Scientist Says Galaxies Shining With Radio Signals Could Indicate Numerous Advanced CivilizationsVictor Tangermann
FuturismSun, October 5, 2025 at 12:00 PM EDT
3 min read
Galaxies "blazing with technosignatures" could suggest the existence of a "large number" of "different metasocieties."The Fermi Paradox, first devised by physicist Enrico Fermi in the 1950s, asks why we haven’t detected alien civilization yet, despite the vast universe teeming with countless potentially habitable planets.
While many theories have been put forward in response to the paradox, many experts believe that it’s only a matter of time until we can detect alien signals. In fact, as Breakthrough Listen Initiative astronomer Brian Lacki suggests, the universe could be teeming with billions of extraterrestrial intelligences (ETIs) — and, in a striking claim, all that activity just might explain “radio bright” active galaxies that emit powerful radio emissions across vast distances.
In a series of
three yet-to-be-peer-
reviewed papers, first spotted by Universe Today, Lacki raised the possibility that galaxies “blazing with technosignatures” could suggest the existence of a “large number” of “different metasocieties” sending broadcasts across the radio spectrum.
Basically, the idea is that alien civilizations might be rare — but that once one has attained a certain level of technological capability, it’s likely to expand or seed elsewhere within its galaxy.
“If interstellar travel and migration are indeed possible, then ETIs are unlike known astrophysical phenomena in that they can reproduce,” he wrote in his first paper. “Replication can amplify quirks of history onto galactic scales.”
“Thus, supposing that starfaring ETIs are rare, one galaxy could have no ETIs while another, astrophysically indistinguishable, could have billions of inhabited worlds,” he added. “This motivates the use of a probabilistic treatment of the observable technosignatures of galaxies, wherein different galaxies can have wildly different broadcast distributions.”
In one of the papers, Lacki suggests that placing “constraints on radio broadcasts from entire populations of inhabited galaxies” instead of focusing on efforts to observe individual star-bound civilizations.
“If you have some subset that has a lot of radio transmissions, they will appear radio-bright,” he told Universe Today. “Since we know basically how many galaxies there are at each level of flux, we can set upper limits on how many of these ‘artificial radio galaxies’ there are.”
Lacki suggests detecting the combined glow of the emissions of several civilizations. It’s an approach that comes with its own challenges, as separating technological signatures from other natural sources of radio transmissions, like supermassive black holes at the center of galaxies, could prove difficult.
“The trouble is that you can’t tell whether that emission is natural or artificial just from knowing how bright it is in the radio,” Lacki told Universe Today, noting that “we expect it is natural in almost all, if not all, cases.”
Of course, probing distant galaxies for radio signatures is only one tiny piece of a much greater puzzle, and just one method among many. For instance, we could identify star systems that give off huge amounts of infrared emissions with the hopes of spotting a Dyson sphere, a hypothetical megastructure an alien civilization could build around a star or black hole to capture most of its power.
Regardless of our approach, having a robust framework to know where to look seems like a wise first step to take in our effort to figure out if we’re alone in the universe or not.
https://www.yahoo.com/news/articles/scientist-says-galaxies-shining-radio-160000255.html
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