The Last Cry of an Alien Civilization ⚡ экспресс
The history of astronomical discovery shows that the most conspicuous phenomena, especially first detections, often turn out not to be typical members of their class, but rare extreme cases with disproportionately strong observational signatures. Based on this, the "Eschatian hypothesis" is formulated: the first confirmed detection of an extraterrestrial technological civilization will most likely be atypical — unusually "loud" (with an anomalously intense technosignature) and possibly in a transitional, unstable, or even terminal phase. Using a toy model, the conditions for such loud civilizations to dominate the detection sample are derived; in particular, if a civilization remains loud for only $$10^{-6}$$ of its existence, to outperform quieter populations it must radiate $${\gtrsim}1\%$$ of its total available energy budget. The hypothesis naturally motivates an agnostic search for anomalies in wide-field, multi-channel, continuous surveys as a practical strategy for the first detection of extraterrestrial technology.
The galaxy is like a city at night: most windows shine steadily, but sometimes a skyscraper lights up all its lights and then goes dark. Just like that, according to a new hypothesis about planets around alien stars (exoplanet), we might first notice another civilization — by a short but blinding flash that could mark its demise. Astronomers have long known: the most noticeable objects are the ones that behave extremely. For example, an exploding star (supernova) is visible across half the universe. Likewise, a civilization becomes 'loud' when it spends colossal energy — building megastructures or burning resources. Calculations show that in that phase it must radiate at least 1% of its total historical energy.
This brief flash is likely what we'll take as first contact. So we should search not for familiar signals, but for any anomalies: sudden excess heat, a strange chemical fingerprint in light (studied by spectroscopy). If such a civilization is on the other side of the Galaxy, its last 'cry' will travel for thousands of years — we'll see the flash of a world long gone.
🎯 An example of a 'loud' technology might be a Dyson sphere — a giant shell around a star that an advanced civilization could build to harvest all its energy. Such a structure would completely enclose the star, but would itself glow in infrared, giving away its creators.