The Eclipse of 21 June 1629 in Beijing in the Context of the Reform of the Chinese Calendar

TL;DR

This paper analyzes the 1629 Beijing eclipse predictions by Chinese, Muslim, and Jesuit astronomers, revealing Jesuits' superior accuracy and their role in initiating Chinese calendar reform and European-Chinese scientific collaboration.

Contribution

It demonstrates that Jesuit predictions were the most accurate and highlights their influence on the Chinese calendar reform and early Sino-European scientific exchange.

Findings

Jesuits made the most accurate eclipse predictions.

The eclipse prediction influenced the Chinese calendar reform.

This event marked the start of significant European-Chinese scientific collaboration.

Abstract

This paper examines the predictions made by Chinese, Muslim and Jesuit astronomers of the eclipse of 21 June 1629 in Beijing, allegedly the event that determined Emperor Chongzhen's resolution to reform the calendar using the Western method. In order to establish the accuracy of these predictions, as reported at the time by the Chinese scholar and convert Xu Guangqi, we have compared them with an accurate reconstruction of the eclipse made at NASA. In contrast with current opinions, we argue that the prediction made by the Jesuits was indeed the most accurate. It was in fact instrumental in dissipating Chongzhen's doubts about the need to entrust Jesuit missionaries serving at the Chinese court with the task of reforming the calendar, leading to the first important scientific collaboration between Europe and China.