Manhattan Project

How did one of the most devastating scientific accomplishments of the twentieth century come to be? With the rise of the National Socialist German Worker's Party in Germany in 1920, concern grew over the country's capabilities. When two German scientists successfully split an atom in 1938, British scientists encouraged America to begin researching atomic energy. Continue reading to see how the Manhattan Project impacted the world.

Manhattan Project Definition

The Manhattan Project is an American research project that began in 1942 that ultimately produced the atomic bomb. The project started with the intent of combatting German attempts to develop a nuclear bomb. With the rise of the Nazi party in Germany, concerns grew over atomic power in Adolf Hitler's hands. In 1942, America's Office of Scientific Research and Development (OSRD) joined with the Army Corps of Engineers and officially began the Manhattan Project.

Scientists began researching how to separate uranium and produce plutonium. In 1945 in New Mexico, the first test successfully produced a giant nuclear explosion.

Manhattan Project Location

Concern over German nuclear capabilities grew in 1938 when two German scientists successfully split an atom. President Franklin Roosevelt established an advisory committee in 1939, but with the urging of British scientists, Roosevelt implemented an atomic weapons program. US Army General Leslie R. Groves led the Manhattan Project and chose three different locations for its undertaking. Oak Ridge, Tennessee, Los Alamos, New Mexico, and Hanford, Washington were selected based on the project's specific requirements.

Fig. 1 Manhattan Project US Map

Los Alamos, New Mexico

The most remote community was Los Alamos, New Mexico. The town was simply called "Site Y" or "The Hill." The town was in the mountains of New Mexico, which gave the lab a natural barrier. Scientists J. Robert Oppenheimer would come to lead the new lab and would spend several months developing the perfect team. The research lab at Los Alamos was organized into four distinct categories: theoretical, experimental physics, chemistry and metallurgy, and ordnance.

Manhattan Project History

The images below shows the first nuclear test explosion.

Fig. 2 The first nuclear test explosion

The Beginnings of the project

In 1938 German scientists Fritz Strassmann and Otto Hahn successfully split an atom, spreading fear throughout other countries. At the urging of others, President Roosevelt established a committee in 1938, but research remained slow for the first years. However, in 1941 British scientists reported the making of an atomic bomb to be viable. The program hit several delays initially and eventually had to turn to the Army.

Fig. 3 Westinghouse Atom Smasher

Early Research

Atomic research was ongoing in various American universities before World War II. For example, researchers at the University of California at Berkeley made numerous important discoveries. Ernest Lawrence founded the "atom smasher" capable of creating atomic collisions upwards of 25,000 miles per second. At Columbia University, scientists experimented with a chain reaction that proved to be sustainable in 1942.

The Manhattan Project

The official creation of the Manhattan Project occurred on August 13, 1942. The project's first office was established in Manhattan, giving it its name. Though the project was in three separate locations, most research, and construction were completed in Los Alamos, New Mexico. Scientist J. Robert Oppenheimer directed the research and development of the bomb, while the Army was tasked with guarding the highly confidential work.

Manhattan Project WW2

In May 1945, Germany was defeated by the Allies, but the war with Japan continued. In July of the same year, the Potsdam Conference was held in Germany, in which America warned Japan to surrender or face an alternative outcome.

Fig. 4 Clemente Attlee, Harry S. Truman, and Joseph Stalin at the Potsdam Conference in 1945

The terms of the Potsdam Conference did not include the emperor in Japan's future. Therefore, Japan was unwilling to accept America's terms.

Manhattan Project Atomic Bomb

As tensions rose between the US and Japan, an invasion seemed unavoidable. However, advisors warned President Truman that an attack would cost hundreds of thousands of American soldiers their lives. With no response from Japan, President Truman authorized the use of the atomic bomb on Japan.

Hiroshima

On August 6, 1945, the United States dropped an atomic bomb known as "Little Boy" on Hiroshima, Japan. It is estimated that roughly 90,000 and 166,000 people died from the bomb. However, Hiroshima has estimated the number to be closer to 237,000. The Hiroshima operation was code named Operation Centerboard I and was carried out by a B-29 plane name the "Enola Gay." The city's infrastructure was decimated entirely, with 70,000 buildings destroyed.

Nagasaki

In just three short days, the US dropped another bomb on Nagasaki on August 9, 1945. Nagasaki had not been the original target of the bomb, known as "Fat Man." Japan's city of Kokura was the initial target based on its large munition plants. Due to dense clouds, the bomber known as "Bockscar" dropped Fat Man at 10:58 am. The town of Nagasaki had seen small-scale bombing earlier during the war, triggering many residents to flee the area. However, the bomb had devastating consequences, killing roughly 80,000 people.

After the bombing of Nagasaki, Japan surrendered on August 14. The official surrender took place on September 2, 1945, aboard the USS Missouri in Tokyo Bay, ending WWII. The technology of the atomic bomb was an incredible discovery with devastating consequences.

Manhattan Project Scientists

Oppenheimer is an American physicist who graduated from Harvard in three years and is well known for his role in the Manhattan Project. After studying under a well-known German physics professor, Oppenheimer returned to America and worked as a physicist. In 1942, he became the lead scientist on the Manhattan Project. Initially, he was given a two million dollar budget to develop an atomic weapon. The Manhattan Project reached its goal of weaponizing nuclear energy in three short years.

Leo Szilard

Before the creation of the Manhattan Project, Eisenhower and Hungarian physicist Leo Szilard penned a letter to President Roosevelt urging him to create the atomic bomb research team. Szilard completed most of his research and worked in Germany, but left the country when the Nazi party gained power. Szilard worked side by side with Enrico Fermi to successfully create the first nuclear chain reaction.

Hans Bethe

Leaving Germany after the Nazis gained power, Hans Bethe became the Chief of the Theoretical Division for the Manhattan Project. Bethe was critical in discovering several vital processes in the project's atomic research. One of his most important contributions was nuclear fission, where an atom splits and releases immense energy.

Fig. 6 Cyclotron Patent 1934 by Ernest Lawrence

Ernest O. Lawrence

Before being chosen for the Manhattan Project team, Ernest Lawrence graduated from Yale with a Ph.D. and became a professor of Physics at the University of California, Berkeley. One of Lawrence's most important contributions was the cyclotron, which he built in 1929. The machine was capable of accelerating nuclear particles to speeds that disintegrated them. Lawrence would go on to discover hundreds of radioactive isotopes and build larger cyclotrons.

The End of the Manhattan Project

After the bombing of Hiroshima and Nagasaki, the Manhattan Project and other nuclear research continued. At the end of World War II in 1946, the federal government created the Atomic Energy Commission (AEC). The AEC was designed to foster nuclear research and development throughout peacetime.

In 1947 President Truman signed the Atomic Energy Act, giving control of nuclear research to civilians. The AEC gained full control of equipment, personnel, and plants that were used for the Manhattan Project. The nuclear technology discovered during the Manhattan Project became the foundation for modern day nuclear generators, reactors, and medical equipment.

1. Atomic Heritage Foundation, Bombings of Hiroshima and Nagasaki-1945