Astral computers in Asia

Certainly one of the earliest astrological calculators known, the 式 shì is an ancient Chinese analog computer dating sometime before 165 BCE.¹ Generally, the most primitive form is composed of two parts: a free-spinning, circular 天盤 tiānpán “heaven plate,” marked with the Big Dipper and centered on the pole star, set inside a square, stationary 地盤 dìpán “earth plate” with directions and astrological information marked.² By rotating the heaven plate around the axis and aligning it with the date, one can compute the exact position of the Northern Dipper at any point of the year, which is essential for the practice of Chinese astrology.

Throughout the intervening centuries, the shì was constantly re-contextualized and applied to new ritual modes. The 3rd century Central Scripture of Laozi appears to map the shì onto the body and equates the material manipulation of the board to the meditative manipulation of inner gods within the body.³ After being introduced to Japan, the shì became an important tool of esoteric priests in the Shingon (真言宗 Shingon-shū) and Tendai (天台宗 Shingon-shū) lineages and among Yin-Yang specialists (陰陽師 Onmyōji). In the Shingon tradition, the earth and heaven plates were identified with the Womb Realm (胎蔵界 Taizōkai) and Diamond Realm mandalas (金剛界 Kongōkai.)⁴ Though the popularity of such devices has waned, some of these methods are extant. Ramble (2021) describes a volvelle (paper wheels used for calculation, immensely popular in medieval and Renaissance Europe) used in a Tibetan Bon exorcism, which calculates the position of an earth divinity named Toche Nakpo, who lives in the earth and can be struck with disastrous results.⁵

The motif of a rotating sphere (or projection of a sphere) systematically rendering combinations of elements, and instrumentalized for magical means, is strikingly similar to the development of the zairja in the Middle East and thus warrants further comparative study. Indeed, van Binsbergen parenthetically attributes the shì as the likely ancestor of the zairja.⁶ A similar parallel, outside the scope of this article, can be seen in the use of the structure of the human hand in mnemonic, ritual, and computational contexts, independently produced in Europe and East Asia. A popular, though academically sound, introduction can be found in the Public Domain Review.⁷

Most importantly, it illustrates a close relationship between ritual and technique where “[t]he ritual and the technical are commingled” and “thoroughly enmeshed.”⁹ Rather than inert, the process of mechanical computation is numinous and effective. Thus, it justifies a useful suspension of received notions of technique as purely instrumental, abstract, and ends-oriented, in which the phenomenology of manipulating wheels-within-wheels, and the materiality of such an instrument, is important.

1. Morgan, D. P. (2020). Reflections on Visual and Material Sources for the History of the Exact Sciences in Early Imperial China. NTM Zeitschrift für Geschichte der Wissenschaften, Technik und Medizin, 28(3), 325-357. ↩︎
2. Harper, D. J. (1978). The Han cosmic board (shih). Early China, 4, 1-10. ↩︎
3. Steavu, D. (2017). The Allegorical Cosmos: The Shi 式 Board in Medieval Taoist and Buddhist Sources. In Coping with the Future (pp. 196-232). Brill. ↩︎
4. Trenson, S. (2012). Shingon divination board rituals and rainmaking. Cahiers d’Extrême-Asie, 107-134. ↩︎
5. Ramble, C. (2021). The Volvelle and the Lingga: The Use of Two Manuscript Ritual Devices in a Tibetan Exorcism. In Exploring Written Artefacts (pp.1025-1042). De Gruyter.
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6. Van Binsbergen, W. M. (2012, April). The relevance of Buddhism and Hinduism for the study of Asian-African transcontinental continuities. In International Conference ‘Rethinking Africa’s transcontinental continuities in pre-and protohistory’, Leiden, African Studies Centre (pp. 12-13). ↩︎
7. Cooperrider, K. (2022, April 21). Handy mnemonics: the five-fingered memory machine. Public Domain Review.
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8. Schäfer, D., Zhao, L., & Lackner, M. (2019). Accounting for Uncertainty: Prediction and Planning in Asian History. ↩︎
9. Steavu, D. (2017). The Allegorical Cosmos: The Shi 式 Board in Medieval Taoist and Buddhist Sources. In Coping with the Future (pp. 196-232). Brill. ↩︎