According to ancient Indian theories the optics came into light in the early 5th – 6th century BC. Sushrutha proposed to world that light which falls on the retina illuminates the world. Ancient scientist Varahamihira explained the rainbow concept in his book Brihat Samhita.

There are many Ancient Indian shlokas and sculpture which give an evidence for the excellent planning of the people in the ancient era. The shlokas from Brahad-vimana-sastram explains about the build of aircrafts. It is portrayed in Vimana sastram that aircraft has bird like structure with light body. The metals used for the body of aircraft should be heat proof, Non malleable, Anti-toxin, Acid proof, Weight-proof, wind proof, cold proof and wrought metal. The selection of metals for aircraft should be based on the thermal resistance capacity and light weight

About a hundred years before Brahmagupta, astronomer, Varahamihira had proposed the theory for the first time that there should be a force which might be keeping bodies stuck to the Earth, and also keeping heavenly bodies in their determined places. Hence, the existence of some attractive force that administers the falling of objects to the Earth and their remaining still after having once fallen; and also determines the positions which celestial bodies occupy. It was also recognized that this force is attractive force.

The astronomical model where in the sun is at the center of the earth and all the other planets move around the sun. The ancient India were aware that the earth and all the other planets in the solar system moved around the sun. This is Heliocentric Model. Ancient Hindu temple dating back to 5000 years used to have ‘Navagraha Mantap’ where in the Sun would be placed in the center and all the other planetary gods would revolve around the sun. This Navagrah mantap is still followed till date. Hence this clearly indicates that our ancestors clearly knew about heliocentric model.