[tikwidd]

We now know that exoplanets and the conditions for life abound in the universe. Where the conditions for life abound, the null hypothesis ought to be that life abounds. In discussions of alien life and intelligence, we are often biased by earlier states of knowledge about the universe and our position in it. When we first started digging up dinosaur bones, we came up with fantastical notions of creatures to explain these artifacts that were mysterious to us. Notions that fit into our existing worldview, drawn from folk knowledge and cultural history. Once archeologists started studying the bones carefully, they gave us stories more fantastical than we could have ever imagined in the framework of our folk knowledge. I suspect the same will turn out to be true of UAPs.

For example, UAP stories are often ridiculed on the premise that intelligent alien life would not bother to come all this way just to hide out in the ocean. That's our folk knowledge of aliens: they like to travel, are eager to make contact with other life forms and are capable of doing so. But the elusive behaviour of UAPs is exactly what we would expect from an "unmanned" scientific probe. The home planet would be dozens or hundreds of light years away, so the craft would need to be completely autonomous in the absence of any communication system. Where does an autonomous probe go to look for signs of life? Oceans.

[tedivm]

Knowing that life may be common is a lot different than knowing that intelligence is.

[jay_kyburz]

Yes, but the universe is so mind mindbogglingly vast. So many galaxies and so many stars!

It just doesn't seem right that what happened here didn't happen somewhere else.

[BobbyJo]

But claiming it definitely isn't is just as absurd as claiming it definitely is. Maybe even more so.

[thatjoeoverthr]

Regarding oceans, I want to add that the overwhelming majority of our land is in the northern hemisphere. Add the speed of light time lag, and anyone starting with a southern perspective will see a water-world with no technosignature whatsoever.

If one were to send a probe, one could wisely plan on purpose to land it in the ocean, deploy submersibles with flight technology and have them just go around and lay low.

They would hide, lay low and their aerodynamic performance might simply be their idea of a modest, basic platform. They would otherwise be wholly unprepared to make contact or perform in air to air combat.