Thread by @jmkorhonen

Here's an interesting paper that tries to answer the Fermi Paradox: why haven't we seen aliens yet?

I have my own answer, though.

I don't believe species capable of crossing interstellar distances COULD be very expansionist. #SETI

grabbyaliens.com/paper

A strongly expansionist civilization - one that basically takes over every possible nook and cranny in the parts of the universe it can reach - implies a civilization that hasn't solved the problem of limiting its powers. It doesn't live within its means.

But technologies that are needed for interstellar travel are extremely powerful.

A civilization that develops such technologies before learning to limit its powers is one civil war or industrial accident away from an existential catastrophe.

Furthermore, space colonization and interstellar travel require a society that not only can use great powers safely, but can also live peacefully within the very limited confines of space habitats.

That is, a fairly non-competitive society satisfied with what they have.

A civilization that routinely uses powers necessary for interstellar travel cannot permit cutthroat competition for resources.

Such competition would inevitably - and probably very rapidly - lead to 1) resource exhaustion, 2) destructive conflict, or 3) both.

Here, for example, is a calculation of how rapidly historical expansion rates would exhaust the material resources in our Solar System.

We're talking about centuries, not even millennia.

Expansionism isn't sustainable over astronomical timescales.

doi.org/10.1016/j.acta…

Mathematics can't add up here. Strongly expansionist civilizations that we could detect would be extremely unlikely to survive long enough for us to detect them unless they arise very close to us. And that's unlikely.

It's very likely that others are out there. But like biologists or birdwatchers, they probably try to _avoid_ leaving a trace.

They don't need to. A habitat whose community survives interstellar travel without killing each other doesn't need to strip mine planets for resources.

But it may well be that we are the first ones or one of the first ones.

If so, then it's even more imperative for us to solve the problem of limiting our powers before we destroy ourselves. That's the challenge of this millennium.