The winner of the 2018 Physics World Book of the Year is a profound take on the true meaning of quantum mechanics, and the limits of our knowledge itself
“Anyone who is not shocked by quantum theory has not understood it.” Since Niels Bohr said this many years ago, quantum mechanics has only been getting more shocking. We now realize that it’s not really telling us that “weird” things happen out of sight, on the tiniest level, in the atomic world. Rather, we can now see that everything is quantum: our everyday world is simply what quantum becomes at the human scale. But if quantum mechanics is right, what seems obvious and right in our everyday world is built on foundations that don’t seems obvious or right—or even possible. An exhilarating tour of the contemporary quantum landscape, Beyond Weird is a book about what quantum physics really means—and what it doesn’t. Science writer Philip Ball offers an up-to-date, accessible account of the quest to come to grips with the most fundamental theory of physical reality, and to explain how its counterintuitive principles underpin the world we experience. Over the past decade it has become clear that quantum physics is less a theory about particles and waves, uncertainty and fuzziness, than a theory about information and knowledge—about what can be known, and how we know it. Discoveries and experiments over the past few decades have called into question the meanings and limits of space and time, cause and effect, and, ultimately, of knowledge itself. The quantum world Ball shows us isn’t a different world. It is our world, and if anything deserves to be called “weird,” it’s us.
Richard Feynman famously said that nobody understands quantum mechanics and cautioned against asking: "But how can it be like that?" Something about the conceptual foundations of the theory is profoundly puzzling, but just what is so disturbing is not easy to pin down. Three books by Olival Freire (The Quantum Dissidents), Adam Becker (What is Real?), and Philip Ball (Beyond Weird) are about rival attempts to say how it can be like that and, in the case of the Freire and Becker books, about the hostility between opposing camps, which sometimes had devastating consequences for the professional careers of the protagonists. I review the issues raised in the three books, and I discuss what Bohr could have meant by the statement (attributed to Bohr by Aage Petersen) that "there is no quantum world," along the lines of a neo-Bohrian, non-representational interpretation of quantum mechanics. (Originally published, with minor changes, as a review article "Interpreting the quantum world: old questions and new answers.")