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james_nicoll for his link to Charlie Stross and Karl Schroeder, who opened up at their blogs discussions at their blog (Schroeder with substantially more commentary than Stross) of a paper--Keith Wiley's "The Fermi Paradox, Self-Replicating Probes, and the Interstellar Transportation Bandwidth"--that takes an innovative new look at the Fermi paradox. Formulated by Italian physicist Enrico Fermi, the paradox is based on the observation he made more than a half-century ago that given the size and age of the universe there should be other extraterrestrial civilizations visible to us, maybe even interacting directly with us, but so far none have been found or even detected remotely through astronomical observations. What's going on?
The Fermi paradox--the apparent failure of a prediction of detectable extraterrestrial civilizations--would no longer be a paradox, no longer unexplainable, if the fact or facts explaining the discrepancy between the prediction and the reality could be determined. The major problem is that the explanation--a single fact or, maybe more likely, a combination of facts--would have to apply everywhere to explain the fact that nowhere is extraterrestrial intelligence visible. Where is our understanding of the universe wrong?
Making predictions about extraterrestrial biology is obviously problematic, although the principle of mediocrity--briefly, that our part of the universe is fundamentally no different from other parts--would suggest that if life exists on Earth it should also exist on other worlds. What particular bottlenecks would prevent life from evolving to produce the sorts of tool-using intelligence that could conceivably produce detectable signs of civilization everywhere except Earth?
Making predictions about extraterrestrial intelligences' cultures is obviously even more problematic, in that an explanation would have to explain behaviour of civilizations everywhere, if biological bottlenecks limiting extraterrestrial tool-using intelligence don't exist. The cultural factors--rapid self-destruction, say, or a fear of being detected by potential competitors--would have to apply universally for them to work. They imply cultural norms that, honestly, haven't been present on Earth: expansionistic cultures, their descendants, and their various associates currently dominate the world. And if interstellar travel is possible--even very slow interstellar travel--then things become even more problematic. If self-replicating automated interstellar probes, travelling at slow speeds through space, could be made, then they should be ubiquitous. They should be here.
Wiley's contribution to the discussion is his convincing argument that, contrary to criticism, self-replicating interstellar probes are entirely plausible contrary to critics who argue that the technology would ultimately be unusable owing to replication failures and the like. In fact, Wiley produces an estimate claiming that there should be hundreds to hundreds of billions of probes in our solar system right now. He further suggests, in his proposal of "Interstellar Transportation Bandwidth", that different planetary systems colonized by a single civilization would be insulated from the failures (and successes) of their peers. Humanity's Tau Ceti colony might eventually collapse horribly, in other words, but there's no reason to expect that to devastate the adjacent Epsilon Eridani colony, or maybe even to prevent Epsilon Eridani's eventual recolonization of its neighbour. Interstellar civilizations will not die out easily.
Read the entire paper. It's amazing.
This, obviously, is a complex issue that won't be answered quickly, almost certainly not within my lifetime. I like Schroeder's commentary.
Who knows? Maybe the probes Wiley predicts are here, quietly hiding about. It's not as if we've got the entire solar system under lockdown, after all.
What say you?
james_nicoll for his link to Charlie Stross and Karl Schroeder, who opened up at their blogs discussions at their blog (Schroeder with substantially more commentary than Stross) of a paper--Keith Wiley's "The Fermi Paradox, Self-Replicating Probes, and the Interstellar Transportation Bandwidth"--that takes an innovative new look at the Fermi paradox. Formulated by Italian physicist Enrico Fermi, the paradox is based on the observation he made more than a half-century ago that given the size and age of the universe there should be other extraterrestrial civilizations visible to us, maybe even interacting directly with us, but so far none have been found or even detected remotely through astronomical observations. What's going on?In 1950, while working at Los Alamos National Laboratory, the physicist Enrico Fermi had a casual conversation while walking to lunch with colleagues Emil Konopinski, Edward Teller and Herbert York. The men discussed a recent spate of UFO reports and an Alan Dunn cartoon facetiously blaming the disappearance of municipal trashcans on marauding aliens. They then had a more serious discussion regarding the chances of humans observing faster-than-light travel by some material object within the next ten years, which Teller put at one in a million, but Fermi put closer to one in ten. The conversation shifted to other subjects, until during lunch Fermi suddenly exclaimed, "Where are they?" (alternatively, "Where is everybody?"). One participant recollects that Fermi then made a series of rapid calculations using estimated figures (Fermi was known for his ability to make good estimates from first principles and minimal data, see Fermi problem.) According to this account, he then concluded that Earth should have been visited long ago and many times over.
The Fermi paradox--the apparent failure of a prediction of detectable extraterrestrial civilizations--would no longer be a paradox, no longer unexplainable, if the fact or facts explaining the discrepancy between the prediction and the reality could be determined. The major problem is that the explanation--a single fact or, maybe more likely, a combination of facts--would have to apply everywhere to explain the fact that nowhere is extraterrestrial intelligence visible. Where is our understanding of the universe wrong?
Making predictions about extraterrestrial biology is obviously problematic, although the principle of mediocrity--briefly, that our part of the universe is fundamentally no different from other parts--would suggest that if life exists on Earth it should also exist on other worlds. What particular bottlenecks would prevent life from evolving to produce the sorts of tool-using intelligence that could conceivably produce detectable signs of civilization everywhere except Earth?
Making predictions about extraterrestrial intelligences' cultures is obviously even more problematic, in that an explanation would have to explain behaviour of civilizations everywhere, if biological bottlenecks limiting extraterrestrial tool-using intelligence don't exist. The cultural factors--rapid self-destruction, say, or a fear of being detected by potential competitors--would have to apply universally for them to work. They imply cultural norms that, honestly, haven't been present on Earth: expansionistic cultures, their descendants, and their various associates currently dominate the world. And if interstellar travel is possible--even very slow interstellar travel--then things become even more problematic. If self-replicating automated interstellar probes, travelling at slow speeds through space, could be made, then they should be ubiquitous. They should be here.
Wiley's contribution to the discussion is his convincing argument that, contrary to criticism, self-replicating interstellar probes are entirely plausible contrary to critics who argue that the technology would ultimately be unusable owing to replication failures and the like. In fact, Wiley produces an estimate claiming that there should be hundreds to hundreds of billions of probes in our solar system right now. He further suggests, in his proposal of "Interstellar Transportation Bandwidth", that different planetary systems colonized by a single civilization would be insulated from the failures (and successes) of their peers. Humanity's Tau Ceti colony might eventually collapse horribly, in other words, but there's no reason to expect that to devastate the adjacent Epsilon Eridani colony, or maybe even to prevent Epsilon Eridani's eventual recolonization of its neighbour. Interstellar civilizations will not die out easily.
Read the entire paper. It's amazing.
This, obviously, is a complex issue that won't be answered quickly, almost certainly not within my lifetime. I like Schroeder's commentary.
I've lately been trumpeting my revision of Clarke's Law (which originally said 'any sufficiently advanced technology is indistinguishable from magic'). My revision says that any sufficiently advanced technology is indistinguishable from Nature. (Astute readers will recognize this as a refinement and further advancement of my argument in Permanence.) Basically, either advanced alien civilizations don't exist, or we can't see them because they are indistinguishable from natural systems. I vote for the latter.
This vote has consequences. If the Fermi Paradox is a profound question, then this answer is equally profound. It amounts to saying that the universe provides us with a picture of the ultimate end-point of technological development. In the Great Silence, we see the future of technology, and it lies in achieving greater and greater efficiencies, until our machines approach the thermodynamic equilibria of their environment, and our economics is replaced by an ecology where nothing is wasted. After all, SETI is essentially a search for technological waste products: waste heat, waste light, waste electromagnetic signals. We merely have to posit that successful civilizations don't produce such waste, and the failure of SETI is explained.
And as to why we haven't found any alien artifacts in our solar system, well, maybe we don't know what to look for. Wiley cites Freitas as having come up with this basic idea; I'm prepared to take it much further, however.
Elsewhere I've talked about this particular long-term scenario for the future, an idea I call The Rewilding. Now normally one can't look into the future; in the case of the long-term evolution of technological civilization, however, that is precisely what astronomy allows us to do. And here's the thing: the Rewilding model predicts a universe that looks like ours--one that appears empty. The datum that we tend to refer to as 'the Great Silence' also provides the falsification of certain other models of technological development. For instance, products of traditionally 'advanced' technological civilizations, such as Dyson spheres, should be visible to us from Earth. No comprehensive search has been done, to my knowledge, but no candidate objects have been stumbled upon in the course of normal astronomy. The Matrioshka brains, the vast computronium complexes that harvest all the resources of a stellar system... we're just not seeing them. The evidence for that model of the future is lacking. If we learn how life came to exist on Earth, and if it turns out to be a common or likely development, then the evidence for a future in which artificial and natural systems are indistinguishable is provided by the Great Silence itself.
Who knows? Maybe the probes Wiley predicts are here, quietly hiding about. It's not as if we've got the entire solar system under lockdown, after all.
What say you?
