Chien-Shiung Wu
Wu, Chien-Shiung (1912-1997) was a Chinese-born American experimental physicist who did groundbreaking research on the physical interactions of fundamental nuclear particles. She helped disprove a law of physics that had been held as a universal principle for about 30 years.
Wu was born in Liuhe, China, near Shanghai. Her father ran a school for girls, which she attended until transferring to a private high school. She received a bachelor's degree from the National Central University at Nanjing. Wu moved to the United States in 1936 and received her doctorate from the University of California at Berkeley.
During World War II (1939-1945), Wu worked at Columbia University in New York on the Manhattan Project, a program to create the first atomic bomb. After the war, she taught at Columbia and became a full professor in 1957.
In 1956, Wu used atoms of cobalt 60 to disprove the law of the conservation of parity. As cobalt 60 decays, it gives off two kinds of radiation—beta particles and gamma rays. Part of the law of conservation of parity stated that beta particles are released in any direction, regardless of the spin of the nucleus. Wu demonstrated that beta particles are more likely to be emitted in a certain direction that depends on the spin of the cobalt nuclei.
Wu's experiment confirmed the theory proposed in 1956 by Chinese-born American physicists Tsung Dao Lee and Chen Ning Yang, for which they shared the 1957 Nobel Prize in physics.
In 1958, Princeton University honored Wu with its first honorary doctorate of science degree awarded to a woman. She was elected to the National Academy of Sciences, served as president of the American Physical Society, and won the Wolf Prize for physics.