There is definitely a case for enhancing the Indian public’s awareness of the genuinely impressive accomplishments of their forebears (of which more below), rather than remaining schooled in a colonial-era Westernised view of the world. But the uncritical, indeed fantasy-laden, manner in which its Hindutva aficionados have advocated the cause has only discredited it.
The dominance of the BJP at the Centre and in the states has propelled a number of true believers of Hindutva into positions of unprecedented influence, including in such forums as the Indian Council for Historical Research, the University Grants Commission, and, it turned out, the programme committee of the Indian Science Congress, which scheduled a talk on "Vedic Aviation Technology" in 2015 that elicited howls of protest from many delegates.
It has also given a licence to unqualified voices who gain in authority from their proximity to power - none more significant than the prime minister himself, who suggested in a speech at a hospital, no less, that lord Ganesha’s elephant head on a human body testified to ancient Indians’ knowledge of plastic surgery.
The idea that the smallest conceivable elephant head could fit on the largest imaginable human neck defies rationality, but this appears not to have occurred to the literal-minded Hindutvavadis. Such ideas, because they are patently absurd, except in the realm of metaphor, have embarrassed those who advance them as well as those who cite them in support of broader, but equally unsubstantiated, claims to past scientific advances from genetic science to cloning and interstellar travel and the use of nuclear devices (by the philosopher-sage Kanada in the first century BCE).
Petty chauvinism is always ugly but never more so than in the field of science, where knowledge must be uncontaminated by ideology, superstition or irrational pride. But the controversy also discredits the modern rationalists who, in their contempt for such exaggerated and ludicrous claims, also dismissed the more reasonable propositions pointing to genuine Indian accomplishments by the ancients.
It is not necessary to debunk the genuine accomplishments of ancient Indian science in order to mock the laughable assertions of the Hindutva brigade. Separating the reasonable from the absurd is a necessary condition of well-founded criticism. A BJP government choosing to assert its pride in yoga and Ayurveda, and seeking to promote them internationally, is, to my mind, perfectly acceptable.
Not only are these extraordinary accomplishments of our civilisation, but they have always been, and should remain, beyond partisan politics. It is only if the BJP promoted them in place of fulfilling its responsibility to provide conventional healthcare and life-saving modern allopathic medicines to the Indian people, that we need object on policy grounds. But when the national manifesto of the BJP for the 2009 General Election claimed that in ancient times, rice yields in India stood at 20 tonnes per hectare - twice what farmers can produce today using intensive agriculture in the most fertile and propitious conditions imaginable - all one can do is to throw up one’s hands in despair.
On the other hand, in asserting (in his own speech to the Indian Science Congress) that ancient Indians anticipated Pythagoras, science and technology minister Harsh Vardhan was not incorrect and should not have been ridiculed. In fact, he could have added Newton, Copernicus, Kepler and Galileo as well, every single one of whom had been beaten to their famous "discoveries" by an unknown and unsung Indian centuries earlier.
The Rig Veda asserted that gravitation held the universe together 24 centuries before the apple fell on Newton’s head. Scholars working in Sanskrit anticipated his discoveries of calculus by at least 250 years. The Siddhantas are amongst the world’s earliest texts on astronomy and mathematics; the Surya Siddhanta, written about 400 CE, includes a method for finding the times of planetary ascensions and eclipses. The notion of gravitation, or gurutvakarshan, is found in these early texts. Lost Discoveries, by the American writer Dick Teresi, a comprehensive study of the ancient non-Western foundations of modern science, spells it out clearly: "Two hundred years before Pythagoras," writes Teresi, "philosophers in northern India had understood that gravitation held the solar system together, and that therefore the sun, the most massive object, had to be at its centre."
Aryabhata was the first human being to explain, in 499 CE, that the daily rotation of the earth on its axis is what accounted for the daily rising and setting of the sun. (His ideas were so far in advance of his time that many later editors of his awe-inspiring Aryabhatiya altered the
Source: https://www.dailyo.in/arts/book-extract-hinduism-science-history-mughals-hindutva-shashi-tharoor-hin