Is the multiverse science? Multiverse theorists often say yes. They argue that eternal inflation and string theory point to infinitely many unobservable parallel universes, and that this multiverse can explain the fine-tuning of our one ordered universe. But the multiverse departs from the core method that made modern science so powerful: prediction, testing, and observation. A theory about infinitely many unobservable universes can accommodate almost any possible outcome, bu

Physicist Lee Smolin’s cosmological natural selection is one of the most creative attempts to explain fine tuning without God or a standard multiverse. The basic idea is simple: new “baby universes” may be born inside black holes, and each baby universe inherits the same laws but with slightly different constants. Over many generations, universes that produce more black holes would become more common, in a process Smolin compares to natural selection. Biologist Richard Dawkin

Did the universe really have a beginning, or was the Big Bang just one phase in an endless cosmic cycle? Paul Steinhardt’s theory of Bouncing cosmology attempts to explain our universe’s highly ordered beginning without requiring either an infinite multiverse or an intelligent cause. It is one of the most imaginative scientific attempts to avoid a true beginning, and in this essay, we’ll break it down as clearly and simply as possible. In this essay, we discuss: Introduction

Conformal Cyclic Cosmology (CCC) is an unusual theory proposed by physicist Roger Penrose. It tries to explain the extremely special conditions of the Big Bang without appealing to an intelligent cause or a multiverse. Instead of a single beginning, CCC suggests that our universe is just one “cycle” in an endless series of universes, where each one somehow gives rise to the next. Penrose has stressed just how extraordinary the beginning of our universe appears to be. Using th