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74 of 82 people found the following review helpful:
5.0 out of 5 stars
Examining their navels?, March 27, 2003
This is the most up-to-date and thorough discussion of the Fermi Paradox that I have read. Stephen Webb examines all the popular solutions as well as some esoteric ones, giving us considerable background on each along with the benefit of his knowledge on a wide range of relevant subjects including microbiology, plate tectonics, evolution, intelligence, language, philosophy, as well as astronomy and cosmology. And then he gives his solution: we are alone.That was Fermi's solution of course, and it is a popular one; however I don't think that Webb comes anywhere near to making a convincing case; and at any rate he is somewhat equivocal about whether his answer applies to the entire universe or to just the galaxy. It is clear that his answer applies only to life as we know it, having a carbon based biochemistry and a cellular structure. My feeling is that intelligent life forms may evolve from some other chemical basis or even from some use of energy and matter we know nothing about. On pages 237 to 239 Webb presents his argument that we are the only extraterrestrial civilization (ETC) in the galaxy by a process of elimination, i.e., life must be on a planet within both a galactic habitable zone (GHZ) and a solar continuously habitable zone (CHZ) around the right kind of star; must avoid cosmic disasters like supernovae; must have the right kind of moon, Jupiter, and plate tectonics; must evolve beyond single cells; must develop tool use and language, etc. He ends up sifting out everything except us, and the only reason he doesn't sift us out is that he has set us aside since we actually exist! This is close to sophistry, perhaps, but it has been argued before. I might call it the Fallacy of Elimination by Unknown Probabilities about Matters that May or May Not Be Essential. Putting that aside, consider this: If we extrapolate from what we know (as opposed to any speculation) about the existence of life in just our own galaxy, we should expect on average--at the very least--one ETC per galaxy. Wow. Far from being alone, this suggests more than 100 billion other ETCs are out there, although we are not likely to ever communicate with them. One of the things this book demonstrates, as others have before (see especially, Peter D. Ward and Donald Brownlee's Rare Earth: Why Complex Life Is Uncommon in the Universe [2000], which Webb acknowledges as influential), is that when you're dealing with so little concrete information in such a vastness, it is impossible to be entirely convincing one way or the other. The conclusion in Rare Earth, with which Webb concurs, is that life is common in the universe, but intelligent life is rare. I agree substantially with this, but my "rare" is perhaps larger than their "rare." Some of the familiar but crucial questions considered here were addressed in the excellent Extraterrestrials: Where Are They? (1995) edited by Ben Zuckerman and Michael H. Hart. For example, How long do ETCs exist before they go extinct? Is space travel enormously difficult and expensive or is it just very difficult? Do ETCs have a psychology similar enough to ours to make them want to communicate? How would they communicate, using what sort of medium?--even: would we recognize a communication from an ETC if we received one? The answer to these questions and many others is, we don't know. But it's fun to speculate; and in speculating at least we can eliminate many conceptual and logical errors that might crop up. Furthermore such speculations expand the mind and allow the imagination a greater range. In direct contrast to Webb I think there's only the smallest chance that we are alone. Amazing how people can come to such divergent conclusions from the same evidence! For such answers as, They are so advanced that they have no interest in communicating with us, and They are so into their own self-constructed pleasure-enhancing virtual existence that they care not to look outward, etc., Webb has a ready response. For such answers to solve the Fermi paradox, he says, they have to apply to every single ETC. Surely, he posits, not all ETCs would have such a psychology. But, by taking all such solutions and playing an elimination game similar to the one Webb plays on pages 237-239, we can reverse his conclusion and eliminate all existing ETCs as non-communicative for one reason or another, arriving at the grand conclusion that we are not alone and that there are indeed a whole bunch of ETCs out there. I wish I had the space to address some other Stephen Webb arguments that I think are faulty, but perhaps just one more will be suggestive. On page 229, while arguing that only humans have symbolic language, he relates an experiment in which a dolphin learns to operate an apparatus to release food. The dolphin is timed. Then the scientists close that dolphin off and release a second dolphin into the pool with the apparatus. The first dolphin can send signals to the second dolphin. The scientists then time how long it takes for the second dolphin to learn to work the apparatus. They discover that it takes the second dolphin on average just as long as it did the first. Webb writes: "We can conclude from this that the first dolphin was unable to tell the second dolphin how the apparatus worked." Well, maybe. But replace the dolphins with humans, and the reward of food with hundred dollar bills, and perhaps we might conclude that humans are also unable to communicate how the apparatus worked! Bottom line: for SETI enthusiasts and anyone interested in the prospect of extraterrestrial life, this is a book, despite its flaws, not to be missed.
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35 of 38 people found the following review helpful:
5.0 out of 5 stars
Billions Of Channels And Nothing's On?!?, January 1, 2003
Four guys walk into the caf at Los Alamos for lunch and start discussing extraterrestrial intelligence. They decide that life, intelligence, and conquering the galaxy shouldn't be that hard. Then one of them asks, "where is everybody?" Far from being the beginning of a bad nerd joke, this lunchtime discussion actually took place in the summer of 1950 and Enrico Fermi really did ask the now famous Fermi Question. The discussion and question led to the Fermi Paradox: if the universe is as old as it is, and if the Earth isn't the oldest planet with intelligent life, and conquering the galaxy is as easy as it seems, then where the heck are they?Physicist Stephen Webb does an admirable job of discussing some possible answers to the Fermi Paradox in If The Universe Is Teeming With Aliens...Where Is Everybody?: Fifty Solutions To The Fermi Paradox And The Problem Of Extraterrestrial Life. It's a tough job, even for a fan of the Fermi Paradox like Webb, since it means being well versed in a wide range of subjects AND it means thinking like an alien intelligence. Webb describes and critiques 49 of his favorite solutions, starting with They Are Here And They Call Themselves Hungarians, and then throws in a fiftieth solution of his own design. The solutions are subdivided into three sections: 1) They Are Here, 2) They Exist But Have Not Yet Communicated, and 3)They Do Not Exist. The book is set up so that after reading Chapters 1 and 2, a person can read the solutions as they wish. Some basic math and science skills are required, but the book should be accessible to a wide reading audience. Albeit not a perfect book, I enjoyed reading Where Is Everybody?, especially since it made me think A LOT! This is NOT a book about flying saucers, alien abductions, and forced interspecific sex, so if that's what you're looking for, STAY AWAY from this book. Besides appealing to folks interested in the question of life elsewhere, it should appeal to any person with wide-ranging interests [both the natural sciences and the social sciences] who wants to exercise the full range of their brain power. For serial readers like me, read this one in combination with Rare Earth by Ward and Brownlee and What Does A Martian Look Like? by Cohen and Stewart for a mind expanding [and exploding] experience. The answer to the question "is there life elsewhere?" is profound no matter which way it is answered. I continue to run my SETI@home screensaver and hope. It would be terrible if there were billions of channels and nothing is on.
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24 of 26 people found the following review helpful:
4.0 out of 5 stars
A Bigger Picture, April 9, 2005
In "If the Universe is Teeming with Aliens ... WHERE IS EVERYBODY?: Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life," Stephen Webb has written a clever exposition of 50 hypothetical solutions to Fermi's famous paradox. Webb organizes these solutions into three categories: (1) they (the aliens) are here, (2) they exist but have not yet communicated, and (3) they do not exist. The appropriateness of these categories and the specific selection of solutions are arguable, but I will not address this in this review. The fiftieth solution, Webb's personal view, is a refinement of the view that intelligent, communicating extraterrestrial civilizations (ETCs), do not exist. He believes we are alone. Some of his arguments are persuasive, but only superficially so. They are reminiscent of the ancient argument that the earth is at the center of the universe because it looks that way, or because this view conformed to one or another philosophical dogma. But now, in Webb's view, it is intelligent life on earth that is "alone" and consequently the earth is its lonely center.
Webb makes several assumptions that underlie the solutions he presents and his own conclusions. He does not directly explain them nor even explicitly refer to them. Four assumptions merit particular attention: (1) ETC populations increase without bound, (2) ETCs maintain biological and cultural cohesiveness and continuity over millions of years and tens of thousands of light years, (3) The Kardashev model is the measure of how advanced an ETC is, and (4) At least some ETCs use communication technologies we would recognize. These assumptions are questionable. (Some are discussed later in this review.)
Using these assumptions, Webb presents most of the forty-nine solutions in ways that ultimately support the fiftieth. Moreover, in most solutions he concludes that if ETCs have ever existed, then surely at least one will have beat the odds, and would have long ago established a permanent presence throughout the galaxy. But this apparently hasn't happened, which to Webb means that no ETCs have arisen in the past, and which thus solves Fermi's paradox. Webb's repetition of this reasoning becomes more than a little irritating long before his last solution is offered. Webb does a good job of inviting the reader to think (irritations aside). To his credit, he frequently reminds the reader of the absence of real evidence for or against ETCs. And, although some readers have pointed out computational errors, in the end they are not central to his conclusions.
What Webb and many others fail to recognize is the simple fact that Fermi's paradox is also contingent on social and cultural factors ... our own. The 30s, 40s, and 50s were decades in which science fiction flourished, with tales of interstellar conquest, galaxy-wide colonization, and empire building by ETCs. This leitmotif reached its zenith with Asimov's Foundation series and, of course, Lucas's Star Wars double trilogy. These elements have their roots in real-world history of previous centuries: from the age of exploration, soon followed by conquest and colonization, through the empire building that (may have) ended in the 20th century. Empire building and its precursor forces operated for only a small part of human history, long after hunter-gathers became farmers and then city dwellers. However, during that historical outburst of energy, and powered by it, human population exploded.
Now the third millennium has arrived and with it a hint that the world's population may ultimately stabilize and even decline. Several first-world nations are already experiencing this (Italy, Japan, and Sweden, for example). There are many reasons for this: wealth, leisure, longevity, and reproductive choice. It is simplistic to believe that an advanced ETC would be interested in propagating itself throughout even small regions of the galaxy. There is no advantage to an ETC, whose individuals probably enjoy almost unlimited resources and life spans, to promote an exponentially growing population. Any ETC with the technology to reach its neighboring star systems will also have the technology to understand and control its genetic destiny.
The "first law" of understanding ETCs is that natural selection applies to all life in the universe, intelligent and otherwise. The "second law" is that all ETCs are comprised of social animals. These two laws imply cooperation (reciprocal altruism). Advanced civilizations whose members are extremely long-lived individuals ultimately become extremely conservative in the sense of being risk averse. Preservation of both the individual and the supporting social structure becomes a central factor in their behavior. Risky exploration and riskier colonization are out. Robotic surrogates are in. Both communication and exploration (robotic or otherwise) would range from being cautious to stealthy or secretive. Exposure is dangerous. This is another solution to Fermi's paradox.
Here is the "third law" of understanding the nature of advanced ETCs: any ETC advanced enough to communicate or travel over interstellar distances must understand atomic and nuclear physics, which implies that it understands the chemical/molecular basis of life, which means that it not only has reproductive choice but also that it can control its genetic destiny.
The earth has an almost four billion-year history of life, from the earliest prokaryotes (and for most of the time the only form of life) and eukaryotes, to the dinosaur, and finally to Homo sapiens. Sixty five million years ago very large animals populated the earth. The age of dinosaurs lasted millions of years ... and hundreds of millions of individuals lived and died. Yet, of their fossilized remains we find only a very small (and certainly incomplete) sample of their once global and epoch-spanning reign. It is likely that we have identified only a very small fraction of the species of dinosaurs that once roamed the earth. Interestingly, this hints that it is at least possible that the earth might have been explored by ETCs and that they might have established temporary outposts many times... and yet it is likely that we will find no trace of this occupation. Continental drift, subduction associated with plate tectonics, volcanism, glaciations, weathering, and other natural forces all act to obliterate any evidence. Thus, to claim that no evidence of this means no ETC contact ever occurred is a weak and unsupportable argument.
Every year one or two supernovas explode in our galaxy. Gamma-ray bursters and other energetic events add to the violence and destruction. This means that any expanding "wave-front" of exploration and colonization would be rapidly reduced to Swiss cheese, with more holes than cheese ... disintegrating into isolated outposts totally cut-off from any putative galaxy-wide integrated civilization. If the speed of light is an insurmountable limit to any form of communication, then beyond a very few hundred light-years, the ability to maintain communication, command, and control breaks down. An ETC's attempt to form an integrated galactic empire ETC would fail ... natural selection, and catastrophic events make such dreams impossible. Consider also that since galaxies are so energetic and violent, the safest place for really advanced ETCs is in the depths of intergalactic space. Command, control, and communication cannot be maintained over tens of thousands, let alone millions, of years required for galactic colonization and rule. An ETC's original species will "mutate", or evolve, from natural or self-imposed causes into hundreds of new species and cultures over that time. To assume otherwise is to assume a culture that has stagnated into a uniformity that defies imagination. For example, could the British have maintained their colonies, say India, if it took 500 years or more to communicate the latest edict or to respond to a problem already 500 years old at its reporting to London?
Speaking of violent places to colonize and thrive, here is another solution to the Fermi paradox. And it is a very ominous one. An ETC that might otherwise be in our neighborhood may have forecast an unacceptably high probability of, say, supernova activity around these parts, or some other impending violent events that we cannot even guess. Should we call this the "Doug Adams" solution to the Fermi paradox ("Goodbye, and thanks for all the fish.")?
Finally, the Kardashev measure of technological advancement dependents on how much energy a civilization controls: all the energy resources of a planet (K1), all the energy output of a star (K2), or all the energy output of a galaxy (K3). We are almost at the K1 stage. Obviously, this criterion predates the information age. Today, we would choose information processing capability as a measure of advancement. This makes a big difference in how we search for SETI and is itself a subject worthy of a deep analysis (too much to go into in this review).
It is very likely that most of our galaxy's worlds, whether dead or teeming with life, intelligent or otherwise, will remain forever untouched and even unobserved by others. There is no Fermi paradox to solve. Today, Fermi himself would recognize that galactic empires are simply dreams of childhood. Over time, and within less than galaxy-spanning groups of stars and worlds, some ETCs will interact, either through communication or, more rarely, through "close encounters of the third kind."
How exciting that will be!
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