by numerous colleagues, including Stuart Bowyer, James Overduin, Hongya Liu, Bahram Mashhoon, and Jaime Ponce de Leon. Ideas in cosmology often require dedicated technical work to show their viability, and in this regard he thanks his graduate students, notably Dimitri Kalligas, Tomas Liko, and Sanjeev Seahra. The inspiration for many of the topics discussed here goes back to Sir Arthur Eddington, and it is a pleasure to know that Paul Halpern shares the respect due this great thinker.
Both Pauls acknowledge the help and suggestions provided by Giles Anderson of the Anderson Literary Agency. We appreciate the comments of John Huchra and Rabindra Mohapatra in reading over a draft of the manuscript. Many thanks to our editor, Jeff Robbins, our project editor, Sally Stanfield, and the staff of the Joseph Henry Press for useful advice and assistance.