Why did the ancients in China study astronomy?

China is one of the earliest and fastest developing countries in astronomy in the world. Astronomy is also one of the four most developed natural sciences in ancient China. Others include agronomy, medicine and mathematics. Astronomy has repeatedly innovated excellent calendars, amazing inventions and insightful world views, which all occupy an important position in the history of world astronomy development. Ancient astronomy in China began to sprout from primitive society. During the reign of Emperor Yao in the 24th century BC, a full-time civil servant was set up, specializing in "watching images and timing". As early as the Yangshao culture period, people described the radiant image of the sun, and then recorded the changes on the sun, depicting the sun's edge as large as a projectile, showing an inclined sunspot.

Before16th century, the development of astronomy in Europe was very slow, and from the 2nd century to16th century, 1000 was almost at a standstill. During this period, astronomy in China developed steadily and made brilliant achievements. The achievements of ancient astronomy in China can be summarized in three aspects, namely, astronomical observation, instrument manufacturing and calendar compilation.

The earliest astronomical observations in China can be traced back to thousands of years ago. No matter the sun, moon, planet, comet, nova, star, solar eclipse, lunar eclipse, sunspot, prominence, meteor shower and other rare phenomena, there are long and rich records, with meticulous observation, accurate records, detailed descriptions and high level, which have reached the level of amazing people today. These records still have high scientific value. There are abundant astronomical records in the Oracle Bone Inscriptions of Yin Ruins unearthed in Anyang, China. This shows that as early as14th century BC, the astronomy of our ancestors was already very developed. It is universally acknowledged that China has the earliest and most complete astronomical records in the world. China was the most accurate observer of astronomical phenomena and the best record keeper before the Renaissance in Europe.

China made outstanding contributions to the creation of astronomical instruments in ancient times, and creatively designed and manufactured a variety of exquisite observation and measuring instruments. The oldest and simplest astronomical instrument in China is the earth gauge, also called the ghost watch. It is used to measure the length of the sun's shadow, and it is impossible to verify when it was first produced. In addition, Luoxia Hong in the Western Han Dynasty changed the armillary sphere, the main instrument for measuring the position of celestial bodies in ancient China, and it was improved in almost all dynasties. Zhang Heng of the Eastern Han Dynasty created the world's first elephant powered by water conservancy. In Yuan Dynasty, Guo Shoujing successively created and improved many astronomical instruments, such as simple instrument, high meter, inverted instrument and so on 10. China's observation record of Halley's Comet is long and detailed, which is recognized by the world's planetarium historians, and no country can compare with it. The comet recorded in China in 240 BC is considered as the earliest Halley's comet record in the world. From then on to 1986, Halley's Comet * * * returned 30 times, which was recorded in China. 1973, Chinese archaeologists found a beautiful comet map in Mawangdui, Changsha, Hunan. Besides comets, there are clouds, gas, occultation stars and stars in the photos. Astronomical historians have made textual research on this ancient picture and called it "astronomical and meteorological miscellaneous business", believing that it is the oldest comet map found in the world so far. As early as more than 2,000 years ago in the pre-Qin period, our ancestors had made detailed observations on various forms of comets, not only drew three-tailed comets and four-tailed comets, but also seemed to be able to peep into the comet nucleus, which is difficult to see with large telescopes today, which is enough to show how meticulous the astronomical observation in ancient China was.

The ancients were diligent in observing the positions of the sun, moon and stars and their changes. The main purpose is to grasp the regularity of such astronomical phenomena by observing them, so as to determine the four seasons, compile calendars and serve production and life. The ancient calendar in China includes not only the calculation of solar terms, the allocation of days per month, the arrangement of months and leap months, etc. It also includes many astronomical contents, such as the calculation and prediction of the occurrence time and visibility of solar and lunar eclipses, and the calculation and prediction of the positions of the five major planets. On the one hand, it shows that China paid attention to astronomy and astronomical phenomena in ancient times. At the same time, this astronomical phenomenon is also one of the important means to verify the accuracy of the calendar. Determining the length of the tropical year is the basis of the calendar? The time interval between two consecutive winter solstices is a tropical year. According to the observation results, China improved the calendar hundreds of times in ancient times. The Calendar of Service compiled by Guo Shoujing in A.D. 1280, after more than three years and 200 calculations, adopted 365.2425 days as the length of a tropical year. This value is the same as the current Gregorian calendar in the world, and Guo Shoujing was able to measure it so accurately six or seven hundred years ago, 300 years earlier than the European Gregorian calendar, which is really remarkable. When China's ancestors were still living in the era of eating and drinking blood, they already knew how to "work and rest at sunrise and rest at sunset" according to the "schedule" arranged by nature. The repeated movement of the sun rising in the east and setting in the west has formed the most basic concept of time-"day" and produced the most basic unit of time "day". Around the Shang Dynasty, the ancients had the concept of dividing a day into dawn, early morning, noon, afternoon, afternoon, dusk and night. After the invention of clepsydra, people usually divide the day into 100 minutes. From summer to around, "the day is sixty minutes long and the night is forty minutes short"; Around the winter solstice, "the day is forty minutes shorter and the night is sixty subjects longer"; Around the vernal equinox and autumnal equinox, there are 50 hours of day and night. Although the length of day and night is different, the total length of day and night is the same, which is 100 minutes a day. The great development of modern natural sciences, including astronomy, first began in the European Renaissance. The Renaissance is roughly from14th century to16th century, which is roughly equivalent to the period from the early Ming Dynasty to Wanli in China. Astronomical historians in China believe that during these 200 years, the main progress of astronomy in China can be listed as follows: (1) translating astronomical events in Arabia and Europe; During the 20-odd years of 1405- 1432, Zheng He led his fleet abroad many times. During the ocean voyage, these ships used "pulling stars" to determine their own direction, which contributed to the development of marine astronomy. Some special astronomical phenomena have been carefully observed, such as "Gedaokexing" in 1572 and "Tailing Kexing" in 1604, which are two rare supernovae.

There are many names of ancient astronomical observatories in China, such as Lingtai, Stargazing Platform, Four Rooftops, Stargazing Platform and Observatory. The best preserved today are the Dengfeng Observatory in Henan and the Beijing Ancient Observatory.

There are many sunspot records in China. For example, Huainanzi, written around 140 BC, said: "There are black spots in Japan and China." A record in BC 165 said: "Japan and China each have a king." A record from the Warring States Period described it as "a statue of a man standing in Japan and China". Earlier observations and records can be traced back to the records of sunspots in Oracle Bone Inscriptions, which has been more than 3,000 years. There were more than 1, 000 detailed and reliable sunspot records in China from 28 BC to the end of Ming Dynasty. These records not only have exact dates, but also describe the shape, size, location, division and change of sunspots in great detail and seriously. This is a very precious scientific heritage of China and people all over the world, and it is also a very precious historical material, which has important reference value for studying solar physics, solar activity law and global climate change.

The comet of the seventh year of Qin Shihuang (240 BC) recorded in Historical Records of Qin Shihuang is regarded by scholars all over the world as the earliest Halley's comet record in the world. From then to 1986, Halley's Comet * * * returned for 30 times, which was recorded in China local chronicles and local chronicles. In fact, China recorded Halley's Comet earlier. In his later years, Yuzhe Zhang, a famous astronomer in China, made textual research on the words "The King of Wu cut down the tomb, welcomed the Spring Festival in the east, and gave the Yin people a handle when the comet came out" in the book "A Brief Introduction to the Soldiers in Huainan", and thought that the comet that appeared at that time was also Halley's comet. He calculated the orbit of Halley's comet for nearly 4,000 years, and confirmed from other mutually corroborating historical materials that the exact age of the Wuwu attack should be 1056 BC, thus advancing the earliest recorded age of Halley's comet in China by more than 800 years.

In ancient China, famous meteor showers, such as Lyra meteor shower, Perseid meteor shower and Leonid meteor shower, were recorded many times, including Lyra at least 10 and Perseid at least 12. The Leonid meteor shower is especially famous for its grand performance in 1833. From 902 to 1833, China, Europe, Arabia and other countries recorded 13 Leonid meteor showers, including 7 in China, and the earliest one was on February193, which is the second chronicle in the world. Since the 7th century BC, there have been at least 180 such meteor showers in ancient China.