Tibetan astronomy

Abstract

Towards the end of the first millenium, there existed in the north-west of India a remarkable Buddhist teaching, called Kâlacakra (the Wheel of Time). This religious system presents us with various cosmographic and astronomical conceptions, not only from India but also from other countries, even from Persia. Some of the Kâlacakra pamphlets give instructions on the reckoning of time and how to calculate the planets' passage of the Zodiac. There are lists of the lunar mansions and descriptions of heaven and earth. One of the texts is ascribed to the legendary Indian astronomer Garga. It may be that a close study of the Tibetan texts will enable us to elucidate the pre-siddhântic epoch of Indian astronomy; but the apparently crude character of the calculations might also be due to a secondary simplification for practical use. Geometry is nowhere used; nor do we read anything about actual observations. Although most of the original Buddhist Sanskrit texts are lost, fortunately two of the Kâlacakra texts on astronomy have been preserved in both languages. Critical editions of the pertinent texts will be given in collaboration with the indologist, Professor H. Hoffmann, who is head of the flourishing centre of Tibetan and Buddhistic studies in Munich. Besides the several Kâlacakra texts from about the eleventh century, there exists a huge encyclopedia on astronomy and related matters. It was compiled originally in Tibetan, in the second half of the seventeenth century and is called Vaidûrya-dkarpo (White Beryl). Notwithstanding its late date, its astronomy looks essentially the same as in the much earlier Kâlacakra treatises. Chinese influence is secondary and mostly superficial. The influence of Indian astronomy extended even beyond Tibet. In mediaeval Uigur (Turkish) fragments from Turfan, the lunar mansions are listed by their Sanskrit names and in the same way as in the Tibetan books. Moreover, a survey of the history of astronomy in Mongolia (L. S. Baranovskaya, 1955) reveals that the Indo-Tibetan astronomical ideas and names were alive there until modern times.