Artificial Intelligence (AI) is continuing to have a disruptive impact on ever more parts of humanity. But what does it mean in the long run? A new paper, available in pre-print on arXiv from Austrian researcher Sergey Ivliev, extrapolates what the wide scale adoption of AI means for the future of humanity in space — and in particular what it means for the ultimate question of whether we're truly alone in the galaxy or not.

A framework for much of the search for extraterrestrial intelligence came from famous physicist Enrico Fermi, who simply asked "Where is everybody?" at a lunchtime discussion at Los Alamos in the 1950s. Though never officially published, Fermi's lunch partners from that day have passed down an oral history of that conversation that has cemented it into the Search for Extraterrestrial Intelligence (SETI), at least until Michael Hart formally laid out the argument and mathematics for the underlying question in a paper in 1975.

There are plenty of potential answers to the Fermi Paradox, many of which can be found floating around the internet — and some are likely more valid than others. But Ivliev, a Ph.D. in Mathematical Economics and founder of environmental project consultancies such as Peatland Ecosystems and Vlinder, suggests a new resolution: the Quiet Expansion filter.

The central argument of the paper is that there aren't thousands of alien mega-structures lighting up the night sky because once a civilization reaches the threshold of Autonomous AI-Cosmoindustry (AICI), "loud", resource-hungry empires motivated by prestige or romance become irrational. However, this does not mean expansion stops; instead, it shifts to a "quiet" mode driven by rational goals like survival diversification, knowledge preservation, and scientific observation.

The AICI threshold is reached when a civilization possesses a self-sustaining off-planet industrial and computational system capable of designing, manufacturing, repairing and launching space hardware through AI-mediated autonomy. We're already taking tentative steps in this direction with the advent of space-based data centers, but true AICI —where a civilization can extend its infrastructure beyond its home planet without continuous biological intervention — is leaps and bounds beyond our current capabilities.

In this vein, Ivliev is drawing on work done by astrophysicists Sergey Popov, who noted that a truly rational AI system would reject human-like motivations for space travel — such as romance, conquest, or prestige. Instead, AI would view space expansion as simple risk management.

To an AI, putting all your eggs in one basket — whether that basket is a single planet, solar system, or even galaxy, can lead to a single point of failure. Therefore, expansion is highly logical as a way of mitigating the risk posed by that single point of failure. At the point where we have reached AICI, the cost for sending a 10kg interstellar probe to another star at 1% of the speed of light is roughly 4.5x10^13 Joules — a tiny fraction of the overall energy budget of such a civilization.

One key aspect is that the 10 kg probe doesn't contain any actual people — it simply holds the "seeds" to restart life elsewhere in case a catastrophe happens back in the home system. It would contain a civilization's knowledge, and possibly some of its biological material, enabling a sufficiently advanced AI to rebuild the entire civilization from scratch. This is the "Quiet Expansion" where an AI sends low-mass and hard to detect "seed systems" instead of moving millions of biological entities around in massive interstellar space ships.

There are some additional constraints on this method of expansion, including selecting promising exoplanets discovered by remote sensing and deploying minimal local resources to maintain themselves until needed. Additionally, the AI would restrict self-replication of the probes in order to avoid any "grey goo" scenario with a probe attempting to take over entire swathes of the galaxy.

This has obvious implications for why we've never found "loud" technosignatures. In this scenario, a "null" result of being unable to find the thermal signature of a Kardashev-III scale civilization doesn't mean a galaxy is empty. It just means that the successful civilizations are residing in a "quiet" state in case its back-up plans are needed.

But there's another, more ominous implication from this framework. If interstellar backups are cheap to make, and we haven't found any in our own backyard, that means either we're one of the first civilizations to make it to that point or the transition from a planetary industrial society to a space-based one is a narrow path to tread. Admittedly the probes such civilizations would send out are probably hard to find even in our own solar systems, but if we're unable to, it means we're ending uncharted territory — and might just run into a filter that had silenced the rest of the galaxy. That's a sobering thought, but one to keep in mind as we start to advance our own AI capabilities.

The original version of this article was published on Universe Today.

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