Are We Alone?: The Possibility of Extraterrestrial Civilizations

Rood and Trefil wrote this book because the media were being influenced primarily by scientists who were very optimistic about finding extraterrestrial life. The two authors describe "the conventional wisdom" as defined by Carl Sagan, Frank Drake and others. Then Rood and Trefil examine the key factors one by one, ending each chapter with a section called "Consequences for SETI" or "Implications for SETI." Basically, they come up with much lower numbers than the optimists; the Earth is special after all. Rood and Trefil do quick surveys of space colonization and the prospects for interstellar travel, dismissing the idea that UFOs carry alien visitors. Each author wrote a separate conclusion to the book, giving his personal views. Though now slightly dated, Are We Alone makes points that still must be addressed by SETI advocates.