On this day in 1912 was the birth of Chien-Shiung Wu, a Chinese-American experimental physicist who was well known in the field of nuclear physics. Born and educated in China, she eventually studied at the National Central University in China, where she studied mathematics before switching to physics. In a time of strife between China and Japan, Chien-Shiung was elected as a student leader by her peers, who believed that her status as a top student meant that the authorities might overlook any involvement in political protests. She worked hard at her studies, but still lead protests, including a sit-in at the Presidential Palace in Nanjing.
After graduating, she did two years of graduate study at Zhejiang University, before taking the advice of a Professor and journeying to the U.S., where she was accepted at the University of Michigan. After arriving in California and visiting the University of California, Berkeley, however, Chien-Shiung changed her mind about which school she wished to attend; this was a decision aided by her discovery that the University of Michigan did not let their female students use the front door. (It was also at Berkeley that she met Luke Chia-Liu Yuan, a physicist who was the grandson of Yuan Shikai– the first President of the Republic of China, who was also self-proclaimed Emperor of China– who would later become her husband.)
During World War 2, Chien-Shiung joined the Manhattan Project, working in their Substitute Alloy Materials (SAM) Lab at Columbia University. Here, she helped “develop the process for separating uranium metal into uranium-235 and uranium-238 isotopes by gaseous diffusion”. She is perhaps best known for conducting the “Wu Experiment”, which was designed to decide whether or not conservation of parity, previously established in electromagnetic and strong interactions, also applied to “weak interactions”. Essentially, she showed that “weak force violates the law of parity”, by determining that electrons (which are produced by a weak force interaction, beta decay) always flew in the same direction, rather than be affected by a magnetic field. (If this is confusing, you can read more here.) Suffice it to say that it was Chien-Shiung who developed this experiment, and she who performed it with the help of lab workers– but the Nobel Price for this discovery went instead to Tsung-Dao Lee and Chen-Ning Yang, her (male) colleagues who provided the theoretical knowledge, but nonetheless needed Chien-Shiung to design and perform the experiment.
Chien-Shiung did later win the inaugural Wolf Prize in Physics, however, 13 years later for the same experiment, and in her time she was known as “the First Lady of Physics”, the “Queen of Nuclear Research”, and “the Chinese Madam Curie”. In her later life, she became a lot more outspoken, especially about gender equality. She corrected any men who tried to refer to her by her married name, rather than as Professor Wu, worked to eventually have her pay adjusted to be equal to that of her male colleagues at Columbia University, and also spoke out about Chinese politics, including the crackdown in China following the massacre at Tiananmen Square.
“I wonder”, she said once, during a speech at Massachusetts Institute of Technology symposium in 1964, “whether the tiny atoms and nuclei, or the mathematical symbols, or the DNA molecules have any preference for either masculine or feminine treatment.”