English

Broadcasting but not receiving: density dependence considerations for SETI signals

General Physics 2010-02-07 v3 Popular Physics

Abstract

This paper develops a detailed quantitative model which uses the Drake equation and an assumption of an average maximum radio broadcasting distance by an communicative civilization to derive a minimum civilization density for contact between two civilizations to be probable in a given volume of space under certain conditions, the amount of time it would take for a first contact, and whether reciprocal contact is possible. Results show that under certain assumptions, a galaxy can be teeming with civilizations yet not have a guarantee of communication between any of them given either short lifetimes or small maximum distances for communication.

Keywords

Cite

@article{arxiv.0901.3863,
  title  = {Broadcasting but not receiving: density dependence considerations for SETI signals},
  author = {Reginald D. Smith},
  journal= {arXiv preprint arXiv:0901.3863},
  year   = {2010}
}

Comments

11 pages, 2 figures; note revised 2/6/2010 to correct minor mathematical errors. The conclusions and final numbers of the paper only change slightly so its findings are not invalidated. Quote as Int. J. Astrobio but arxiv version is most correct and updated

R2 v1 2026-06-21T12:04:22.545Z