Person · Indian astronomer at Tang court
Gautama Siddha (Qutan Xida)
An astronomer of Indian descent working in eighth-century Chang'an, from a family that had served the Tang court across generations. In 718 he produced the Jiuzhi-li, the Nine Seizers Canon, a Chinese rendering of an Indian astronomical system that introduced the sine table and the decimal zero as a written symbol into Chinese computational practice, and he compiled the Kaiyuan Zhanjing, the great Tang treatise on astrology and astronomy. He held office in the imperial astronomical bureau.
- Function
- Science & medicine
- Confidence
- Qualified / contested
Worth knowing
His name in Chinese, Qutan Xida, is a transliteration of Gautama Siddha, and his family held posts at the Tang court for at least three generations — an Indian astronomical dynasty inside the Chinese civil service.
The Jiuzhi-li's Indian source and the extent of its influence on later Chinese astronomy are debated; his precise office and dates are known only from Chinese records and a tomb inscription.
Connections (2)
- Imperial administration ofChang’an / Xi’an, China
An Indian astronomical family held office in the Tang capital for at least three generations. Gautama Siddha — Qutan Xida in Chinese — produced the Jiuzhi-li in 718, a Chinese rendering of an Indian system that brought the sine table and the written decimal zero into Chinese computational practice, and compiled the Kaiyuan Zhanjing. Chang'an was the terminus of the Buddhist translation traffic, so Indian mathematics arrived in the same city and by much the same route as Indian scripture, and was put to work by the state.
- AnalogueNīlakantha Somayāji
The sine table that Gautama Siddha carried into Chinese practice in 718 came from the Indian astronomical tradition that Āryabhata began and that the Kerala school later pushed furthest — Nīlakantha Somayāji working out planetary models and infinite series in the fifteenth century. What moved east was the computational apparatus rather than the cosmology: Chinese astronomy took the trigonometry and the decimal notation and left the Puranic frame, which is the usual shape of a successful technical transmission.
On these journeys
Sources
Wikipedia, “Gautama Siddha” and “Chinese astronomy”. Yabuuti Kiyosi on the Jiuzhi-li; Joseph Needham, Science and Civilisation in China, vol. 3; Bi Bo and Sun Xiaochun on the Gautama family tomb inscription.
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