What I cannot understand why, if such civilizations existed, evidence of advanced metallurgy has not been found, advanced alloys and metals and other evidence of advanced technology. Why only stone work and elementary ceramics?
Also I wonder why so many ancient sites are deep under the oceans and why in some, Göbekli Tepe e.g., include extensive underground networks and, apparently, dwelling places. Why were these people underground? Were they seeking refuge there?
Oh, but they have. Google OOPARTS (Out of place artifacts)
advanced societies need not mean flying machines and the such—but perhaps earlier civilizations had a difference scientific approach to things, such as using sound to move objects. There is some evidence that sound was used to vitrify stones used in the walls in Peru (the ancient walls, not the Incan walls) —
We have the ancient Vedic stories of flying machines of course—
Its all tantalizing. I am wondering how Graham Hancock would categorize this latest information.
Metal is recyclable. In fact it is the most recyclable thing we have.
It is like going into an old house and wondering where all the wiring and piping are. Gone to the scrap yard everyone.
I find this whole line of thought fascinating. The best explanation I've heard is that 12,000 years ago the earth was hit by a series of asteroids or a comet breakup flying through the Taurid Meteor Stream.
It wiped out a developed civilization...perhaps not developed along the same lines as ours and perhaps with different technologies. The survivors figured out it would likely happen again and so built ancient structures like the pyramids and a number of underground cities in Cappadocia Turkey in order for humanity to ride out the next one. The Taurids happen in spring and fall and so they also became fixated on the solstices and built structures to calculate and warn future humans. Randall Carlson, Graham Hancock and others paint a fascinating picture of this.