M
ost of the time we hardly notice that we're moving through air. But when a storm system whips it into a whirling mass that grows into a tornado or a hurricane, then the air around us makes headlines. Science consultant Walker (Snowball Earth
) presents a lively history of scientists' and adventurers' exploration of this important and complex contributor to life on Earth, from Galileo's early attempts to show that it has weight to the explorations by 20th-century scientists Oliver Heaviside and Edward Appleton of the ionosphere, which acts as a giant mirror bouncing radio waves from one side of the globe to another. Walker provides readers with easy-to-follow discussions of the science behind the discovery that carbon dioxide levels are rising exponentially; the theoretician who left her computer for Antarctica and discovered a huge ozone hole created by chlorofluorocarbons; why hurricanes form only in the tropics and why global warming may lead to more violent storms. She goes far afield at times, spending too much time on the Van Allen belts, for instance, but readers will find this informative book to be a breath of fresh air. (Aug.)
