2025/04/30 by Matthew Civiletti, Civiletti, Matthew · 5 voices
Physics and Astronomy · #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.2505.00062
In this paper we consider the extent to which a lack of observations from SETI may be used to quantify the Fermi paradox. Building on previous research, we construct a geometrical model to compute the probability of at least one detection of an extraterrestrial electromagnetic (EM) signal of galactic origin, as a function of the number N of communicative civilizations. We show how this is derivable from the probability of detecting a single signal; the latter is ≈ 0.6 δ/R, where δ is the distance between the initial and final EM signals and R is the radius of the Milky Way, for δ/R ≪ 1. We show how to combine this analysis with the Drake equation N = \mathscrN δ/c, where c is the speed of light; this implies, applying a simplified toy model as an example, that the probability of detecting at least one signal is >99 % for δ/ c \gtrsim 102.8 years, given that \mathscrN = 1. Lastly, we list this toy model's significant limitations, and suggest ways to ameliorate them in more realistic future models.