Modern science is undoubtedly a contribution of the west. That way, in all societies, there were attempts of obstruction to progress of science. In India they got more success. There was a time in Indian history when Indian science was not only famous in the country, but it was so all over the world. If the progress of Indian science would have been maintained unhindered after the sixth century A.D., we Indians, today, would have been foremost in the scientific field.
From the ruins of Harappa and Mohenjodaro, it is clear that there existed a pre Aryan urban civilization of Dravidians, which went by the name of Nagas. It shows great development of town planning, water supply and urban facilities, sanitary drainage and granaries. Gold used for ornaments in Harrapan culture was from Kolar gold mines, the only source available, which is proved by a committee of metallurgical experts under sir Edwin Pascoe, who performed chemical analysis, under the direction of Sir John Marshall. So gold mining was a flourishing industry of the time.
The copper used in Harrapan civilization was imported from Rajputana, and tin from Hazaribagh. It used various types of stones quarried all over India, and some imported from outside. The modern number system of 0 to 9 with use of decimal point is the contribution of Indian mathematicians. It spread to Europe via Arab countries.
We know the importance of Ashokan pillars for aesthetic beauty, craftsmanship and religious declarations, but it was also known for the science of polishing of stones to such an extent that it became the distinguishing mark, the structures with high polish being ascribed to Ashokan period. Such gloss and polish, Marshall says, "no modern mason can produce", Vincent Smith calls it "the despair of modern masons", Tom Coryat and Whittekar described it as of brass, Chaplain Terry as a pillar of marble, and Bishop Heber as pillar of cast metal.
Meharauli iron pillar, which is standing in the courtyard of KutubMinar at Delhi, belongs to fourth century A.D. It is standing there, defying the ravages of times, for centuries but not a spot of rust or corrosion on it. Its composition was examined by a committee of experts, who held that, it was beyond the capacity of any Iron foundry in the world of that time to manufacture such a masterpiece.
From Periplus we know that the sword made of Indian steel is proverbial in Arabic literature, showing the highest skills and knowledge of metallurgy. The famous Damascus blade was made from Indian steel. Ancient South Indian bronzes are praised even now in the whole world not only for their craftsmanship but also for metallurgy. Sultanguanj colossal Buddha in copper is a metallurgical masterpiece and a marvel, still preserved in Birmingham museum.