Every human being contains a billion times more atoms than all the grains of sand in the earth’s deserts. If you weigh 150 pounds, you carry around enough carbon to make 25 pounds of charcoal, enough salt to fill a saltshaker, enough chlorine to disinfect several backyard swimming pools, and enough iron to make a 3-inch nail. But how did these elements combine to make us human? It turns out that all matter—everything around us and within us—has an ultimate birthday: the day the universe was born. This fascinating book is the story of our atoms’ long strange journey from the Big Bang to the creation of stars, through the assembly of Planet Earth, and the formation of life as we know it. It’s also the story of the scientists who unearthed these extraordinary insights into the composition of life. Behind their unexpected findings were investigations marked by fierce rivalries, obsession, heartbreak, flashes of insight, and flukes of blind luck.