This essay is part of the special feature “Core Stories,” which commemorates the 75th anniversary of the first controlled, self-sustaining nuclear chain reaction.

Scientists built the bomb.

I was first introduced to the atomic bomb and the scientists behind it in an elementary school civics class in late 1990s China. As seven- and eight-year-olds, we were taught that the bomb was a symbol of righteous might.

The power from splitting the atom brought the evil Japanese empire to surrender in World War II and was the ultimate defense for the fledgling “New China.” Our beloved motherland, battered and bruised at the hands of foreign foes over a hundred years of humiliation since the Opium Wars, emerged undefeated and was soon impenetrable as she erected the new Great Wall of nuclear defense. So the lesson went.

The nuclear physicists were the superheroes. The best and the brightest of a generation gave up enticing offers from the West and devoted themselves to the defense and revitalization of the motherland, working in secrecy for years upon decades in the remotest of locations and the harshest of conditions, far away from family, friends, and the world at large.

The lead figure in that heroic tale was a man named Deng Jiaxian. Regarded as the father of China’s nuclear program, Deng was born in my home province of Anhui in the tumultuous 1920s. After completing his undergraduate studies in China, he went to the United States for graduate school. Inspired by the founding of the new People’s Republic of China in 1949, Deng boarded a ship back to his homeland nine days after receiving his PhD in physics from Purdue University in 1950. His education and expertise, rare in China at the time, were quickly put to use as the country started pursuing its nuclear ambitions.

We learned about Hiroshima and Nagasaki in school as well, but in contrast to the life epics of Chinese nuclear scientists, the uses of the atomic bomb were painted as isolated instances and in the broadest strokes. Any elaboration of the aftermath would risk humanizing the Japanese and cast doubt on the necessity of the bomb, including China’s own nuclear weapons.

China started its nuclear weapons program in the mid-1950s, during the First Taiwan Strait Crisis, successfully detonating its first atomic bomb in 1964 and its first hydrogen bomb in 1967. From 1966 to 1976, in the decade of madness called the Cultural Revolution, Chinese intellectuals—including nuclear scientists—were branded counterrevolutionaries. Many of them and their family members were persecuted and killed. These 10 years of turmoil claimed the life of Deng’s sister and almost his own.

Direct interventions from the Chinese premier at the time, Zhou Enlai, helped rescue Deng from remote labor camps at the height of the Cultural Revolution. Driven by the same patriotic conviction that brought him back to his motherland two decades earlier, Deng resumed his work on China’s nuclear weapons program, working until he died of cancer in 1986.

One of Deng’s closest friends since adolescence was the Nobel Prize–winning physicist Chen Ning Yang, PhD’48. A native of my hometown of Hefei, Yang worked with Edward Teller and Enrico Fermi at the University of Chicago. Unlike Deng, Yang stayed in the United States after graduation, continuing a stellar career in theoretical particle physics, including the establishment of the groundbreaking Yang-Mills theory.

I arrived at the same Hyde Park campus in the fall of 2009 for my PhD in experimental particle physics. I worked on the Large Hadron Collider with thousands of colleagues from scores of countries around the world to probe some of the most fundamental questions of our universe. For my six years at the University of Chicago, my office overlooked the iconic Henry Moore sculpture marking the site of first self-sustained nuclear reaction.

My profession originated from that first reaction in the fall of 1942, as did the bomb. The science that taught us how every human being is made of the same subatomic particles, bound by the same forces, and created from the same burst of star dust also delivered us the weapons to kill every single living person on this planet.

The collision that split the atom brought into the foreground another clash, that between the universality of science as an ideal and the parochialism of science as a human practice. In the Chinese media and blogosphere, Yang’s life story is often compared with Deng’s, with Deng almost always portrayed as the superior scientist. Unlike Yang, Deng did not make significant contributions to advancing the human understanding of nature, but in this view Deng’s science served a higher purpose: the defense of one’s country and people.

What the government-sanctioned discussions never asked was why a scientist would build the most powerful weapon on earth for a government that had killed more of its own citizens than any foreign invader in its history, including the scientist’s own family and colleagues. When a state could not trust its people with basic human rights, should a scientist have trusted that state with nuclear weapons?

Just three years after Deng’s passing, the inner city of Beijing, which had been spared from armed conflict over the fall of dynasties and numerous wars, saw its greatest bloodshed as more than two hundred thousand regular troops rolled in with tanks and machine guns to crack down on a peaceful student demonstration. Fewer allied troops fought on the shores of Normandy against an enemy the bomb was originally created to defeat.

When Deng Jiaxian pledged his career and his life to the Chinese nuclear weapons program, he was no longer just a scientist, but a soldier in service to his government.

In a war, there are no perfect heroes or villains. There are no clean battle lines when it’s human beings on both sides of the fight. A soldier follows his command, without questioning its righteousness.

In middle school in China we read in our government-issued textbooks a moving article by Chen Ning Yang in memory of his old friend. Toward the end of the beautifully written eulogy, Yang recalled the Tang-era prose work “Elegy for the Ancient Battlegrounds,” a classic piece of traditional Chinese literature he used to recite with Deng during their college days. The lifeless deserts in northwestern China, where battles were fought over millennia and haunted spirits whispered in the wind, became the research and test sites for the country’s nuclear weapons program.

“I wonder how Jiaxian felt, when he buried his fellow soldiers in the sand among the withering grass?” Yang asked in tear-drenched prose. The Chinese scientists who gave up their lives for the country’s nuclear weapons program had joined the ancient warriors in martyrdom. They were not colleagues, not even comrades, but fellow soldiers.

Yangyang Cheng, PhD’15, is a postdoctoral research associate at Cornell University’s Cornell Laboratory for Accelerator-based ScienceS and Education (CLASSE). She received her bachelor’s degree from the University of Science and Technology of China. A particle physicist, Cheng works on the CMS (Compact Muon Solenoid) experiment at the Large Hadron Collider, where she looks for dark matter and designs the next-generation silicon tracking detectors.