太白行度考--中國古代の惑星運動論(一)

Abstract

In this paper Venus, the star that the ancient Chinese called Tai Bai, is studied as the first step to analyze the theory of planetary motion in ancient China. The main material for this study is the Wuxingzhan 五星占, The Divination of Five Planets, which is one of the silk manuscripts excavated in from Mawangdui Han tombs 馬王堆漢墓. In the Wuxingzhan, the theory of five planetary motion and the divination are described. It gave a detailed description of the period and speed of Jupiter, Venus and Saturn’s. The most remarkable description is that of Venus, a very unique theory that has never been known up to now. The theoretical ground of the Wuxingzhan is Zhuanxu li 顓頊暦. The theory of planetary motion of Zhuanxu-li has not been known at all. The discovery of the Wuxingzhan made it possible to discuss the primary formation of the theory. After correcting the restored texts, the author made a mathematical analysis of the period and speed of Venus’ motion described in the Wuxingzhan. Then the author tried to compare it with the Chapter of Celestial Governors (Tianguanshu 天官書) of the Shiji 史記 and Kaiyuan Zhanjing 開元石經. The Tianguanshu of the Shiji written by Sima Qian 司馬遷 who played an important role in establishment of Taichu-li 太初暦 is too difficult to read. Comparing it with the Wuxingzhan, however, enables us to read it and it turned out the reason why the description of the Tianguanshu has some incoherency. Following the former theory, The Tianguanshu adopted the new theory of Zhuanxu li and Taichu li and modified them partly, so the old theory and the new one were intermingled there. In addition, by comparing with the theory of planetary motion in Santong-li 三統暦 and Sifen-li 四分暦 the author tried to find out the process of its development.