Sibling Theories, Fraternal Twins: What Darwinian Evolution and the Multiverse Have in Common

At Quanta Magazine, a well-reported article by Jennifer Ouellette is a reminder of how arguments for the multiverse are built by stacking conjecture upon conjecture upon conjecture ("Multiverse Collisions May Dot the Sky"). Cosmologists Hiranya Peiris and Matt Johnson seek evidence in patterns in the cosmic microwave background (CMB) for past collisions of bubble universes with our own. They think there may be as many as four such patterns identifiable in the CMB. But it all depends...

Let th...