The Science Behind Christopher Nolan’s Oppenheimer


The world is buzzing with the release of Christopher Nolan’s latest film. Oppenheimer follows the journey of the titular scientist who led the development of the atomic bomb for the United States during World War II. The development and use of the atomic bomb is one of the most controversial feats of engineering in human history, and this theme is explored heavily throughout the film.

The first half of the film heavily explores the science of quantum physics and how the development of the field contributed to an eventual nuclear arms race. In real life, the events leading up to the Manhattan Project were not very different. The United States government viewed nuclear weapons development as a necessity, despite being driven by fear. The subject of quantum physics was largely only explored in Europe, particularly Germany, until it came to the United States in the late 1920s. Therefore, the historical events surrounding the engineering of the atomic bomb helped forge its development.

In 1905, Albert Einstein published a paper explaining a new theory for the photoelectric effect — the fact that the photoemission of electrons is based on the frequency of light — explaining that light does not carry energy in a wave but in bundles of photons. In 1913, Niels Bohr attempted to further define the atomic model, described previously as a solar system in which electrons rotate about the nucleus. Using Einstein’s theory, he hypothesized that electrons can only absorb or release energy in quantized packets, and therefore electrons must exist at defined energy levels.  At approximately the same time in 1925, German physicist Werner Heisenberg and Austrian physicist Erwin Schrodinger discarded the idea of orbital atoms. Schrodinger discovered the now-famous principle that electrons travel in waves until they interact with matter, forcing them to a single point. He wrote the famous Schrodinger wave equation, and his ideas established a field called wave mechanics. In turn, Heisenberg developed matrix mechanics: numbers representing the energy and orbitals of electrons, forming the foundation of modern quantum mechanics. 

Up until this point, any experimentations in quantum mechanics were in the field of thought only. That changed on December 17, 1938, when three chemists in Berlin managed to split the uranium atom, proving nuclear fission was possible. They discovered the amount of energy given off by such a reaction was tremendous. Unfortunately, the occupation of Nazi Germany and the beginning of the Second World War accompanied this discovery. Only seven months prior, Hitler began his invasion of Austria. Ten months after the uranium atom was split, on September 1, 1939, Hitler invaded Poland and started World War II.

The German chemists’ discovery led to Einstein’s famous letter to President Roosevelt in 1939, in which he warned the United States that Nazi Germany was already working on developing a weapon of mass destruction: the atomic bomb. Roosevelt, in turn, established a committee to investigate the radiative properties of uranium: the first decision that ultimately led to the establishment of the Manhattan Project. 

Seemingly, this led to labeling the United States’ development of atomic weapons as an unfortunate necessity. While it was immoral for the United States to have a weapon so powerfully destructive, it certainly was worse for Germany to have it. This idea held merit until Germany’s surrender on May 7, 1945 – before the completion of the bomb. Still, the project continued, and on July 16, 1945, the first successful test of the atomic bomb occurred in Alamogordo, New Mexico. The bomb would later be dropped without warning on the Japanese cities of Hiroshima and Nagasaki, leading to a level of destruction and loss of life that is, to this day, one of the most horrific feats of engineering. 

While it seems rather apparent that there is no justification, not even war, for using these weapons, it is important to understand the historical context surrounding the pursuit of this project. When evil pervades society, fear leads to the belief that the only response is choosing a lesser evil. The evil deemed “lesser” depends on which side of the conflict one stands. This begs the question: how do we let political events color the way we view scientific research and experimentation? It is exciting to prove a concept that was previously only theoretical. However, the way we explore those concepts must always include consideration for their potential impact on the future. Nolan acknowledges this in the film. Early on, one of the scientists learns that there is a chance that setting off the bomb would cause a series of unending nuclear reactions that would cause the atmosphere to combust – that there was a chance humanity would begin a chain reaction that would destroy the world. If we continue scientific research with the same short-sighted goals as the Manhattan Project, we will perpetuate that chain reaction.