AHC/WI: scientific revolution in ancient India or China

In India, the funny thing is that this'd be likelier the earlier it takes place. Cārvāka, aka Lokāyata, offers the perfect philosophy upon which to found a scientific revolution; but it's also one of the most ancient and basal schools of Hinduism known, dating back to at least the Vedic Period- cited as having potentially been established prior to 1000BCE (with the earliest potential origins of this school and its attributed founder dating back to the city of Prayag, today known as Allahabad, at the boundary between the Late Harappan Period and Vedic Period; and with the Indus Script still remaining undeciphered, who's to say it didn't have its origins there?) and definitely having been established prior to 500BCE. So long ago, that all copies of the original Sanskrit texts which comprise the foundation of this school of materialist, skepticist, anti-theistic and non-orthodox Indian philosophy, the Brihaspati Sutras, have been lost forever; and even its accredited author and founder, in spite of having purportedly cited by all and sundry as the most outspoken, overt and radicalist anti-theist in the entirety of the ancient world, wound up becoming exalted and deified to join the Hindu pantheon, as the God Brihaspati.

The last of these manuscripts were wiped out under Mughal rule, after a symposium of philosophers of all faiths which was held in 1578 at Akbar's insistence; with Mughal historian Abu'l-Fazl ibn Mubarak having summarized the Cārvāka philosophy as "unenlightened"- noting that Cārvākas considered paradise as "the state in which man lives as he chooses, without control of another", while they considered hell to be "the state in which he lives subject to another's rule". On state craft, Mubarak stated that Cārvākas believed that it was best when "knowledge of just administration and benevolent government" is practiced, and their works of literature were accordingly characterized as "lasting memorials to their ignorance", which posed an existential threat to the proper rule of (sharia) law, and thus merited only destruction. And the only traces of these texts which remain are the abundant references to and citations of them in the manuscripts of multiple other schools and religions, with Cārvāka predating the Āstika schools, as well as being the philosophical predecessor of numerous subsequent philosophies in the classical period of Indian philosophy, including Ajñana, Ājīvika, Jainism and Buddhism.

So I'm going to go out on a limb here, and posit the equivalent of OTL's European scientific revolution taking place in India almost as far back in time as one could plausibly go anywhere in the world; in the Late Harappan Cemetery H Culture, which followed on from the gradual decline and abandonment of the Indus Valley Civilization's urbanization between 1900BCE and 1700 BCE. Recent examination of human skeletons from numerous Harappan sites has demonstrated that this period of demise for the Indus Valley Civilization saw an increase in inter-personal violence, and in infectious diseases in spite of its cities having boasted superior urban sanitation systems than any others that'd arise in the world up until the early industrial period; tuberculosis became rampant, and this is also the earliest identified point of origin to which we can trace human outbreaks of leprosy. IOTL, this in turn engendered a breakdown of urban networks and an expansion of rural ones, along with the transition from the IVC's funerary custom of burial in wooden coffins, to the Cemetery H Culture's funerary custom of cremation and storing ashes in burial urns, which Vedic civilization later inherited from them (which now appears most likely to have originated as a rational attempt to quell these pandemics, and reduce the rates of human infection).

 In this scenario though, let's say that someone in the Haryana/Uttar Pradesh region, on the borderline between the Cemetery H and Vedic Cultures in both time and location (c.1300BCE), decides to go farther still, and in accordance with Cārvāka's epistemological argument (holding only direct perception, empiricism, and conditional inference as proper sources of knowledge, whilst wholly rejecting ritualism and supernaturalism as intrinsically flawed), decides to conduct as thorough an investigation as possible into exactly why and how these diseases afflict people in the first place. Even IOTL, in the Nidána Sthána chapter of the Sushruta Samhita, a Sanskrit medical treatise written around the sixth century BCE by the ancient Indian physician Sushruta (cited as having been a follower of the Cārvāka school), regarding pathology, we can find perhaps the earliest documented instance of germ theory, with Sushruta having theorized that "leprosy, fever, consumption, diseases of the eye, and other infectious diseases spread from one person to another by sexual union, physical contact, eating together, sleeping together, sitting together, and the use of same clothes, garlands, and pastes."

Indigenous development of glass (aka Kanch or Kaca in Sanskrit) technology in the Indus Valley Civilization is now known to have begun at least as early as 1730 BCE, when the manufacture of glass beads in the Indus Valley locations is first documented, and became adopted by the Vedic Culture from at least 1200BCE onwards; but in India IOTL, this never progressed any farther, since glass never acquired any societal value comparable to those of metals or pottery, the latter of which was preferred to glass vessels in all religious functions and iatro-chemical practices. As such glass objects remained nothing more than a curiosity in India, typically imported from the Greco-Roman world, until some time after the birth of Christ, with glass playing an insignificant role in the Indian socio-cultural life. As such, the rasavadins (alchemical-cum-medicinal chemists) of India never employed glass vessels for their chemical operations involving distillation, steaming, mild heating and the like.

Their apparatus was by and large earthen, which didn't permit them to actively observe the way in which the chemical processes took place; the fabrication of glass apparatus, like those which placed chemistry on a solid foundation in the West in the 17th century, never happened in India. A major factor in OTL's scientific revolution was the development of what are known as tank furnaces for large-scale commercial production of glass, along with the standardization of fabricating methods such as the pot method, and the use of the finest raw materials (silica and compounds of sodium, magnesium as well as calcium), facilitating the production of optical glass which had the required degrees of hardness, desired refraction and dispersive powers to facilitate the crafting of lenses, prisms, mirrors, glass tubes and vessels; all of which played critical roles in the new experimental methods that led to the growth of physics, chemistry and biology IOTL's scientific revolution.

In Indian ethos, however, glass was completely ignored for millennia, dismissed as only fit for decorative beads and bangles. Thus glass-making in India never managed to advance beyond the first and the very rudimentary stage on the 'tech ladder', and thus all of the technological and scientific advancements which were unlocked via the glass-making 'tech tree' remained locked permanently. ITTL though, let's say that this individual goes further still; dissatisfied with merely settling for proof via inference and assumptions based upon correlations, as Sushruta had to, he seeks to obtain empirical 'proof beyond all reasonable doubt' for germ theory (and by extension, numerous other quandaries and curiosities which require greater acuity of perception than can be provided by the human eye unaided). And thus, via sufficiently advancing indigenous Indian glass research to facilitate the creation of simple optical lenses, either he or a follower of the school founded by him successfully creates the the first simple microscope, up to 3000yrs earlier than IOTL.

Thus, via this method, germ theory is confirmed; and with the crafting of lenses, prisms, mirrors, glass tubes and vessels having been made possible in Indian society, the Cārvāka philosophers immediately set about conducting empirical research to experiment and affirm (or disprove) as much of that which could previously only be assumed via the flawed methodology of indirect inference (i.e, 'correlation=causation'), lending itself to superstitions and ritualization; leading to an explosive growth of scientific knowledge, and a full-blown Vedic Indian scientific revolution (wherein the Indus Valley/Harappan civilization effectively never 'falls', but transitions almost immediately to another phase of even greater urbanization, in concert with basal pre-industrialization)...