there are lots of facts and evidences for our past that are neglected due to lack of knowledge and understanding. scientists are working and have found many of so called Indian mythical stories are true and all such mythical characters really existed in past. Their technologies were simple (can be launched from bow and arrows), less harmful to environment but were much powerful and advanced than now. scientists today are re-searching (working on the work that were already existed/found). The VEDA also known as first book in HINDU texts are the base of every technology that exist today (even NASA and MIT also studying to find new technology) we today don’t understand the text in the VEDAS as they were written in Ancient SANSKRIT language. if I start talking of ancient technologies it will take me whole day to highlight a little of it.
I’ll quote one very popular example of distance between Earth and Sun. Based on Valmiki’s Ramayan(the original verse) saint Tulsidas written Ram-Charit-Manas in around 16th Century (according to wikipedia it’s 1633 AD) at this time astrology and astronomical calculations were not developed to that extent to calculate distances between celestial bodies but at same time Tulsidas written Hanuman Chalisa where he quoted distance between Sun and Earth. see these references:
coming back to point in around India much before industrial revolution we have texts that describes the use of Mercury as fuel for ancient Vimanas that were able to travel interstate, intercountry and interplanet. These Vimanas were laced with stealth technology were used in wars.
scientists in modern days tried to implement Mercury Vapour Engine and made a flying object, it went high in sky (that shows ancient flying Indian theories were not wrong) but explode after some time. scientists some of ancient concepts in now used Ion engines for movement in space.
India’s ancient theories are huge pool of real knowledge but due to modern industrial revolution and westernization we are lacking this knowledge, many of modern scientists, researchers and solars have quoted slokas/hymns/references form Vedas and other Indian texts.