Every one of us contains a billion times more atoms than all the grains of sand in the earth's deserts. If you weigh 150 pounds, you've got enough carbon to make 25 pounds of charcoal, enough salt to fill a saltshaker, and enough iron to forge a three-inch nail. But how did these elements combine to make us human? Tracing the journey from the Big Bang through the creation of you, Dan Levitt also profiles the ambitious, sometimes scientists who uncovered these secrets of the universe.