Vortex

ACKNOWLEDGMENTS

This book couldn’t have been written without the help and patience of friends and family members too numerous to mention; needless to say, I thank them all. Thanks also to Glenn Harper, who generously answered a technical question (about the relative size of a human being vis-à-vis the Planck length and the limits of the observable universe)—the answer didn’t make it into the final text of Vortex, at least not explicitly, but it helped clarify my thinking about the nature of “the Hypotheticals” and their intervention in human history. On the subject of oceanic eutrophication and the fate of the Earth, I drew on Under a Green Sky and The Medea Hypothesis, by the reliably pessimistic Peter Ward, and I commend both books to the attention of curious readers.