Women’s History Month: Chien-Shiung Wu (1912-1997)

March is Women’s History month, so at I, Science we are highlighting some of the incredible women who have contributed to the fields of science, technology, engineering, and maths - who have often been overlooked in our textbooks.

Chien-Shiung Wu photo in the lab — Chien-Shiung Wu.
*Image source: 90-105 – Science Service, Records, 1920s-1970s, Smithsonian Institution Archives*

Chien-Shiung Wu’s research in experimental nuclear physics was pivotal to our understanding of the Standard Model – the list of fundamental particles and forces that make up the whole of our universe.

After her undergraduate degree in China, she moved to Berkeley to start her PhD, but moved to Caltech after her first year as she could not secure a scholarship for the former. Her initial work in and thesis in radioactive decay led her to join the Manhattan Project in 1944.

After the war, Wu continued her research on Beta-decay, designing experiments that proved Enrico Fermi’s theory. She then collaborated with the theorists Tsung-Dao Lee and Chen Ning Yang to investigate the conservation of parity – which is whether tiny fundamental particles have a positive or negative charge – and this charge should be the same before and after a particle interaction. Their work proved that parity was conserved in two of the four fundamental interactions between particles (strong nuclear force and electromagnetic interaction) , but not the weak nuclear interaction which is involved in radioactive decay. Lee and Yang received the Nobel Prize for this work in 1957.