SETI & Technosignatures

Longevity Is The Key Factor In The Search For Technosignatures

By Keith Cowing
March 4, 2021
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Longevity Is The Key Factor In The Search For Technosignatures
Each row shows the unconditional probability distribution of longevities τ (left) and time of appearance ti (right) and the probability distribution of the same quantities conditioned to detection. In both rows, the unconditional probability distribution for τ is a log-uniform, while ti is uniformly distributed in the upper row (Model 1 in the text) and normally distributed in the lower row (Model 2 in the text).

It is well-known that the chances of success of SETI depend on the longevity of technological civilizations or, more broadly, on the duration of the signs of their existence, or technosignatures.

Here, we re-examine this general tenet in more detail, and we show that its broader implications were not given the proper significance. In particular, an often overlooked aspect is that the duration of a technosignature is in principle almost entirely separable from the age of the civilization that produces it. We propose a classification scheme of technosignatures based on their duration and, using Monte Carlo simulations, we show that, given an initial generic distribution of Galactic technosignatures, only the ones with the longest duration are likely to be detected.

This tells us, among other things, that looking for a large number of short-lived technosignatures is a weaker observational strategy than focusing the search on a few long-lived ones. It also suggests to abandon any anthropocentric bias in approaching the question of extraterrestrial intelligence. We finally give some ideas of possible pathways that can lead to the establishment of long-lived technosignatures.

Amedeo Balbi, Milan M. Ćirković
Comments: Accepted for publication in The Astronomical Journal
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Popular Physics (physics.pop-ph)
Cite as: arXiv:2103.02923 [astro-ph.IM] (or arXiv:2103.02923v1 [astro-ph.IM] for this version)
Submission history
From: Amedeo Balbi
[v1] Thu, 4 Mar 2021 10:08:25 UTC (405 KB)
Astrobiology, SETI,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻