The question of, if there are aliens out there, where are they? In short, they ain’t. From Dissolving the Fermi Paradox by Anders Sandberg, Eric Drexler, Toby Ord:
Abstract: The Fermi paradox is the conflict between an expectation of a high {\em ex ante} probability of intelligent life elsewhere in the universe and the apparently lifeless universe we in fact observe. The expectation that the universe should be teeming with intelligent life is linked to models like the Drake equation, which suggest that even if the probability of intelligent life developing at a given site is small, the sheer multitude of possible sites should nonetheless yield a large number of potentially observable civilizations. We show that this conflict arises from the use of Drake-like equations, which implicitly assume certainty regarding highly uncertain parameters. We examine these parameters, incorporating models of chemical and genetic transitions on paths to the origin of life, and show that extant scientific knowledge corresponds to uncertainties that span multiple orders of magnitude. This makes a stark difference. When the model is recast to represent realistic distributions of uncertainty, we find a substantial {\em ex ante} probability of there being no other intelligent life in our observable universe, and thus that there should be little surprise when we fail to detect any signs of it. This result dissolves the Fermi paradox, and in doing so removes any need to invoke speculative mechanisms by which civilizations would inevitably fail to have observable effects upon the universe. (public access) More.
The authors conclude: When we take account of realistic uncertainty, replacing point estimates by probability distributions that reflect current scientific understanding, we find no reason to be highly confident that the galaxy (or observable universe) contains other civilizations, and thus no longer find our observations in conflict with our prior probabilities. We found qualitatively similar results through two different methods: using the authors’ assessments of current scientific knowledge bearing on key parameters, and using the divergent estimates of these parameters in the astrobiology literature as a proxy for current scientific uncertainty.
When we update this prior in light of the Fermi observation, we find a substantial probability that we are alone in our galaxy, and perhaps even in our observable universe– Scientific Paper: It’s Likely We Are Alone In The Observable Universe – By HANK BERRIEN – June 26, 2018 More.
But we are never alone as long as we have imagination!
Hat tip: Philip Cunningham
See also: Crackpot cosmology offers us a future worse than extinction
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Question of the hour: Are space aliens hoarding stars in an expanding universe? If the aliens are really advanced, they can shop for stars in the past and the future and have them delivered. There’s nothing wrong with this stuff at all except that it isn’t science. It uses the trappings of science, in the same way perhaps as Hollywood Bible movies use the trappings of religion. The more “daring” the stuff is, the more likely it is to be off the track.