Tom Zoellner ’91 has at least one high-profile fan of his latest book “Uranium”: former President Bill Clinton. Zoellner’s book, “a global yarn that is equal parts travelogue, history and adventure story, as well as a nonfiction portrait of the most powerful substance in the earth’s crust, one that will help define the shape of the world in the 21st century,” turned up in a letter Clinton sent to Carolyn Kellogg of the Los Angeles Times, who writes the blog, “Jacket Copy.” In a list of books Clinton indicated he was currently reading, Zoellner’s “Uranium” was listed second.