雙語科技百科(天文) 第2期:古人觀天
Heaven in the Eyes of Ancient Chinese People
It is said in the ancient times, Gong Gong (a half man and half snake monster) and Zhuan Xu (a god) had a hard fight for control of the heaven, with Zhuan Xu emerging as the perated by failure, Gong Gong went to the northwest corner of the earth and knocked down the Buzhou Mountain,which was one of the eight pillars supporting the sky. As a result, the northwest sky collapsed and the southeast earth sank. Subsequently, the sun, moon, and stars in the sky all slid to the northwest, while the water and silt on the earth flowed to the southeast.
相傳在遠古時候，共工和顓頊兩人爲了爭奪天下發生了爭戰。共工失敗後，一氣之下跑到了大地的西北角，撞倒了那裏的不周山。不周山原是八根擎天柱之一，撞倒之後，西北方的天就塌了，東南方的地也陷了下去。於是，天上的日月星辰都滑向西北方，地上的流水泥沙都流向了東南方。Whenever encountered with natural phenorpena they could not explain, the ancient Chinese people tended to create various legends with their imagination to show their abovementioned is a legend vMdly showing their spec-ulation on the cosmic structure.
當古人對自然現象的成因不能理解時，他們往往會藉助想象，創造出各種各樣的神話傳說，以表達他們對自然界發生的各種現象的揣測。這則神話生動地反映了古人對於天地結構的推測。
The period between the 3rd and 6th centuries witnessed enormous develop-ment in China's astronomy, with the rise of many theories on the cosmic most important of these were the theory of canopy-heavens, the theonrt of sphere heavens, and the theory of expounding appearance in the night sky.
公元3到6世紀是中國天文學快速發展的時代。在這段時期內，涌現了許多討論天地結構的學說，其中最重要的是蓋天說、渾天說和宣夜說。The Theory of Canopy-Heavens
蓋天說The oldest theory on cosmic structure, the early school of canopy-heavens claimed that the heaven, shaped like a big pan, covered the earth, shaped like a chessboard.
蓋天說是中國最古老的討論天地結構的體系。早期的蓋天說認爲：天就像一個扣着的大鍋覆蓋着棋盤一樣的大地。According to the theory, the sun moves all year round along seven paths,called Qi Heng, and the innermost one was called Nei Heng (Inner Path) , along which the sun moved on the Summer Solstice ( around June 22～ 23) outer-most one was called Wai Heng ( Outer Path) ,and the sun moved along on the Winter Solstice (around December 22～ 23)ng other solar terms, the sun moved along the middle five cators of this school also claimed the sun-light could only reach a maximum distance of 167,000 11 (83,500 km) , and noth-ing could be seen beyond. Therefore, they said, the sun moved within the said distance during the day, and beyond during the night.
蓋天說認爲，太陽在天蓋上的週日運動一年中有七條道路，稱爲“七衡”。最內一道叫“內衡”，夏至日太陽就沿內衡走一圈；最外一圈叫“外衡”，是冬至日太陽的路徑；其他節氣裏，太陽沿中間的五道運行。他們還主張，太陽只能照射16.7萬里（83500千米），超過這個距離就什麼也看不見了。因此白天就是太陽走到距離我們16.7萬里以內的範圍，而晚上則在該範圍之外。The Theory of Sphere-Heavens
渾天說In his book Note to the Arm,illary Sphere , Zhang Heng(78～ 139) , a famous astronomer in the Eastern Han Dynasty,wrote that the heaven was like an egg,with the earth as the yolk inside, and that the heaven wrapped up the earth just as the eggshell did the yolk. This represents a classic elaboration on the theory of sphere-heavens.
東漢著名天文學家張衡(78—139)在《渾天儀注》一文中寫道：“渾天如雞子，天體圓如彈丸。地如雞子中黃，孤居於內，天大地小……天之包地如殼之裹黃”。天就像一個雞蛋，大地像其中的蛋黃，天包着地如同蛋殼包着蛋黃一樣。這是對渾天說的經典論述之一。According to the theory, the heaven was higher in the north and lower in thesouth, revoMng around a north-south axis. The east-west axis, vertical to the north-south one, was the heavenly equator. The plane to which the equator is tilt-ed 24。was the ecliptic, and the sun moved along the plane.
渾天說還認爲．天球北高南低，通過南北天極的軸旋轉。垂直於南北極軸把天球平分成南北兩半的大圓就是天赤道。與赤道斜交成大約240角的大圓是黃道，太陽在黃道上運行。The theory of sphere-heavens played an important part in the history of Chi-nese astronomy, exerting significant influence on the design and manufacture of anaent astronomic instruments, as well as on the explanation of relevant astro-nomic theories.
渾天說在中國天文學史上佔有重要的地位，對中國古代天文儀器的設計與製造產生了重大的影響，對天文學的有關理論問題的解釋也產生了重大影響。The Theory of Expounding Appearance in the Night Sky
宣夜說As a legend goes, during the Warring States Period, a man from the Qi State,having known that the heaven was constituted of gas, in which the moon and stars floated, feared the heaven might collapse one day. Thinking that he would have nowhere to go by then, the man became deeply worried, and lost his of his friends brought him to a wise man that helped him to put the things in the right perspective by saying, "The sun, the moon, and the stars are also com-posed of gas. Even if they drop from the heaven, it would mean a collision be-tween gas, and no harm will be caused."
傳說戰國時期，杞國有一個人聽說天是由氣體形成的，日月星辰就漂浮其中之後，他非常擔心天體會掉下來，讓他無處躲藏，於是整日憂心忡忡，茶飯不思。朋友1把他拉到一位智者那裏，智者開導他說：“日月星辰也是氣體形成的，即使它們掉下來，也是氣體落入氣體中，不會造成任何損傷。”In the previously two cosmic theories, the sun, the moon, and the stars all had a shell, meaning there was no reason for them to fall from the r,however, the ancient people found the celestial bodies moved freely from one place to another at a fast or slow speed, and sometimes, they might not move atall, hence giving rise to the new theory of expounding appearance in the night sky.
蓋天說和渾天說中的日月星辰都有一個可供附着的天殼，都不用擔心會掉下來。但是後來人們觀測到日月星辰的運動各自不同，有的快、有的慢，有的甚至在一段時間中停滯不前。所以就又產生了一種新的理論“宣夜說”。The advocators claimed the heaven was composed of boundless gas with no said the reason that people felt themselves so small was that the heaven was too far away from earth. The celestial bodies floated in the gas with no support, following their own movement rules. The theory broke the boundary ofheaven, exhibiting a boundless universe.
宣夜說主張：天是無邊無涯的氣體，沒有任何形質，我們之所以看天有一種蒼蒼然的感覺，是因爲它離我們太深遠了。日月星辰漂浮在空氣中，不需要任何依託，因此它們各自遵循自己的運動規律。宣夜說打破了天的邊界，爲我們展示了一個無邊無際的宇宙空間。
