What happened before the primordial fire of the Big Bang: a theory about the ultimate origin of the universe. In the beginning was the Big Bang: an unimaginably hot fire almost fourteen billion years ago in which the first elements were forged. The physical theory of the hot nascent universe—the Big Bang—was one of the most consequential developments in twentieth-century science. And yet it leaves many questions unanswered: Why is the universe so big? Why is it so old? What is the origin of structure in the cosmos? In An Infinity of Worlds , physicist Will Kinney explains a more recent theory that may hold the answers to these questions and even explain the ultimate origins of the universe: cosmic inflation, before the primordial fire of the Big Bang. Kinney argues that cosmic inflation is a transformational idea in cosmology, changing our picture of the basic structure of the cosmos and raising unavoidable questions about what we mean by a scientific theory. He explains that inflation is a remarkable unification of inner space and outer space, in which the physics of the very large (the cosmos) meets the physics of the very small (elementary particles and fields), closing in a full circle at the first moment of time. With quantum uncertainty its fundamental feature, this new picture of cosmic origins introduces the possibility that the origin of the universe was of a quantum nature. Kinney considers the consequences of eternal cosmic inflation. Can we come to terms with the possibility that our entire observable universe is one of infinitely many, forever hidden from our view?

A concise and accessible explanation of the science and technology behind the domestication of nuclear fusion energy. Nuclear fusion research tells us that the Sun uses one gram of hydrogen to make as much energy as can be obtained by burning eight tons of petroleum. If nuclear fusion—the process that makes the stars shine—could be domesticated for commercial energy production, the world would gain an inexhaustible source of energy that neither depletes natural resources nor produces greenhouse gases. In Star Power , Alan Bécoulet offers a concise and accessible primer on fusion energy, explaining the science and technology of nuclear fusion and describing the massive international scientific effort to achieve commercially viable fusion energy. Bécoulet draws on his work as Head of Engineering at ITER (International Thermonuclear Experimental Reactor) to explain how scientists are trying to “put the sun in a box.” He surveys the history of nuclear power, beginning with post–World War II efforts to use atoms for peaceful purposes, and describes how energy is derived from fusion, explaining that the essential principle of fusion is based on the capacity of nucleons (protons and neutrons) to assemble and form structures (atomic nuclei) in spite of electrical repulsion between protons, which all have a positive charge. He traces the evolution of fusion research and development, mapping the generation of electric current though fusion. The ITER project marks a giant step in the development of fusion energy, with the potential to demonstrate the feasibility of a nuclear fusion reactor. Star Power offers an introduction to what may be the future of energy production.