Solar Eclipses in Chinese History and Mythology
Solar eclipses have been observed throughout history. Ancient eclipse records made in China are believed to be over 4,000 years ago. In ancient China, the solar and lunar eclipses were regarded as heavenly signs that foretell the future of the Emperor; predicting eclipses were of high importance for the state. Over four millenniums ago, two Chinese astrologers were murdered as they failed to predict a solar eclipse.
The ancient Chinese believed that solar eclipses occur when a legendary celestial dragon devours the Sun. They also believed that this dragon attacks the Moon during lunar eclipses. In the Chinese language, the term for eclipse was "Shi"(食) means "to eat". One ancient Chinese solar eclipse record describes a solar eclipse as "the Sun has been eaten".
It was a tradition in ancient China to bang drums and pots and make loud noise during eclipses to frighten that dragon away. In the nineteenth century, the Chinese navy fired its cannons during a lunar eclipse to scare the dragon that was eating the Moon.
Astronomical computations enable astronomers to calculate the dates and paths of future and past eclipses with great accuracy. Some ancient eclipse records have been particularly significant to astronomers and historians as they enabled certain historical eras and events to be dated accurately.
Astronomers can also examine ancient eclipse records to measure the rate of Earth's spin about its axis over the past millenniums. They used Chinese observations of five solar eclipses that occurred between 1161 BCE and 1226 BCE to study the rate of Earth's axial rotation over the past 3,200 years. These eclipses were scratched on oxen shoulder blades in the Chinese city of Anyang(安阳).
By determining exactly when each of these eclipses was seen and where the Moon's shadow fell on Earth in each eclipse, the scientists found that the day in 1200 BCE was 0.047 second shorter than the present day. As Chinese astronomers realized the true nature of solar eclipses, they were able to predict solar eclipses by analyzing the motion of the Moon.
Astronomy flourished in Mesopotamia, the plain between the two great rivers Tigris and Euphrates, in the dawn of civilization. Like the Chinese and Egyptian astronomers, the Babylonian astronomers observed the motions of the Sun, Moon and planets carefully and kept records of the celestial events. They are also credited with remarkable contributions to ancient astronomy.
Ancient Chinese Solar Eclipse Records
Ancient Chinese astronomy was primarily a government activity. It was the astronomer's role to keep track of the solar, lunar, and planetary motions as well as divine what astronomical phenomena may mean for the ruling emperor. Solar eclipses, infrequent and dramatic, were important enough to be recorded in chronicles and on "oracle" bones. Below are a few translated eclipse records found in the documents of ancient China from various dynasties.
"Oracle" bones are pieces of animal bones and tortoise shells inscribed with astronomical observations, that were probably used for divinations. Oracle bones hail from the Shang dynasty (c. 1600 - 1050 BC) and make many references to solar eclipses. The eclipse records are often incomplete, however, and the dating of the bones is not reliable.
On day kuei-yu it was inquired: "The Sun was eclipsed in the evening; is it good?"
Eclipse observations from the Chou dynasty and Warring States period (c. 1050-221 BC), and onward, have been reliably dated, and it appears that some astronomers recognized eclipses as naturally occurring phenomena. From the Chou dynasty, 36 solar eclipse observations are recorded in the Ch'un-ch'iu(Spring and Autumn) beginning around 720 BC. The Piao and the Shih-chi documents refer to nine solar eclipses from the Warring States period.
Jul 17, 709 BC: "Duke Huan, 3rd year, 7th month, day jen-ch'en, the first day.
Records of solar eclipses from the Han dynasty (206 BC - 220 AD) are found primarily in two official histories: the Han-shu and the Hou-han-shu. There are no records of eclipses from the Ch-in dynasty which came just prior to the Han dynasty (221 BC - 206 BC).
Jan 18, 120 AD: "Yuan-ch'I reign-period, 6th year, 12th month, day wu-wu, the first day of the month. The Sun was eclipsed. It was almost complete; on Earth it was like evening. It was 11 deg in Hsu-nu. The Female Ruler was upset by it; two years and three months later, Teng, the Empress Dowager, died." (Hou-han-shu, chp. 28)
Aug 10, 454 AD: "Hsiao-chien reign period, 1st year, 7th month, day ping-shen, the first day of the month. The Sun was eclipsed; it was total; all the constellations (i.e. lunar lodges) were brightly lit." (Sung-shu, chp.34)
In records from the T'ang dynasty (617-960 AD; dates include the Wu-tai period), eight solar eclipses are cited as being either total or very large. These were recorded in 756, 761, 879, and 888 AD (total solar eclipses) and 702, 729, 754, and 822 AD (partial eclipses).
The principle source of solar eclipse observations from the Sung, Kin, and Yuan dynasties (960-1368 AD) are the astrological treatises. Total eclipses are listed for the years 977, 1221, and 1275 AD. Annular, partial and unspecified eclipses are noted for 1022, 1054, 1135, 1214, 1292 and 1367 AD.
Jan 21 1292 AD: "Chih-yuan reign-period, 29th year, 1st month, day chia-wu. The Sun was eclipsed. A darkness invaded the Sun, which was not totally covered. It was like a golden ring. There were vapors like golden earrings on the left and right and a vapor like a halo completely surrounding it." (Yuan-shih, chp. 48)
During the Ming dynasty (1368-1644 AD), total solar eclipse observations are found in the histories of Ming provinces after 1500 AD. Prior to 1500 AD, eclipse records can be found in the Imperial Annals. These observations, however, are not of total solar eclipses.
Aug 20, 1514 AD: "At the hour of wu suddenly the Sun was eclipsed; it was total. Stars were seen and it was dark. Objects could not be discerned at arm's length. The domestic animals were alarmed and people were terrified. After one Shichen(means two hours) it became light." (local history of Tung-hsiang county, Chiang-his province)
Accurate eclipse timings can be used to determine the rate of the Earth's rotation. Solar eclipse timings can be found from the periods between 600 and 800 AD, 1000 and 1300 AD, and a brief period during the Ming dynasty. These solar eclipse timings are accurate to about 0.4 hours.