Life-hostile conditions in the early universe can increase the present-day odds of observing extragalactic life

Autor:	Olson, S. Jay
Rok vydání:	2017
Předmět:	Physics - Popular Physics Astrophysics - Cosmology and Nongalactic Astrophysics
Druh dokumentu:	Working Paper
Popis:	High-energy astrophysical events that cause galaxy-scale extinctions have been proposed as a way to explain or mollify the Fermi Paradox, by making the universe at earlier times more dangerous for evolving life, and reducing its present-day prevalence. Here, we present an anthropic argument that a more dangerous early universe can have the opposite effect, actually increasing estimates for the amount of visible extragalactic life at the present cosmic time. This occurs when civilizations are assumed to expand and displace possible origination sites for the evolution of life, and estimates are made by assuming that humanity has appeared at a typical time. The effect is not seen if advanced life is assumed to always remain stationary, with no displacement of habitable worlds. Comment: 4 pages, 1 figure
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1704.04125 Zobrazit plný text záznamu View this record from Arxiv