Apart from the hard evidence, there are a few elements in Hindu astronomical tradition which would not count as evidence all by themselves, but which may gain a new significance when studied in the company of the more solid elements already considered.  We will mention four of them: the Saptarshi cycle, the Vedic description of a particular eclipse, cosmic number games in Vedic texts and ritual, and the surprising presence of the Zodiac.

2.4.1. The Saptarshi cycle

A lesser-known Hindu system of time-reckoning is the Saptarshi cycle of 3600 years (possibly based on the 60-year cycle, see ch. 2.4.5. below).  At any rate, by the Christian age we find writers who take this concept of a 3600-year cycle literally, and it is hard to either prove or refute that this may have been a much older tradition.

The medieval Kashmiri historian Kalhana claimed that the previous cycle had started in 3076 BC, and the present one in AD 525.  J.E. Mitchiner has suggested that the beginning of the Saptarshi reckoning was one more cycle earlier, in 6676 BC: “We may conclude that the older and original version of the Era of the Seven Rsis commenced with the Seven Rsis in Krttika in 6676 BC, used a total of 28 Naksatras, and placed the start of the Kali Yuga in 3102 BC. This version was in use in northern India from at least the 4th century BC, as witnessed by the statements of Greek and Roman writers; it was also the version used by Vrddha Garga, at around the start of the Christian era.”²² This would roughly coincide with the start of the Puranic dynastic list reported by Greco-Roman authors as starting in 6776 BC.

Indeed, the Puranic king-list as known to Greek visitors of Chandragupta’s court in the 4th century BC or to later Greco-Roman India-watchers, started in 6776 BC.  Pliny wrote that the Indians date their first king, “Liber Pater” (Roman equivalent of Dionysus), to “6,451 years and 3 months” before Alexander the Great (d. 323 BC), while Arrian puts “Dionysus” as head of the dynastic list at 6,042 + 300 + 120 = 6,462 years before Sandrokottos (Chandragupta), to whom a Greek embassy was sent in 314 BC.²³ Both indications add up to a date, give or take a year, of 6776 BC.  This would, according to the implicit chronology of Puranic tradition, be the time of Manu’s enthronement, Manu being the Aryan patriarch who established his kingdom in North India after having survived the Flood.  One of Manu’s heirs was Ila, ancestress of Yayati, whose five sons became the patriarchs of the “five peoples” who form the ethnic horizon of the Vedas, one of them being Puru; in Puru’s tribe, then, one Bharata started the Bharata clan to which most of the Vedic seers belonged.

It so happens that in the 7th millennium BC, the oceans were still in the process of recovering the ground they lost during the ice Age, when the sea level was for thousands of years nearly a hundred metres below the present level.  The importance of the Glaciation, which peaked ca. 16,000 years ago, in the reconstruction of Eurasian migration histories can hardly be overestimated.  The Channel between Britain and France, with sea bottom at ca. 40 metres, was a walkway until it was inundated again in ca. 6500 BC, when the sea was already more than halfway back to its normal (or at least its present) level.  This means that for centuries before and for some more centuries after that time, the sea level was progressively rising.  Since large populations had settled in the coastal areas vacated by the receding sea at the beginning of the Ice Age, the progressive melting of the ice-caps led to the progressive flooding of ever higher-situated population centres, for several millennia until perhaps 5,000 BC.

One can imagine what would happen if today the sea level would rise a mere 10 metres: densely populated countries like the Netherlands and Bangladesh would get largely submerged, along with major cities like New York and Mumbai, and at least a quarter of the world population would have to move.  But that was, for several millennia, the human condition: one after another, low-lying villages had to be abandoned to the rising sea.  It must have seemed like a law of nature to them that the sea was forever rising, forcing men to seek higher habitats.  And this process was probably continuous only when looked at from a distance, the reality being more like periods of stable sea levels followed by sudden jumps, catastrophes when considered on the scale of a human lifetime.  Most probably, that is the origin of the Flood story.²⁴ The Puranas describe Manu as the leader of mankind after the Flood, and if we apply a realistic average length to the rulerships of the kings mentioned in the Puranic dynastic lists, Manu may have lived in the 7th millennium BC, the time of the rising waters, warranting the suspicion that the Flood story is related to historical events at the end of the ice Age.

The myth of Atlantis and other submerged continents probably has a similar origin.  The Tamils have a tradition of a submerged land to India’s south, of which the Maledives and Sri Lanka are remaining hilltops: KumArIkhaNDam or, in the parlance of the Madras-based Theosophical Society, Lemuria. The city in which their poets’ academy or Sangam (recorded in the early Christian era, but claimed to be ten thousand years old) was established, was said to have been moved thrice because of the rising waters.  Though it is hard to see how poets working at the turn of the Christian era could have a memory of events five millennia older, one cannot dismiss as pure fable a story which tallies neatly with the known geological facts of the rising sea level at the end of the Ice Age.

And if such memory was possible, the existence of a system of time-reckoning going back that far is not impossible either.  But we must admit that for the time being, this is merely “not impossible”.  However, even if we let the Saptarshi cycle start only in 3076 BC, unrelated to Manu and the Flood, this is still hard to reconcile with the theory of an Aryan invasion in the 2nd millennium BC.

2.4.2. A remarkable eclipse

For another chronological marker, Rg-Veda 5:40:5-9 describes a solar eclipse.  From the description, one can deduce a number of conditions determining the times at which it could have taken place: it was at that site a central, non-total eclipse, which took place in the afternoon on the Kurukshetra meridian, on a given day after the summer solstice, at least in the reading of P.C. Sengupta.  Only one date satisfies all conditions, which he calculated as 26 July 3928 BC.²⁵ We have to add, however, that this calculation stands or falls with the accuracy of the unusual translation of the word brahma as “solstice”.  This reading is supported by later scriptural references to the same event, Shankhayana Aranyaka 1:2,18 and Jaiminiya Brahmana 2:404-410.  N.S. Rajaram has identified an even more explicit use of brahma in the sense of “solstice”: in Rg-Veda 10:85:35, where brahma is associated with the division of the solar cycle in two halves.²⁶

Moreover, the astronomical interpretation (e.g. by B.G. Tilak) of Rg-Veda 10:61:5-8, where brahma is the equinox and the fruit of the union between a divine father and daughter, i.e. the two adjoining constellations MRgashira/Orion and Rohini/Aldebaran, if not more abstractly the intersection of two related celestial circles, may be cited in support: equinox is not the same as solstice, but it is at least one of the cardinal directions, a purely astronomical rather than a religious concept; the common meaning of brahma would then be “cardinal direction”.  The division of the ecliptic in 4 parts of 90⁰ by the solstice axis and the equinox axis is already obliquely referred to in RV 1:155:6, so the concept of “cardinal direction” was certainly understood.  Still, this construction remains sufficiently strange to be a reasonable ground for skepticism.  On the other hand, it is up to the skeptics to come up with a convincing alternative translation which fits the context.

2.4.3. Cosmic data in Vedic ritual

A different type of astronomical evidence, not to fix a precise date but to give an idea of the scientific spirit of the Vedic Aryans, is the interpretation of numerical facts about the Vedas as implicit references to astronomical data.  If this seems far-fetched, it should be borne in mind that ancient mythology and religion were primarily concerned with the visible heaven-dwellers, i.e. the heavenly bodies.  Many myths are nothing but anthropomorphic narrations of celestial phenomena such as eclipses, solstices and equinoxes, the angular relations between the orbiting planets (e.g. the regular overtaking of the planets by the fast-moving moon, therefore imagined by the Greeks as a huntress, Artemis), the analogy between the twelve-month solar cycle and the twelve-year Jupiter cycle, and even the precession.²⁷

Apart from this figurative representation, there is also a numerical representation of astronomical data in ancient traditions.  Thus the Bible, written by a satellite culture of the astronomically astute Babylonians, used the device of enciphering astronomical data in all kinds of contingent numerical aspects of the narrative, e.g. the ages of the antediluvian patriarchs in Genesis turn out to be equal to the sums of the planets’ synodic cycles (period from one conjunction with the sun till the next): Lamech dies at age 777 = 399 (number of days in Jupiter’s synodic cycle) + 378 (Saturn’s); Mahalalel at 895 = 116 + 779 (Mercury:  Mars); Yared at 962 = 584 + 378 (Venus + Saturn).  Similarly, the symbolism of 12 and 13, referring to the lunar months in a year, is omnipresent in the Bible: 12 sons of Jacob plus 1 daughter; 12 tribes of Israel with a territory plus the 1 priestly tribe of Levi; 12 regular apostles of Jesus plus the one substitute for the traitor Judas, Matthias; the “thirteen-petalled rose” as Talmudic symbol of the Torah.

In the past decades, scientists and orthodox religionists have often made fun of attempts to connect religion with science, as in Frithjof Capra’s Tao of Physics and numerous other books.  Yet, in ancient religious texts we already see this attempt of religious thinkers to keep up with the latest in science, as outlined above for astronomy.  In his Gospel, John takes the trouble of counting the fish caught by the apostle-fishermen in their nets: 153.  Number theory was fairly advanced among the Pythagoreans, and some of its remarkable findings were well-known among the educated in the Hellenistic world.  They were aware of the unique property of 153: it is equal to the sum of the third powers of its own constituent figures: 1 + 125 + 27.  Somehow, John assumed that the religious depth of his text would gain from including some allusions to mathematics.  In ancient Pagan civilizations, this fusion of religion and proto-science was the done thing; it was usually the priests who used their leisure to develop scientific knowledge, for they were not troubled by the conflict between faith and religion which would characterize the Christian and Islamic Middle Ages.

So in the Vedas as well, we find astronomical data enciphered in all kinds of ways.  Thus, the Hindus’ most sacred number 108 is, with an inaccuracy of only 1%, the distance earth-sun expressed in solar diameters (i.e. the radius of the earth’s orbit divided by the sun’s diameter), as well as the distance earth-moon expressed in lunar diameters.  Subhash Kak has checked if such numerical combinations as just cited from Genesis also appear in the Vedas.²⁸ They do, though they are often quite complicated and only obvious to someone well-versed in the idiosyncrasies of the multiple Vedic calendar systems.  An easy example is: the number of hymns in books 1, 2, 3 and 4 of the Rg-Veda adds up to 354, the number of days in the Lunar year consisting of 12 moon cycles.  Similarly, the total number of hymns in books 4, 5, 6 and 7 is 324, the number of days in the so-called Nakshatra year, being the duration of the sun’s stay in 24 of the 27 lunar mansions. Coincidence?

According to Kak: “By adding the hymn counts of the ten books of the Rig-Veda in different combinations, we obtain numbers that are factors of the sidereal periods and the five synodic periods (…) The probability of this happening is about one in a million.  Hence whoever arranged the Rig-Veda encoded into it not only obvious numbers like the lunar year but also hidden numbers of great astronomical significance.”²⁹

This choice of numbers in a cosmically meaningful way is also present in the construction of the Vedic altar, such as the numbers of bricks in each layer being equal to the number of days in given planetary cycles.³⁰ It involves fairly complicated arithmetic, and shows the kind of concern which the Vedic seers had for the harmony between their own religious practices and the astronomical cycles.  That mentality led logically to painstakingly accurate observations and calculations, and thereby supports the suspicion of reliability of the internal Vedic astro-chronology.

2.4.4. The Zodiac

To conclude this brief acquaintance with Vedic astronomy, we want to draw attention to the possible presence in the Rg-Veda of a momentous cultural artifact, the origin of which is usually situated in Babylonia in about 600 BC: the twelve-sign Zodiac.  In RV 1:164:11, the sun wheel in heaven is said to have 12 spokes, and to be subdivided into 360 pairs of “sons”: the days (consisting of day and night), rounded off to an arithmetically manageable number, also the basis of the “Babylonian” division of the circle in 360⁰.  The division in 12 already suggests the Zodiac, and we also find, in the footsteps of N.R. Waradpande, that a number of the Zodiacal constellations/rAshis (classically conceived as combinations of 2 or 3 successive Lunar mansions or nakshatras of 13⁰20’ each) are mentioned: SiMha/Leo (5:83:3 and 9:89:3), KanyA/Virgo (6:49:7), Mithunal/Gemini (3:39.3), and VRshabha/Taurus (6:47:5 and 8:93:1).³¹

Here again, the precession has located them where we would expect them in about 4000 BC.  The VRshabha rAshi is said to have stabilised the heavens with a mighty prop, apparently a reference to the Taurus equinox in the 4th millennium BC; the same verse links the Taurus month with its opposite, Shukra/JyeshTha (coinciding with Scorpio, which contained the autumnal equinox), confirming it least that VRshabha, “bull”, is used here in an astronomical-calendrical sense.  That the seasons are linked with the constellation which is “heliacally rising” (i.e. rising just before dawn) is perhaps indicated by RV 8:93:1: “Surya, thou mountest up to meet the vRshabha”, the sun rises as if to meet the constellation which is just above the horizon.

We are aware that, like the Chinese, the Hindus link the season to the lunar constellation/nakshatra in opposition, i.e. the one which rises at sunset and may contain the full moon.  This approach, if applied to modem astrology, would mean that those who think they are Taurus (sun in Taurus) would become its opposite, Scorpio (sun opposite Scorpio, full moon in Scorpio).  By contrast, the Babylonians linked the seasons to the solar constellation/rAshi in heliacal rising.  If that method were used in modem astrology, those who consider themselves Taurus (sun in Taurus) would find themselves to be Aries (last constellation to rise before the sun-in-Taurus rises).³² However, Waradpande’s discovery seems to imply that the Hindus too used the constellation (at least the rAshi, not the nakshatra) in heliacal rising, like the Babylonians did.

If in Rg-Vedic astronomy the twelve constellations are not linked to the time of the year when they are heliacally rising, but to the time when they are “inhabited” by the sun (as is the practice in modem Hindu astrology), then the whole story would move up at least a thousand and possibly two thousand years, putting the Rg-Veda in about 2000 BC.  This is because the sun is in mid-Taurus a month before Taurus’s heliacal rising, or about 3⁰ of the cycle, a distance covered by the precession of the equinox in about two thousand years.  But it is unlikely that they considered the constellation containing the sun rather than the constellation heliacally rising, as astronomy was based on actual observation more than on calculation, and consequently required that the constellation be visible.³³ The constellation temporarily inhabited by the sun is invisible, and that is why the ancients made do with the constellation rising before the one in which the sun is located (heliacal rising), or the one rising when the sun sets, in practice the one inhabited by the full moon (opposition).

The difference between the sun, which obscures the constellation it inhabits, and the moon, which is seen against the background of the constellation it inhabits, explains why a moon-based system uses moon-in-constellation or, via full-moon-in-constellation, sun-in-opposition (the full moon being by definition opposite to the sun); while a sun-based system had to make do with a derivative relation between sun and constellation, typically the constellation’s heliacal rising.  The implication is that India originally had both systems: a Lunar 27-part Zodiac (nakshatras) using the opposition, exactly like in China (and its derived system of 12 months, based on combinations of 2 or 3 nakshatras and still in use); and a Solar 12-part Zodiac (rAshis) using the heliacal rising, exactly like in Babylonia.

The Mithuna rAshi/Gemini is said to destroy darkness and to be basis (budhna) of heat (tapes) (RV 3:39:3).  During Gemini’s heliacal rising in 4000 BC, the sun was in Cancer, then coinciding with our month of May, in northern India the first month of summer (May-June), a season of drought and extreme heat.  During Leo’s heliacal rising, around summer solstice in 4000 BC, the rainy season began.  Therefore, verse 5:83:3 says: “Like the charioteer driving the horse by the whip, he releases the messengers of shower.  From afar the roars of the siMha declare that the rain-god is making the sky showering.” It could not be clearer.

Leo is followed by Virgo, indicating the second half of the rainy season, when the water level in the rivers rises dramatically: in verse 6:49:7, she is called “the purifier KanyA with ChitrA as her life”, and equated with the river Saraswati, the “waterstream-full”.  At this point I must disagree with Waradpande, who takes Saraswati, “waterstream-full,” in its literal meaning, when obviously it is used as the name of the Vedic river.  But at least the reference - the reference to ChitrA, the asterism Spica, the most conspicuous part of the constellation Virgo, dispels any lingering doubt that in this context, KanyA/Virgo does indeed mean the sixth constellation of the Zodiac.

If this is correct, it means that the Zodiac is as old as the oldest Veda, and that the Zodiac itself helps to date the Vedas to the age when Leo and Virgo were connected with the rainy season.  Even if we consider sun-in-Virgo rather than Virgo’s heliacal rising, this would still indicate the centuries around 2000 BC, well before the 1500 BC taught in our universities as the earliest possible date of the Rg-Veda.  Either way, it also upsets the current assumption that the Zodiac was invented in Babylon in the last millennium BC.

2.4.5. India as the metropolis

Off-hand, while trying to give a solid astronomical basis to Vedic chronology, we discover a case of cultural transmission in which India is no longer a rather late receiver but, on the contrary, the extremely ancient source. Indeed, both the solar and the lunar Zodiac may well originate in India.  If the Rg-Veda does refer to a 12-part Zodiac, it precedes the Babylonian Zodiac by centuries even in the lowest AIT-based chronology for the Vedas.  As for China: in his famous Science and Civilization in China, Joseph Needham notes, again by using the precession as a time marker, that the Chinese 27-part Zodiac dates back to the 24th century BC.³⁴ He recognizes a common origin with the Hindu nakshatra Zodiac, and then surmises that the Hindus had it from China, on the assumption that the Vedic references to the nakshatras are from 1500 BC at the earliest.  But that assumption, a by-product of the AIT, is seriously undermined by all the data we have been considering here.

Another indication for Indian influence on Chinese astronomy is the 60-year century, known in Vedic literature (the Brhaspati cycle) and still commonly used in the Chinese calendar.  The 6th-century astronomer Aryabhatta reports that he was 23 when the 60th cycle ended, implying that the system was set rolling in 3102 BC.  In China, the system was adopted a few centuries later: according to Chinese tradition, it started with the enthronement of the legendary Yellow Emperor in 2697 BC.

A stellar myth which was apparently transmitted from India to China is the notion that after death, the souls go to the Scorpio-Sagittarius region of the sky (specifically Phi Sagitarii), where the autumnal equinox was located in the 4th millennium BC.  There, they were to be judged by Yama or a similar god of the dead.

The influence of Indian astronomy on both China and Babylonia confirms the Vedic-Harappan civilization’s status as the world metropolis in the 4th-3rd millennium BC.  In the official cults in imperial China and in Babylon, stellar science, stellar symbolism and stellar worship were central.  But the same central place had already been accorded to astronomy in the Vedas, as we have seen here (if only fragmentarily, for numerous Vedic motifs not discussed here are also related to astronomy, e.g. the twelve Adityas or divine children of the sun, Prajapati as personification of the year cycle, etc.); and also in the culture and religion of the Indus-Saraswati civilization, as Asko Parpola and others have shown.³⁵

Remark that Parpola often tries to make sense of Harappan data by referring to Vedic data, on the AIT-based assumption that the Aryan invaders integrated Harappan astronomy and religion.³⁶ This is again a case of multiplying entities without necessity: instead of saying that there are two cultures which happen to share some astro-religious lore, we might assume that these two cultures are one, until proof of the contrary.  Parpola’s arguments for a Harappan origin of Vedic and Hindu cultural items, e.g. of astronomy-based nomenclature (names like KRttikA, “of the Pleiades”), are just as much arguments for an identity of Vedic and Harappan.³⁷ The point to remember is that even Parpola, often cited as an argument of authority by Indian defenders of the AIT, fully acknowledges the continuity between Vedic and Harappan culture.  The common emphasis on astronomy in both Vedic and Harappan sources is certainly an indication of their close kinship if not their identity.
 

Footnotes: 
 

²²J.E. Mitchiner: Traditions of the Seven Rishis, Motilal B Delhi 1982, p. 163.  I thank Prof. Subhash Kak for this reference.

²³Pliny:Naturalis Historia 6:59; Arrian: Indica 9:9. I thank Dr. Herman Seldeslachts for checking these references.

²⁴The worst case was probably the Black Sea, which was a lake during the Ice Age, until some time in the 7th millennium BC.  When rising waters in the Mediterranean inundated the dry Bosporus straits and plunged into the Black Sea, the latter rose dramatically, forcing coast-dwellers to flee as much as a mile a day for months on end.  Many of them didn’t survive, and entire states (or whatever political units were in existence) were drowned.  The fact that the Biblical Flood story has Noah land on Mount Ararat, not far from the Black Sea, may be due (apart from the presence of a boat-like rock formation there) to the memory of the Black Sea flood drama.  In most parts of the world, the flooding of coastal villages must have been more gradual.

²⁵P.C. Sengupta: “The solar eclipse in the Rgveda and the Date of Atri”, Journal of the Royal Asiatic Society of Bengal Letters, 1941/7, p.92-113, also included in his Ancient Indian Chronology, Calcutta 1947; discussed in K.V. Sarma: “A Solar Eclipse Recorded in the Rgveda”, in Haribhai Pandya et al., eds.: Issues in Vedic Astronomy and Astrology, Motilal Banarsidass.  Delhi 1992, p.217-224.

²⁶N.S. Rajaram (with D. Frawley): Vedic ‘Aryans’ and the Origins of Civilization, WH Press, Québec 1995, p.106.

²⁷This position is argued powerfully in the classic study by Giorgio de Santillana & Hertha von Dechend: Hamlet’s Mill, David R. Godine, Boston 1992 (1969); in Norman Davidson: Astronomy and the Imagination, Routledge & Kegan, London 1986 (1985); and in Thomas D. Worthen: The Myth of Replacement. Stars, Gods and Order in the Universe, University of Arizona Press, Tucson 1991.

²⁸S. Kak: Astronomical Code of the Rig-Veda, Ch.5-6.

²⁹Georg Feuerstein, Subhash Kak and David Frawley: In Search of the Cradle of Civilization, Quest Books, Wheaton IL 1995, p. 208.

³⁰Kak: Astronomical Code, Ch.4.

³¹Argued in N.R. Waradpande: New Light on the Date of the Rgveda, Sanskrit Bhasha Pracharini Sabha, Nagpur 1994, p.13-24.

³²This remains true whether one uses the Tropical (abstract, solstice/ equinox-based) or the Sidereal (visible, constellation-based) Zodiac, a question which is not really relevant here.  The Vedic Zodiac was sidereal, more based on observation than on calculation; the tropical Zodiac apparently dates from the time when sidereal and tropical signs coincided (around the turn of the Christian era), i.e. when the constellation of Aries filled the 300 sector following the spring equinox in the sun-earth cycle, a tropical sector known since then as Aries regardless of the position of the constellation Aries.

³³Other possible Vedic indications that the seers used the concept of heliacal rising, are the descriptions of the last stars fading before the almost-rising sun: RV 1:50:2, and metaphorically RV 7:36:1, 7:81:2, 9:69:4.

³⁴Joseph Needham: Science and Civilization in China, part 1, ch-20: “Astronomy”, p.253-254.