Liu Hong (astronomer)

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Liu Hong
劉洪
Chancellor of Qucheng (曲城相)
In office
? (?) – ? (?)
MonarchEmperor Xian of Han
Administrator of Shanyang (山陽太守)
In office
? (?) – ? (?)
MonarchEmperor Xian of Han
Commandant of the East District of Kuaiji (會稽東部都尉)
In office
? (?) – ? (?)
MonarchEmperor Xian of Han
Gucheng Menhou (穀城門候)
In office
? (?) – ? (?)
MonarchEmperor Xian of Han
Personal details
Born129[1]
Mengyin County, Shandong
Died210 (aged 81)[1]
OccupationOfficial, astronomer, mathematician
Courtesy nameYuanzhuo (元卓)
Nickname"Mathematical Sage" (算聖)

Liu Hong (129–210), courtesy name Yuanzhuo, was a Chinese official, astronomer and mathematician who lived in the late Eastern Han dynasty. He developed a work on predicting the passage of the moon which was in use during the Three Kingdoms period of China.

Life[edit]

Liu Hong was from Mengyin County (蒙陰縣), Taishan Commandery, which is present-day Mengyin County, Shandong, and was a descendant of Liu Yu, the Prince of Lu, a son of Emperor Jing (r 157–141 BCE). He developed an interest in astronomy at an early age. He was made an officer at the Imperial Astronomy around 160 CE which led to him writing the lost works Qi Yao Shu (七曜術; The Art of the Seven Planets) and Ba Yuan Shu (八元術; The Art of Eight Elements).[1]

After the death of his father, Liu Hong retired for a short time but returned to his work, collaborating with Cai Yong on the Qian Xiang Li (乾象曆; Qian Xiang Calendar),[2] this was considered so advanced for its time that it was adopted by the Han government immediately. The calendar predicted the movement of the moon, the first time such considerations had been made in ancient China.[1] This system marked the first appearance of the argument of periapsis, a means to calculate syzygy (the calculation between three celestial bodies), and a means of charting the moon through the seasons.[3] His means of establishing the accuracy of the calendar was by the detection of eclipses.[4]

This system replaced one which had been used by the Han dynasty since 85 CE, and following the end of the Han dynasty and beginning of the Three Kingdoms period, it was adopted by the Eastern Wu state (229–280 CE) until China was re-unified under the Jin dynasty in 280 CE.[5] In 179 CE, he was asked by the Imperial Secretariat to consider proposals made by a private scholar called Wang Han regarding lunar calendars, but did not support those proposals. A year later, the Minister of Ceremonies assigned him to review alternative means of calculating eclipses

Throughout his service under the Han government, Liu Hong held various positions, including: Internuncio (謁者), gucheng menhou (穀城門候), Commandant of the East District of Kuaiji (會稽東部都尉), Administrator of Shanyang (山陽太守), and Chancellor of Qucheng (曲城相).[2]

References[edit]

  1. ^ a b c d Selin, Helaine, ed. (1997). Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures. Boston: Kluwer Academic. p. 514. ISBN 9780792340669.
  2. ^ a b De Crespigny, Rafe (2007). A Biographical Dictionary of Later Han to the Three Kingdoms (23–220 AD). Boston: Leiden. p. 510. ISBN 9047411846.
  3. ^ Zhang, Qizhi (2015). An Introduction to Chinese History and Culture. New York: Heidelberg. p. 387. ISBN 9783662464823.
  4. ^ Lingfeng, Lü (2007). "Eclipses and the Victory of European Astronomy in China". East Asian Science, Technology, and Medicine (27): 127.
  5. ^ North, John (2008). Cosmos: An Illustrated History of Astronomy and Cosmology. Chicago: University of Chicago Press. pp. 139–140. ISBN 9780226594408.