Advanced alien civilizations could be communicating 'like fireflies' in plain sight, researchers suggest

Advanced alien civilizations may communicate via a series of flashing lights, similar to how fireflies do, a new paper hints. This would potentially make extraterrestrials much harder to spot if we continue to rely on our current observation techniques, the researchers argue.

However, while this thought experiment raises interesting questions about alien intelligence, it does not provide any evidence that these signals actually exist.

So far, the quest to uncover alien intelligence has focused on finding evidence of distant human-like civilizations. For example, the Search for Extraterrestrial Intelligence (SETI) Institute — the world's leading organization dedicated to searching for alien life — spends most of its time searching for radio signals from distant exoplanets or heat given off by technological megastructures, such as the theoretical Dyson sphere.

However, some scientists believe that these searches suffer from an "anthropocentric bias" — meaning we're trying to understand nonhuman entities through a distinctly human lens — and do not account for potential civilizations that are wholly different from our own. Due to this bias, we may be overlooking promising signs of life.

In the new study, uploaded Nov. 8 to the preprint server arXiv, researchers proposed a new way that an alien civilization could communicate — by flashing to one another like fireflies. These flashing signals could be used for specific and complex communications. However, the researchers argue that they are more likely being widely broadcast to other civilizations, like a luminous repeating beacon. (This paper has not yet been peer reviewed, but is now under consideration for publication in the journal PNAS.)

On Earth, fireflies communicate via a series of regularly repeating flashes caused by internal chemical reactions. These flashes are mainly used to find mates. But while these signals are simple, they do allow distinct firefly species to tell each other apart.

The researchers argue that similar flashing could be used as "here we are" signals by an alien civilization. And space is plentiful with repetitive bursts of light.

In the new paper, researchers analyzed the flashes of more than 150 pulsars — rapidly spinning, highly magnetized neutron stars that shoot out regular beams of electromagnetic radiation — as a proxy for what these signals may look like. And while they found no evidence of any artificial signals, they did note some similarities between the pulsars and firefly signals, and proposed ways of being able to detect future firefly-like flashes from other natural objects, like pulsars.

The study team argues that these signals could be more likely to evolve in long-lasting alien civilizations that progress past the need for widespread use of radio waves. A similar progression is already happening on Earth, where the use of communications satellites with more specific and concentrated radio signals is making our planet appear more "radio quiet" from afar, the researchers wrote.

And just because we may not naturally think to communicate in this way, it doesn't mean that other civilizations wouldn't, they added.

"Communication is a fundamental feature of life across lineages and manifests in a wonderful diversity of forms and strategies," study co-author Estelle Janin, a doctoral candidate at the School of Earth and Space Exploration at Arizona State University, recently told Universe Today. "Taking non-human communication into account is essential if we want to broaden our intuition and understanding about what alien communication could look like, and what a theory of life ought to explain."

This is just one example of what non-human signals may look like, and the researchers encourage others to think outside of the anthropocentric box to come up with other ways that a non-human-like civilization could communicate.

"Our study is meant as a provoking thought-experiment and an invitation for SETI and animal communication research to engage more directly and to draw more systematically on each other's insights," Janin said.