2.2.1. Astronomical tables

One of the earliest estimates of the date of the Vedas was at once among the most scientific.  In 1790, the Scottish mathematician John Playfair demonstrated that the starting-date of the astronomical observations recorded in the tables still in use among Hindu astrologers (of which three copies had reached Europe between 1687 and 1787) had to be 4300 BC.³ His proposal was dismissed as absurd by some, but it was not refuted by any scientist.

Playfair’s judicious use of astronomy was countered by John Bentley with a Scriptural argument which we now must consider invalid.  In 1825, Bentley objected: “By his [= Playfair’s] attempt to uphold the antiquity of Hindu books against absolute facts, he thereby supports all those horrid abuses and impositions found in them, under the pretended sanction of antiquity.  Nay, his aim goes still deeper, for by the same means he endeavours to overturn the Mosaic account, and sap the very foundation of our religion: for if we are to believe in the antiquity of Hindu books, as he would wish us, then the Mosaic account is all a fable, or a fiction.”⁴

Bentley did not object to astronomy per se, in so far as it could be helpful in showing up the falsehood of Brahminical scriptures.  However, it did precisely the reverse.  Falsehood in this context could have meant that the Brahmins falsely claimed high antiquity for their texts by presenting as ancient astronomical observations recorded in Scripture what were in fact back-calculations from a much later age.  But Playfair showed that this was impossible.

Back-calculation of planetary positions is a highly complex affair requiring knowledge of a number of physical laws, universal constants and actual measurements of densities, diameters and distances.  Though Brahminical astronomy was remarkably sophisticated for its time, it could only back-calculate planetary position of the presumed Vedic age with an inaccuracy margin of at least several degrees of arc.  With our modern knowledge, it is easy to determine what the actual positions were, and what the results of back-calculations with the Brahminical formulae would have been, e.g.:

“Aldebaran was therefore 40’ before the point of the vernal equinox, according to the Indian astronomy, in the year 3102 before Christ. (…) [Modern astronomy] gives the longitude of that star 13’ from the vernal equinox, at the time of the Calyougham, agreeing, within 53’, with the determination of the Indian astronomy.  This agreement is the more remarkable, that the Brahmins, by their own rules for computing the motion of the fixed stars, could not have assigned this place to Aldebaran for the beginning of Calyougham, had they calculated it from a modern observation.  For as they make the motion of the fixed stars too great by more than 3” annually, if they had calculated backward from 1491, they would have placed the fixed stars less advanced by 4⁰ or 5⁰, at their ancient epoch, than they have actually done.”⁵

So, it turns out that the data given by the Brahmins corresponded not with the results deduced from their formulae, but with the actual positions, and this, according to Playfair, for nine different astronomical parameters.  This is a bit much to explain away as coincidence or sheer luck.

2.2.2. Ancient observation, modern confirmation

That Hindu astronomical lore about ancient times cannot be based on later back-calculation, was also argued by Playfair’s contemporary, the French astronomer jean-Sylvain Bailly: “The motions of the stars calculated by the Hindus before some 4500 years vary not even a single minute from the [modem] tables of Cassini and Meyer.  The Indian tables give the same annual variation of the moon as that discovered by Tycho Brahe - a variation unknown to the school of Alexandria and also the Arabs.”⁶

Prof. N.S. Rajaram, a mathematician who has worked for NASA, comments: “fabricating astronomical data going back thousands of years calls for knowledge of Newton’s Law of Gravitation and the ability to solve differential equations.”⁷ Failing this advanced knowledge, the data in the Brahminical tables must be based on actual observation.  Ergo, the Sanskrit-speaking Vedic seers were present in person to record astronomical observations and preserve them for a full 6,000 years: “The observations on which the astronomy of India is founded, were nude more than three thousand years before the Christian era. (…) Two other elements of this astronomy, the equation of the sun’s centre and the obliquity of the ecliptic (…) seem to point to a period still more remote, and to fix the origin of this astronomy 1000 or 1200 years earlier, that is, 4300 years before the Christian era”.⁸

All this at least on the assumption that Playfair’s, Bailly’s and Rajaram’s claims about the Hindu astronomical tables are correct.  Disputants may start by proving them factually wrong, but should not enter the dispute arena without a refutation of the astronomers’ assertions.  It is something of a scandal that Playfair’s and Bailly’s findings have been lying around for two hundred years while linguists and indologists were publishing speculations on Vedic chronology in stark disregard for the contribution of astronomy.

2.2.3. The start of Kali-Yuga

Hindu tradition makes mention of the conjunction of the “seven planets” (Saturn, Jupiter, Mars, Venus, Mercury, sun and moon) and Ketu (southern lunar node, the northern node/ Rahu being by definition in the opposite location) near the fixed star Revati (Zeta Piscium) on 18 February 3102 BC.  This date, at which Krishna is supposed to have breathed his last, is conventionally the start of the so-called Kali-Yuga, the “age of strife”, the low point in a declining sequence of four ages.  However, modem scholars have claimed that the Kali-Yuga system of time-reckoning was a much younger invention, not attested before the 6th century AD.

Against this modernist opinion, Bailly and Playfair had already shown that the position of the moon (the fastest-moving “planet”, hence the hardest to back-calculate with precision) at the beginning of Kali-Yuga, 18 February 3102, as given by Hindu tradition, was accurate to 37’.⁹ Either the Brahmins had made an incredibly lucky guess, or they had recorded an actual observation on Kali Yuga day itself.

Richard L. Thompson claims that in Indian literature and inscriptions, there are a number of datelines expressed in Kali-Yuga which are older than the Christian era (and a fortiori older than the 6th century AD).¹⁰ More importantly, Thompson argues that the Jyotisha-shAstras (treatises on astronomy and, increasingly, astrology, starting in the 14th century BC with the VedANga Jyotisha as per its own astronomical data, but mostly from the first millennium AD) are correct in mentioning this remarkable conjunction on that exact day, for there was indeed a conjunction of sun, moon, Mercury, Venus, Mars, Jupiter, Saturn, Ketu and Revati.

True, the conjunction was not spectacularly exact, having an orb of 37⁰ between the two most extreme planetary positions.  But that precisely supports the hypothesis of an actual observation as opposed to a back-calculation.  Indeed, if the Hindu astronomers were able to calculate this position after a lapse of many centuries (when the Jyotisha-ShAstra was written), it is unclear what reason they would have had for picking out that particular conjunction.  Surely, such conjunctions are spectacular to those who witness one, and hence worth recording if observed.  But they are not that exceptional when considered over millennia: even closer conjunctions of all visible planets do occur (most recently on 5 February 1962).¹¹ If the Hindu astronomers had simply been going over their astronomical tables looking for an exceptional conjunction, they could have found more spectacular ones than the one on 18 February 3102 BC.  And why would they have calculated tables for such a remote period, sixteen centuries before the Aryan invasion, nineteen before the composition of the Rg-Vedic hymns, a time of which they had no recollection?
 

Footnotes: 
 

³Playfair’s argumentation, “Remarks on the astronomy of the Brahmins”, Edinburg 1790, is reproduced in Dharampal: Indian Science and Technology in the Eighteenth Century, Academy of Gandhian Studies, Hyderabad 1983 (Impex India, Delhi 1971), p.69-124.

⁴John Bentley: Hindu Astronomy, republished by Shri Publ., Delhi 1990, p.xxvii; also discussed by Richard L. Thompson: “World Views: Vedic vs. Western”, The India Times, 31-3-1993.  On p.111, we find that Bentley has "proven" that Krishna was born on 7 August in AD 600 (the most conservative estimate elsewhere is the 9th century BC), and on p.158ff., that Varaha Mihira (AD 510-587) was a contemporary of the Moghul emperor Akbar (r.1556-1605).

⁵J. Playfair in Dharampal: Indian Science and Technology, p.87. 

⁶Quoted in S. Sathe: In Search for the Year of the Bharata War, Navabharati, Hyderabad 1982, p.32.

⁷N.S. Rajaram: The Politics of History, p.47.

⁸J. Playfair in Dharampal: Indian Science and Technology, p-118.

⁹J. Playfair in Dharampal: Indian Science and Technology, p.88-89.

¹⁰R.L. Thompson: Vedic Cosmography and Astronomy, Bhaktivedanta Book Trust, Los Angeles 1989, p. 19-24. Unfortunately, he gives no examples of the early use of Kali-Yuga, contenting himself with references to Indian publications offering such examples, unlikely to convince Western scholars, viz.  S.D. Kulkarni: Adi Sankara, Bombay 1987, and G.C. Agrawala: Age of Bharata War, Motilal Banarsidass, Delhi 1979.  Kulkarni’s book (p.281ff) offers Kali-Yuga dates such as 509 BC, but from marginal Sanskrit sources which most Western scholars would consider unreliable.

¹¹On that day, Hindu astrologers gathered for prayer-sessions on hilltops to avert the impending catastrophe; they were moderately successful.