Three of the most important words in science are I don't know. Not knowing implies a universe of opportunities—the possibility of discovery and surprise. Our understanding of science has advanced immeasurably over the last 500 years, yet many fundamental mysteries of existence persist: How did our universe begin? How big is the universe? Is time travel possible? What’s at the center of a black hole? How did life on Earth arise? Are we alone? What is consciousness, and can we create it?

In The Allure of the Multiverse, physicist Paul Halpern tells the epic story of how science became besotted with the multiverse, and the controversies that ensued. The questions that brought scientists to this point are big and deep: Is reality such that anything can happen, must happen? How does quantum mechanics "choose" the outcomes of its apparently random processes? And why is the universe habitable? Each question quickly leads to the multiverse. 

Whether pondering black holes or predicting discoveries at CERN, physicists believe the best theories are beautiful, natural, and elegant, and this standard separates popular theories from disposable ones. This is why, Sabine Hossenfelder argues, we have not seen a major breakthrough in the foundations of physics for more than four decades. The belief in beauty has become so dogmatic that it now conflicts with scientific objectivity: Observation has been unable to confirm mindboggling theories, like supersymmetry or grand unification, invented by physicists based on aesthetic criteria.

There may never be another era of science like the first half of the twentieth century, when many of the most important physicists ever to live—Marie Curie, Max Planck, Wolfgang Pauli, Niels Bohr, Werner Heisenberg, Ernst Schrödinger, Albert Einstein, and others—came together to uncover the quantum world: a concept so outrageous and shocking, so contrary to traditional physics, that its own founders rebelled against it until the equations held up and fundamentally changed our understanding of reality. Tobias Hürter takes us back to this uniquely momentous and harrowing time.

Sean Carroll, theoretical physicist and one of this world’s most celebrated writers on science, rewrites the history of 20th-century physics. Already hailed as a masterpiece, Something Deeply Hidden shows for the first time that facing up to the essential puzzle of quantum mechanics utterly transforms how we think about space and time. His reconciling of quantum mechanics with Einstein’s theory of relativity changes, well, everything. Most physicists haven’t even recognized the uncomfortable truth: Physics has been in crisis since 1927.