To give our readers the opportunity to dig deeper into books about aviation and space, Air & Space/Smithsonian has started an online book club. The second selection is The Eerie Silence: Renewing Our Search for Alien Intelligence by Paul Davies. A physicist, cosmologist, and astrobiologist at Arizona State University, Davies has written a book that examines why it is taking so long to establish communications with other life forms in the universe. Those who would like to participate are encouraged to read the book in preparation for the online discussion on the Air & Space Web site in September. The book’s author will be available to answer questions from readers. For more details, visit www.airspacemag.com/bookclub.
The Eerie Silence: Renewing Our Search for Alien Intelligence
By Paul Davies. Houghton Mifflin Harcourt, 2010. 288 pp., $27.
SETI, the search for extraterrestrial intelligence, began in 1960 when an astronomer by the name of Frank Drake pointed a radio telescope toward the stars and proceeded to hear…false alarms, interstellar static, and random noise. Beyond that: absolutely nothing. That has been the fate of the dozens of ever-more sophisticated sky searches in the 50 years since, a disappointing result that Paul Davies refers to as “the eerie silence.”
In this exhaustively researched, clear, and intelligently written book, Davies sets out to explain that result, and to assess the prospects for success in the future. It would be an understatement to say that Davies covers the waterfront. He canvases all the usual explanations, and then some: the ETs are not actually out there; they are, but aren't broadcasting; they are broadcasting, but not by radio; they started broadcasting but stopped; and so on, down a long list.
On the other hand, Davies also seriously considers some wilder possibilities: the ETs have already been here and left; they’re here now, but are unwilling to reveal their presence; they’ve left artifacts or sentinels around, and all we have to do is find them. More speculatively still, ETs might exist in an exotic shape or form, such as a truly jumbo, hyper-intelligent quantum computer, whose intellectual concerns and modes of thought are so incommensurate with and different from our own that it would have no reason for contacting us. “What could we possibly say to it?” he asks.
In the end, everything hinges on whether life and intelligence are rare in the universe, or abundant. Of the millions of species that have lived on Earth, technological intelligence has arisen only once, which means that it is probably a rare commodity, even if life itself is widespread. But Davies believes that life is almost certainly not common. “We are probably the only intelligent beings in the universe,” he concludes, “and I would not be very surprised if the solar system contains the only life in the universe.” An eerie silence indeed.
Ed Regis edited Extra-terrestrials: Science and Alien Intelligence (Cambridge Press, 1985).