In this book, physicist Matt Strassler tells a startling tale of elementary particles, human experience, and empty space. He begins with a simple mystery of motion. When we drive at highway speeds with the windows down, the wind beats against our faces. Yet our planet hurtles through the cosmos at 150 miles per second, and we feel nothing of it. How can our voyage be so tranquil when, as Einstein discovered, matter warps space, and space deflects matter? The answer, Strassler reveals, is that empty space is a sea, albeit a paradoxically strange one. Much like water and air, it ripples in various ways, and we ourselves, made from its ripples, can move through space as effortlessly as waves crossing an ocean. Deftly weaving together daily experience and fundamental physics—Strassler shows us how all things, familiar and unfamiliar, emerge from what seems like nothing at all.