Typical longevity and distribution of technosignatures

Determine whether a meaningful “typical” value exists for the longevity L of technosignatures (the time interval over which such evidence of technological activity manifests), and if applicable, ascertain its order of magnitude; alternatively, establish whether the probability distribution ρ_L(L) of technosignature longevities is so broad (e.g., fat‑tailed) that averages are not descriptive and a typical value is inapplicable.

Background

The paper emphasizes that the detectability of technosignatures depends critically on their longevity L, but notes a lack of a priori understanding of typical durations and potentially very broad distributions. This uncertainty directly impacts both the prior assumptions used in models and the inferences drawn from any detection. The authors motivate exploring Lindy-type power-law priors for ρ_L(L), but explicitly highlight that current knowledge does not establish whether a typical longevity exists or whether the distribution is so broad that averages are not meaningful.

Resolving whether a typical value exists (and its order of magnitude), or confirming that averages are non-descriptive due to a fat-tailed ρ_L(L), would inform priors for longevity and hence influence expectations for first contact and the design and interpretation of technosignature searches.