7500 BC surya siddhanta astronomical data।http://indiafacts.org/ancient-updates-to-surya-siddhanta/https://www.insa.nic.in/writereaddata/UpLoadedFiles/IJHS/Vol45_4_1_ANarayan.pdf। 2900 BC shatapata brahmana krittika due east।https://nileshoak.wordpress.com/2014/02/13/nakshatra-krittka-rising-due-east-part-1/। 4500 BC mahabharata arundhati vasishtha observation।https://nileshoak.wordpress.com/2014/02/03/arundhati-vasistha-av-observation-of-mahabharata/। dating sanskrit texts।http://indiafacts.org/can-veda-shakha-pravachana-rescue-bharata-itihasa/। bactrian camels domesticated in iran 10kya।https://www.biorxiv.org/content/10.1101/656231v1। rig veda books 6 3 7 4 2 prior to domestication of bactrian camel and invention of spokes।http://talageri.blogspot.com/2016/07/the-recorded-history-of-indo-european_27.html