The Eschatian Hypothesis

TL;DR

The paper proposes the Eschatian Hypothesis, suggesting that the first detection of extraterrestrial civilizations is likely to be an extreme, 'loud' and possibly transient example with strong technosignatures, guiding search strategies.

Contribution

It introduces the Eschatian Hypothesis and a toy model demonstrating how rare, loud civilizations could dominate detection probabilities, informing future search strategies.

Findings

Loud civilizations can dominate detection if they emit a significant energy fraction during brief phases.

A society loud for only 10^-6 of its lifetime must emit over 1% of its energy during that phase.

The hypothesis supports wide-field, multi-channel anomaly searches for extraterrestrial technosignatures.

Abstract

The history of astronomical discovery shows that many of the most detectable phenomena, especially detection firsts, are not typical members of their broader class, but rather rare, extreme cases with disproportionately large observational signatures. Motivated by this, we propose the Eschatian Hypothesis: that the first confirmed detection of an extraterrestrial technological civilization is most likely to be an atypical example, one that is unusually "loud" (i.e., producing an anomalously strong technosignature), and plausibly in a transitory, unstable, or even terminal phase. Using a toy model, we derive conditions under which such loud civilizations dominate detections, finding for example that if a society is loud for only $10^{-6}$ of its lifetime, it must emit ${\gtrsim}1$% of its total observable energy budget during that phase to outrun quieter populations. The hypothesis naturally motivates agnostic anomaly searches in wide-field, multi-channel, continuous surveys as a practical strategy for a first detection of extraterrestrial technology.