As moon-gazers look skyward during the Mid-Autumn Festival weekend, they should spare a thought for Wang Zhenyi, one of China’s most notable astronomers and mathematicians – and a woman. Living during the Qing dynasty (1644-1912), when a learned woman was expected to do little more than ornament a household with poetry, Wang wanted something bolder: to explain eclipses. Her answer was physical, not mystical. It involved light, shadow and the movement of the moon. Using a round table for the...