
Dr. Chien-Shiung Wu (1912-1997) was a Chinese-born American physicist who worked on the covert Manhattan Project developing the first nuclear weapons for the U.S. during WWII and later conducted a landmark experiment that established her as one of the premier experimental physicists in history.
Born in a small town near Shanghai, Wu attended a school started by her father who believed in education for girls, an uncommon belief in China at the time. In 1929, Wu went on to study education and physics at the National Central University in Nanking, China. After graduating, she emigrated to the United States in 1936 to pursue a graduate degree in physics at the University of California at Berkeley and studied under Ernest O. Lawrence, a Nobel Prize-winning pioneer of nuclear science.
After Wu received her doctorate in 1940, she taught physics at Smith College and at Princeton University. She married Luke Yuan, a fellow physicist, in 1942. Two years later, she joined the Manhattan Project at the Substitute Alloy Materials (SAM) Lab at Columbia University where her work focused on radiation detection. When the B Reactor at the Hanford Nuclear Site in the state of Washington mysteriously shut down just after it began operating, Wu helped identify xenon-135 poisoning as the culprit.
Wu was offered a position at Columbia University after the war and she began investigating beta decay, which occurs when the nucleus of one element changes into another element. Through her work, she made several significant contributions to nuclear physics, including being the first to confirm Enrico Fermi’s theory of beta decay.

In 1956, Wu was approached by theoretical physicists Tsung-Dao Lee of Columbia and Chen Ning Yang of the Institute of Advanced Study at Princeton who were aware of her expertise in beta decay. They proposed that parity is not conserved for weak nuclear interactions and they asked her to devise an experiment to prove their theory. For years, physicists were married to the principle of conservation of parity, which held that nature does not distinguish between left and right in nuclear reactions; two phenomena, one of which is an exact mirror of the other, behaves identically, except for the mirror image effect. Researchers made all their observations fit this theory, even though no experiments had ever solidly confirmed it.
With a group of scientists from the National Bureau of Standards in Washington, DC, Wu tested the proposal by experimenting with radioactive cobalt-60 at near zero temperatures and proved that identical nucleus particles do not always act alike, shattering the fundamental concept of nuclear physics. The success led to worldwide acclaim and resulted in Lee and Yang receiving the Nobel Prize in Physics in 1957 for their theory, although Wu’s work was not acknowledged.
Wu continued to make significant contributions throughout her life, including in 1958, when her research helped answer important biological questions about blood and sickle cell anemia. That same year, she was elected as a member of the National Academy of Sciences and later, in 1975, she was elected as the first female president of the American Physical Society.
She received several prestigious awards and honors for her work. Her eight honorary degrees included the first honorary doctorate awarded to a woman by Princeton University. She was awarded the first Research Corporation Award given to a woman (1959), the Comstock Prize in Physics (1964), the National Medal of Science (1974), and the first Wolf Prize in Physics (1978). In 1990, Wu became the first living scientist to have an asteroid named after her. Additionally, her book Beta Decay, published in 1966, remains a standard reference text for nuclear physicists to this day.

Wu retired from her professorship at Columbia in 1981. She died in New York City in 1997.
As one of the foremost nuclear physicists in the world, Dr. Wu’s work fundamentally shaped modern physical theory and blazed a trail for women in science.
Discover more:
- Find more newspaper coverage of Dr. Wu and her career in *Chronicling America!
- Read the blog post “Historical Women in STEM” and discover the stories of Dr. Wu and other pioneering women in science.
- Dr. Chien-Shiung Wu, The First Lady of Physics– National Park Service, Manhattan Project National Historic Park website
- Chien-Shiung Wu - Atomic Heritage Foundation in partnership with the National Museum of Nuclear Science & History website
- Dr. Chien-Shiung Wu - National Women’s History Museum website
*The Chronicling America historic newspapers online collection is a product of the National Digital Newspaper Program and jointly sponsored by the Library and the National Endowment for the Humanities.
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