Someone asked: Is it possible that humans created advanced civilizations tens of thousands years ago, but everything related to them completely disappeared due to sudden and very large natural disasters (Toba eruption, deluges at the end of the ice age, etc.)?
Advanced civilizations have been destroyed by periodic.
1 – very little of our civilization would remain after even 10,000 years. The rubble at Hoover Dam and the Great Wall of China – assuming they remain above the surface, should be among the few signs of an earlier civilization. The pyramids at Giza might be one of the few signs of an earlier civilization – though many
2 – technology might be destroyed by survivors if they think the gods punished mankind for eating too much from the tree of knowledge or building too high or trying to be like gods. Cities and universities are largely coastal and would be destroyed. Survivors would mostly be primitive tribes at higher altitudes.
3 – governments and religious organizations might find relics and destroy or hide them to preserve history and beliefs as people know them, and avoid causing a panic. Ancient India had Sanskrit books detailing flying machines for hundreds of pages. If anyone ever found a– it might have been destroyed, or hidden by the Vatican or the CIA… If America is just an Atlantis-like myth someday thousands of years from now… would archeologists reveal evidence that went against their cultural/religious beliefs – or is it possible some Mysterium or Ministry of Truth would kill them for it?