A collaboration between the Oxford Journal of Archaeology and the Central Asian Manuscript Project has led to the successful decipherment of a rare 6th-century birch-bark manuscript found in the Gilgit region. The text, written in a transitional Post-Gupta script, contains a series of mathematical formulas for calculating the positions of celestial bodies on a curved surface, indicating a sophisticated understanding of spherical trigonometry.
Unlike other known manuscripts of the period, these fragments include a unique set of 'sine-chord' tables that were used to predict planetary altitudes during lunar eclipses. The lead researcher noted that the manuscript acts as a 'missing link' between the early Siddhantic period and the later advanced calculus of the Kerala school, proving that ancient Indian science had already formalized the principles of spherical geometry by the middle of the first millennium CE.