a life-permitting universe depends crucially on its precise expansion rate. Since the discovery of the red shift of the light coming from distant galaxies, astronomers have discovered that if the universe were initially expanding even a smidgeon faster or slower,15 either stable galaxies would not have formed in the universe because matter would have dissipated too quickly for galaxies to congeal or else the universe would have quickly collapsed in on itself. Cosmologists refer to the first scenario as the “heat death of the universe” and the second scenario as the “big crunch.” Neither
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