Book Reviewed: The Life of the Cosmos by Lee Smolin

Physical evolution of our universe The theory of cosmological natural selection proposed by author Lee Smolin states that a process analogous to biological natural selection applies to the evolution of our universe. In this theory, a black hole from a previous universe creates a white whole on the other side of space-bulk to create a new universe (a white hole, an equivalent of a Big Bang), whose physical parameters such as, mass of an elementary particle, Planck constant, speed of light, electrical charge, etc. differ slightly from that of the previous universe where the black hole collapsed. A universe with "unsuccessful" physical parameters is predicted to reach heat death before being able to evolve, that is some physical parameters become more likely than others. The physical laws like the relativistic physics, and quantum physics are postulated to evolve over time and the future will evolve. Hence, the laws of physics we experience today is not fixed but evolved over time for the past 13.8 billion years. The author differs from other physicists who believe that laws of physics are immutable. Natural selection, according to this theory guide the laws of physics favoring those universes which best reproduce and give opportunities for life to be born and evolve. However, there is no direct selective pressures of biological systems in the evolution of the cosmos (and the origin of laws of physics.) The theory predicts that nature's parameters should be optimized for birth, growth, and death of a star that may result in black holes. Our universe has billions of black holes, and according to this book, it would give rise to billions of new universes. For the author Time is an important fabric of the universe where cosmos evolved over billions of years. For many physicists like Julian Barbour, Carlo Rovelli, and others time is a human construct and therefore an illusion. If you could get outside the universe and observe the cosmos, you would see that every moment of this universe. Smolin differ from the other physicists and argues that the fabric of the universe is made of Time only. This is an elegant, comprehensive, and radically different from anything proposed before. The author appears to be a heretic but writes with passion and a force of scientific ideas that is readable and enjoyable for professionals as well as a layperson interested in physics. Lee Smolin is one of the leading physicists of our time. He is a philosopher and a great thinker who disfavors non-testable concepts in physics and offers testable and verifiable suggestions for his idea of cosmological natural selection.