Book excerpt: Although vital to our well-being and even to our success as a species, the physical sense of balance has never attained the same recognition as sight, hearing, touch, smell, or taste. Now, with an epidemic of debilitating falls sweeping America's aging population, the time is ripe for a lively and illuminating tour of the human body's most exquisitely intricate and least understood faculty. Balance is the first book written for a general audience that examines the mysteries of the human balance system -- the astonishingly complicated mechanisms that allow our bodies to counteract the force of gravity as we move through space. A scientific, historical, and practical exploration of how balance works, Balance also provides the keys to remaining upright for as long as humanly possible. From simple motion sickness to astronauts' "space stupids," and from fetal somersaults to the Flying Wallendas, McCredie guides readers on a delightful quest to elevate balance to its rightful place in the pantheon of the senses.