Dennis Danielson is Professor Emeritus of English at the University of British Columbia. In addition to four authored books, he has edited The Book of the Cosmos: Imagining the Universe from Heraclitus to Hawking (Perseus Books, 2000) and received the 2011 Konrad Adenauer Research Prize from Germanyâs Alexander von Humboldt Foundation. Christopher M. Graney is an astronomer and historian of science at the Specola Vaticana (the Vatican>'s astronomical observatory) and the Vatican Observatory Foundation. He is the author of four books and numerous scholarly and popular articles on the history of astronomy.