Earlier quoted context omitted.
You take the word of few random soldiers and some output of some devices over accumulated effort of generations of scientists who brought us all of technology and you accuse others of hubris? It's quite a hubris to say that something is evidence of violation of known laws of physics on the basis of personal direct observation and output of devices that you find trustworthy only because known laws of physics do work a…
Every new discovery, by definition, begins with new observations. The word you're clinging to is "known". We've been spectacularly wrong in the past (the sun orbited the earth, which was flat, etc.). As for history, there's no reason to suspect they would have made their presence known in any undoubtable manner. They may have been here just to observe. > Every observation that we ever managed to explain was explained…
Ah, so now we don't just assume alien tech on Earth. Now we need to also assume aliens intent? Are you sure you are not adding epicycles to your model of reality?
> “Any sufficiently advanced technology is indistinguishable from magic.” Clarke
And yet no technology we ever seen actually IS magic or of alien origin.
I'm not sure what's your point is? That alien tech might look like magic? Sure. But we have never observed any magic either in our world. So they both belong squarely in the world of dreams not reality.