kuo shou jing
Guo Shoujing, yu think, Xingtai (now Hebei Xingtai), was born in a family of scholar, his grandfather Guo Rong proficient in astronomy, mathematics, water conservancy, is a famous scholar in Jin and Yuan dynasties. The monasteries, Guo Shoujing was interested in scientific knowledge, 20 years old when he made a very precise copper lotus leakage (timer). Later, he put the lotus leakage to Kublai Khan, deep appreciation. Because of his familiarity with the water conservancy, Khan appointed him to have less water (water, the prison officials) Guo Shoujing embarked on the road of scientific inventions.
Kublai unified Chinese, in order to grasp the laws of climate change throughout the season, the guidance of agricultural production, the establishment of specialized agencies, in Yuan Yuan thirteen years (AD 1276), the appointment of the famous scientist Guo Shoujing, Wang Xun made a huge calendar reform. Guo Shoujing is an outstanding scientist, he first proposed: "the calendar is in the test, and the test apparatus, not ahead of the instrument" correct proposition. In support of Kublai Khan, in the calendar reform, with his hand to create astronomical instruments: simple instrument, high table, planetarium and other 18 kinds, among which the most important is simple and high table. At that time, in the east of the Korean Peninsula, from the west to the Hexi Corridor, north to Siberia, South China Sea, set up 27 observatories, a "Four Seas" test". Dengfeng Gaocheng Observatory, was the center of observation station. Yuan sixteen years (1279), Guo Shoujing came to Dengfeng Gaocheng town. The history of Nangong, the Duke of Zhou Ji Dan, said Yao Xuan, a bank and other sages all made the earth center, measuring the shadow of the sun, the seasonal variation of seasonal verification, after some investigation, Guo Shoujing decided to build a center here in the observatory. He designed the building project, led by people in the "sunshine measurement Taiwan" next to set up their own "Observatory", which is now the Dengfeng observatory.
The Observatory for the masonry structure building, covered by a bucket shaped body and Shi GUI (GUI). Taiwan is observation astrology and calculation of data locations; Shi GUI also known as the "ruler", is an instrument for measuring the level of. Guo Shoujing, Wang Xun, et al. Measurement of shadow, two flat ditch in the Shi GUI above, were filled with water, according to the principle of "pinhole imaging" placed "Jing fu". In table 40 a foot frame beam. In Japan, "Jing Fu" by beam shadow projection in Shi GUI, this is the day of the length of shade, Guo Shoujing et al. Through field test, grasp the operation law of the sun and the moon and the stars and the earth, by twenty-four, especially the exact moment of summer solstice, winter solstice and equinox, estimated a return to the length of the year is 365.2425 days, and 365 days at 5:49 today for 12 seconds, only 26 seconds of real time measuring the earth orbits the sun and modern astronomers with precision instruments. Guo Shoujing yuan eighteen years (1281) worked out a new calendar, according to the "book of history" in the "King Day Award" this sentence, Kublai Khan to the new calendar named "calendar time", and the architect of the country. "Calendar time" and many countries in the world use the Gregorian calendar (the Gregorian calendar) minute, but high in beeghly calendar three hundred years earlier.
The Dengfeng Observatory is an astronomical building the earliest extant Chinese intact, is currently the world's one of the earliest observatory. The observatory can not only measure the shadow, but also can measure the stars. Historical records: the Observatory's role is "day. The shadow of the sun, night view star, is to one day". The observatory is the precious heritage of astronomical science in Chinese, and it Chinese ancient "four great inventions" - papermaking, printing, the compass and gunpowder are equally important, is the symbol of the Chinese nation. Now, Guo Shoujing and the Observatory has been included in the fifth grade China primary school textbooks, become an important chapter of life, promote the scientific enlightenment. High table style observatory as Guo Shoujing's original, the country was only six, but from the measured records and real, only the most (now Beijing) and Yangcheng (now Gaocheng two), has been preserved, only one of the yangcheng. The observatory is a valuable heritage of the history of the development of astronomical science in China and the important physical data, reflects the outstanding achievements in the development of ancient astronomical science in China, for there is a very high value of China's history and architectural history of astronomy.
Due to Guo Shoujing's great contribution, in 1977, by the international Asteroid Research Association approved, the Chinese Academy of Sciences Purple Mountain Observatory in 1964 found 2012nd asteroid, officially named "Guo Shoujing star."". In 1981, the International Astronomical Society meeting in Beijing, the United States decided to found on the moon in a crater, named "Jing shan".