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Badass Ladies of Chinese History: Wang Zhenyi

This master astronomer and mathematician solved the mystery of lunar eclipses


Welcome back, “Badass Ladies” fans. If you’re new to the series, every Friday we’re highlighting exceptional women from history, from war heroes to pioneering physicians. To celebrate these women’s accomplishments, we tell the stories of their trials and tribulations, including all the places where they got to be badass along the way.

In an age when most people thought that an eclipse was a sign of angry gods, Wang Zhenyi quietly wrote a book where she said, “Actually, it’s definitely because of the moon.” Wang Zhenyi was a brilliant astronomer, mathematician, and scholar, who worked tirelessly to publish her discoveries about space. A champion of teaching math and science, she was a bit like the Qing Dynasty’s Neil Degrasse Tyson.

Wang was born in 1768 CE, which wasn’t a great time to be a woman who loved learning. The mid-1700s were rife with Neo-Confucianism, a particularly conservative strain of social philosophy. Her grandfather was a former district governor and had a preposterously large library for someone in the 1700s – over 70 books. Wang learned to read at an early age simply because books were ever-present in her home. As a teenager, she traveled extensively with her father around Eastern China.

Although Wang was happily married at age 25, education was always her first love. Because she was almost entirely self-taught, Wang understood the importance of making math and science accessible for common people, so she revised other scientists’ work to make the wording more manageable – and simplified a few dozen mathematical proofs in the process. While most mathematical texts during the Qing Dynasty were written in difficult, aristocratic language, Wang wrote two simple primers specifically for beginners. She even wrote a short paper describing gravity to laypeople, and why nobody falls off the Earth, even though it’s a sphere.

While myths and legends about space permeate Chinese history, Wang approached her study of the skies with scientific vigor. Chinese scientists have been gazing at the heavens for hundreds of years, but Wang’s application of hard mathematics to her astronomy set her apart. Wang’s focus in mathematics was primarily in trigonometry, and she independently discovered and wrote papers on the Pythagorean Theorem for the scientific community. Her brilliance was so well-renowned, she even took on a few male pupils, which was unheard of at the time.

One of Wang’s most famous demonstrations showed why lunar eclipses occurred. After consulting decades of astronomical records, she measured and arranged several objects to mimic the conditions of an eclipse; a round table in the center of a pavilion as Earth, a lamp standing in for the sun, and a mirror for the moon. By moving them precisely to reflect the way the moon and the sun moved in the sky, she showed that lunar eclipses happen when the moon passes into the earth’s shadow. Her subsequent article, “The Explanation of a Lunar Eclipse” is still considered highly accurate for its time.

Wang also prolifically wrote poetry, usually about traditionally feminine subjects like scenery or her travels with her father. She also wrote a few more subversive poems which advocated equality between men and women – quite a feat in the Neo-Confucian Qing Dynasty. She believed that women and men had the same desire to learn, so both should have equal opportunity to do so.

Wang’s contributions continue to be recognized in modern times; in 1994, the International Astronomical Union named a crater on Venus after her. While in the 21st century people are still fascinated by space (and you can even pay 580,000 RMB to visit),  it was people like Wang Zhiyi who worked to foster our natural curiosity about the cosmos into the body of knowledge we have today.


Image courtesy of She Is An Astronomer (X)

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