Our universe seems to be strangely "bio-friendly", that is, it seems to provide a hospitable environment for life. Can such a thing be considered luck, providence, or coincidence? According to cosmologist Martin Rees, the answer depends on an answer to another question that arises from Einstein's famous observation: "What interests me most is whether God could have created the world differently." This fascinating book examines the impressive consequences if the answer to the previous question is affirmative. Rees explores the perception that our universe is part of a vast "multiverse," or a collection of universes, in which the majority of other universes do not host life. Then what we call "laws of nature" will be nothing more than local internal regulations imposed after our Big Bang. In this scenario, our residence in the universe will be a particular, possibly unique universe, where the dominant laws of physics allowed the emergence of life.

Rees begins by exploring the nature of our solar system and examining a series of related topics such as whether our universe is infinite or not. For example, he asks questions like: How likely is the emergence of life? How reliable is the theory of the Big Bang? He then delves into the large-scale future of the universe before identifying the causal chain as the beginning of the universe. Finally, he concludes by attempting to explain the paradoxical perception that our entire universe, which extends 10 billion light-years in all directions, emerged from an infinitely small speck.

As the author argues, we may already have indications from other universes. However, the fate of the concept of the multiverse depends on the as yet unknown fundamental nature of space and time on scales a trillion trillion times smaller than an atom, in the field dominated by the quantum physics of gravity. The bio-friendly universe will be read and entertain, contributing to a deeper understanding of the world by all those - scientists and non-scientists alike - who are fascinated by the universe we inhabit, just like the author himself.