Chien Shiung Wu: The First Lady Of Physics

Simran Buttar

Editor at ‘The Secrets Of The Universe’, I have completed my Master’s in Physics from Punjab, India and I am currently pursuing my doctoral studies on Radio Emissions of Exoplanets in Barcelona, Spain. I love to write about a plethora of topics concerned with planetary sciences, observational astrophysics, quantum mechanics and atomic physics, along with the advancements taking place in the space industry.

Whenever it comes to talking about women in science, the only sure shot names that hit our mind are those of Marie Curie, Lise Meitner, Rosalind Franklin, Maria Mayer, etc.. And, we generally fail to add another women scientist to our list who thoroughly altered the modern physical theory and changed our accepted view of the structure of the universe.

Well, most of you won’t know about her, but here I’m talking about Chien-Shiung-Wu, the Queen of Nuclear Research! So today, on the occasion of her 108th birth anniversary, let’s delve into the life and glorious achievements of this wonderful lady!

Early life and Education:

On May 31, 1912, a girl was born to two politically progressive parents, Zhong-Yi and Fanhua Fan in a small town located near Shanghai, China. During those times, prejudice against women’s education was on peak. But, things were different for Wu’s family as they knew and understood the importance of education. Wu’s parents saw her as the shining future of their country and always encouraged her to pursue Science and Mathematics.

Read all the articles of Basics of Astrophysics series here

Wu completed her elementary education with flying colors from the school built by her parents to promote girls’ education. Then, she became the first girl from her region to leave her hometown to pursue higher studies.

Her grades in high school were so impressive that the usual entrance examination required for admission to university was waived off for her and she was immediately offered a place at the National Central University in Nanjing.

Here, she initially pursued a degree in mathematics, but soon she switched her major to physics, after being inspired by her idol Marie Curie, and hence, set herself on the path that eventually got her the nickname “Chinese Marie Curie”!

The Journey To Become The “Queen of Nuclear Research”:

Wu conducted her first experimental research in X-ray crystallography under the mentorship of Dr. Gu and it was Dr. Wu who encouraged her to pursue her graduate studies and then the doctorate in the United States.

Wu’s brilliance and expertise were at par with leading experimentalists of that era and this made her quite famous in the experimental community. Among physicists, the saying went like this: “If the experiment was done by Wu, it must be correct.” Once, Enrico Fermi had some issues with one of his experiments, and even he was advised to consult Wu regarding this.

Related:
The woman who wrote the most brilliant “Ph.D. thesis in Astrophysics”
Most inspiring quotes by Richard Feynman
3 life lessons that we can learn from Paul Dirac

The Manhattan Project:

Taking into consideration Wu’s expertise, in 1944, she was invited to join the top-secret Manhattan Project under the auspices of her former professor, Robert Oppenheimer. There, she worked on some crucial problems including uranium enrichment and radiation detection at Columbia University. Wu was the only Chinese person to work in the war department and one of the only women among its senior researchers.

After leaving the Manhattan Project in 1945, Wu went to spend the rest of her career in the Department of Physics at Columbia. And, this is where she performed the most elegant experiment of her life, the parity violation experiment. So let’s find out what this experiment was and how it changed our perspective of nature.

Wu’s Parity Violation experiment :

Until 1956, the conservation of parity was considered as a law of nature. Parity conservation simply means that the laws of physics are the same in a mirror reflected universe. Parity operation means changing the coordinates of a system from (x,y, and z) to (-x,-y, and -z). It was assumed that when an isolated system of fundamental particles interacts, the overall parity remains the same, that is, it is impossible to distinguish left from right and clockwise from anti-clockwise.

In other words, the symmetry is always retained. This law had become an intrinsic part of quantum mechanics and was seen as a fundamental law of nature. However, Lee and Yang had something else to say. They theorized that parity conservation does not apply to the weak force and must be violated in beta decay. But they needed someone to prove them true. And, this is when they approached the queen of experiments, Chien Shiung Wu.

Using super-cooled radioactive cobalt, Wu devised a series of experiments to prove this so-called fundamental law of science wrong. Wu compared the detection rate of β-particles when the Co-60 nuclei were polarized in the positive z-direction to when they were polarized in the negative z-direction. An anisotropy was recorded which indicated a violation of parity.

If the law of parity conservation was true, the cobalt nuclei would have broken down into the same number of electrons in symmetrical directions, but this was not the case. And thus, after months of operating on only a few hours of sleep a night, she was able to prove the violation of parity. Wu even canceled a long-awaited return visit to China to make this experiment a success. Such was the level of her dedication and commitment!

More in particle physics:
Understanding the Feynman diagrams in physics
The experience of an internship at CERN’s LHC
How the daughter of a physics teacher created the 5th state of matter at home

Though the fact that parity is violated in weak decay does not sound that exciting, but back then, it spread like a wildfire. Compare it to today’s hypothetical news, “An experiment confirmed particles moving faster than the speed of light.” This sounds quite exciting because a major principle of a well-established theory or the so-called ‘law of nature’ has been broken by something new. Similarly, parity conservation was a well established and its violation was a very important milestone in physics.

The Nobel Prize and Wu :

Lee and Yang were later awarded the Nobel Prize in Physics in 1954 to disprove the Conservation of parity. But sadly, Wu’s efforts in proving their theory right went unacknowledged.

She was excluded from the well deserved Nobel, as were many other female scientists during that time. Wu was well aware of gender-based injustice and at an MIT symposium in October of 1964, she stated “I wonder whether the tiny atoms and nuclei, or the mathematical symbols, or the DNA molecules have any preference for either masculine or feminine treatment.”

Although her experiments did not win her a Nobel in Physics, they definitely gave her the title “The First Lady of Physics,”. Wu was decorated with honors in every other way, including the National Medal of Science and the Wolf Prize in Physics. She even had an asteroid named after her in 1990.

But for this genius lady, the glory of her scientific discoveries was the best award one could ever get. Due to her extreme devotion to her work and a dynamic attitude towards her life, Wu is rightly remembered as a trailblazer in the scientific community and definitely serves as an inspirational role model for many.