고대 동양 별자리와 하늘 방위의 기원

Abstract

Although the earth was believed to be a center of the Universe, the ancient Chinese astronomers thought that the rotating celestial sphere had 4 directions. Defining the celestial direction appears to be originated from the knowledge of the seasonal change and the Sun's culmination and location on a particular sky. We investigated various ancient chinese astronomical records including Huai Nan Tzu (around 139 BC) and Shih Chi (BC 104 - BC 91) to find out the sources of the celestial direction defining work. Using the `Starry Night' simulation program, we investigated the location and change of the winter solstice point on the ancient sky. We confirmed that the celestial northern point on the sky was fixed at the ‘emptiness’ constellation (one of 28 lunar mansions), which had been a Winter solstice point around BC 1700-1800. About 1500 years later, when ancient chinese astronomers observed the easterly shift of the Winter solstice point, not fixed at the previously defined N point on the sky. Apparently, their finding of the discordance between N-sky point and Winter solstice around BC200 had a strong influence on their ancient cosmological view: they thought the sky (celestial sphere itself) had shifted westerly and its north-west part tilted downward, while the south-east part of the earth slightly moved upwards.