What Happened to Oppenheimer After World War II?

J. Robert Oppenheimer was born in New York City on April 22, 1904. Oppenheimer graduated with a chemistry degree from Harvard University and a doctorate in physics from the University of Göttingen in Germany by the age of 23.

Oppenheimer traveled around Europe between 1927 and 1936, meeting and working with some of the greatest minds in the 20th-century scientific community, including such prominent physicists as Albert Einstein, Neils Bohr, Ernest Lawrence, Edward Teller and Enrico Fermi.

In 1936, Oppenheimer began teaching at the University of California Institute of Technology, where "Oppie" and his students pushed the field of quantum physics into unknown territory.

As war broke out across Europe and the United States was being pulled into the fray, the U.S. military appointed Oppenheimer to oversee a secret project in the deserts of New Mexico that would alter the course of human history forever.

General Leslie Groves selected Oppenheimer to manage the Manhattan Project, a secret project in Los Alamos, New Mexico, that housed many top American and European physicists.

Oppenheimer directed his fellow scientists in cutting-edge experimental physics and nuclear research that he hoped outpaced German scientists developing a devastating weapon for Nazi Germany.

Oppenheimer served as an ad hoc mayor for the small town of atomic scientists, their families and a small group of military personnel with top-secret security clearance. The talent and hard work of Los Alamos culminated in the first nuclear explosion at the Trinity Test Site on July 16, 1945.

Less than a month later, on August 6 and 9, the United States detonated two atomic weapons, killing between 150,000 and 250,000 Japanese civilians.

These attacks forcibly ended the war and installed the United States as the supreme world power until hydrogen bomb plans were leaked to the Soviet Union.

Oppenheimer opposed the use of nuclear weapons, but that didn't stop the Los Alamos laboratory from working tirelessly to advance theoretical physics, even if the result was apocalyptic genocide.

Even after witnessing the horrors of Hiroshima and Nagasaki, world governments have continued to invest billions of dollars in amassing world-ending armaments — the most common being atomic or hydrogen.

An atomic bomb strictly uses nuclear fission to split atoms, while a hydrogen bomb uses both fission and fusion (combining atoms). Hydrogen bombs are significantly more powerful, with the largest ever being 1,570 times more powerful than the first atomic bomb.

This Soviet Union's "Tsar Bomba" detonated in 1961 with an explosive yield that was equivalent to 50 megatons of TNT. As of 2024, Russia has roughly 5,500 nuclear weapons, while the U.S. has roughly 5,050.

Oppenheimer retired from teaching soon after Los Alamos. In 1946, Oppenheimer accepted a position on the general advisory committee of the United States Atomic Energy Commission (AEC). More specifically, he was the scientific director of the Institute for Advanced Study and chairman of the AEC.

During his time at the AEC, Oppenheimer lobbied for international oversight as the Soviet Union developed a working hydrogen bomb. This led the two once-allied world powers into a decades-long Cold War.

However, the more clandestine sides of Oppenheimer's life came to light during a security hearing orchestrated by J. Edgar Hoover and the FBI.

Oppenheimer's stance on nuclear supremacy, mixed with his close connections with members of the Communist Party, placed him in the crosshairs of anti-Soviet McCarthyists and former ally Lewis Strauss during the Second Red Scare.

His close relationship with his brother Frank, a left-leaning physics teacher and founder of the San Francisco Exploratorium, led to the suspension of Oppenheimer's security clearance and subsequent termination at the AEC.

Before Oppenheimer's death, he spent most of his time in the U.S. Virgin Islands. He continued to lecture and teach through public writings and traveling lectures, but he would never hold another high-level government position.

In 1959, President John F. Kennedy denied former Oppenheimer "frenemy" Strauss his confirmation as Secretary of Commerce. Four years later, Oppenheimer was awarded the Enrico Fermi Award from his old organization, the AEC.

Oppenheimer died from throat cancer in 1965. His complicated and controversial life is often summed up in his quoted utterance of the Hindu scripture Bhagavad Gita during the Trinity Test: