By 
October 5th, 2025
Image credit: UCLA SETI
A tactic used in the search for extraterrestrial intelligence (SETI), historically focused on detecting electromagnetic technosignatures from other starfolk, is a paradigm that is being challenged.
Highly advanced, potentially post‑biological civilizations may undergo rapid technological acceleration, quickly progressing beyond recognizable or detectable phases.
That’s the view of Michael Garrett, the Sir Bernard Lovell Chair in Astrophysics and director of the Jodrell Bank Center for Astrophysics. “It has long been recognized that the longevity of a technosignature is a critical factor in determining the likelihood of its detection ,” he explains.
Garrett argues that “successful detection also depends on the period during which our technologies overlap with those of the civilizations we seek.”
Image credit: SETI Post-detection Hub
Narrow detection window
Garrett introduces the concept of a “narrow detection window,” the notion that advanced, potentially post-biological civilizations may produce technosignatures that are detectable for only brief periods of time.
Technosignatures are indicators or evidence of advanced extraterrestrial civilizations, perhaps via artificial structures, communication networks, or other technological artifacts.
Giving a listen for other star folk, the Allen Telescope Array in California.
Image credit: SETI Institute
At issue is how brief is the period of time during which a civilization produces technosignatures that remain detectable by current instruments implemented by Earthkind?
Reevaluate strategies
What’s needed is a reevaluation of current SETI strategies to increase the likelihood of detecting such civilizations, suggests Garrett in a research paper appearing in the journal, Acta Astronautica.
“As humanity itself approaches potential post-biological transitions, SETI’s greatest challenge, and opportunity,” Garrett states, “lies in recognizing that the universe’s most advanced civilizations may not conform to our expectations.”
Garrett acknowledges that this expanded and open approach “does not discard traditional SETI but complements it.” Indeed, while some civilizations might still emit recognizable electromagnetic signals, “others may operate in ways we cannot yet imagine.”
Image credit: Breakthrough Listen
To read the full paper – “Blink and you’ll miss it – How Technological Acceleration Shrinks SETI’s Narrow Detection Window” – go to:
Posted in Space News
