If the Tropicalists “tropicalise” the Vedic Zodiac ( “which is imported from the West” ), it will go the Gregorian Way. The Vedic Astro Calender will become the Gregorian Calender ( again to be rectified later ! )
We have the Pingree and Van der Werden Hypothesis, the Naugbuer Hypothesis that the multi step algorithms of Indian Astronomy approximated a Greek Planetary Model, an eccentre and epicyclical Model. We have to respect them, as at least they admitted that India has an Astronomy. Not like Thibeau or Whitney who said that the ancient Indians had no knowledge of Astronomy or Maths, when they saw gigantic calculations like 311.04 trillion year cycles ( Maha Manvantara ) and the Cosmological Cycle (4.32 billion years ). They said these calculations are plagiarised from the Romans and the Greeks!
Dr Carl Sagan opined that while Christians were calculating in thousands, Hindus were calculating in trillions !
The Radius Vector, said Kepler, sweeps out equal areas in equal time. Parameswara in the 15th century and Nilakantha in the 16th talked about Vyasardha Manda Karna. Vyasa is Diameter. Vysardha is Radius and Vyasardha Mandakarna is nothing but Radius Vector.
Kepler’s Second Law states that
All planets move faster at Perihelion and move slower at Aphelion. That was known to the Indian astronomers. Otherwise they wouldnt have called Aphelion, Mandoccha ( Manda – slow ) and Perihelion, Sheegrocha ( Sheeghra – fast ) !
Let us get the dates of the astronomers
Parameswara – 15th century C E
Nilakanta – 16th
Kepler – 17th
Laplacae – 18th
The Nine Orbital Elements of the Kerala School of Astronomy and Maths, from which planetary longitudes are computed.
Mean longitude of Planet, Graha Madhyama , M
Daily Motion of the Mean Longitude, Madhyama Dina Gathi, Md
Aphelion, Mandoccha, Ap
Daily Motion of Aphelion, Mandoccha Dina Gathi, Apd
Ascending Node, Patha, N
Daily Motion of Ascending Node, Patha Dina Gathi, Nd
Heliocentric Distance, Manda Karna, radius vector, mndk
Maximum Latitude, L, Parama Vikshepa
In Western Astronomy, we have six orbital elements
Mean Anomaly, m
Argument of Perihelion, w
Ascending Node, N
Inclination, i, inclinent of orbit
Semi Major Axis, a