Anytime the topic of Indian vedic science comes up, there's always that one guy who mentions something about the 'Vyamanika Shastra', a Hindu book that told people how to make planes. Damn, we literally had a 'shastra' for planes - of course we were a science superpower. That is until you actually analyse the shastra and try to make a damn plane from it. We went through this detailed debunking of our high flying mythology by the fine folks at the Indian Institute of Science.

We don't even know who wrote it.

The sage Maharshi Bharadwaja? Nope. There is no proof that he wrote it. It was dictated by Pandit Subbaraya Shastry of Anekal to Shri G. Venkatachala Sharma, but we have no idea where it came from before that.

Even the Vedic slokas referenced don't seem, well, Vedic

"The text...language is quite simple and modern. Again, in its introduction, BVS mentions that a few words did have a structure similar to that of the Vedic Sanskrit.