Study On Biaodushuo

Biaodushuo, an astronomical work, was spread to China under the background of Chinese and Western cultural exchange in late Ming Dynasty. It mainly introduces the measurement principle and operation steps are based on the West sundial, reflecting the axiomatic arguments ideas of the western astronomy. In particular, the standards and measurement rules about “cross gnomon” and the method of making and using column sundial are first introduced in the late Ming.The paper uses some methods, such as the method of the original document textual research, comparative analysis method and comprehensive analysis method. The main works in this paper is as follows:The first chapter introduces Biaodushuo from different aspects.The second chapter introduces the traditional Chinese standard measurement from the following several aspects: measuring the sun’s altitude, determining the direction, calculating the shadow length of the24 Solar Terms and measuring object height. This chapter summarizes the characteristics of the traditional standard Chinese measurement in astronomy.The third chapter analysis the theoretical basis of gnomon measurement in Biaodushuo. The following five topics are discussed: the sun moves around the earth at a fixed speed, the earth is in the middle of the heavens, the earth has the ratio of a point to the heavens, the earth is a sphere and the bottom of the gnomon is the core of the earth. Combining the content of Ptolemy’s Almagest volume I, the author thinks that the theory is based on ancient Greek geocentrism.The forth chapter further studies the gnomon measurement technology, moreover, combining the theoretical basis of gnomon measurement, the paper demonstrates the Western axiomatic system in Biaodushuo.The fifth chapter explores the reason that Biaodushuo was introduced into China in the late Ming. Compare it with Jianpingyishuo, Tianwenluo, Riguituf a and Celiangf ayi, the author gets it has some relevance with the works the same period. This paper holds that the propaganda of Western astronomy knowledge in biaodushuo was not isolated but related. They are introduced into China in the form of knowledge.The final chapter as the conclusion of this paper expounds the impacts of Biaodushuo. Especially in the calendar reform and sundial making.