Bharat - 2 million years (Sūrya Siddhānta)
or
presently believed 6th-century BC, which still makes it oldest book on earth in Astronomy to mention Earth as sphere not flat
Sūrya Siddhānta has fourteen chapters
All copied it
1/n
Al-Biruni 11th-century Persian scholar and polymath mentioned about text named Surya Siddhanta written Lāta
He copied many things from it
Surya Siddhanta attributes the words to an emissary of solar deity as recounted to Maya at end of Satya Yuga two million years ago
2/n
Translation of Greek works was taken up in 9th century
Arabs embarked upon translation of Sanskrit texts from India much before that
These works were translated in Arabic by Al-Fazari,who emerged as first Arab Astronomer of great repute
Basically He copied and pasted
4/n
Acc to Tabqatul Umam a delegation from India came to Baghdad in 771
some 250 years after death of Aryabhatta
One of them was Kanaka, who carried with him a small library including a book titled Surya Siddhanta and works of Aryabhata and Brahamgupta
5/n
Table of contents in Surya Siddhanta are :-
The Mean Motions of the Planets
True Places of the Planets
Direction, Place and Time
The Moon and Eclipses
The Sun and Eclipses
The Projection of Eclipses
Planetary Conjunctions
Of the Stars
Risings and Settings
6/n
Cont...
The Moon’s Risings and Settings
Certain Malignant Aspects of the Sun and Moon
Cosmogony, Geography, and Dimensions of the Creation
The Gnomon
Thread on Calculation of time as per Surya Sidhant 🌞
Surya Sidhant is ancient science of Astronomy which is kept by Sun himself, was described to Maya by Partakes of Sun's nature after his penance for enquiring about this in the end of Krita Yuga
It was compiled many times 1/n
Types of time two
1. Continues and endless - destroyes all animate and inanimate things (cause of creation and preservation)
2. Can be Known - Two types
MURTA (measurable) begins with Prana=4 seconds
AMURTA (immeasurable)begins with Truti=1/33750th part of second
2/n
6 Prana = Pala
6 Pala = Ghatika
60 Ghatika = Nakshatra Ahoratra (a side real Day and Night)
Months:-
30 Nakshatra Ahoratra = Nakshatra Masa
30 Savana Day(terrestrial day from sun-rise to sun-rise) = Savana month