Aryabhata
He proposed a heliocentric model with Earth rotating on its axis and accurately calculated the length of the sidereal year.
Most quoted
"Just as a person in a boat going forward sees the stationary objects on the shore as moving backward, just so are the stars, though stationary, seen by the people on the earth as moving westward."
— from Aryabhatiya, Gola (Sphere) Chapter, Verse 9
"Just as a man in a boat going forward sees the stationary objects on the shore as moving backward, just so are the stars seen as moving backward by the people on the Earth moving forward."
— from Aryabhatiya (rephrasing of a core concept)
"Just as a person in a boat moving forward sees the stationary objects on the bank as moving backward, in the same way, a person on the Earth sees the stationary stars as moving backward."
— from Aryabhatiya, Gola (Sphere) 9, 499
All quotes by Aryabhata (366)
The moon shines by reflecting the light of the sun.
The planets move in elliptical orbits around the sun.
One day of the gods is equal to one year of humans.
The circumference of a circle is approximately 3.1416 times its diameter.
The square root of a number can be found by an iterative method.
The sum of the cubes of the first n natural numbers is (n(n+1)/2)^2.
The sine of an angle can be calculated using a table of differences.
The planets have their own light, but they are illuminated by the sun.
The moon is closer to the Earth than the sun.
The moon's shadow causes solar eclipses.
The planets move in their orbits with varying speeds.
The stars are fixed in the sky and do not move.
The Earth is suspended in space and is not supported by anything.
The sun is the source of all light and heat.
The planets have different sizes and distances from the Earth.
The moon has phases because of its position relative to the sun and Earth.
The Earth's rotation causes the cycle of day and night.
The planets have their own orbits and do not collide with each other.
The stars are countless and cannot be numbered.
The sun is much larger than the Earth.