Born in a village near Shanghai, China, she received her first education at home, as girls were not allowed to attend school. In 1923, she enrolled at Suzhou Women’s Normal School, one of the first Chinese schools open to girls, founded by her father. After graduating, she was admitted to the National Central University in Nanjing, where she graduated in 1934 with a degree in mathematics and, two years later, in physics.
In 1936, she moved to the United States to pursue her doctorate. She had considered attending the University of Michigan, but when she learned that women were not allowed to use the front entrance to the lecture halls, shocked by American sexism, she decided to stay in Berkeley, California, where she had been visiting a Chinese friend. There, she met her future husband, physicist Luke Chia-Liu Yuan. During her doctorate, she worked on Ernest O. Lawrence’s first cyclotron with Emilio Segrè. She and her husband then moved to the East Coast of the United States and found a job teaching at Smith College, a private women’s university in Massachusetts. Things there were unsatisfactory; women, especially Asian women, struggled to advance their careers, and Wu was unable to continue her research. Only after Lawrence’s intervention did Smith College grant her a position as an associate professor, a small raise, and the opportunity to alternate her work at Smith College with a similar position at Princeton University. The turning point came in 1944, when she became involved in the Manhattan Project. She joined a group of scientists at Columbia University working on the separation of Uranium 235 from Uranium 238 by gaseous diffusion and on the development of new Geiger counters. After the war, Wu Chien-Shiung continued to work at Columbia University, where she was able to resume her research, which she directed toward the study of beta decay. Since Fermi’s 1934 theory, numerous discrepancies between theory and experiments had been observed. With meticulous experiments conducted between 1949 and 1960, she corrected previous experimental data and confirmed Fermi’s theory. These studies brought her to the attention of physicists Tsung Dao-Lee and Chen Ning-Yang, who, in 1956, proposed that she design an experiment that would confirm their hypothesis of the non-conservation of parity in beta decay³. Wu’s experiment, along with others using Cobalt-60 at temperatures near absolute zero, was a turning point in modern physics and proved the non-conservation of parity and charge conjugation (CP symmetry breaking). It was the starting point for subsequent research into the violation of fundamental symmetries. Lee and Yang received the 1957 Nobel Prize for their theory, but the decisive experiment that confirmed their theory was not considered equally worthy, and Madame Wu, scandalously—according to the majority of the physics community—did not receive the award she deserved. She did, however, receive numerous honors and awards throughout her life. She was the first woman elected President of the American Institute of Physics in 1975. In 1995, four Chinese Nobel laureates (T. D. Lee, C. N. Yang, S. C. Ting, and Y. T. Lee) established the Wu Chien-Shiung Foundation in Taiwan to financially support young aspiring Chinese/Taiwanese scientists. She wrote, alone or with others, several treatises that are still considered classics in nuclear physics. Alongside her scientific work, Wu Jianxiong championed gender equality and fought for the recognition of human rights in China.
After her death at the age of 84 in 1997, her ashes were buried, at her request, at Mingde High School in New York, where her husband was later buried in 2003. On their graves, inscriptions in Chinese calligraphy were written by the four Chinese Nobel laureates, and T. D. Lee wrote: C. S. Wu was one of the giants of physics.