Ours would be extraordinary difficult to hide. Stuff in Clarke orbits could still be there when we are no longer recognizable as our current species.
That's the first time I'd ever come across that term ("OOPArt").
FR, an opportunity to learn something every day...
And, as they say, extraordinary claims require extraordinary evidence.
Yep. I'm open to such evidence being found. Until then, it's just speculative fiction/fantasy.
Shades of Asimov's "Nightfall"!
Opposite, really. In Nightfall the church tried to provide continuity.
A blend of militant islam and wacko environmentalism, with a leavening of Luddites, rage, and post collapse PTSD-like insanity wouldn't leave much behind.
Not so. In the short story, there was a group known as the Cult which used their scriptures to predict the Nightfall itself. While they were in fact correct, they didn't want to preserve civilization...that was the goal of a group of scientists.
In Stephen Baxter's fairly recent novel, "Evolution" (highly recommended, BTW), one chapter entitled "The Hunters of Pangaea" posits a stone-age civilization of humanoid dinosaurs, but they don't have enough of an impact on the environment to be noticed by humans, 145 million years later. Quoting from the book:
The whole of the orniths’ rise and fall was contained in a few thousand years, a thin slice of time compared to the eighty million years the dinosaur empire would yet persist. They made tools only of perishable materials — wood, vegetable fiber, leather. They never discovered metals, or learned how to shape stone. They didn’t even build fires, which might have left hearths. Their stay had been too brief; the thin strata would not preserve their inflated skulls. When they were gone the orniths would leave no trace for human archaeologists to ponder, none but the puzzle of the great sauropods’ abrupt extinction.
When asked whether some of the strange species he invented for the book actually existed, he answered essentially, "Of course not".
Fun to read about, though!