What Is the Fundamental Nature of Space?
What does the space between this book and your eyes consist of? Although it looks like nothing at all, just empty space, we know that there are air molecules floating around. However, what if we were to get rid of all the air molecules and create a complete vacuum between the book and your eyes? Then surely that volume of space would be truly nothing—an empty void with no properties of its own. Right? It may surprise you to learn that this “common sense” view of space is, in fact, wrong. Modern physics has shown that space—even an absolute vacuum—has a number of surprising properties. In fact, a vacuum is full of activity, with various kinds of particles winking in and out of existence and tiny bundles of energy interacting with each other. In the late 1990’s, researchers were trying to gain a more complete understanding of the bizarre conditions that characterize the fundamental nature of space, one of the great remaining mysteries of science. Our usual notion of space goes back to Ar
