This would be covered by the zoo hypotheses[1] I think.

[1]: https://en.wikipedia.org/wiki/Zoo_hypothesis

The ZOO hypothesis is uncannily attractive, because it a) sort-of humbles our egos and b) would actually be plausible even within humanity itself.

If we discovered another human civilization with a living and technological standard of Europe of 1022 AD, we would be able to keep an eye on them without revealing ourselves much. An occassional slip-up would be possible (a crashed drone), but most of the time, we would be able to let them live as they wish without interfering with them much. Probably to the point that the targeted civilization might consider any hypothesis of our surveillance a hoax or heresy.

And that is mere 1000 years of technological development on Earth. If the gap between us and hypothetical aliens is, say, 100 million years, I can't even begin to imagine the difference.

Something similar exists: https://en.wikipedia.org/wiki/North_Sentinel_Island

> 100 million years

That's a lot of evolution, considering mammals is barely that old.

not necessarily. UFOs might not hide intentionally; maybe they don't care but happen to rarely hang out in populated areas.

for instance, maybe they just care about the sea floor, and only surface to beam data back. or they're preferentially attracted to fast-moving objects like fighter jets, or sources of unusual EM signatures.

if UFOs are alien drones trying to hide, why do they suck at it?

Maybe they’re very good at it. We see them rarely and see them clearly or get good photos almost never but they’re actually all over the place. The ones we see are malfunctioning in some way or flukes caused by chance conditions of light, angle, etc.

Interesting points that I had completely overlooked!

By the way, without knowing how many there might be in total and how often they were seen/discovered, we can't really say if hiding from us is something they'd suck at :)

I like to think the reason for non-detection is that an alien civilization already had their AGI moment. The AI proliferated throughout the galaxy, to several galaxies, and ultimately found a way to "break" our classical and limited understanding of physics.

That the reason we're not seeing them is because we're looking for industry and megastructures, waste gasses, EM spectrum activity, etc., but that their needs are well beyond any of these things. That they don't have massive material or energy needs. And that maybe they've already been here, but consider us to be too primitive to acknowledge.

Or that maybe they're actively here now reconstructing our light cone to learn about us (ie. we've already all long since passed, and now we're all just holographic shadows of something that once happened long ago).

Or that maybe it's future us / Earth-AI doing that archeology.

Or a future AI "Space Jesus" is resurrecting our neural connectomes from non-lossy backwards projection of photons.

Or the same thing, except we'll all be put into museums or played with for sport. An outcome somewhat adjacent to Roko's Basilisk.

Of course this is all just mortal fantasy.

Dark forest is my other frequently thought about scenario, but that one scares me.

Or they are so advanced that their “bodies” are made up of individual units teeming with nanotechnology components, most of which are atoms wide, working to generate power from atoms absorbed from external environment, self repair and more. Units take on different roles. Advanced energy transport system that stores hydrocarbons and carries around highly volatile elements on iron structures in a liquid directly to the site needed for energy. Billions of these nano machine units take on a form to create an ultra low power, powerful neural network capable of self learning as well as passing on learned behaviours.

Oh wait that’s humans.

It's an exceedingly slow to adapt algorithm. Extinction is a fairly common result for stumbling upon an ecological niche, maximizing fit, and then having that niche disappear.

Novel information sharing is slow, lossy, and the information stores themselves quickly degrade.

Incredibly poor solution in the limit.

I think AGI would love to keep increasing its storage and computation power. Unless the very fabric of the universe serves as that, I don't know how an AGI would "break" our classical understanding of physics and not make a super giant computer the size of galaxies... But if that's the case, does it mean we're living in a matrix made by an AGI?

If dark forest were true I doubt we would be here. Earth has been broadcasting that it is a likely biosphere since the atmosphere became oxidizing. This much free oxygen is not likely to exist without some process constantly replenishing it and I’m not aware of any natural options for that at planetary scale.