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Dr. Chien-Shiung Wu, The First Lady of Physics

Dr. Chien-Shiung Wu at Columbia University, 1958. Collections of the Smithsonian Institution
Photo courtesy of the Smithsonian Institution (www.flickr.com/photos/smithsonian/6891734015/)

Dr. Chien-Shiung Wu at a gathering at Columbia University in 1958.

Quick Facts

Chien-Shiung Wu is a pioneer and pivotal figure in the history of physics. An immigrant to the United States from China, she did important work for the Manhattan Project and in experimental physics. Her crucial contribution to particle physics was, however, ignored by the Nobel Prize committee when it awarded the 1957 Nobel Prize in Physics.

Chien-Shiung was born on May 31, 1912 and raised in a small fishing town just north of Shanghai, China. She had two brothers and was the middle child. Although relatively uncommon for girls to attend school, Chien-Shiung went to Mingde Women’s Vocational Continuing School. It was founded by her father, who believed that girls should receive an education.

In 1934, Chien-Shiung graduated at the top of her class with a degree in physics from the National Central University in Nanking, China (now known as Nanjing University). After graduation, she worked in a physics lab in China. Her mentor, Dr. Jing-Wei Gu, another woman working in the field of physics, encouraged Chien-Shiung to continue her education in the United States.

With financial support from her uncle, Chien-Shiung took a ship to San Francisco. She was likely processed for immigration to the United States at the Angel Island Immigration Station located in San Francisco Bay.[1] She enrolled at the University of California Berkeley in 1936.[2] Her academic advisor was Ernest Lawrence. In 1939, while Chien-Shiung was still his student, he received the Nobel Prize in Physics for inventing the cyclotron particle accelerator. In 1940, Dr. Chien-Shiung Wu graduated with her PhD in physics.

In 1942, she married Luke Chia-Liu Yuan, who she had met during her studies at Berkeley. Neither of their families were able to attend the wedding because of World War II fighting in the Pacific. They moved to the east coast where Dr. Wu taught physics at Smith College in Northampton, Massachusetts and at Princeton University in New Jersey.[3] She was the first woman hired as faculty in the Physics Department at Princeton. Shortly afterwards, in 1944, Dr. Wu took a job at Columbia University in New York City, and joined the Manhattan Project. The Manhattan Project researchers were working towards the creation of the atomic bomb. Chein-Shiung’s research included improving Geiger counters for the detection of radiation and the enrichment of uranium in large quantities.

Once communications with China were restored after World War II, Wu received a letter from her family. She was making plans to visit them when the Chinese Civil War started, and her travel was put on hold. Later, her father told her not to return to Communist China. She was not able to return to China until 1973. By then, her parents had died and their tombs destroyed. Both her uncle and brother were also gone, killed in the Chinese Cultural Revolution. Luke and Chien-Shiung had a son in 1947. Following in his parents’ footsteps, he also became a nuclear scientist. In 1954, Chien-Shiung became a US Citizen.

After World War II, Dr. Wu continued on at Columbia University, becoming a full professor in 1958 and the Michael I. Pupin Professor of Physics in 1973. In 1975, her pay as a professor was raised to be equal to that of her male colleagues. Among her important contributions to physics was the first confirmation of Enrico Fermi’s 1933 theory of beta decay (how radioactive atoms become more stable and less radioactive). She also played a crucial role in an important advancement in atomic science. In 1956, physicists Tsung-Dao Lee (at Columbia University) and Chen Ning Yang (Institute for Advanced Study at Princeton) asked Dr. Chien-Shiung Wu to create an experiment. The purpose was to test their theory that the conservation of parity did not apply during beta decay. The conservation of parity is the scientific principle that identical nuclear particles act alike. Dr. Wu agreed to design the experiment. She carried it out at laboratories at the National Bureau of Standards (now the National Institute of Standards and Technology) in Washington, DC.[4]

To test the theory, she put cobalt-60 (a radioactive variety of cobalt) into a strong electromagnetic field at temperatures near absolute zero. The cold helped eliminate the effect of temperature on the atoms. If the conservation of parity held true, particles expelled by the cobalt-60 as it decayed from radioactive to stable should fly off in all directions. What she observed was that more particles flew off in one direction (the direction opposite to the spin of the nucleus). Therefore, conservation of parity did not happen during beta decay. The experiment, known as the Wu Experiment, is named for her. Yet, in 1957, Lee and Yang were awarded a Nobel Prize in Physics for their work. Like the contributions of many women in science at the time, Dr. Chien-Shiung Wu’s work was not acknowledged. In 1964, at a symposium at MIT in Cambridge, Massachusetts, she asked her audience “whether the tiny atoms and nuclei, or the mathematical symbols, or the DNA molecules have any preference for either masculine or feminine treatment.”

Chien-Shiung Wu continued to be a leader in the field of physics, and her work even crossed over to biology and medicine. Some of her research included looking at the molecular changes in red blood cells that cause sickle-cell disease. Although denied recognition with the Nobel Prize, Dr. Wu received many honors during her career. These include being only the seventh woman elected to the National Academy of Sciences (1958); the Comstock Prize in Physics given by the National Academy of Sciences; the first woman to be president of the American Physical Society (1975); the first person to receive the Wolf Prize in Physics (1978); and the first honorary doctorate awarded by Princeton University to a woman. In 1990, she had an asteroid named after her (2752 Wu Chien-Shiung).

Dr. Chien-Shiung Wu retired from Columbia in 1981 and died of a stroke in New York City on February 16, 1997. Her ashes were buried in the courtyard of the Mingde School in China that she had attended as a girl.

Notes
[1] Angel Island was listed on the National Register of Historic Places on October 14, 1971 and designated a National Landmark Historic District on December 9, 1997.

[2] Sather Tower, also known as The Campanile, is a highly visible and noted feature of the University of California Berkeley campus. Built in 1914, it was listed on the National Register of Historic Places on March 25, 1982.

[3] Much of Princeton University’s campus is part of the Princeton Historic District. It was listed on the National Register of Historic Places on June 27, 1975.

[4] None of the buildings from the National Bureau of Standards campus formerly located in Washington, DC survive. The agency is now known as the National Institute for Science and Technology.

References
Benczer-Koller, Noemie. Chien-Shiung Wu 1912-1997: A Biographical MemoirNational Academy of Sciences, Washington, DC, 2009.

Biography.com. “Chien-Shiung Wu Biography.” Biography.com.

Chiang, Tsia-Chien. Madame Wu Chien-Shiung: The First Lady of Physics Research. Translated by Tang-Fong, Wong. 2003.

DeFerrari, John. “The Lost Hilltop Home of the National Bureau of Standards.” Streets of Washington, 2013.

History of Scientific Women. “Chien-Shiung Wu.” History of Scientific Women.

National Science Foundation. “Chien-Shiung Wu (1912-1997).” National Science Foundation, Virginia.

National Women’s Hall of Fame. “Chien-Shiung Wu.” National Women’s Hall of Fame

Smeltzer, Ronald K. “Chien-Shiung Wu, Physicist, Columbia University.” Atomic Heritage Foundation.

Last updated: January 23, 2020