The essential guide to radiation: the good, the bad, and the utterly fascinating, explained with unprecedented clarity. Earth, born in a nuclear explosion, is a radioactive planet; without radiation, life would not exist. And while radiation can be dangerous, it is also deeply misunderstood and often mistakenly feared. Now Robert Peter Gale, M.D,—the doctor to whom concerned governments turned in the wake of the Chernobyl and Fukushima disasters—in collaboration with medical