SETI & Technosignatures

Long-term Consequences of Observing an Expanding Cosmological Civilization

By Keith Cowing
Press Release
September 11, 2016
Filed under
Long-term Consequences of Observing an Expanding Cosmological Civilization

Suppose that advanced civilizations, separated by a cosmological distance and time, wish to maximize their access to cosmic resources by rapidly expanding into the universe.

What sort of boundary forms between their expanding domains, and how does the presence of one limit the ambitions of another? We describe a general case for any expansion speed, separation distance, and time. We then specialize to the main question of interest. How are the future prospects for a young and ambitious civilization altered if they can observe the presence of another at a cosmological distance? We treat cases involving the observation of one or two expanding domains. In the single-observation case, we find that almost any plausible detection will be limiting to some extent. Also, practical technological limits to expansion speed (well below the speed of light) play an interesting role.

If a domain is visible at the time one embarks on expansion, there exists an optimum value for the “practical speed limit,” and if the speed limit is much higher than optimal, one’s future will be severely limited. In the case of two visible domains, it is possible to be “trapped” by them if the practical speed limit is high enough and their angular separation in the sky is large enough, i.e. one’s expansion in any direction will terminate at a boundary with the two visible civilizations.

S. Jay Olson
(Submitted on 26 Aug 2016)

Comments: 7 pages, 7 figures
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); Popular Physics (physics.pop-ph)
Cite as: arXiv:1608.07522 [astro-ph.CO] (or arXiv:1608.07522v1 [astro-ph.CO] for this version)
Submission history
From: Stephan Olson [view email]
[v1] Fri, 26 Aug 2016 16:56:20 GMT (17132kb,D)

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) 🖖🏻