Thread by @Hiranyareta

Surya Siddhanta describes its model for precession of equinoxes as follows:

"त्रिंशत्कृत्यो युगे भानां चक्रं प्राक् परिलम्बते।
तद्गुणाभूदिनैर्भक्ताद् द्युगणाद्यदवाप्यते॥
तद्दोस्त्रिघ्ना दशाप्तांशा विज्ञेया अयनाभिधाः।
तत्संस्कृताद्ग्रहात् क्रान्तिच्छायाचरदलादिकम् ॥"
1/

For the source of the abv refer here. Chapter-3, Shloka (9-10)
2/
vedicreserve.miu.edu/jyotish/surya_…

"Gudhartha Prakashaika" commentary of Surya Siddhanta by Acharya Rangantha, compiled and edited by Prof Ramchandra Pandey (Head Jyotisha Dept, BHU), explains abv as follows:
3/
archive.org/details/suryas…

If you find Sanskrit and Hindi explanations abv too complicated then here is an explanation in English.
4/
archive.org/details/SuryaS…

What it says that the vernal equinox point (the point of Aries) oscillates around a point located in Ashvini Nakshtra with an amplitude of 27° and a period of 7200 years.
5/

Therefore, the precession model described in Surya Siddhanta is a different one from what's accepted and used in today's modern astronomy. The present model is the one with circular movement of the point of Aries with a period of 26000 Years.
See this.
6/

The Surya-Siddhanta model of precession has been explained by @jayasartn in this video. But I guess whatever she says gets dismissed without any hearing as she has been labeled "unscientific" by the Maharashtrian Mahabharata Mafia.
7/

The one consequence of the model proposed in Surya Siddhanta is that the Dhruva star will never change as claimed by Oak and many others. It will remain the same as what it is today and 13000 years from now.
8/

And if that is the case, irrespective of whether it's Scientifically correct or not, then ancient Indian astronomers never used the present circular movement model of precession.
9/

In the light of this, how accurate (and scientific) it would be to make sense of astronomical observations mentioned in Hindu texts assuming a circular model of precession (which was never used)?
All the findings (hoaxes) of Oak are based on this faulty assumption.
10/10

To the best of my knowledge, there is no scientific evidence to support the circular model of the precession of equinoxes. It would seem that ever since Hipparchus noted it is precessing. west has had assumed it will precess forever and formed this model.
1/2

But look at the highlighted part of the paper (pointed by @jayasartn) given at the following link. It kind of supports Surya Siddhanta's model of precession.
agupubs.onlinelibrary.wiley.com/doi/full/10.10…
2/2

https://twitter.com/Hiranyareta/status/1354627123105976324?s=20

A finding from JPL-NASA supporting Surya Siddhanta Model of precession.

"Around the year 2000, Earth's spin axis took an abrupt turn toward the east and is now drifting almost twice as fast as before, at a rate of almost 7 inches (17 centimeters) a year.

1/3

It's no longer moving toward Hudson Bay, but instead toward the British Isles," said Adhikari. "That's a massive swing. Adhikari and Ivins set out to explain this unexpected change."

2/3

jpl.nasa.gov/news/nasa-stud…

Read this blog for the Surya Siddhanta context of the abv finding by NASA.
3/3
jayasreesaranathan.blogspot.com/2020/07/my-res…

Unless you show a real observation confirming the presence of equinox beyond 27° relative to the original point of Aries on the Zodiac, the oscillatory movement of equinox described in SS is as valid as the circular movement of western astronomy.
1/3

https://twitter.com/UltDeath/status/1354661235875143686?s=20

Let us not become a Faith-Fool of Scientism. As far as rigor part is concerned, the problem with Hindu RW/Scientific/Trad etc is that they are totally ignorant about the language of Vedanga Jyotish.2/3

https://twitter.com/UltDeath/status/1354661235875143686?s=20

@jayasartn uses that language in her blogs and videos when she talks about the ideas and topics of Jyotish and it appears as "astrology" to these deracinated ignorant people. Hence this urge to declare her "unscientific".
Read her blogs and book, logical and organized.

3/3