During nearly all of its 53-year life, Puerto Rico’s Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC), was the world's largest single-aperture telescope and the go-to telescope for searching for signs of intelligent life. After two cable breaks in 2020, Arecibo collapsed before it could be given a proper sendoff, but it still remains a sentimental favorite among radio telescope fans. The Five-hundred-meter Aperture Spherical Telescope (FAST) in China is working hard to change that. Just days after it was announced that FAST was responsible for picking up over 1,600 fast radio bursts from a single source in a 47-day period, a respected scientist says FAST is the key to finding self-replicating probes from other civilizations … and is probably pointed at them right now.
“In this paper we have extended our previous work (Osmanov 2019) and considered spectral characteristics of interstellar non-relativistic Type-II and Type-III Von-Neumann probes. It has been shown that by means of the proton capture, required for replication, strong bremsstrahlung emission will be generated. We have found that for both types of civilizations the probes might be visible mainly in the infrared spectral band, but as it has been found the probes might be visible in the ultraviolet as well. For both cases it was shown that differential power has dips for equally spaced frequencies, which might be a significant fingerprint to identify such exotic interstellar objects.”
In his preprint paper, Dr. Zaza Osmanov, Professor of Physics at the Free University of Tbilisi (Georgia), explains that he chose to search for von Neumann probes – self-replicating spacecraft first conceived by mathematician John von Neumann – because they appear to be the most efficient method of exploring the galaxy without the need for mortal living creatures onboard. Banking on the odds that there are civilizations that have been around far longer than Earthlings and are far more advanced, Osmanov speculates that their power usage would also be more advanced. The Kardashev scale is popular way to estimate a civilization’s overall energy usage on a planetary or star scale (Type II civilization can use and control the energy of its planetary system; Type III civilization can control energy of its entire galaxy), and Osmanov thinks it can be tuned for focus on the energy output of a swarm of self-replicating Von Neumann probes traveling around the galaxy.
“Like all imperfect systems, those self-replicating machines would emit some form of radiation, which, after some simplifying assumptions, Dr. Osmanov calculates should be visible in the radio spectrum. Specifically, it would fall right in the middle of the spectrum that FAST is designed to pick up.”
Universe Today explains that according to Dr. Osmanov, the key is not picking up the energy output of the von Neumann swarm but calculating how far away from us it is – key information if it’s headed our way to conquer our almost-intelligent civilization so their advanced civilization can abandon their collapsing planet and take over … or some such scenario. Since Type III civilizations use more power, their von Neumann machines will be more powerful and thus able to be seen farther away. Osmanov says FAST could be tuned to spot von Neumann swarms within about 16,000 light-years for Type II civilizations, and within 400 million light-years for a Type III civilization – that would be from a nearby galaxy.
The most exciting part of Osmanov’s theory is that FAST is capable of seeing the radio emissions of von Neumann swarms right now – assuming they exist. All he has to do now is get his peers to review the paper and get time on FAST to look for them. And if he can do that, FAST may soon make us forget Arecibo.