What if the technological advancements in the history of mankind were in fact given to us by beings from another planet and our ancestors simply called them angels and Gods because they had no other way to define what they were. Ancient texts state that their ancestors were visited by and given knowledge from other worldly beings that came from the stars. Look no further than the similarity in temple construction around the ancient world. For civilizations that had no contact with each there construction designs are oddly similar. The only logical explanation is that some alien civilization came down and taught the people of Earth how to build these monolithic structures. I don't think that it could be anymore clear. Ancient human beings were visited, in the past, by aliens.