This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.

The Cosmic Coincidence as a Temporal Selection Effect Produced by the Age Distribution of Terrestrial Planets in the Universe

and

© 2007. The American Astronomical Society. All rights reserved. Printed in U.S.A.
, , Citation Charles H. Lineweaver and Chas A. Egan 2007 ApJ 671 853 DOI 10.1086/522197

0004-637X/671/1/853

Abstract

The energy densities of matter and the vacuum are currently observed to be of the same order of magnitude: (Ω ≈ 0.3) ~ (Ω ≈ 0.7). The cosmological window of time during which this occurs is relatively narrow. Thus, we are presented with the cosmological coincidence problem: why, just now, do these energy densities happen to be of the same order? Here we show that this apparent coincidence can be explained as a temporal selection effect produced by the age distribution of terrestrial planets in the universe. We find a large (~68%) probability that observations made from terrestrial planets will result in finding Ωm at least as close to ΩΛ as we observe today. Hence, we, and any observers in the universe who have evolved on terrestrial planets, should not be surprised to find Ω ~ Ω. This result is relatively robust if the time it takes an observer to evolve on a terrestrial planet is less than ~10 Gyr.

Export citation and abstract BibTeX RIS

Please wait… references are loading.
10.1086/522197