If alien civilizations exist, they may have opened a Pandora's box.
It may sound far-fetched, but self-replicating probes from an alien civilization could become a serious nuisance to budding societies like ours. While this is pure speculation, we have an ace in the hole: China's new massive radio telescope might be capable of detecting swarms of alien probes, also called von Neumann probes, at relatively vast distances from our sun, according to a recent study shared on a preprint server.
And when it comes to galactic annihilation by alien probe swarms, a word of warning far in advance would be greatly appreciated!
China's FAST radio telescope could detect incoming alien probe swarms
The Fermi Paradox asks why we haven't observed alien visitors from older solar systems, since humans have come so far technologically on a comparably short cosmic timescale. Some scientists think we already have the technology to construct a small probe capable of traveling to other star systems, but if this is the case, why haven't we witnessed alien probes? The idea was first put forward by Enrico Fermi, an Italian physicist who also created the first nuclear reactor, according to a Space.com report. While we have yet to confirm an alien presence in our solar system, one idea from science fiction may soon pass into the realm of empirical science.
Called von Neumann probes, the idea of a self-replicating swarm of robots from an alien world has remained science fiction for decades, possibly because we haven't really looked for them, but this might change thanks to the new Five-hundred-meter Aperture Spherical Radio Telescope (FAST). And, recent calculations in the study suggest that this colossal observational platform could detect swarms of von Neumann probes, even if they're comparably far from our sun.
Zaza Osmanov of the Free University of Tbilisi in Georgia wrote a study that showed how von Neumann probe swarms could be visible in the radio spectral band that is the specialty of FAST. But to assist in this search for extraterrestrial swarms, Osmanov employed two frameworks to limit possible solutions. First off was the notion of Kardashev civilizations, and second were estimates of the electromagnetic and thermal emissions profiles of such a hypothetical swarm of alien probes.
Modern astronomy has advanced to passive levels of participation in galactic society
The Kardashev scale is a concept more on the speculative side of scientific consensus, emphasizing the total energy used by a civilization, with tiered milestones of advancement, dubbed Type I, Type II, or Type III. Type I civilizations imply a society that can harness the energy of one planet, while the other two require that a civilization control the power produced by a star, and a galaxy, respectively. At present, our human civilization is considered to lie somewhere near a 0.75 on the Kardashev scale. But, since we've only existed in a society for a few thousand years, life elsewhere in the galaxy has likely enjoyed a much longer timeline of history, and thus has probably developed far more advanced technology, like K-II (harnessing a star's energy) or perhaps even K-III (controlling the energy of an entire galaxy).
Given tens or hundreds of thousands or perhaps even millions of years, an alien civilization will inevitably develop self-replicating machines like Neumann probe swarms. But it's also possible that this threshold of technology will lead to a runaway rate of self-replication that will see entire galaxies ravaged or consumed by the machines as they become obsessed with reproduction. But Osmanov thinks we would see such a path of cosmic destruction coming, since they would emit some kind of radiation that modern radio telescopes, like FAST, could detect. There's much more to reflect on about Osmanov's study, like calculating the distance (and thus time to defend ourselves or flee the solar system), but in the most basic sense, this means that astronomy is rising to the level of passive participation in the galactic neighborhood, thanks to China's novel telescope, and many others. Let's just hope an apocalypse by alien probe swarms remains speculation. At least until humanity reaches a much more advanced technological stage, like K-II.