Office of Scientific Research and Development. This led to the Manhattan Project, which got its codename from the early work done at Columbia University in Manhattan. Here, General Leslie Groves led the effort to create the atomic bomb, working with a team of military and science personnel.

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