Emergence of Celestial Study in china

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Canon of Yao，which reflects some historical facts of time immemorial，mentions that there are 356 days in four seasons adjusted by an intercalary month in the lunar calendar.

The early ancient time was the fundamental stage for Chinese ancient astronomy（also known as the celestial study）.In the inscriptions on bones or tortoise shells of Shang dynasty there are records about solar eclipses and novas.Western Zhou dynasty was the time of great development in celestial study，with successive occurrence of series of lunar phases such as the 1st day，the 15th day and the end of a lunar month，in which the key word“new moon”was first mentioned.

According to the poem titled Tenth Lunar Month in the volume of Minor Festal Songs of the Classic of Poetry，“There Do occurred a solar eclipse at 5 o’clock in the afternoon on the first day of the 10th month bythe lunar calendar.”Apart from records of the solar eclipse，the solar-lunar combination of。oracle bone insciplion “new moon”marked the recording new stars beginning of a month. In the Spring and Autumn & Warring States period, Chinese celestial study developed from the stage of observation to that of quantitative study. Spring and Autumn Annals kept records of 37 times of solar eclipse. Astronomy by Shi Shen of the Wei state, in eight volumes, located 121 fixed stars, as the earliest extant star catalogue.

Another eight-volumed works, Astronomic Star Observation by Gan De of the Qi state, described the world’ searliest observational data for the satellite of Jupiter,2,000 years earlier than the European pioneer Galileo. These twoworks are also the world’s earliest books on astronomy. In the same period, numerous other masterpiece works came out, including The Revolution of Heaven in Book of Master Zhuang, Heavenly Questions in Collection of Elegies of Chu State, and Treatise on the Patterns of Heaven in Book of Master Huainan during Western Han dynasty. In particular the astronomical and calendar specific descriptions in Records of Grand Historian started with thetradition of including astronomical and calendar records in rich collections of Chinese historical literature over an uninterrupted period of 2,000 years or longer, as a distinctive feature of Chinese ancient astronomy or celestial science. There are records of the “four-quartering calendar” in Master Zuo Qiuming’s Commentary on Spring and Autumn Annals division of 28 star constellations and duodecimal ecliptic units in Rites of Zhou Dynasty; the first listing of all the 24 solar terms in Treatise on the Patterns of Heaven in Book of Master Huainan. The 24 seasonal division points comprise 12 seasonal markers and 12 corresponding weathers by Chinese solar calendar while the “new month”is a concept of its lunar calendar, quartering division combines the solar and lunar calendar and 365 days are adopted, adjusted with an intercalary month every four years. The quartering calendar or the “earliest calendar”, which was enacted by Emperor Wudi of Han dynasty in 104 B.C., is similar to all the previous similarcalendars such as the ancient six portioning calendar. Then this improved calendar was maintained until the 17thcentury. The aforesaid was a prominent feature of the Chinese calendar in combination with its celestial observation. One more feature is that China mainly used sundials to measure the shadows for timing, while the Western countries hardly used such devices. The Chinese celestial study took shape and laid its basis in the early ancient time.

As of the middle ancient time, Chinese celestial study experienced three times of climax:

① The first climax wasrepresented by Zhang Heng of Eastern Han dynasty. Zhang’s great astrophysical works Spiritual Constitution of the Universe was never exceeded substantively for 1,500 years afterward; it was written at a very high cognitive level, and his works on spherical astronomy, Illustrated Instructions for Armillary Sphere Making long remained the representative standard model based on ancient Chinese cosmology. Zhang Heng was also a pioneer in making the first water-driven planetarium using two-level clepsydras. The instrument, through improvement by Su Song and other scientists of Song dynasty, became the world’s earliest astronomical clock.

② The second climax occurred with Monk Yixing of Tang dynasty as the representative.Yixing was the world’s first checker of the meridian，based on which he worked out the Dayan calendar that reached a very high level of Chinese calendar systems and was referred to as a typical model by later calendar specialists.

③The third climax occurred in Song and Yuan dynasties marking the highest peak for ancient Chinese astronomical development.Then there were records of supernovas；six sets of large-scale observation instrument were already built，each weighing 10 tons，with such achievements of the astronomical phenomena observation as the Star Chart Tablet engraved on a stone in Suzhou; the scientist Su Songwrote his great works New Project for Armillary Sphere and Terrestial Globe, Shen Kuo and Guo Shoujing also made revolutionary improvements on the Chinese traditional equator observing armillary sphere, and their designing and scaling levels were 300 years ahead of the world’s level of the time, in comparison with the counterpart instrument invented by Tycho Ottesen Brahe in 1598; Guo Shoujing even formulated a more advanced Grant-to-farmer calendar in 1280, which remained useful till the end of Ming dynasty (1644). 200 years after the early Ming dynasty, Chinese celestial study entered a slump period. And not until the end of Ming dynasty, when Western study prevailed across the country, did the country enjoy some further development in astronomy.