Today is the birthday of the world. In the 17th century, an Irish divine, James Ussher, the archbishop of Armagh, calculated that “the Beginning” occurred 6,016 years ago, on October 23, 4004 BCE. During the last two weeks of this past July, I floated down the Colorado River through the Grand Canyon, where I was surrounded by rocks, the youngest of which were 300 million years old. At one stop, I laid my hands on rocks that were 1.7 billion years old. Yes, that’s billion with a “b.” While cross-examining a character based on William Jennings Bryan, a former U.S. …