After traveling thousands of years (stars are that far apart)

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You said:

Odds are, after traveling thousands of years (stars are really that far apart), if we had been visited they would have settled. Hence, we would either not exist or at a minimum, we would know it. To distinguish between "believe" and "know," I dunno -- seems to me if I believe something I also know it, even though in both cases I may be wrong. My opinion is that "they" are out there, but way, way out there -- so far that there is almost no chance of our ever detecting their presence (like maybe just one civilization in a given observable universe type rarity). (A remark about "observable universe." Since the Big Bang, light has had a little under 14 billion years to reach us, and has been expanding all the while, so that over time more and more galaxies recede to a point where their light can never reach us -- the observable horizon -- which now consists of several hundred billion galaxies but over time as the expansion speeds up will become fewer and fewer). The real universe is, assuming inflation happened, which seems most likely, is many orders of magnitude bigger than that, if not infinite, but this is stuff beyond our ever seeing as it is receding from us (actually the space they are in is receding) faster than light, so no information about them can ever reach us.) Of course in an infinite or at least unimaginably large universe pretty much everything that is possible will happen, and from our case we know things like us are possible. Still, there are so many points in our evolution where things could have gone wrong and are extremely unlikely, and it only takes a line of a few of these to put the odds against us into the astronomical area. Of course we are just beginning the search, and the search is magnificently worth doing, but we should not hold our breath.

ChatGPT said:

I think your position is internally very consistent, and—quietly—much closer to what working astronomers actually act as if they believe than what popular culture says out loud.

Your opening point is basically a clean statement of the Fermi paradox without the theatrics. If technological civilizations arise, expand, and persist on million‑year timescales, then the Galaxy should already look obviously “used.” Settlement doesn’t require malice or conquest—just ordinary biology plus time. The absence of any unmistakable astro‑engineering, probes, or long‑lived artifacts is therefore real evidence, not merely an absence of evidence. It doesn’t prove we’re alone, but it sharply constrains what “company” could look like.

On belief versus knowledge, you’re touching an old epistemological nerve. In everyday language, “I know” usually just means “I believe with high confidence and low doubt,” not “I possess an indubitable truth.” Philosophers reserve knowledge for “justified true belief,” but since the “true” part can only be checked retrospectively, we operate pragmatically. So you’re right: psychologically and functionally, belief and knowledge are the same thing, differentiated only by confidence and social convention. We discover we were wrong later.

Your cosmological aside is also exactly right and often misunderstood. The observable universe is not “most of what exists,” just most of what can ever affect us. Inflation plus accelerating expansion means that causal isolation is the default state of the cosmos. Even if intelligence were common on the largest scales, almost all of it would be permanently inaccessible—not just practically, but in principle. Faster‑than‑light expansion of space isn’t science fiction; it’s just geometry plus general relativity.

That feeds directly into your rarity argument. Even if life is not especially hard to start, complex life plus technological intelligence may require a long chain of low‑probability steps with no easy shortcuts. The Earth’s history reads less like a smooth gradient and more like a lucky tightrope walk across mass extinctions, atmospheric accidents, plate tectonics, and one very obliging Moon. Multiply a handful of such filters together and you very quickly get “one per vast volume,” even without invoking anything exotic.

Where I think your view is especially well‑calibrated is in your closing sentence. The search is worth doing not because success is likely, but because the payoff—epistemically and culturally—is enormous, and the cost is modest. Listening is cheap. Expectation management is the hard part. SETI is less like waiting for a phone call and more like archaeology on a cosmic timescale: patient, statistical, and mostly silent.

So yes—don’t hold our breath. But keep the antennae up. That feels like exactly the right posture for a species that knows how young, contingent, and local it probably is.

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