Chujia Kuang (邝楚嘉)
Independent Researcher, Jieyang, Guangdong, China
Corresponding author: Chujia Kuang, Independent Researcher, Jieyang, Guangdong, China. Correspondence: kuangchujia.com/contact
Abstract
A star-chart application on a phone answers the question “what is out there”. A Tang-dynasty star chart or a Song-dynasty engraved celestial map answers a different question: “where are we, and how should we live”. This preface to a series on ancient Chinese astronomy sets out the method rather than the findings. It argues that celestial observation in early China was a matter of state: the calendar fixed the times of sowing and of taxation, and the sky supplied the observable evidence that political legitimacy required. Against that background the series adopts a narrow definition of evidence — only claims traceable to observable, checkable, comparable material are treated as such, and everything beyond that is labelled as inference. Two kinds of material are used in harness: transmitted texts, which supply the frame, and excavated material, which X-rays it. Three conventions govern the reading: no formulas, a strict separation between astronomy and astral divination, and an explicit label on every contested point. The note is methodological; it makes no original claim and no prediction.
Keywords: history of astronomy; ancient Chinese calendrics; oracle bones; transmitted texts; source criticism; astral divination; archaeology of astronomy
1. Two charts: why look up at all
Load a star-chart application on a phone and point it at the night sky. Constellation lines, planetary names, satellite orbits — even the minute at which the International Space Station will pass overhead — appear on the screen at once. The chart is clean, immediate and available to anyone. Behind it lie several centuries of celestial mechanics, several generations of survey telescopes, and a globally shared coordinate system. It answers the question “what is out there”.
Set an old star chart beside it — the Dunhuang chart of the Tang dynasty (S.3326), for instance, or the celestial map engraved on stone at Suzhou in the seventh year of Chunyou in the Southern Song. The first renders more than thirteen hundred stars in fine ink, graded by brightness, with the Milky Way drawn as a washed band and the distances of the twenty-eight lunar mansions written alongside. The second places the north celestial pole at its centre: more than fourteen hundred stars between the inner and outer circles, the ecliptic and the equator crossing obliquely, and a text on the structure of heaven and earth engraved at the side.
Neither chart is immediate, and neither is convenient. They do not tell you where to look at this moment. What they do is compress an entire account of time, order and human affairs into lines and dots of ink. They answer the question “where are we, and how should we live”.
Hence the first question: why go back to a sky that modern astronomy has already explained completely?
The answer has to be sought on the ground.
For the people of early China, heaven was an institution. The calendar was the state’s public clock: when to sow, when to tax, when to promulgate the month and to announce it at the ancestral temple — all of it was settled by the calendar. The stars were the instruction manual of political legitimacy; the mandate of heaven required observable evidence to back it. Anomalies and auspicious signs were among the few soft restraints on sovereign power. A revision of the calendar therefore touched finance, ritual, imperial authority and scholarship at once; a single failed prediction of a solar eclipse could cost an astronomer his office, or give a coup its pretext.
When we look up today, we are in fact looking at the people who wrote the stars into the institutions.
There is a more practical reason as well: this sky is disappearing. Light pollution means that a child in the city may go a whole year without identifying the Dipper. Over the same period we are losing, on an unprecedented scale, the capacity to understand what the ancients experienced. When 「七月流火」 is reduced to an adjective for midsummer heat, and 「参商不相见」 survives only as a line in a dictionary of idioms, we have lost not only the poetry but the key to an entire intellectual world. So the first reason for doing empirical work is a plain one: before the memory is gone altogether, verify what can still be verified.
As for myself, the starting point was more modest. How my forebears sowed their seed, how they looked up and recognised stars, how they wrote the stars they recognised into a calendar — these have interested me for a long time. Accumulated over the years, that interest became the series that begins here: an exposition, section by section, of how the ancients observed the sky and how they made their calendars, together with the anecdotes attached to both.
2. Two legs: transmitted texts and excavated material
The word “empirical” has a precise and narrow sense in this series: only a claim that can be brought to bear on material that is observable, re-checkable and comparable counts as empirical; anything beyond that is labelled as inference without exception.
The rule comes from an uncomfortable fact. The transmitted literature of ancient Chinese astronomy and calendrics is almost entirely a layered product.
The clearest example is the Ganshi Xingjing. The title sounds like the original work of Gan De and Shi Shen in the Warring States period, but the book was long ago dispersed; what survives is largely text copied and re-copied through encyclopaedias and divination compendia of the Tang and later, supplemented by later hands and in places attributed to authors who never wrote it. To argue from it directly for a Warring States star catalogue is to hold a Qing mirror up to a Warring States face. The Kaiyuan Zhanjing, by contrast, has value precisely because it does not compose: Gautama Siddha copied out long passages from works now lost, and recorded his sources, so the text is traceable.
Transmitted texts supply the frame. Frames may have been reassembled by later hands.
The function of excavated material is to X-ray that frame. A century of archaeology has turned the field from a branch of textual criticism into a genuinely empirical discipline:
The lacquer chest from the tomb of Marquis Yi of Zeng (c. 433 BCE): the names of the twenty-eight lunar mansions are written in vermilion on the lid, with the Azure Dragon and White Tiger painted alongside. This is the earliest systematic set of mansion names yet found, and it pins the lower limit of the system firmly to the early Warring States.
The silk manuscript Wuxing Zhan and the comet chart from Mawangdui: the first gives numerical values for the synodic periods of the five planets, of surprising accuracy; the second classifies comets by shape, and is among the earliest comet-morphology charts in the world. Together they show that Han observation had a quantitative tradition, not merely divinatory formulas.
The Rishu from the Qin bamboo slips of Shuihudi and Fangmatan: these show how a local community used the calendar and selected days for its affairs — a rare sample of calendrics descending into daily life.
The calendar registers and daily logs among the Han slips from Juyan and Dunhuang: dates, weather and distances recorded day by day by frontier clerks, and thus first-hand evidence for how the Han calendar actually ran.
The Suzhou engraved celestial map and the star chart in the Liao tomb at Xuanhua: transverse coordinates of comparison for the traditions of star-drawing under different regimes and different cultures.
The point of walking on two legs is mutual correction: excavated material punctures the later embellishments of a transmitted text, and the transmitted text supplies context for fragmentary slips. A conclusion resting on one leg only is unfinished by the standard of this series.
The boundary of the empirical must be stated at the same time. Some things the material does not permit us to establish:
Silence is not absence. The absence of a record of a particular kind of omen in a period means only that none has been found so far; it does not follow that none existed. Archaeology samples; it cannot conduct a census.
The world of meaning in astral divination cannot be tested experimentally. We can check whether a given eclipse occurred and whether it was recorded; we cannot check what the ancients read into it when they wrote 「君有忧」, “the ruler has cause for concern”. That is the business of intellectual history. Astronomy cannot reach it.
Back-calculation has hard limits. To project an event three thousand years into the past by modern celestial mechanics, the accumulated error from the long-term change in the earth’s rotation (ΔT) has to be handled. For the same eclipse the computed time and zone of visibility may differ by tens of minutes and hundreds of kilometres. There is a further layer: ancient records often served political ends — good news reported and bad news suppressed, observations written up after the fact, errors of copying. A record of an omen that “came true” may have had the event first and the phenomenon attached afterwards.
Falsification is far more powerful than confirmation. This is the methodological floor of the series: we can say reliably that a given claim could not hold, but we can seldom say that a given claim certainly does.
Two examples show where the boundary lies:
The clam-shell dragon, tiger and Dipper at Xishuipo M45 in Puyang, Henan (c. 4500 BCE): the image certainly exists, and the orientation of the dragon and tiger is certainly suggestive. But to read it as a prototype of the four images or of the Dipper requires bridging a gap of six thousand years in the material. It is a hypothesis. It has not reached the point of a conclusion.
The observatory at Taosi in Xiangfen, Shanxi (c. 2100 BCE): the excavators proposed that thirteen rammed-earth columns formed observation slots from which the solstices could be determined. After publication, the scholarly response raised a series of objections concerning the formation of the column trenches, the feasibility of observation, and the chronological fit. It remains a proposal awaiting test, and should not be written into textbooks as settled.
Only by admitting the boundary does the field stand up. The argument now turns to how those positions are to be applied in reading, which requires three conventions.
3. Three conventions of reading
Convention one: no formulas.
This series will not derive calendrical procedures, will not set out spherical trigonometry, and will not give a single line of astronomical algorithm. This has nothing to do with disparaging technique. Quite the opposite: those computations are highly specialised, and I should not relay them in a half-understood form. Where computation enters, I will state three things only — what record went in, what result came out, and where the error may come from. Readers who wish to pursue it will find primary sources and specialist studies listed at the end, and it is there that the real formulas live.
Convention two: astronomy and astral divination are strictly separated.
Modern Chinese tends to run the two together; in antiquity they were two distinct operations:
| Astronomy | Astral divination | |
|---|---|---|
| Object | Observable positions, periods, moments | Correspondences between celestial phenomena and human affairs |
| Method | Measurement, record, computation, verification | Drawing images, analogy, interpretation |
| Testability | Recomputable, re-checkable | Not falsifiable (interpretations are always adjustable) |
| Stance of this series | Treated as history of science | Treated as intellectual and political history |
That is to say: I will discuss the star-officer system of the Shiji, Treatise on the Celestial Offices, and its observational basis seriously; I will also discuss its underlying logic of power seriously. But I will not use today’s astronomy to “prove” that a divinatory formula worked, nor will I dismiss the whole thing with the word “superstition”. To prove a divination formula by modern astronomy is pseudoscience; to dismiss it in one word is laziness.
Convention three: every contested point is labelled.
This is the most tightly fixed convention of the series. Wherever scholarship has not reached agreement, an explicit label is attached, and no single scholar’s view is written up as fact. There are three levels:
【通说】 tongshuo: accepted by most researchers, on a fairly complete chain of evidence.
【一说】 yishuo: maintained by a substantial number of scholars, but on insufficient evidence or with competing explanations.
【待检】 daijian: a hypothesis only, with no key evidence yet available to test it.
For example: “Of the solar eclipses recorded in the Chunqiu, most can be matched by modern back-calculation 【通说】”; “The event recorded as 「天再旦于郑」, ‘the sky dawned twice at Zheng’, is the eclipse of 899 BCE and can serve as a chronological anchor 【一说】”; “The Xishuipo clam-shell figures represent a prototype of the Dipper and the four images 【待检】”.
Believe what you will, but you can always find out which of them you are believing.
4. So this is where it begins
In 1054 the Song astronomical office recorded a “guest star”. The Songshi, Treatise on Astronomy, notes: 「至和元年五月己丑，出天关东南可数寸，岁余稍没」 — “on the ji-chou day of the fifth month of the first year of Zhihe it appeared a few inches southeast of the celestial gate, and faded after more than a year”. The Song Huiyao, chapter 52, adds that it 「昼见如太白，芒角四出，色赤白，凡见二十三日」 — “was visible by day like Venus, with rays spreading in four directions, of a reddish-white colour, and was seen for twenty-three days in all”.
Nine hundred years later astronomers identified that region as the “celestial gate” of the Song record, which is the Crab Nebula. But when they used the expansion rate to run the clock backwards, the date they obtained was eighty to a hundred and twenty years later than 1054. The mismatch forced a new recognition: the nebula is expanding at an accelerating rate.
To my mind, this is what empirical work looks like at its most moving: a sentence copied for nine hundred years, and an instrument invented nine hundred years later, addressed to the same question. Even when the first number failed to agree, it was an encounter. In that moment the ancients’ act of looking up and our act of looking down met.
The aim of this series is to find as many such points of contact as possible. Where none can be found, that too will be marked honestly.
As for where the first contact point lies, the next piece will show. Four thousand years ago a tribal leader had to decide when to sow. He had neither clock nor calendar.
5. Where the series is going
The structure first. The series is arranged chronologically: the pre-Qin period first, then Qin and Han, then down to Ming and Qing. The first collection, “Sources of Pre-Qin Calendrics”, begins with qualitative observation — a time when there were no coordinates and no degrees, and the only instruments were the stars overhead and the changing length of day and night.
| No. | Title | Status |
|---|---|---|
| Preface | Between Looking Up and Looking Down: The Origin of an Empirical Study of Ancient Chinese Astronomy and Calendrics | this piece |
| 001 | The Four Fixed Stars of the Yaodian: A Set of Numbers That Will Not Agree | forthcoming |
| 002 | The Verifiability of the Oracle-Bone Records of 「日有食之」 | forthcoming |
| 003 | The Twenty-Eight Mansion Chart on the Lacquer Chest of Marquis Yi of Zeng: A Lower Limit for the Four-Image System | forthcoming |
| 004 | Gnomon Shadow Measurement and 「日至」: The Observational Tradition before the Dengfeng Observatory | forthcoming |
| 005 | The 「Zhuanxu Calendar」 and the Archaeological Evidence for Qin and Early Han Calendrics | forthcoming |
| 006 | The Taichu and Santong Calendars: Errors in the Synodic and Intercalation Cycles | forthcoming |
| 007 | The Gnomon Data in the Zhoubi Suanjing and the Twelve-Month Deity Chart on the Chu Silk Manuscript (one of the two) | to be selected |
| 008 | Closing Piece: Where the Verifiable and the Unverifiable Divide | forthcoming |
What the collection sets out to answer can be put in one sentence: in a time without clocks and without coordinate systems, on what basis did people fix their days.
Note on the text
This is a popular exposition of material treated in the author’s teaching notes on the foundations of four-pillar practice, and it makes no claim to original research. The astronomical constants cited are standard values. This English version is issued alongside the Chinese original as the same article in another language. The author’s name is 邝楚嘉, Chujia Kuang; he writes under the pen-name 嘉言一得 (Jiayan Yide).
Declarations
Funding. This research received no external funding.
Competing interests. The author declares no competing interests.
Data availability. No new data were created or analysed in this study.
Language. The original Chinese text is deposited as a companion file to this record.
References
[1] 尚书 [Book of Documents]. Pre-Qin.
[2] 史记 [Records of the Grand Historian]. Sima Qian 司马迁. Western Han.
[3] 春秋 [Spring and Autumn Annals]. Pre-Qin.
[4] 宋史 [History of Song]. Tuotuo 脱脱 et al. Yuan.
[5] 宋会要辑稿 [Song Huiyao Jigao]. Compiled by Xu Song 徐松. Qing.
[6] 甘石星经 [Ganshi Xingjing]. Attributed to Gan De 甘德 and Shi Shen 石申. Warring States (the present text is a later reconstruction, attributed to Tang–Song and after).
[7] 瞿昙悉达. 开元占经 [Kaiyuan Zhanjing]. Tang.
[8] 长沙马王堆汉墓帛书整理小组. 五星占 [Wuxing Zhan]. In 马王堆汉墓帛书: 肆. Beijing: Wenwu Press, 1985.
[9] 睡虎地秦墓竹简整理小组. 睡虎地秦墓竹简 [Shuihudi Qinmu Zhujian]. Beijing: Wenwu Press, 1990.
[10] 甘肃省文物考古研究所. 居延新简 [Juyan Xinjian]. Beijing: Wenwu Press, 1990.
[11] 敦煌星图（S.3326）[Dunhuang star chart, S.3326]. Tang manuscript. London: British Library.
[12] 苏州石刻天文图 [Suzhou stone-carved star map]. Engraved in the seventh year of Chunyou, Southern Song (1247). Suzhou: Suzhou Stele Museum.
[13] 湖北省博物馆. 曾侯乙墓 [Tomb of Marquis Yi of Zeng]. Beijing: Wenwu Press, 1989.
[14] 河南省文物考古研究所. 濮阳西水坡遗址发掘报告 [Excavation report of the Xishuipo site, Puyang]. 文物 [Cultural Relics], 1988(3).
[15] 中国社会科学院考古研究所山西队. 山西襄汾县陶寺城址祭祀区大型建筑基址2003年发掘简报 [Brief report on the 2003 excavation of a large rammed-earth foundation in the ritual area of the Taosi city site, Xiangfen, Shanxi]. 考古 [Archaeology], 2004(7).
[16] 太初历 [Taichu calendar]. In 汉书·律历志 [Book of Han: Treatise on Pitch Pipes and the Calendar]. Ban Gu 班固. Eastern Han.
[17] 三统历 [Santong calendar]. In 汉书·律历志 [Book of Han: Treatise on Pitch Pipes and the Calendar]. Ban Gu 班固. Eastern Han.
[18] 周髀算经 [Zhoubi Suanjing]. Author unknown. Western Han (date of compilation disputed).
This article is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
You are free to reprint, redistribute, or build upon it, including for commercial purposes, provided you credit the original author as 「嘉言一得（Chujia Kuang 邝楚嘉）」 and include a link to the original publication.
Copyright in the excavated Qin and Han bamboo-slip photographs and in the transmitted texts quoted here remains with their respective rights holders and is not covered by this licence.
For the full terms of the licence, see: https://creativecommons.org
Related articles
- The Four Fixed Stars of the Yaodian: A Set of Numbers That Will Not Agree — the four stars in the Shangshu, and why they yield an eight-thousand-year spread.
- The Verifiability of the Oracle-Bone Records of 「日有食之」 — three heaps of inscriptions, three positions; only a small part can be computed at all.
- Three Calendars, Three Kinds of Time — the three scales, and what each is set to.
Chinese editions: 抬头与低头之间：古天文历法实证研究的缘起（the original Chinese text of this essay） ｜ 尧典四仲中星：一组对不上的数字 ｜ 甲骨文「日有食之」诸条的可核验性 ｜ 三本历法·三种时间 ｜ 立春换岁，还是正月初一换岁？ ｜ 立春不是一整天，只有一秒钟 ｜ 正月本来不是一月 ｜ 节与气：二十四节气的两半 ｜ 尧帝派人看星星，是为了种地 ｜ 古人的一天，从晚上十一点开始 ｜ 钟表上的出生时间，不等于你出生的时辰 ｜ 时间是怎么产生的？ ｜ 天上三条道：黄道、白道、赤道 ｜ 古人的星空：三垣与二十八宿 ｜ 没有指南针，古人怎么定方向 ｜ 干支：从一棵树到二十二个字 ｜ 十个字配十二个字，为什么只剩六十组
Site hubs: Glossary ｜ Calendar Reform ｜ Publications
All data in this article were collected and compiled by Chujia Kuang.
Author: Jiayan-Yide (Chujia Kuang 邝楚嘉) ｜ Independent researcher of astronomical calendrics, committed to verifiable primary sources and to the open archiving of calendrical data.
Plain record · Datasets · Preprints: GitHub / WordPress / Zenodo (DOI: 10.5281/zenodo.22788686)
