Various contemporary incidents, taking place around us, may not affect us directly, although these affect indirectly few or many of us. Despite limitations and unfavourable situations, still there are few who continues to pen down the correct information and truth ignoring the mockery, ridicule and bad comments made by some people. I am thankful to Prof. Ananda Dasgupta, IISER Kolkata for drawing my attention to a brilliant piece on 'gravity' written by Prof. Amol Dighe, TIFR Mumbai. Prof. Dighe explains gravity very nicely and beautifully in the language of common people, a topic which we started studying from our high school days and clarifies the statement 'we knew about gravity before Newton.'  The original article is appended below. Please enjoy the 'easy parts, the not so easy parts and the extremely difficult parts about understanding 'gravity'.'
----------------------------------------------------------------
This post has its origin in the recent statement by the Indian MHRD minister (this ministry controls and provides funds to most higher education institutions in India) that gravity was mentioned much before Newton in ancient Indian astronomical texts.

The first three are observations, the next three theoretical conjectures, while the last one involves some deeper insight. Of course all the above was known before Newton. It is quite likely that most of 1-6 was known to (and done by)  ancient Indian astronomers (though I am not an expert in history). I am not sure about 7.
Now while politicians have their ways of making statements that walk the thin line between truth and misinformation (and irking us short-trigger scientists), this is perhaps an opportunity to bring out some important points about how science has progressed, that may be appreciated by everyone. 

There are many distinct steps in the understanding of gravity. (I may be missing many) :

1. Noticing that all bodies fall to earth
3. Making measurements and calculations of motions of astronomical bodies
2. Making measurements and calculations of motions of falling bodies
5. Getting the idea that there is some force that makes the  astronomical bodies move.
4. Getting the idea that earth pulls the falling bodies to itself
6. Getting the idea that earth may be going around the Sun.
But Newton's work involves insights far beyond these.
7. Realizing that heliocentric system gives simple rules for planetary motion (Kepler's laws).
8. The idea that the same law that governs bodies falling to ground on earth governs planets going around the sun. 
(I have restricted myself to pre-Einstein understanding, so no  General Theory of Relativity here, which of course improved our understanding of gravity by one more leap.)
9. Showing by astronomical calculations that this law is inverse square law (1/r^2).
10. Realization that the gravitational force of sun and planets acts as if the mass of each body is at its centre.

When one  says "Newton discovered gravity", one is normally referring to 8 and 9 above. (Point 10 is rather underappreciated even in the scientific community, however it induced Newton to write his famous treatise "Principia Mathematica ...". See the commentary by S. Chandrasekhar. )

Saying someone "mentioned gravity"  earlier is trivializing the meaning of the phrase "Newton discovered gravity", and indeed, of what the discovery means.
19.08.2019