China Studies Program
East Asia Center
Friday October 31, 2014
12:00 p.m.
Thomson Hall 317
By the end of the Ming dynasty (1368-1644), the Jesuit missionaries introduced the concept of geographical longitude to China. The longitudinal measurement was important to the Chinese in two respects: astronomically and geographically. The Chinese astronomers were obliged to predict ominous celestial phenomena such as solar and lunar eclipses. The measurement of longitude was necessary for predicting the exact moment of an eclipse in different places, especially for provincial capitals. Also it was realized that accurate measurement of longitude and latitude were essential for map making. From 1708 to 1707, the Kangxi Emperor commissioned Jesuit missionaries to survey the empire. The result was the unprecedented work entitled "The Complete Atlas the Qing Empire." In this talk the speaker will investigate the methods used for measuring the longitude, and the accuracy of this data. He will also point out that the geodesic survey was not only a Chinese undertaking of calendar-making and the geodesic survey of the Qing Empire, but also a part of a global endeavor for the measurement of the meridian and for the controversy over the shape of earth.
Sun Xiaochun is Professor of the History of Science at the Institute for the History of Natural Science at the Chinese Academy of Sciences. He studied astronomy in Nanjing University. He received his Ph.D. in History of Astronomy from the Chinese Academy of Sciences in 1993 and his second Ph.D. in History and Sociology of Science from the University of Pennsylvania in 2007. He has published primarily on the history of Chinese astronomy and co-authored "The Chinese Sky During the Han: Constellating Stars and Society" (1997). Currently he serves as Vice-President of Commission 41 on History of Astronomy of International Astronomical Union, and a corresponding member of International Academy of the History of Science.