Chien-Shiung Wu: Courageous hero of physics

This is an extract from our first women in STEM anthology, A Passion for Science: Stories of Discovery and Inventionavailable as an ebook for £1.99 from Amazon.

Maia Weinstock

It is the afternoon of 31 May 2012, and the skies above Liuhe in the Chinese province of Jiangsu are overcast but resplendent in silver and grey. A late-spring chill fills the air as a crowd of expectant locals and distinguished guests, including a number of representatives from the People’s Government, gathers in a circular stone-walled courtyard to honour a hometown legend. Scores of women, men and children who have made the journey here huddle in their well-worn jackets and coats as they wait for the memorial ceremony to begin.

Over the next two hours, attendees of this spirited congregation will take turns paying their respects with flowers, speeches and songs to one of the most decorated and esteemed scientists of the 20th century. She has been dubbed the “First Lady of Physics” and the “Chinese Marie Curie” for her groundbreaking work in nuclear science—some of which, controversially, helped earn her male colleagues, but not her, a Nobel Prize. But here in Liuhe, where she was born exactly 100 years ago (and where she was buried after her death in 1997) she is known simply as Chien-Shiung: “Courageous Hero”.

For one who faced so many uphill battles on the road to worldwide recognition and acclaim, physicist Chien-Shiung Wu more than lived up to the moniker her parents conferred upon her the day she came into the world in Liuhe, some 30 miles northwest of the port city of Shanghai. To begin with, Wu was born at a time when her homeland forbade girls from going to school. This was still an era when Chinese girls were expected to bind their feet and grow up to serve their male compatriots.

And yet, only a year before Wu’s birth, the Xinhai Revolution had overthrown the last Chinese dynasty and established the new Republic of China. With that massive uprising came a sea change of attitudes and a new generation of leaders eager to overturn the status quo. One of those leaders was Wu’s father, Zhongyi Wu. An engineer by training who believed strongly in equal rights for women, Zhongyi felt that the best thing he could do to help his daughter and her peers was to start a school for girls — the region’s first. With the aid of his wife, Fan Fuhua, who persuaded other families to let their young ones enrol, Zhongyi Wu opened the Mingde School for Girls and became its principal. And so, young Chien-Shiung, an inquisitive child from the get-go, was one of the first girls to obtain formal education in China.

But her father’s school could only take Wu so far. To continue learning, her only option was to enrol at a girls’ boarding facility 50 miles from home. She was all of 10 years old when she began classes at the Suzhou Girls’ School, where she quickly came to discover the beauty and intrigue of physical science. It was, of course, not easy for a child so young to be away from her family, but her parents gave her strength. “Ignore the obstacles,” her father told her. “Just put your head down and keep walking forward.”

With such encouragement, Wu dedicated herself to the goal of studying math and science at the university level. She practically lived at school for seven full years, during which time she worked twice as hard as many of her peers so that she would have the skills required to earn a place in the physics department at the National Central University in Nanjing. Her commitment paid off: In 1930, she completed high school and began at NCU as a math major, transferring later into physics.

Wu graduated from NCU in 1934 as the school’s undisputed top student. But she once again found herself up against a wall: While the world was beginning to unravel the mysteries of the atom, a topic that intrigued her immensely, China had no graduate programs in physics. And so, at the suggestion of a mentor and with the financial backing of an uncle, Wu left for the United States on what she thought would be a brief detour in her journey to a scientific career in China. Little did she know that the course of her life would take a dramatic turn almost as soon as she landed on the California coast — nor that she would never again set eyes on the family she was leaving behind.

A life atomic

The United States of the 1930s saw the dawn of a new era in scientific inquiry. Atomic physics in particular took a major step forward in 1931, when future Nobel Prize-winner Ernest Lawrence, with the help of graduate student M Stanley Livingston, built the first cyclotron, a particle accelerator that uses magnetic fields to speed up and smash together atomic bits so that their interactions can be studied precisely.

Lawrence and his cyclotron were based at the University of California at Berkeley, which was fast becoming the world’s leading hotspot for the study of the atom. It was also a stone’s throw from San Francisco, the city where Chien-Shiung Wu landed in the late summer of 1936 after her ship had crossed the vast and turbulent Pacific on her way to graduate school. Wu’s ultimate destination was the University of Michigan, where she planned to study for her PhD, but with some down time before classes began, she decided to pay a visit to the Berkeley campus and its world-class physics department.

Only a few days into her California sojourn, Wu’s plans changed completely. For starters, she made the acquaintance of a fellow Chinese physics student named Luke Yuan, who would go on to become a permanent fixture in her life. Furthermore, after meeting with an obviously impressed Professor Lawrence, she was invited to pursue her graduate work at Berkeley. An opportunity to study under some of the legends of nuclear physics — which included not only Lawrence but also future Manhattan Project director Robert Oppenheimer — was a dream come true for Wu, who desperately wanted to learn as much as she could about the fundamental nature of matter. In an abrupt and daring move, she abandoned her plans to enrol at Michigan.

As a graduate student, “Miss Wu” was very popular with her peers. She also became notorious for an unwavering work ethic that saw her toiling in the lab well into the small hours of morning on many a night. It was a reputation that would follow her for her entire professional career. “I have always felt,” she later explained, “that in physics, and probably in other endeavours, too, you must have total commitment. It is not just a job, it is a way of life.”

The truth is, however, that Wu had something of a difficult time adapting to American culture. English was a tricky language to master, and she would spend her adult life fumbling with certain pronunciations and grammatical rules. What’s more, she missed Chinese food and preferred the Chinese style of dress — so much so that she would continue to wear traditional high-necked qipao dresses well into her old age, oftentimes underneath a white lab coat.

Not quite a year after Wu’s arrival in California, international headlines reported devastating news: By the end of 1937, Japan had invaded China. Since landing in the US, Wu had remained in close contact with her parents, brothers and sister, but after the invasion, she wouldn’t hear another word from her family for eight long years. It was a trying time, as horrific updates from the front trickled overseas: by the end of 1937, some 42,000 civilians in her home province of Nanjing alone had been raped or murdered by Japanese troops. Four years later, the conflict would officially merge with World War II after Japan surprised the United States with its attack on Pearl Harbor.

With nothing she could do to help her loved ones, Wu attempted to tune out the war and focus instead on her work. She pursued her thesis under Lawrence and his assistant, another future Nobelist, Emilio Segrè. By 1940, Wu had completed her PhD and was considered an expert — “the authority,” according to Robert Oppenheimer — in the new science of nuclear fission, the splitting of large atomic nuclei either by an induced nuclear reaction or by natural radioactive decay.

Ask Miss Wu

Wu stayed on at Berkeley as a research assistant for two years, solidifying her reputation as one of the most capable experimental physicists in the country. It was during this time that scientists led by physics icon Enrico Fermi were attempting, unsuccessfully, to produce the first large-scale, self-sustaining plutonium chain reaction at a research facility in Hanford, Washington. Fermi’s reactions to that point would run for a few hours but then sputter out without explanation.

Legend has it that someone suggested to Fermi that he “ask Miss Wu” for advice. He did, and Wu swiftly deduced that the problem was the buildup of xenon, a plutonium fission by-product. Xenon is an inert noble gas, but it turned out that the particular isotope produced in Fermi’s chain reaction had a tendency to capture stray neutrons.

Wu knew that the more xenon built up in the reaction chamber, the more neutrons would be captured, and the fewer neutrons would be available to induce future reactions. She was right, and Fermi’s team corrected the glitch in short order. Just like that, Wu had solved one of the trickiest problems in all of experimental physics.

In 1942, Wu and her new husband, Luke Yuan, moved to the East Coast. While many of her colleagues at Berkeley had been recruited for the war effort, Wu was not asked to join, despite her considerable knowledge of atomic physics. Neither was she asked to remain on at Berkeley in a more permanent role. It was an unfortunate reality that Wu encountered discrimination for being female at a time when most of the top American universities still refused to accept women, either as students or professors. During wartime, she also faced significant ethnic racism.

When Yuan obtained a position at RCA Laboratories in Princeton, New Jersey, to work on the development of radar, Wu accepted an assistant professorship at Smith College, a women’s school in Northampton, Massachusetts. The scenario was far from ideal. The newlyweds, living 200 miles apart, only saw each other on weekends in New York City. And while Wu enjoyed teaching upstart female scientists like she had once been, she had very few opportunities to do what she relished most: solve problems in the lab.

It wasn’t long before Wu began to feel unhappy at Smith. When she vented her frustrations to her former advisor, Ernest Lawrence, he recommended her to a number of institutions in need of professors to pick up the slack while many of their staff members were on leave to help with the war. In short order, Wu was offered positions at eight prestigious universities, three of which still barred women from matriculating. She chose Princeton to be near Yuan and, in so doing, became that institution’s first female professor.

You can read this rest of this chapter in A Passion for Science: Stories of Discovery and Inventionavailable as an ebook for £1.99 from Amazon.

About the author

Maia Weinstock is an editor and writer specialising in science and children’s media. She has contributed to outlets including BrainPOP, Discover, SPACE.com, Aviation Week & Space Technology, and Science World. Maia is a strong advocate for girls and women, particularly in the areas of science, technology, politics, and athletics. Most recently, she has led efforts to increase the participation and visibility of women on Wikipedia. She has also been responsible for the creation of several short biographical cartoons of historical women in STEM, including Ada Lovelace, Sally Ride, and Jane Goodall. Among other projects, Maia is working on a documentary film profiling human-computer interaction expert Catherine Wolf and a book that takes a close look at pioneering women in the STEM fields. She also spearheads Scitweeps, a photo collection of scientists and sci/tech popularisers in LEGO. Maia has been a proud contributor to Ada Lovelace Day each year since its inception.

Web: maiaw.com
Twitter: @20tauri