Someone who works within SETI has written a candid book that seems to explain some astronomical concepts in a generally clear manner to a general reader. It dispenses with some popular misconceptions about what is possible for space travel and communication via radio waves. It challenges the very methodology of using radio telescopes to attempt to find extraterrestrial communication. Likewise, it raises interesting questions that challenge the cherished "rare earth" hypothesis. This book is reasonably comprehensible to the general reader. It’s been more than 50 years since human beings began to search for other intelligent civilizations in the universe – and all we’ve heard so far, as the title of Paul Davies’ latest book captures succinctly, is an “eerie silence.”The first effort was a modest one. Back in 1960, a young astronomer named Frank Drake aimed a radio telescope at a nearby, sun-like star known as Tau Ceti. He reasoned that if an alien civilization had developed a technology roughly similar to our own, it would be sending radio waves out into space, and that some of those radio waves would reach our telescopes. (This could be either the result of a directed message aimed specifically at us, or accidental “leakage” from such a civilization; humans, for example, have been beaming everything from “I Love Lucy” to Rush Limbaugh out into the ether for decades now.) Other astronomers have followed in Drake’s footsteps, and to date they’ve examined several thousand stars, out to a distance of 100 light years or so (still relatively nearby in astronomical terms). The quest is known as “SETI” – the Search for Extraterrestrial Intelligence.What they’ve been listening for is any kind of unambiguously intelligent signal that stands out above the “noise” of normal radio emissions from astrophysical objects. And so we come to the one of the biggest “ifs” in human history: If we were to find such a signal, we would know we are not alone in the cosmos. “The consequences of such a success would be truly momentous,” Davies writes early in the book, “having a greater impact on humanity than the discoveries of Copernicus, Darwin and Einstein put together.” He quickly adds: “But it is a needle-in-a-haystack search, without any guarantee that a needle is even there.”Indeed: The simplest explanation for the “eerie silence” is that ET simply doesn’t exist, and beyond our Pale Blue Dot (to use Carl Sagan’s phrase) the universe may be a lonely place indeed. Of course, even that would be a profound discovery – and although you can’t prove a negative, if SETI searches are thorough enough, and are carried out for long enough, we might eventually be forced to admit that we are, in fact, alone – a sobering thought, to say the least.The Eerie Silence is a comprehensive analysis of the SETI question, from the scientist who is likely the most qualified Earthling to tackle the subject. Davies is a physicist, astrobiologist, and prolific science writer now based at Arizona State University, where he heads the Beyond Center for Fundamental Concepts in Science. He also chairs the “Post-Detection Taskgroup,” a committee charged with figuring out “what to do next” if ET does happen to call. (The committee has no legal power, but even so, it’s a heck of a title to put on your business card, and Davies takes the responsibility seriously.)It’s only natural, of course, to try to work out the a priori probability of ET being out there – to try to estimate how many (if any) needles are in the metaphorical haystack. Drake himself attempted to do so, multiplying a string of probabilities together in what has become known as the “Drake equation.” The problem is, each of those factors is exceedingly hard to pin down.For example, given an Earth-like planet, what is the likelihood that life will take root? At this stage, we simply don’t know, because we only have data for one such planet – our own. (Yes, life evolved here – but was it inevitable, or was it a fluke?) And, given a planet on which life has evolved, what is the likelihood that it will eventually evolve into intelligent life – the sort that might eventually use radio technology, or seek out other like-minded beings? The development of such life on Earth – that is, us – seems to rest on contingency upon contingency. If we could “rewind the tape” of Earth’s history, so to speak, would we have the plough, the pyramids, and the iPod once again? The answer is far from clear, Davies says. And so the number of civilizations out there is frustratingly difficult to even estimate.There is much more to digest here. Among Davies’s bold assertions is the idea that squishy, biological life is probably transitory; if we do eventually find an alien intelligence, it will likely be mechanical in nature. Oh, and if we find ET, our belief systems may need an overhaul: The discovery of aliens, Davies says, “would deal a severe blow not only to Christianity, but to all mainstream religions.”Some readers may quibble with that statement, or with some of the author’s more speculative arguments. But Davies, to his credit, is careful to distinguish established science from speculation, and speculation from opinion, at every turn. The Eerie Silence is honest yet provocative – and enormously entertaining. (Adapted from a review I wrote for The Globe and Mail.)
What do You think about Uno Strano Silenzio (2012)?
Brief review to come. A spirited, engaging read, and not just because it talked about the Mekons.
—vandeverb
Very good book if your looking for ammunition to disprove Aliens among us theories.
—malini
Very repetitive, highly speculative, largely irrelevant, and lightly educational.
—adunson01
