A group of researchers working within the Search for Extraterrestrial Intelligence (SETI) program has published a conceptual study in the journal Scientific Reports, proposing a radical overhaul of the principles used to search for signals from hypothetical extraterrestrial civilizations. Instead of the traditional approach—attempts to decipher complex coded messages or laser pulses—the authors suggest focusing on radio signals that differ from the natural cosmic background primarily in their structure and periodicity. According to them, it is this structural difference, rather than the informational content, that serves as the key marker of a signal's artificial origin.
Why the Human Template Can Be Misleading
For several decades, the search for extraterrestrial intelligence has been built on an implicit assumption: potential civilizations will use technologies similar to human ones—radio transmissions, optical laser signals structured according to the logic familiar to terrestrial engineering. The researchers point out that this assumption may be flawed. Even on Earth, intelligent communication does not boil down to a single universal format: dolphins use a complex system of clicks and whistles, crows convey information through specific calls, and fireflies during mating season emit sequences of flashes that vary in duration, frequency, and color. Each of these mechanisms allows the sender to stand out among surroundings with minimal energy expenditure, without resorting to 'complex messages' in the human sense.
A Mathematical Model Based on Pulsar Data
Inspired by natural communication mechanisms, the authors built a mathematical model describing how an artificial signal could stand out against the background of natural cosmic noise. Pulsars—rapidly rotating neutron stars emitting regular pulses in the radio frequency range—were chosen as the baseline for comparison. To calibrate the model, the scientists used data on 158 pulsars located within a 16,000-light-year radius from Earth. Based on this data, the algorithm generated a set of optimal signal structures that require a minimal amount of energy for transmission while remaining easily distinguishable from natural radiation.
The Main Marker Is Difference, Not Content
The central conclusion of the study is that an artificial signal does not need to contain complex information, mathematical sequences, or a cipher. According to the authors, the primary and sufficient marker of artificial origin is the artificially created difference from the natural environment itself. This shifts the focus from the question 'what is the signal transmitting?' to 'how does this signal differ from everything nature emits in this range and at this point in space?' Such a framing of the problem, the researchers believe, significantly expands the search space and allows for the consideration of signals that, under traditional analysis, might be filtered out as 'noise'.
A Supplement, Not a Replacement
The authors emphasize that the proposed methodology is not intended to replace existing SETI systems and protocols. It is positioned as a supplement that allows astronomers to reconsider the very principles of analyzing data received by radio telescopes. Currently, the work remains a conceptual model: it sets a direction for future observational campaigns and proposes a new criterion for candidate selection, but it does not contain specific predictions about where and when a real extraterrestrial signal will be discovered. Nevertheless, the very fact of formalizing an approach inspired by biological communication could already influence how international observatories prioritize telescope time allocation in the coming years.
