The Eerie Silence: Renewing our Search for Alien Intelligence
DOI: 10.1063/1.3502552
After faltering in the latter part of the 20th century, the search for life and intelligence beyond Earth has quickened in the past decade. Hundreds of exoplanets have been sighted; the discovery of “extremophiles” on Earth implies that life might exist even in quite inhospitable exoplanetary environments; and the Allen Telescope Array, managed by the SETI Institute and the University of California, Berkeley, surveys the center of the galaxy for radio messages from aliens. Exolife hunters now argue that perhaps their search should focus on Mars, Titan, or Europa. In short, a new era in the search for extraterrestrial intelligence is upon us.
Giuseppe Cocconi, Freeman Dyson, Enrico Fermi, Philip Morrison, and other important thinkers paved the way for the contemporary search for extraterrestrial intelligence (SETI). Paul Davies, a scientist with roots in cosmology and director of the Beyond Center for Fundamental Concepts in Science at Arizona State University, aims to refocus the quest with The Eerie Silence: Renewing Our Search for Alien Intelligence; it is one of the most interesting books on SETI since the revised edition of We Are Not Alone: Continuing the Search for Extraterrestrial Intelligence (Plume, 1994) by legendary New York Times science reporter Walter Sullivan.
Many physicists don’t think SETI is “true” science. Davies addresses that concern head-on in his preface, noting that “the subject of SETI is speculative to a degree far beyond that of conventional science. It is wise to take any discussion of alien civilizations with a very large dose of salt. But retaining a robust scepticism need not prevent us from approaching SETI in a methodical and penetrating way, informed by the very best science we have.”
Davies characterizes the reach of SETI by the pre-Allen Telescope norm—about one thousand light-years. That is a large distance, and leads one to ponder the eerie silence. That Silence suggests to some that we are alone, but there is a different perspective: At the 2010 Astrobiology Science Conference, the SETI Institute’s Jill Tarter compared the sum of all SETI searches to a glass of water taken out of the ocean.
In addition to his passion for SETI, Davies is the principal advocate of looking for a second type of life, either a different handedness for DNA or a pseudo DNA with arsenic replacing phosphorus. He is also chair of the SETI post-detection task group for the International Academy of Astronautics. An accomplished science popularizer with many books under his belt, Davies has a light touch that is sprinkled throughout The Eerie Silence. Talking about intelligent machines, he cites Samuel Butler’s comment from more than a century ago that “the machines are gaining ground upon us; day by day we are more subservient to them” he recalls President Bill Clinton’s observation that all the information in the Library of Congress could be stored in a device the size of a sugar cube; and he translates aerovirgula multivorans, a faux case of a second form of life that exists on Earth, as an “unfussy little goat.”
Davies is clearly on top of current ideas on exobiology, as is evident from the excellent discussions in the book. He knows most of the players personally. Some are protégées, such as Felisa “Iron Lisa” Wolfe-Simon, an emerging star in the search for arsenic-based life. Regarding the search for intelligent life, Davies argues that the ability of humans to do astronomy and to travel through space sets a high bar for intelligence. “We are probably the only intelligent beings in the observable universe,” he muses, even as he discusses post-biological machine intelligence. Of course birds navigated by the stars long before mankind. Dogs survived space before us and perhaps domesticated us so they could sleep 20 hours a day.
Davies says a few surprising things in this otherwise excellent book. For example, he speculates that aliens might have sequestered monopoles. When it comes to missing monopoles, Alan Guth’s idea of inflating away monopoles in the early universe beats the thrifty-aliens explanation hands down. Still, The Eerie Silence is the best and most current view of the search for intelligence and life elsewhere.
Supplemented by a reference list of 20 or so key scientific articles, most of them accessible to undergraduates, The Eerie Silence could constitute the backbone of a course on SETI, which along with other associated subjects in modern biology form a wonderful fabric of popular science. Else, for an interesting and engaging update on SETI, or something on which to base conversation with a friend at the local Starbucks, this is the place to turn.
More about the Authors
Richard Carrigan. Fermilab, Batavia, Illinois, US .
