Three resolutions could explain the paradox of why the most abundant type of star in the universe is not apparent in the sky, according to a study. Red dwarfs are five times more common and 20 times longer-lived than Sun-like stars called FGK dwarfs, yet none appears in the sky. David Kipping proposes several possible resolutions to this red sky paradox. Using Bayesian statistics, the author calculated the probability of intelligent observers emerging on or near an FGK star versus a red dwarf. Compared with FGK dwarfs, red dwarfs have a lower probability of the emergence of intelligent life, a shorter available time window for the evolution of complex life, and a lower occurrence of surrounding habitable worlds. Theoretically, one or more of these three resolutions could account for the red sky paradox, by inhibiting the opportunities for complex life to develop on or around these stars. According to the author, solving this paradox, a major goal in astrobiology, might inform future remote life-sensing experiments and shed light on the nature and limits of life in the cosmos.
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Article #2020-26808: "Formulation and resolutions of the red sky paradox," by David Kipping
MEDIA CONTACT: David Kipping, Columbia University, New York, NY; email: <d.kipping@columbia.edu>
Journal
Proceedings of the National Academy of Sciences