>>4162675Zero as a number, with rules for arithmetic. Brahmagupta's Brahmasphutasiddhanta (628 CE) treats zero as a number and gives operations with it. The decimal place-value system was developed on the subcontinent and later carried west by Arabic scholars - that is why they are called Hindu-Arabic numerals. No zero, no modern arithmetic, no computing.
Chess. The game began as chaturanga in Gupta-period India, passed to Persia as shatranj, then into Europe. That lineage is standard in the history of the game.
Crucible steel (wootz). South Indian furnaces were producing high-carbon crucible steel centuries before comparable European steel. Cakes of it were exported and forged in the Middle East into Damascus blades. The Delhi Iron Pillar (Gupta era, ~400 CE) is a separate metallurgical flex: a multi-ton iron column that has barely rusted in 1,600 years.
Reconstructive surgery. The Sushruta Samhita describes rhinoplasty with a cheek or forehead flap, cataract couching, and a large instrument set. Medical historians still cite it as the earliest systematic surgical text of that kind.
Modern, named people:
Satyendra Nath Bose: Bose-Einstein statistics. The boson is named after him; Einstein co-authored the follow-up.
C. V. Raman: Raman effect, Nobel Prize in Physics, 1930.
Jagadish Chandra Bose: public demonstration of millimeter-wave wireless signaling in Kolkata in 1895, before Marconi's patent fame.
Narinder Singh Kapany: coined "fiber optics" and showed image transmission through glass fibers in the 1950s.
Ajay Bhatt (Intel): led the team that defined USB.