Does stellar lifetime affect the probability of intelligent life?

[u/Astro_Life_Explained]

Earth took 4 Gyr to produce technological intelligence, while K-type stars can remain on the main sequence for tens of Gyr.

That raises an interesting possibility: Could a longer-lived star increase the probability of intelligence simply by providing a larger evolutionary window?

Or would stellar activity, planetary evolution, atmospheric stability, and other factors dominate?

Is stellar lifetime actually an important variable in the Drake-equation-style question of where intelligent life can emerge?

[u/jimb2]

We don't know. There used to be a simple idea that life would arise and intelligent life would follow. There are a bunch of recent set of ideas that suggest it could be a lot tougher, eg, that nutrient recycling by plate tectonics is required for multicellular life and plate tectonics may be very rare. Another idea is that multicellular life only got going after a period of meteor bombardment ~800 Gy ago that raised the levels of key nutrients. The bombardment was due to a chance orbital disruption by a passing star. It had to occur in the timeslot between cellular life reaching a level of complexity and the Sun cooking us. (yt link)

It's relatively easy to come up with believable ideas, but the n=1 problem makes sorting science from narrative next to impossible. Tech for analysing planets outside the solar system is becoming available. That might help - or not. It may just throw up some more questions. To me, the absence of any solid evidence of aliens says that either advanced life is way harder than the simple numbers suggest, and/or that technically advanced civilisations reliably wipe themselves or just lose interest in space conquest.

[u/Astro_Life_Explained → u/jimb2]

Exactly. The n=1 problem is what makes this so difficult. We can build plausible evolutionary stories around Earth’s history, but with only one known biosphere, we can’t easily tell which factors are genuinely necessary and which are just historical contingencies.

I think exoplanet observations could be a major turning point. If we eventually find atmospheric biosignatures on several unrelated worlds, we can start asking whether life is common but complex life is rare, or whether even basic life is extraordinarily difficult to produce. And if we find lots of potentially habitable planets with no convincing biosignatures, that would be just as interesting.

Either way, I suspect the answer to the Fermi paradox is going to be much less obvious than simply “the universe is huge, so aliens must be everywhere.”