What Is Real?: The Unfinished Quest for the Meaning of Quantum Physics

by Adam Becker

Yet this still leaves us with the question from the Introduction: if subatomic particles can behave so strangely and we and the objects in our everyday lives are composed of such particles, why don’t we see such strange behavior on a regular basis? According to spontaneous-collapse theory, the answer lies in two key facts: entanglement and the vast number of particles that comprise the objects of our everyday experience. Though a single-particle wave function might not collapse on average until a billion years have passed, the solid objects of our everyday lives, like this book, are generally composed of at least 10 million billion billion individual particles. If each one of those particles’ wave functions is compulsively pulling the handle of its own slot machine (Figure 10.3b), then, on average, at least one of them will hit the collapse jackpot every millionth of a second. But because the particles in this book are all continually interacting with each other, they’re all entangled—which means they all share a single wave function. So when one of them hits the jackpot, the wave function for the entire book collapses, meaning this book can’t be in two places at once for much longer than a microsecond or so—a hundred thousand times faster than a blink of an eye. As Bell put it, in spontaneous-collapse theory, Schrödinger’s cat “is not both dead and alive for more than a split second.” This neatly resolves the measurement problem: all objects, large and small, obey the sam...