Why the 27 degree concept is a misnomer?

In my earlier articles, "The Ayana" and "Missing links: The real Surya Siddhanta ayanamsa", I have explained the concept of ayana and why the concept of considering 27 degrees as overall is a misnomer.

Here in this article, I would explain why the popular concept is a misnomer even according to the traditionalists who follow it. For this, we need to refer to the kaliyuga date that has been considered traditionally as February 18, 3102 BC (Julian), whereas the year of coincidence of true siddhantic values with the tropical is considered in 499 AD.

As per the misunderstood 27-degree overall concept, it is assumed that the ayanamsha oscillated 27 degrees in the opposite direction from the kali yuga start date until 499AD in 3600 years. And from 499 AD onwards, it is in line with the modern theory of westward movement of the vernal equinox.

The concept is defeated in the kaliyuga date itself. Had this been the siddhantic concept, the kali yuga date would have been around the vernal equinox in 3102 BC and not about two months earlier in January (Gregorian date of kaliyuga epoch is January 23). Since the chosen kali yuga epoch falls in January, the siddhantic values would not coincide with the tropical in 3102 BC if we do the reverse calculations.

I would like to mention here that the reason for the kali yuga date being about two months earlier in the traditional concept is linked to the surya siddhanta year length. The difference between the SS year and modern tropical year is such that in 3600 years, this difference amounts to about two months and hence the date of epoch is also two months earlier.

Thus, the 27-degree overall concept is a clear misnomer even practically as it does not explain the ayana concept at all.

Next, I would like to mention another misnomer concept related to the lunar-months' naming that is based on the nakshatra at Poornima. We recognize these lunar months in India as Chaitra, Vaisakha etc. Some believe that the naming of the lunar months as based on the nakshatra at Poornima would be disrupted in about 2459 years as per the Surya Siddhantic model and about 3074 years as per the modern figures leading us to not observing the right nakshatra at Poornima according to the naming convention as desired, and when that would happen we would have to rename another month as Chaitra (adjustment of one lunar month). Let me first detail how they arrive at their figures:

The reason they cite for such a disruption is linked to the number of lunar months in 19 solar years that are not exactly 235 lunar months but little more. As per them when that little more is accumulated, it would lead us to needing one lunar month of adjustment in the number of years as mentioned above.

Let us see it mathematically:

Total days in 19 solar years (Surya siddhanta) = 6939.916 days
Total days in 235 lunar months (S. Siddhanta) = 6939.688 days
Difference = 6939.916-6939.688 = 0.2282 days
Difference in 2458.6628324 years = 1 Siddhantic lunar month

Similarly, if we apply the same theory on modern astronomy figures, we get one extra lunar month in about 3074 years.

Fine, there is an extra lunar month, so what? Why would it affect the naming convention?

The fact is this one extra month would automatically be absorbed in the luni-solar calculations of whatever model is followed. Remember, we are not mixing the two models in our calculations above. Let me explain it practically with the Surya Siddhanta model since mean values of SS are more clear and simple.

We can start either from the Srishti epoch or from the present kaliyuga. It would not make a difference since in the SS model, all the planets are at zero longitude even at the start of the present kaliyuga.

No. of years at the start of kaliyuga since Srishti epoch = 1955880000
Let us see 3000 years onwards since one extra lunar month is achieved in 2458.6628324 years as explained above:

Moon revolutions= 3000*365.25875648*57753336/1577917828
Moon's mean longitude (deduced from above)= 174 degree
Moon's tithi = 3000*365.25875648*53433336/1577917828 = 15th

It is clear that the mean longitude of the Moon would be in the nakshatra Chitra at the Poornima at the end of the 3000 years which is more than 2458 years. So, the naming convention is working fine and does not require any shift.

If we calculate after 5000 years,
Moon's mean longitude = 50 degree

And the Poornima happens when the mean Moon is in the Swati nakshatra, still meeting the naming convention since Chitra and Swati pair makes a Chaitra month.

We can calculate similarly for 10000 years and still the naming convention is not disrupted.

Hence, the mentioned one extra lunar month is absorbed in the model itself without requiring any need to make the adjustment for the extra lunar month.

Let us strive to chase the truth leaving behind the misnomer concepts.

Note: Those who disagree have a right to do so but I am open for a healthy discussion anytime. I request especially those people who have a following to know and spread the truth since they are also harming their followers with wrong knowledge if they have a misnomer concept in their mind.

Click the following link for supplement of this article:
Why the alternative linking is also a misnomer