The following text is a brief description of breakthrough work Dr. Subhash Kak published in nearly two decades ago. My sincere thanks to Dr. Kak for publishing such revolutionary thought, sometimes challenged by other scholars, however I remain very grateful!
The Astronomical Code of the Rigveda (New Delhi: Aditya Prakashan, 1994; revised and enlarged edition, New Delhi: Munshiram Manoharlal, 2000) claims regularities in the organization of the Rigveda, connecting the structure to certain numbers in the astronomy-based ritual of the five-layered brick altars of the Vedic times.
Kak’s archaeoastronomical claims have the effect of significantly extending the Vedic period, postulating the arrival of ethnic Indo-Aryans to the 7th millennium BC. This claim is in contradiction with mainstream Indology and historical linguistics and science historians
Kak arranges the number of hymns in each book of the Rigveda as follows, and compares the arrangement to a Vedic fire altar:
He then computes various sums and subtractions within the diagram, finding numbers related to the distance between the Earth and the Sun, and the sidereal periods of various planets. According to Klaus Klostermaier, “Subhash Kak, with his ‘decoding of the Rigveda’ has opened up an entirely new approach to the study of Vedic cosmology from an empirical astronomical/mathematical viewpoint.”
Kak’s method depends on the structure of the Rigveda as redacted by Shakalya in the late Brahmana period as opposed to the intrinsic content in the oldest portions of the text. Specifically, Witzel (2001) believes that Kak’s approach relates to the organizations of the Rigveda into mandalas (“books”), a process of redaction undertaken by the shakhas long after the composition of the individual hymns (the samhita prose period, dating to well within the Indian Iron Age), rendering the attempt to date the text in this flawed. Other scholars have discredited Kak’s claims and methods. Nanda has said that Kak’s “method is breathtakingly ad hoc and reads like numerology 101.”
Kak prepared the section on archaeoastronomical sites in India for the thematic study on Heritage Sites of Astronomy and Archaeoastronomy in the context of the UNESCO World Heritage Convention prepared for UNESCO by the International Council on Monuments and Sites (ICOMOS) and the International Astronomical Union (IAU).