Chinese Astronomy

Freddie Yao

AN INTRO TO CHINESE ASTRONOMY

1

The Chinese have a rich history in terms of what they know about constellations, eclipses, and accurate time measurements. Their astronomical knowledge dates back to the Shang Dynasty which went from 1600 - 1046 BC. They had a unique system of naming stars called the “Twenty-Eight Mansions.” From this, they were able to keep immaculate records of solar and lunar eclipses, comets, novae, sunspots, and meteors. Chinese astronomy differed from the western world in that they believed it was polar and equatorial rather than planetary and eclip-tic. One important thing to note was that the Chinese believed that the earth was flat until the 17th century, which was quite extraordinary considering how accurate their measurements of the sky were. Historians believed that the Chinese were the most accurate observers of celestial phenomena like eclipses. The Chinese had many foreign influences which helped them thrive in their astronomical research. Also, their understandings of the sky influ-enced Chinese astrology, which is world-renowned.

Influences

2

Indian AstronomyMany elements of Indian astronomy reached China through the expansion of Buddhism. The Indians used a con-stellation system called the nakshatra, which was equivalent to the famous “28 Mansions” of the Chinese. The Chinese used the nakshatra to refine their own “28 Mansion” system. The Indians also brought in a table of sines that helped with the mathematics used in Chinese measurements. Lastly, the Indians wrote about their knowl-edge in the Rig Veda, which is similar to the “Oracle Bones” of the Chinese.

JesuitsIn the late 1500’s, the first Jesuit missionary fathers succeeded in entering China, and brought their knowledge of the flourishing sciences in Europe. Their scientific work (which was mostly astronomical) was intended to aid their religious teaching. Because of the jesuits, the Chinese were able to get a more westernized view of astronomy and over time, discovered the earth was round. The jesuits also introduced the telescope to the Chinese, which was ex-tremely important for their understanding of the sun, moon, and planets, since they could now look at them in-depth. Lastly, they were able to convince the Chinese that the Earth was round instead of flat.

3

In the Chinese calendar, a year was set to twelve lunar months. Through precise measurements, they calculated that these twelve lunar months were exactly 365.25 days. They then translated 365.25 into a unit of degrees, by setting the number of degrees in a circle equal to 365.25, which is contrary to our 360 degree circle. They also divided the sky into four quarters: they are the Azure Dragon on the east, White Tiger on the west, Black turtle on the north, and the Vermillion Bird in the south. They contained seven so-called “mansions” in each quarter, making 28 in total, and these were used to chart the position of the moon as it crossed the sky. In other words, Chinese astronomers sliced the celestial sphere into 28 unequal segments. Each slice varied from over 30 degrees to less than 2. These slices were called “Hsiu,” though schol-ars today refer to them as “lodges” as opposed to “lunar mansions”. The “Twenty-Eight Mansions” are equivalent to the zodiac constellations in western astronomy, though the Twenty-eight Mansions reflect the movement of the moon through a sidereal month rather than that of the sun through a tropical year. Indian and Islamic astronomy had systems of the same kind: Indian used the nakshatra and Islamic astronomy used the manazil, both of which were used to chart the position of the moon. The manazil, similarly to the Chinese, determined that there was 28 “houses” that the moon moves through in one normal solar year, with each of these “manazils” lasting thirteen days. On top of that, they also divided the sky into four quarters, though they did not assign an animal to each quadrant. Another interesting fact was that the Indian nakshatra basically had the exact same structure as the “28 Mansion.” 18 of the 28 “hsui” determinatives were identical to the corresponding junction stars or the yogataras of the Indians. However, the only major difference between the two systems was that the Indians didn’t show the keying of the “hsui” and the circumpolar stars, which is the essence of the Chinese system.

28 Mansions

Oracle Bones

4

Oracle bones were first used in the 14th century B.C. for the inscription of astronomical records, along with weather, fortunes, and military assignments were. Oracle bones were typically made up of turtle shells or the bones from oxen. The Chinese would then use a sharp heated tool to inscribe Mandarin regarding their astronomical hypotheses or recordings. Through the oracle bones, peo-ple were able to confirm the existence of the Shang dynasty, which was a dynasty many doubted existed. The oracle bones are still studied today by westerners to fully understand the logic of the astronomers from ancient China.

SECTION 4

Gan De (4th Century BC): made some of the first observations of Jupiter. He was also the earliest astronomer to take notice of sun-spots. Also, he and Shi Shen, were the first to observe solar and lunar eclipses.

Shi Shen (4th Century BC): Together, he and Gan De believed that the celestial sphere was 365.25 degrees, while the majority of the other foreign astronomers believed that the celestial sphere was 360 degrees.

Zhang Heng (79-139 AD): He compared the celestial sphere to the diameter of the earth and from that, was able to find the nu-merical value of pi.

Guo Shoujing (1231-1316): He created many important tools used for astronomy. His most famous creation was that of an accu-rate calendar through his observations of the sky, which would be used by China for the next 400 years (1280-1680).

Shen Kuo (1031-1095): He is known for his explanation of the variations of planetary motion. Through his explanations of the variations of the planets, he was able to argue against the previ-ous theory of the earth being flat.

Key Astronomers

5

SECTION 5

Key Dates

6

! •! 2137 BC - On October 22, Chinese finish making the book Classic of History; records the earliest known so-lar eclipse.! •! 2000 BC - claim that Jupiter needs 12 years to complete one revolution of its orbit.! •! 1200 BC - Chinese divide the sky into twenty eight regions( Chinese constellation); for recognitions of the stars.! •! 1100 BC - Chinese first determine the spring equinox.! •! 776 BC - Chinese make the earliest reliable record of solar eclipse.! •! 613 BC - July, a Comet, possibly Comet Halley, recorded in Spring and Autumn Annals.! •! 364 BC - Earliest recorded observation of sunspots made by Gan De. ! •! 185 - The earliest recording of supernova RCW 86! •! 687 - Chinese make earliest known record of the meteor shower.! •! 1054 - July 4, Chinese astronomers noted the appearance of a guest star, the supernova now called the Crab Nebula, Messier's M1.!

CHAPTER 2

7

The Impact of Chinese Astronomy

SECTION 1

Key Contributions to Astronomy

8

-Armillary spheres, astronomical instruments used to represent the celestial sphere, were the most important instruments for Chinese astronomy. They became extremely important for observing the stars since it contained a framework that represented the ecliptic and the lines of latitude/longitude.

-The Chinese celestial globe helped influence western star maps since the Chinese made extremely accurate mappings of the constellations.

-Chinese records are still of value to modern astronomers. For example, obser-vations of sunspots from 1st century BC have been studied as a way of under-standing the variation of solar activity over.

-The Chinese were the first to connect astronomy to navigation. People had to rely on the observations of the sky in order to find out their locations.

SECTION 2

Chinese Astrology

9

The Chinese Zodiac come from the discoveries of Chinese astronomy. It first came to prominence in the Han dynasty. The signs are based on a 12 year cy-cle from the Chinese lunar calendar, with each year representing an animal. The selection of the animals were based on the animal’s characteristics and behavior. To this day, people believe that there is a special relationship with the person and the Chinese zodiac animal he/she is associated with. Accord-ing to Chinese astrology, a person's destiny can be determined by the posi-tion of the major planets at the person's birth along with the positions of the Sun, Moon and comets and the person's time of birth and zodiac sign. The system of the twelve-year cycle of animal signs was built from observations of the orbit of Jupiter.

The Chinese Zodiac animals are the rat, ox, tiger, rabbit, dragon, snake, horse, sheep, monkey, rooster, dog, and pig.

Chinese Astronomy was extremely influential in terms of the ideas that they presented. Though the Chinese were also influenced by others, the idea of the “28 Mansions” is one of the most important astronomical proposals that influenced, and continues to influence, astronomy worldwide due to their precise measurements. The most interesting fact about Chinese Astronomy is that when comparing all of the measurements and discoveries to western measurements, they are almost identical in terms of precision, though all of the Chinese measurements were made around 2,000 years ago. Lastly, the inventions that the Chinese made are still extremely present today. For instance, the celestial globe is still used to map constellations.

CHAPTER 3

10

Conclusion

CHAPTER 4

11

SourcesCullen, Christopher. "Joseph Needham on Chinese Astronomy." Past and Present,      No. 87 (1980): 39-53. Print. Dubs, Homer H. "The Beginnings of Chinese Astronomy." Journal of the American      Oriental Society, 78.4 (1958): 295-300. Print. https://explorable.com. N.p., n.d. Web. 12 Oct. 2014. <https://explorable.com/      chinese-astronomy>.Needham, Joseph. "Astronomy in Ancient and Medieval China." Philosophical      Transactions of the Royal Society of London. Series A, Mathematical and      Physical Sciences 276.1257 (1974): 67-82. Print. http://www.travelchinaguide.com. N.p., n.d. Web 12 Oct. 2014 <http:// travelchinaguide.com/intro/social_customs/zodiac/