New research published in Advances in Historical Astronomy has utilized high-performance computing to evaluate the astronomical tables in Varahamihira’s 6th-century treatise, the Pancha-Siddhantika. The study concludes that Varahamihira calculated the Earth's axial tilt (obliquity) with an accuracy of within 0.1 degrees of modern retro-calculated values for that epoch.
The study highlights the use of a sophisticated mathematical model involving iterative spherical trigonometry that was previously thought to have been developed much later in Europe. This research reaffirms the scientific prowess of ancient Indian astronomers in creating accurate models of the cosmos based on direct empirical observation and advanced calculus precursors.