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Estimates for Number of Visible Galaxy-spanning Civilizations and the Cosmological Expansion of Life

By SpaceRef Editor
October 1, 2015
Filed under , , ,
Estimates for Number of Visible Galaxy-spanning Civilizations and the Cosmological Expansion of Life

If advanced civilizations appear in the universe with a desire to expand, the entire universe can become saturated with life on a short timescale, even if such expanders appear but rarely.

Our presence in an untouched Milky Way thus constrains the appearance rate of galaxy-spanning Kardashev type III (K3) civilizations, if it is assumed that some fraction of K3 civilizations will continue their expansion at intergalactic distances. We use this constraint to estimate the appearance rate of K3 civilizations for 81 cosmological scenarios by specifying the extent to which humanity could be a statistical outlier.

We find that in nearly all plausible scenarios, the distance to the nearest visible K3 is cosmological. In searches where the observable range is limited, we also find that the most likely detections tend to be expanding civilizations who have entered the observable range from farther away. An observation of K3 clusters is thus more likely than isolated K3 galaxies.

(Submitted on 21 Jul 2015)
S. Jay Olson
Comments: 11 pages, 3 figures
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Popular Physics (physics.pop-ph)
Cite as: arXiv:1507.05969 [astro-ph.CO] (or arXiv:1507.05969v1 [astro-ph.CO] for this version)
Submission history
From: Stephan Olson
[v1] Tue, 21 Jul 2015 20:03:52 GMT (73kb,D)
http://arxiv.org/abs/1507.05969

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