The Chinese FAST telescope could be looking for traces of alien probes

One of the most challenging questions to answer when addressing the Fermi paradox is why exponential-scale technologies have not yet conquered the universe. Commonly known as von Neumann probes, the idea of ​​a self-replicating swarm of extraterrestrial robots has been a staple of science fiction for decades. But so far, there has never been any evidence of their existence outside the realm of fiction. This may be due to the fact that we haven't spent much time looking for them - and that could potentially change with the new five hundred meter aperture spherical radio telescope (FAST). According to some recent calculations, the new massive observation platform may be able to detect swarms of von Neumann probes relatively far from the Sun.

These calculations, made by Dr. Zaza Osmanov of the Free University of Tbilisi in Georgia, have demonstrated that the von Neuman probe swarms for highly advanced civilizations could be visible in the radio spectral band that is the focal point of FAST. To aid in the research, Dr. Osmanov used two frameworks to find the potential solution. The first was the idea of ​​the Kardashev civilizations, while the other is the estimation of the thermal and electromagnetic emission profiles of this swarm.

Milky Way, artistic representation Knowing that it will be possible to detect a swarm is only slightly useful, however: knowing how far you can detect it is much more useful. As with potentially dangerous asteroids, the sooner we can be made aware of impending doom, the better - at least to fight it. To try to calculate distances, Dr. Osmanov made some more simplified assumptions, such as the maximum power that could be expected based on the level of Kardashev that civilization has reached. For example, a Type II civilization would not have a von Neumann cluster that emits more light than their entire energy utilization level, as defined by the scale.

With these additional assumptions, Dr. Osmanov has found that FAST could potentially detect a self-replicating robot swarm for both Type II and Type III civilizations. Considering the predicted sensitivity of FAST's instrumentation, it should be able to find such a swarm within approximately 16,000 light-years for Type II civilizations, meaning any Type II spacecraft would be visible within the nearest 15% of the Milky Way. On the other hand, a swarm created by a type III civilization would potentially be detectable within a 400 million light-year bubble - which includes most of the "nearby" galaxies.

So far, the Dr. Osmanov's article has only been published on arXiv and has not yet been peer reviewed by the scientific community, but they still offer a fun thought experiment and point to a potential detection mechanism for some rare events.