Bhagwan VIshnu and bhagwan Shiva(aliens) found Earth a suitable place to reside. They were from different clans probably from different planets. Bhagwan Vishnu setteled into deep sea and bhagwan Shiv decided to live on Himalayas. They both were here for a common cause. They both wanted the good for all living beings of universe. they were of the opinion that intelligent creatures can help them in future to stop the inevitable to occur in the universe. On earth most intelligent organism present at that time were humans. Humans were in their Iron Age. Aliens decided to communicate with them. Aliens made contact first to the most powerful of them. Most powerful on earth that time were kings(Rajas). Aliens influenced them, made them friend and start transferring limited knowledge to them.Aliens selected some persons with the help of Rajas, tought these intelligent persons of that time. These intelligent persons started experiments and building useful gadgets and shared some their knowledge with common people. These intelligent persons were called rishis and maharishis at that time. Rishis and Maharishis chose remote places on earth to settle so that they can peacefully make useful things for mankind and can do experiments for that . Bhagwaan shiv had already started producing different type of robots and mutants(such as bhoot, asurs, pishach, kinner etc.) of different powers and capacities. Basically these were the helper of bhagwaan shiv. Bhagwaan vishnu deputed some of his subordinate(devtas) to look after daily affairs of earth, environment and humans. He also deputed rishis and maharishis to do particular experiments and help rajas. Some asurs misused the powers given to them by bhagawaan shiv and disturbed rishis and maharishis in doing their work and tried to prevent them in doing experiments. Devtas and bhagwaan vishnu helped humans and rishis to get rid of them, sometimes directly, sometimes by giving powers to humans and rishis or taking avtars(Ram and Krishna). Bhagwaan Ram and Bhagwaan Krishna was direct genetic extention of bhagwaan vishnu. Bhagwaan shiv also helped human kind and also assited devtas,rishis to get rid of these asurs.
Now developin intelligent population has started writing text and there was an urgent need of some text books which masses can read directly they couldn't remain dependent upon vocal teachings of their gurus. So aliens decided to create written textbooks. It was decided amongst them that an optimum knowledge, nature and science should be transfered(in written form) to masses in such a way that masses can get it easily. Bhagwaan Vishnu appointed vyas ji to create this written text. Bhagwaan shiv appointed siddhi vinayak bhagwaan ganesh(greatest mutant ever produced on earth) to work with vyas ji. Thus a commitee of two was appointed to write vedas and puranas. Both of them were instructed that no undue scientific technologies could go in the hand of common people of that age. Hence both of them decided to write the vedas and other text very carefully in symbolic language. They both wrote about themselves, about universe. about earth and about human kind in such a way that it very well could benefit human kind without disclosing advance technologies. Hence we find several amazing similarities amongst today's scientific achievements with so called miracles of those days,and as todays science will further develop these miracles will start seeming us more easy to be explained on scientific basis.