Re: ancient tech, I just dont believe in. I cant fathom we would not find any signs of it in any archeological dig. Take for example the Pyramids. they know exactly where the stones were quarried from and to this day no "advanced tools" were ever found. Surely there would be hundreds of tools lost, forgotten about, buried, along the way as the quarried the thousands of huge large blocks over the millenia. And yet they still have not found shit. They dont even know how the fuck these people did all this shit, moved all those stones. Theories? sure, but no concrete evidence.
The thing I find fascinating is even today, using modern machinery and cranes and shit, they still have a hard time moving some of those stones.
Like imagine all of us a suddenly disappearing, some massive extinction event that widdled our population to say a few thousand people. So thousands years go by, population grows again and they start finding ancient shit buried by sands and time. Im sure they would be finding all sorts of shit preserved by time, silicone chips, metal oddly shaped into cell phone shapes, All that shit thats made from non ferrous metals, PLASTICS etc.etc.. shit like that just does not disappear that quick. And maybe you would not know wtf the shit was but you definitely would know it was made by us in the past.