Several friends and colleagues have been kind enough to read an earlier draft and/or make detailed comments that have influenced the book's present form. I am deeply grateful to them, including Frank Drake, Pearl Druyan, Lester Grinspoon, lrving Gruber, Jon Lomberg, Philip Morrison, Nancy Palmer, Will Provine, Stuart Shapiro, Steven Soter, and Kip Thorne. Professor Thorne took the trouble to consider the galactic transportation system described herein, generating fifty lines of equations in the relevant gravitational physics. Helpful advice on content or style came from Scott Meredith, Michael Korda, John Herman, Gregory Weber, Clifton Fadiman, and the late Theodore Sturgeon. Through the many stages of the preparation of this book Shirley Arden has worked long and flawlessly; I am very grateful to her, and to Kel Arden. I thank Joshua Lederberg for first suggesting to me many years ago and perhaps playfully that a high form of intelligence might live at the center of the Milky Way Galaxy. The idea has antecedents, as all ideas do, and something similar seems to have been envisioned around 1750 by Thomas Wright, the first person to mention explicitly that the Galaxy might have a center. A woodcut by Wright depicting the center of the Galaxy is shown on the inside front cover.
This book has grown out of a treatment for a motion picture that Ann Druyan and I wrote in 1980–81.
Lynda Obst and Gentry Lee facilitated that early phase. At every stage in the writing of this book I have benefited tremendously from Ann Druyan—from the earliest conceptualization of the plot and central characters to the final galley proofing. What I learned from her in the process is what I cherish most about the writing of this book.