Hour 1: Who blazed the trail that ultimately led to our understanding of the universe and just how dangerous was his work – to his life and career as a Catholic administrator and physician to bishops and dukes? We’ll spend this hour with Dava Sobel, author of “A More Perfect Heaven: How Copernicus Revolutionized the Cosmos” (Walker & Company, 2011). Sobel will appear at Arts & Letters Live at the Dallas Museum of Art this evening.