Immortality, Expansion, and the Dark Forest
I recently revisited Isaac Asimov’s short story The Last Question. Without spoiling too much, it explores the fate of the universe and humanity’s place in it. The story traces the arc of human civilization: from living alongside artificial intelligence, to merging with it, to eventually spreading among the stars and populating entire galaxies.
Running through the narrative is a powerful theme: human survival. Asimov asks whether, given humanity’s relentless expansion, there will always be enough resources to sustain us — no matter what form we take.
At one point, Asimov describes a future where humans have achieved a kind of immortality. Consciousness is separated from the body, the body is perfectly preserved, and death is no longer possible. This liberation of consciousness allows humanity to exist and act indefinitely.
That idea made me think of Liu Cixin’s The Dark Forest, the second book in his Three-Body Problem trilogy. Its “dark forest theory” offers one of the most chilling answers to the Fermi Paradox — the question of why, in such a vast and ancient universe, we have never encountered alien life.
The dark forest theory suggests that the universe is teeming with intelligent civilizations, but that every civilization is both a potential threat and a potential target. Because resources are finite, any species that expands unchecked could one day endanger others. As a result, the safest strategy for any intelligent lifeform is to eliminate other civilizations as soon as they detect them.
The metaphor is that the universe is a dark forest. Every civilization is a hunter, moving silently through the woods. The moment one becomes aware of another, its survival instincts demand that it attack before it is attacked.
But Asimov’s vision raises an interesting challenge to this grim worldview. If a civilization achieves immortality — true immortality — does it still need to reproduce and expand? Reproduction is, in a way, a biological strategy for achieving immortality by passing on DNA. But if individuals never die, reproduction becomes unnecessary.
A species that no longer needs to reproduce would also no longer expand at the same rate, and its resource needs could eventually stabilize. In that scenario, such a civilization might no longer feel compelled to destroy potential competitors.
Of course, there’s another possibility: immortal civilizations might still feel threatened by species that are reproducing and expanding, and thus act as the “hunters” in the dark forest — wiping out younger species before they grow too large.
This interplay between immortality, reproduction, and survival opens up fascinating philosophical questions. Is endless expansion inevitable? Or could the path to universal peace lie in transcending the need to reproduce at all?
I highly recommend reading both Asimov’s The Last Question and Liu Cixin’s The Dark Forest. Together, they offer two very different but deeply thought-provoking visions of humanity’s future — and the universe we inhabit.1
This post was voice recorded, transcribed with speech to text then cleaned up with ChatGPT