Chien-Shiung Wu
Chien-Shiung Wu was born on May 19th, 1912, in Liuhe, Jiangsu province, China. She was a Chinese-born American Physicist who provided the first experimental proof that the principle of parity conservation does not hold in weak subatomic interactions.
Wu was a middle child, with two brothers, she was born around the same time as the founding of the Republic of China. Her mother (Funhua Fan) was a teacher, and her father (Zhong-Yi Wu) was an intellectual and engineer, he and Wu were very close. In fact he encouraged her to pursue her education as far as possible, even though women in China were not often encouraged to do so.
Wu’s father opened a school, in which she attended as a young girl until she went to a boarding school in Suzhou, where she graduated at the top of her class in 1929. Then, she attended the National Central University in Nanking, and graduated in 1934 with a degree in Physics.
Wu was inspired by female scientists (Ex. Dr. Marie Curie and Dr. Jing-Wei Gu.)
Dr. Jing-Wei Gu actually mentored Wu and encouraged her to go to the United States to pursue an advanced degree in 1926.
Where she would continue studying at the University of California at Berkeley. Wu worked in Lawrence's Radiation Laboratory, where she got the chance to learn from physicists like J. Rober Oppenheimer. She also studied under Ernest O. Lawrence himself. Graduating and receiving a Ph.D in 1940.
In 1942, she married Luke Chia-Liu Yuan, a fellow physicist she met at UC Berkeley. The two moved to the East Coast when Wu got a job teaching physics at Smith College. She then moved to Princeton University the following year, where she would become the first female instructor in the Physics Department.
In 1944, Wu took a job at Columbia University, where she undertook work on radiation detection in the Division of War Research. Wu’s contributions helped determine the process for separating uranium into U-235 and U-238 isotopes by gaseous diffusion, a crucial step in producing uranium in large quantities for the atomic bomb. Her efforts with the project proved invaluable and she remained on the university staff at Columbia after the war, becoming Dupin professor of physics there in 1957.
In 1956, Wu was approached by colleagues and theoretical physicists, Tsung-Dao Lee of Columbia and Chen Ning Yang of the Institute for Advanced Study, Princeton, New Jersey, who were seeking her expertise in beta decay. They proposed that parity is not conserved for weak nuclear interactions, and with a group of scientists from the National Bureau of Standards, Washington, D.C., Wu tested the proposal by observing the beta particles given off by cobalt-60.
Wu observed that there is a preferred direction of emission and therefore, that parity is not conserved for this weak interaction. She announced her results in 1957. Her findings contradicted the law of conservation of parity and supported Chen and Yang’s theory. Both men received a Nobel Prize in Physics in 1957 for their theory. While Wu did not receive the same recognition, in many textbooks it’s referred to as the “Wu experiment.”
In 1958, Wu took a permanent position at Columbia and went on to contribute to the field of medicine, conducting research to help answer important questions about sickle-cell disease. Around this time, Richard P. Feynman and Murray Gell-Mann proposed the conservation of vector current in nuclear beta decay. In 1963, Wu experimentally confirmed this theory in collaboration with two other Columbia University research physicists.
The scope of her contributions touched numerous disciples and Wu was recognized many times for her professional achievements. Wu published a book on Beta Decay in 1965 and it continues to be a reference text for nuclear physicists today.
Wu received the Comstock Prize in Physics (1964), the National Medal of Science (1975), the Wolf Prize in Physics (1978), and she served as the first female president of American Physical Society, and was considered one of the premier experimental physicists in the world.
Altogether, she received more than fifteen major awards, honorary degrees, and held at least a dozen memberships in learned societies. She retired from her professorship at Columbia in 1981.
Chien-Shiung Wu was a trailblazer in a male-dominated field, and with every struggle she faced, she turned them into opportunities to use at her advantage.
Wu died February 16th, 1997, in New York at the age of 84.
