Evolution of the Universe

IN checking the results presented by Gamow in his recent article on “The Evolution of the Universe” [Nature of October 30, p. 680], we found that his expression for matter-density suffers from the following errors: (1) an error of not tailing into account the magnetic moments in Eq. (7) for the capture cross-section, (2) an error in estimating the value of α by integrating the equations for deuteron formation (the use of an electronic analogue computer leads to α = 1), and (3) an arithmetical error in evaluating ρ0 from Eq. (9). In addition, the coefficient in Eq. (3) is 1.52 rather than 2.14. Correcting for these errors, we find The condensation-mass obtained from this corrected density comes out not much different from Gamow's original estimate. However, the intersection point ρmat. = ρrad. occurs at t = 8.6 × 1017 sec. ≌3 × 1010 years (that is, about ten times the present age of the universe). This indicates that, in finding the intersection, one should not neglect the curvature term in the general equation of the expanding universe. In other words, the formation of condensations must have taken place when the expansion was becoming linear with time.