retrograd.io
 
Chinese · System c. 1st century BCE – early 1st century CE; Hanshu compiled c. 58–111 CE

Santong li: the Five Steps

Hanshu 漢書 ch. 21 'Lü li zhi' 律曆志; Santong li 三統曆 planetary section, Wubu 五步

Liu Xin's Santong li system, preserved in the Hanshu, gives each of the five planets a 'Five Steps' entry: its synodic cycle as a sequence of phases with day counts and daily rates, including explicit stations (留) and retrograde phases (逆). Jupiter, for example, stations and turns after 25 days, retrogrades 1/7 degree a day for 84 days, then stations again for about 24 days. It is the earliest fully preserved Chinese numerical model of planetary stations and retrogradation.

Author
Liu Xin
Date
System c. 1st century BCE – early 1st century CE; Hanshu compiled c. 58–111 CE
Original language
Classical Chinese
Key term
留 liu; 逆 ni; 旋 xuan (station (始留 'begins stationing', 復留 'stations again'); retrograde; 'turns', i.e. reverses)
Kind
Mathematical astronomy
Planets
Mercury, Venus, Mars, Jupiter, Saturn
On the shelf · Asia, Islam and medieval Europe · 11−1800 → 2026
−1800−1500−1000−5001500100015002026
Span · System c. 1st century BCE – early 1st century CE; Hanshu compiled c. 58–111 CESame shelfThis source’s span

Editions

2 editions.

YearEdition©
1962Ban Gu, Hanshu, Zhonghua shuju edition (1962), juan 21.?
1969Sivin, Nathan. 'Cosmos and Computation in Early Chinese Mathematical Astronomy.' T'oung Pao 55 (1969): 1–73.©
? unclear · © in copyright

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References

Also on the Asia, Islam and medieval Europe shelf

DateSourcePlanetsKind
c. 100–90 BCEShiji, Treatise on the Celestial OfficesSima QianMa JuAstrological
compiled c. 58–111 CEHanshu, Treatise on Celestial PatternsBan GuVe MaAstrological
499 CEĀryabhaṭīyaĀryabhaṭaMe Ve Ma Ju SaMath. astronomy
c. 6th century CEBṛhat Saṃhitā, ch. 6: the course of MarsVarāhamihiraMaAstrological
c. 900 CE (observations 877–918)al-Zīj al-Ṣābiʾal-BattānīMe Ve Ma Ju SaMath. astronomy
c. 1025–1028 CEDoubts concerning PtolemyIbn al-HaythamGeneralTheory / model