The author is indebted to many who have provided feedback on this manuscript. In particular, I must single out Bob Zannelli, Don McGee, and Brent Meeker for their meticulous multiple readings and their many critical corrections and recommended rewordings. They and other members of the Google discussion group atvoid (“Atoms and the Void”) have been a continual help to me with my previous books and the numerous essays and blogs I generate. This group includes Greg Bart, Lawrence Crowell, Anne O’Reilly, Kerr Regier, Christopher Savage, Brian Stilson, Pete Stewart, Phil Thrift, Jim Wyman, and Roahn Wynar. I am also grateful for comments from author Kim Clark, physicist Taner Edis, and mathematician James Lindsay.

Thanks also go to several professional astronomers, physicists, and cosmologists who have provided invaluable comments. I am especially grateful to astronomer Jay Pasachoff for his meticulous reading of the manuscript and for providing many corrections. Suggested changes to specific portions of the manuscript where they had deep expertise were also made by Sean Carroll, Alan Guth, Lawrence Krauss, Andrei Linde, Robert Nemiroff, Brent Tully, and Alex Vilenkin.

Finally, I have once again benefitted greatly from the support of my work given by Jonathan Kurtz, Steven L. Mitchell, and their dedicated, talented staff at Prometheus Books.