If you want to get something that you never had before, do something that you had never done before!
Let us try to do a simple and straightforward astronomical dating of the actual vedic period.
In the ancient vedic culture, people used to consider the beginning of a new year on the day of the vernal equinox.
Now a bit of equinox.
Earth’s axis of rotation is not perpendicular to that of sun’s equatorial plane and instead is tilted at an angle of about 23 degrees. So, as earth moves around the sun it appears as though the sun is rising slightly north of due east for half of the year, and then slightly south of due east during the other half of the year.
Thus there are two points where as observed from earth Sun makes a transition from north to south and south to north, and at these two points, sun rises exactly due east, and these points are called equinoxes. One is the spring equinox and the other is the vernal equinox.
It is to be observed that in northern hemisphere what looks like a transition of sun from south to north i.e vernal equinox, actually looks like a transition from north to south when observed in the souther hemisphere.
There are also two other points of extremes of north and south which sun touches and comes back as it rises everyday, and these are called summer and winter solstices. So over a period of time it looks as though sun is oscillating on either side of the due east during sun rise (or either side of due west on sunset)!
Note that what we consider as summer solstice in northern hemisphere is winter solstice in southern hemisphere. Seasons on earth are due to the tilting of earth’s axis, and hence when there is summer in the northern hemisphere its winter in south and vice versa.
Now coming back to the equinoxes. During the vedic ages, new year began on vernal equinox and was called Agrahayana. Agrahayana means beginning of the year. The new year then was celebrated in the vedic month of Margashira (named after a star lambda orionis in the constellation of Orion).
Since there is also a precession of the earth’s axis, the equinox dates keep changing every year, and when seen from a stellar background the constellation in which the sun rises on the vernal equinox also keeps changing over a period of time.
In our times today, the sun rises in the background of Pisces (Meena Rashi) on the vernal equinox. Whereas in the vedic period it used to rise in the background of Gemini (Margasira/Orion is in Gemini).
The earth’s precession takes about 25,800 years for one complete cycle. Since there are in total 12 constellations for the sun to make its journey, it means sun stays in every constellation for about 2150 years on the day of the vernal equinox!
Now let us see as to approximately how many years would sun require to move from Gemini to Pisces. This can be achieved by simply calculating the number of constellations in between and multiplying it by 2150. From Gemini we have Taurus, Aries and then Pisces, which means some where between three to four constellations (four including the place of stay)
In other words, we can assume that the vedic age might have been somewhere between 8600 years ago till about 6450 ago. This approximation is also supported by the geological data of the now extinct mighty Saraswati river !
In modern calendar system this would translate to somewhere between 6600 BCE to 4450 BCE, and thats definitely a long long time ago! If modern science can achieve so much in a span of millenia or so, its not surprising that the vedic people would have achieved much more over a period of thousands of years!
Please note that in the above mentioned approach, we can also go back to earlier multiples of 25800 years like (n x 25800)+8600 years ago to (n x 25800)+6450 years ago, by visiting back to all the previous Gemini ages of vernal equinox!
So using some simple astronomy and arithmetics, and a simple clue, we tried to do a simple calculation of the approximate vedic period.
If this calculation sounded complicated to you, well, we have to keep things as simple as possible, but not any simpler
Vedas also talk about vega being the pole star, and this happened the last time at about 12000 BC! Looks like what we read as known history in the text books is just the first line of a huge epic consisting of thousands of pages!
What is history? An echo of past heard in the future, A reflex from the future acted upon the past