Abstract

Physical force strengths, particle masses, the early cosmic expansion speed and many other factors seem "fine tuned for life". Had they been slightly different, life’s evolution would have been impossible. The situation resembles catching a fish with an apparatus unable to catch ones slightly differently sized. One explanation is that the lake contains fish of many different sizes: multiple universes with randomized characteristics, most of them unobservable because observers cannot evolve in them. Another is that God created a fish of the right size, a universe able to generate observers. The article defends these explanations against numerous ingenious objections