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Space Science

The Fermi Paradox is Back 713

nettxzl writes ""Sentient Developments revisits the Fermi Paradox which is "the contradictory and counter-intuitive observation that we have yet to see any evidence for the existence of Extra Terrestrial Intelligence (ETI) although the size and age of the Universe suggests that many technologically advanced ETI's ought to exist." Sentient Development's blog post on the Fermi Paradox states that "a number of inter-disciplinary breakthroughs and insights have contributed to the Fermi Paradox gaining credence as an unsolved scientific problem" Amongst these are "(1)Improved quantification and conceptualization of our cosmological environment, (2) Improved understanding of planet formation, composition and the presence of habitable zones, (3) The discovery of extrasolar planets, (4) Confirmation of the rapid origination of life on Earth (5) Growing legitimacy of panspermia theories" and more ... So, where is everyone?"
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The Fermi Paradox is Back

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  • by h4rm0ny ( 722443 ) on Sunday August 05, 2007 @11:35AM (#20121737) Journal

    Maybe it's been broadcast in a way that we just don't recognize yet. A mere few centuries ago, no-one would have thought to look for alien life (if they thought to at all), by looking at radio waves. Radio what? It's easily possible that there is another great leap just around the corner that is pretty obvious once you reach a certain level of technological or scientific know-how. Maybe someone will discover a sub-ether-o-matic and the whole sky will light up. It's also possible that life forms frequently move toward a smaller population base and thus give off less indicators of their presence.
  • by Jasin Natael ( 14968 ) on Sunday August 05, 2007 @11:43AM (#20121811)

    I'm reminded of an argument put forth in Robert J. Sawyer's Calculating God: If, once we reach a certain level of technological sophistication, it takes only hundreds or thousands of years to either annihilate ourselves or transfer our consciousness into a virtual world, what are the chances that any two types of intelligent life could exist contemporaneously anywhere in the universe, provided that a sufficiently intelligent species develops science and technology only after developing for several billion years?

    We're not even confident that our social experiment will last right now. We've had 120 years or so of real technology -- and there's no guarantee that resource constraints, political strife, or any number of environmental factors won't return us to subsistence farming within a few more generations. The real question is, given not only the incredibly large size of the universe, but also the almost incomprehensibly-long timelines, what are the chances that two intelligent species will be concurrently intelligent, civilized, and looking for each other ... and furthermore, what is the chance that we are one of them (and at this very moment)?

  • by Trevin ( 570491 ) on Sunday August 05, 2007 @11:47AM (#20121855) Homepage
    It takes the power of an entire sun -- something on the order of 10^26 to 10^32 watts -- for us to pick up a tiny pinprick of light, and that's only if our own sun doesn't get in the way. How likely do you think we'll be to pick up a signal sent on a few measly megawatts of power?
  • by Stefanwulf ( 1032430 ) on Sunday August 05, 2007 @11:50AM (#20121877)
    Very often the civilizations that suffered at the hands of colonizers were less technologically advanced because they had less trade and less contact with other civilizations - whether through political choice or geographic isolation. Those civilizations which embrace trade can can very often catch up to their more advanced neighbors in a relatively short period of time - take Europe in the renaissance, for instance. I can't think of a single situation where isolationism allowed a country to overcome a technology deficit, however. In this hypothetical situation of meeting technologically advanced alien life, if we isolate ourselves because we fear that they have better technology then all we are doing is slowing down our own rate of technological development and making the disparity worse when we do eventually come into contact.
  • by Hej ( 626547 ) on Sunday August 05, 2007 @11:58AM (#20121955)
    I found a video from these guys to be rather interesting, if not somewhat convincing: http://http// [http] Video can be found here. Please, anybody with some web space, put up a mirror so that this nice little not for profit group doesn't get slashdotted off the web: []
  • Re:The paradox (Score:5, Interesting)

    by thegnu ( 557446 ) <thegnu@g[ ] ['mai' in gap]> on Sunday August 05, 2007 @12:01PM (#20121987) Journal
    The paradox is that if they have a few thousand or hundred of thousand year ahead of us, then they should have at least by probe or similarly conquered or explored this galaxy, or send a lot of radio signal.
    My girlfriend pointed out that we've been analyzing for hydrogen based signals, because it's the easiest to produce, and we've found nothing. And then it came out in the conversation that WE'RE not sending out signals because we don't want to be found because we're not advanced enough to protect ourselves from someone who could find us.

    Ahem. So in 10k years, we'll be advanced enough to defend ourselves from these theoretical people who are 10k years ahead of us? Will their civilization stop advancing, and we'll catch up? How about maybe aliens aren't sending out signals either?

    How about maybe, just maybe, the way we developed science is not very efficient afterall in the grand scheme of things?

    I love it when people argue the existence or non-existence of super-advanced beings based on our assumptions about how right we are about everything.
  • by Mr. Slippery ( 47854 ) <> on Sunday August 05, 2007 @12:07PM (#20122059) Homepage

    Indeed, as TFA notes, there is "something wrong with our thinking", or at least with that of the author.

    First, interstellar colonization? Unlikely. It makes nice SF, but there's no good economic basis for it. A civilization that survives long enough to reach the technological level necessary for interstellar spaceflight will have stabilized its population and learned how to use local resources to make their home world a paradise. Why go anywhere else? The expense is enormous, the payoff non-existent. (They're working on stellar engineering, of course, so there's no worry about their sun going nova.) Childish species who still imagine faster-than-light loopholes might dream of going swashbuckling across the galaxy, but grown-up races are content to follow more mature pursuits. TFA's claims about "intelligent life's ability to overcome scarcity, and its tendency to colonize new habitats" are simply handwaving, generalizing from one species of half-bright monkeys into sweeping statements about all intelligent life.

    Second, there's the question of signal detection. Contrary to popular belief, radio and TV transmissions [] probably couldn't be detected at interstellar ranges. We've only sent a handful of signals into space that are detectable at long ranges - and mostly that's content-free radar signals. Why do we assume others are more chatty than we are? I imagine a galaxy full of listeners, each waiting for someone else to start talking. Additionally, compression and encryption make signal indistinguishable from noise.

    Third, recognition of "mega-engineering". TFA claims "we see no signs of their activities in space". How would we know? We assume a "natural" explanation for phenomena - as we should - but if we assume the existence of greatly advanced tech, who knows what we think of as "natural" and take for granted out there that's actually engineered?

  • by smallfries ( 601545 ) on Sunday August 05, 2007 @12:09PM (#20122081) Homepage
    Nice. I think you've stitched up all the major avenues of discussion with the first post. Another alternative that made slashdot last year some time was the theory that our galaxy was not conducive to intelligent until recently. The idea is that gamma-ray bursts from pulsars would kill off all life near by. Over time the rate of these events has dropped until the time between them is roughly the length of time for an intelligent species to evolve. At the moment our galaxy is undergoing a phase-transition from an environment that is hostile to life surviving long enough to evolve intelligence, to one that would allow it. So in some sense, all of the intelligent species are "recent" innovations in the galaxy.

    It's an interesting theory, but it is just one possible explanation. James Annis' paper [] describes it well.
  • by postbigbang ( 761081 ) on Sunday August 05, 2007 @12:33PM (#20122357)
    So self important, so smart, and witty, these humans. They'll be just adorable as friends!

    Why, they shoot, rob, kill, maim, pollute, blow up infidels, abuse each other incessantly, lie, cheat, steal, and so on.

    Delightful little interplanetary friends, these people on the third rock from the sun.

    Hey: any evolved civilzation with the brains to travel at C will take one look at us, and fly on by. And I wouldn't blame them a bit. We're barely out of the stone ages. Evolving, yes, but see the above for great reasons to make the Fermi Paradox both laughable and embarrrassing.
  • by Plutonite ( 999141 ) on Sunday August 05, 2007 @12:40PM (#20122431)

    Really the best answer to the Fermi paradox is that Earth-like conditions are rare.
    That is not true. It's not that the conditions and chemical constitution of the environment need to be the same, it's the fact that their needs to be a very low probability event (or set of events) occur for the first "living" cell to result from some arbitrary water-based reaction somewhere in the planet, giving us a cell that has at least basic reproduction and respiratory (energy converting) capabilities. Evolution cannot aid this first cell: there are none before it. It has to come as a result of a single "miracle moment" where the necessary compounds for a connected cell wall, nucleus, DNA..etc all form at the same time AND at the same small point in space, albeit at a much smaller degree of complexity compared to living cells today.

    Your GP does not understand how small the possibility of something like this happening is, even in a vast universe. The living cell is a structure, and the first one is not built by incremental trial&error as in have to have a functional formation who's constituents (DNA or similar) happen to represent the very structure that was arbitrarily formed itself, and are able to replicate themselves into another clone of the original (mitosis or similar).

    We are the ultimate result of a very low probability event, and we are alone.
  • by Mystery00 ( 1100379 ) on Sunday August 05, 2007 @12:45PM (#20122485)
    It's quite possible that they're just waiting for us to stop shooting each other, and act like a single species for once. Which is when we'll be allowed to make contact.

    Out of all the different possibilities of why we haven't made contact, I tend to think it's not that intelligent life doesn't exist, or that they don't care about us, I think it's that they do care, and that's why they're leaving us alone. It's akin to us protecting the animals of this planet, so they can continue to exist and spread. It's quite possible we're under protection also, until we can fend for ourselves.

  • by casca69 ( 795069 ) on Sunday August 05, 2007 @12:50PM (#20122565)
    It behooves us to consider Fermi. The idea is indeed seductive.
    On the other hand, just because WE don't usually quite make one hundred years of consciousness, we assume all things told, that six BILLION is old, and Thirteen Billion is even older.

    One thing no one has pointed out yet. What if that is YOUNG? Vaunted as he was, Fermi didn't include that as a possibility. He either didn't see it, or discounted it. What if we're the FIRST major civilization to grow? Or, let's use our own development as a yardstick. It took us, what seventy five years? to begin putting the broadcast entertainment onto cable, and stop actually advertising our existence. It won't be much longer, and our planet will be nearly invisible.
    Now, if technology develops the same, no matter WHEN, but THAT, it would have taken a hundred years, roughly, for the civ to develop broadcasting, use it, and then, as we are doing, turn it inwards, and not waste power in exo-broadcasting.
    So, any star roughly a hundred light years out would be able to pick up our signals, but if their civ had gotten a start a thousand years before ours, well, then, we missed their shows by a millennium. Talk about the need for TIVO.

    My point is simple. We assume any civ out there is attempting to get our attention. If they developed like ours, even starting the same day, we won't see them at all, UNLESS they are at the right distance. Otherwise, we won't see their signals, as it already passed us by, or the leading edge hasn't hit us yet.

    We won't even go into the many different and varied methods we ourselves use to communicate that never beak the atmosphere, thus making them exo-undetectable. Fermi's assumption is a classic illustration of of assuming... You know, making an @ss out of you and me?
  • We're right here (Score:5, Interesting)

    by symbolset ( 646467 ) on Sunday August 05, 2007 @01:02PM (#20122691) Journal

    An important idea in the panspermia theory is that when a star goes nova, the biomass is not totally eliminated. Some fragments remain. When new stars and planets coalesce around the remnant masses those become the seeds for a new generation of life.

    So according to that theory, we are the alien life forms we're looking for, in a certain sense.

    If mankind is to persist another thousand years we'll have to solve a number of important puzzles. To survive a hundred thousand we'll have to solve many more. By then the pointlessness of immortality as a species may be self evident.

    Any civilization sufficiently advanced to come here in force from another star has solved the energy, food and mortality puzzles, which leaves conquest unlikely as a goal I should think. Why take the trouble to scrap it up with a pestilent life form at the bottom of a steep gravity well when mass and energy are abundant in the oort cloud and asteroid belt free for the taking? Why travel all the way to another star just for that since those things are doubtless abundant where you came from?

    I think what's left is tourism. Intelligence and curiosity are sufficiently linked that a life form evolved enough to solve the necessary problems would want to watch us develop if they could. Perhaps they're here now, secretly recording our ridiculous antics for their own version of reality tv.

  • Re:The paradox (Score:4, Interesting)

    by TheRaven64 ( 641858 ) on Sunday August 05, 2007 @01:16PM (#20122837) Journal

    And then it came out in the conversation that WE'RE not sending out signals because we don't want to be found because we're not advanced enough to protect ourselves from someone who could find us
    It's not a new idea. I read something by Arthur C. Clarke published in the late '60s discussing the idea (and he cited earlier sources) that everyone might be sitting out there behind large radio telescopes waiting for broadcasts. It also argued that leaking EM is something that races are likely to only do for a short period. As technology improves, you move to shorter wavelengths, since these have a greater information carrying capacity. Unfortunately, they also have a shorter range before they are lost in noise, so there's likely to be a very small (in galactic terms) window where a species is using technology inefficient, yet powerful, enough to be picked up at stellar distances. This means that you are only likely to intercept intentional broadcasts, not accidental ones.

    Of course, the problem with the 'everyone's listening' argument is that it requires everyone to be listening. Even if only 1% were actively transmitting, we'd expect a lot more signals than we've found.

  • by localman ( 111171 ) on Sunday August 05, 2007 @01:40PM (#20123075) Homepage
    To me, the Fermi Paradox doesn't necessarily speak to the non-existence of intelligent life. Maybe it says something about the ability of intelligent life to colonize the galaxy. Perhaps it's an energy issue -- were is all the power to travel and colonize the galaxy going to come from and is it worth harvesting it for space travel? Perhaps it's a time issue --even with light speed travel is it worth it to send their people that far? Perhaps it's a socio-political issue -- can a civilization be stable enough long enough to get such huge projects underway and complete them? Perhaps it's an environmental issue -- even the hospitable earth has mass extinctions every 62 million years; perhaps there's no place that's hospitable enough long enough for civilizations to get much further than we have.

    We're an "intelligent" species by some loose definition. We also know that our one intelligent species hasn't achieved meaningful space travel or communication. And I'm not convinced by looking at our collective milieu that we'll be colonizing the galaxy in the next billion years either.

    It's all conjecture; I personally think there's life out there, even intelligent life. But we'll probably never meet -- it's just too much effort. And I don't think the Fermi Paradox (which is based on the assumption that galactic colonization is viable) says much about it.

  • by Gorobei ( 127755 ) on Sunday August 05, 2007 @01:57PM (#20123221)
    That is not true. It's not that the conditions and chemical constitution of the environment need to be the same, it's the fact that their needs to be a very low probability event (or set of events) occur for the first "living" cell to result from some arbitrary water-based reaction somewhere in the planet, giving us a cell that has at least basic reproduction and respiratory (energy converting) capabilities. Evolution cannot aid this first cell: there are none before it. It has to come as a result of a single "miracle moment" where the necessary compounds for a connected cell wall, nucleus, DNA..etc all form at the same time AND at the same small point in space, albeit at a much smaller degree of complexity compared to living cells today.

    Wow. No serious scientist has proposed life starting by a cell miraculously springing into existence with no prior evolution involved.

    Most of the pre-biotic soup theories involve dilute mixtures of animo aids, peptides, sugars, polymers, etc, that replicate as a group. No DNA or similar is involved, there are no cell walls, little or no respiratory capabilities. These features all evolve incrementally and independantly over time. As Darwin noted, the "first life" might have been a salty, slightly greasy, tidal pool.
  • by Sigfried ( 779148 ) on Sunday August 05, 2007 @01:57PM (#20123227)
    Assuming a civilization was advanced enough to be able to travel and communicate galactic distances, they would also have long ago realized what we only recently learned, which is that the Andromeda galaxy is due to collide with our own in about two billion years. Probably not much they could do about that, so they charted out another more hospitable galaxy and took off. So long and thanks for all the fish.
  • by salec ( 791463 ) on Sunday August 05, 2007 @02:04PM (#20123283)

    I'm pretty much convinced that intelligent life is extremely improbable, and that we're alone in the galaxy.

    If by "intelligent life" you mean human-like civilization with very complic... er, "rich material culture" way of life, I completely agree.

    However, it is very much possible that Cosmos is full of various intelligent beings of different kinds, covering spectrum from dolphin-like intelligent, playful, social and friendly creatures, all the way to almost "Alien"-like super tough, hive-building predator killer monsters. However, what we probably won't find in high supply is any kind of beings capable or wanting to travel out of their home worlds.

    Because, you see, the story of humans on Earth is story of a nerd beating all the jocks and becoming the top dog in his school, all that without giving up his nerdness and growing muscles, of course (e.g. by going to the gym and working out). While such story has certain appeal and makes a nice comedy plot, it is very unlikely to happen out of the realm of fiction, and even less likely to happen twice (or at least not very often).

    We as a species broke out of the beaten path of survival because of peculiar pattern of our ancestors' position in food chain and our planet's climate history.

    It is not some inevitable fate that will happen anywhere if you give it enough time, like Karl Sagan believed. It is more of a deviation from usual cycles of evolution. Besides, we still may fall back to self-indulgence (and we actually regularly do, according to history of most successful and organized societies from the past). Once we make it the way we want it and solve all our problems that worry us on this planet, we won't even wish to go out and search for some alien intelligent life, just like those hypothetic intelligent top-of-the-food-chain superbeasts I mentioned before. Absolute success is as much a showkiller as catastrophic failure.
  • No such thing... (Score:2, Interesting)

    by eclectic4 ( 665330 ) on Sunday August 05, 2007 @02:17PM (#20123417)
    They've visited us numerous times, and throughout our Earth's history (humans are relatively very young, and have only been around for a very small portion of time). But, for any semblance of proof, start at this [] non-profit organization. Then, read the hundreds of very well referenced books, talk to the thousands of witnesses, watch the videos, see the images. You can even cut out 99% of the stuff you find on the subject. Cut out the questionable sources that would make any illogical skeptic proud, and you would still have overwhelming evidences. You can even go into the in depth investigation of these by scientist doing nothing more than trying to get us closer to a truth.

    There is in fact a cover-up, it's largely to blame for the missing "proof", and this has been known for decades to many of us. But, there will always be those that choose to believe that these ignorant beings are going to just fly around like bees without any regard for the humans that might be able to see them and ask "why haven't they landed in my front yard? I won't believe until then...", etc... There is far more evidence than what would be needed to prove their existence in a court of law, handily, easily, without question, over and over again. That should be good enough for most, but alas it is not.

    Fermi's paradox is simply partly due to the cover-up, partly due to these beings being intelligent (don't want them to see us? no problem...), and partly due to people just not wanting to realizing the information that is out there for perusal. Nothing more...
  • by 1u3hr ( 530656 ) on Sunday August 05, 2007 @03:00PM (#20123829)
    The idea is that gamma-ray bursts from pulsars would kill off all life near by.

    Stephen Baxter's novel Space uses this idea.

    PS, your link is malformed. Should be An Astrophysical Explanation for the Great Silence [], very interesting despite being a PS file with the ugly bitmapped TeX font.

  • Re:The paradox (Score:3, Interesting)

    by gobbo ( 567674 ) <> on Sunday August 05, 2007 @03:14PM (#20123933) Journal

    The paradox is that if they have a few thousand or hundred of thousand year ahead of us, then they should have at least by probe or similarly conquered or explored this galaxy, or send a lot of radio signal.

    How about: we don't hear giant drums in the forest, so there's no one there? or: none of the smoke clouds we see are arranged into signals, so they are only forest fires?

    One of the things that irks me about so many wannabe futurists, xenophiles, and run-of-the-mill SF is a failure of technological vision. Why would one assume that sending radio signals between the stars makes any sense whatsoever for an advanced civilization, unless we assume that our science has reached a galactic pinnacle?

    Fermi's paradox, to me, ignores:

    • advancements in communications beyond radio
    • the probability that we don't understand what we ARE observing
    • the likelihood that we aren't observing even a significant fraction of what there is to observe
    • some kind of Prime Directive aimed at us
    • inconceivably vast cultural differences
    • a whole host of other simple explanations
  • Consider this... (Score:2, Interesting)

    by Sibko ( 1036168 ) on Sunday August 05, 2007 @03:38PM (#20124111)
    What if we're the first? I mean, someone's gotta be the first. What if that's us? It would certainly explain why we haven't seen anyone else out there yet.
  • by platyk ( 696356 ) on Sunday August 05, 2007 @03:55PM (#20124241) Homepage Journal

    Is intelligent life just a brief transition to a very different form of being? Extrapolating from the history of life on Earth, non-intelligent life seems to exist in a somewhat stable state. Perhaps bacteria-like life is everywhere in the galaxy, and dinosaur-like things are pretty common which gradually evolve for many millions of years without producing human-like intelligence.

    But once human-like intelligence evolves, how long does it take until there is a Technological Singularity that causes human-like life to be superseded by some sort of ultra-intelligent artificial beings (that is beings that are designed by intelligent brains, not by evolution)? Humans have only existed in modern intelligent form for about 50,000 years []. And now we seem more close than far from truly understanding how our own brains work and building machines with superior intelligence which replicate the key features such as consciousness. As a sort of estimate, comparing our knowledge of neuroscience to our knowledge of physics, perhaps neuroscience is now at about the level of Newtonian mechanics. We know some key principles of how the brain works and can apply them. We know how neurons work, we know major functional areas of the brain, and we have had some success developing pharmaceuticals that tweak the operation of the brain. However there is a lot we don't know (like what is "consciousness", really?). What we need are some major revolutions in neuroscience comparable to General Relativity and Quantum Mechanics (with perhaps subsequent revolutions of the superstring or grand unified theory variety). It took about 200 years to get from Newton to Einstein, which is a trivial amount of time in the big scheme of things.

    So could it be that human-like life usually only lasts about 50,000 years before it replaces itself with something vastly superior? If so, then we should not expect to find extraterrestrial human-like life because the window that it exists is so short. So where then are all the artificial super-beings created by extrateresstrials? Perhaps improbable though it may be, a Singularity just hasn't happened in our galaxy yet, because if it had happened then the super-beings would have rapidly converted everything into matrioshka brains [] or something, precluding the existence of humans. Or perhaps the super-beings quickly figured out how to slip away into some dimension of space unknown to us, and they are all having a great party there right now. Or perhaps the super-beings really are out there, but we just haven't figured out how to contact them yet.

  • by geckoFeet ( 139137 ) <> on Sunday August 05, 2007 @04:05PM (#20124293)
    The "increasing complexity" argument seems contradicted by the facts (and the reference is to a 10-year-old paper, which is described as "recent").

    We like to think that intelligence produces a general sort of fitness, but the all of the primates are extremely intelligent, probably the most intelligent creatures on the planet, and with one exception they all live in highly specialized niches, and they're all likely to become extinct within a hundred years or so.

    In spite of what that paper says, increasing complexity does not mean increasing fitness - orchids are among the most complex of flowering plants, but they are also highly specialized and are vulnerable to changes in their habitats.

    The one data point we have is that, although life arose probably as soon as the earth cooled off enough to allow it, for most of earth's history, the highest form of life consisted of algae mats. It may be very, very hard to develop even eukaryotic life, and intelligence may require an outlandishly improbable set of events. Hard to extrapolate from one data point, of course.
  • Re:We're right here (Score:5, Interesting)

    by Stephen Ma ( 163056 ) on Sunday August 05, 2007 @04:07PM (#20124305)
    Any civilization sufficiently advanced to come here in force from another star has solved the energy, food and mortality puzzles, which leaves conquest unlikely as a goal I should think.

    I agree that conquest is unlikely. But how about backup?

    Even stars have a limited life, and stability is not guaranteed within that lifespan. A major stellar flare would be a very bad day for even a strong civilization. And supernovas -- and the resulting sterilization of entire stellar neighborhoods -- are rather common on the cosmological timescale. In other words, huddling forever around one star is a bad idea.

    Therefore, civilizations that really want to endure would want to back themsevles up, preferably thousands of light years away, beyond the sterilization radius of any local supernova. Of course, the backup is a huge civilization in its own right and would want its own backup, and so on.

    So again we have exponential expansion into space, and we are back to Fermi's question: where are they?

  • by Saikik ( 1018772 ) on Sunday August 05, 2007 @04:09PM (#20124323)
    Wait so what this theory is suggesting is that we maybe among the first sets of intelligent life.

    So does that mean that we may end up being the advanced civilizations that other aliens dream of discovering?

    First Contact reversal we land on their planet after they finally discover warp drive.
  • by asupynuk ( 181772 ) on Sunday August 05, 2007 @05:29PM (#20124903)
    The Fermi Paradox is very interesting. However it's not the only one. No one ever discusses the other one.

    The earth is the one place we know is habitable for intelligent life. Life has existed for over 2 billion years. Why is there no evidence of previous intelligent civilizations on our planet?

    Call it Allen's Paradox.
  • Re:We're right here (Score:3, Interesting)

    by networkBoy ( 774728 ) on Sunday August 05, 2007 @06:14PM (#20125207) Journal
    Your argument is deeply flawed. Hydrogen and Oxygen do have potential energy, but as water that energy has been expended, leaving the molecule at a lower energy state. There is already proof of concept for changing kinetic energy to electricity, the piazo-electric stuff the MIT guys put on the steps comes to mind.
    Heck, in a Rube Goldberg sort of way I could imagine the following:
    Large ship of large mass wants to capture angular momentum from small asteroid:
    Capture rock in net on long string
    as string unwinds it spins a flywheel
    at end of string release rock
    wheel string back with flywheel
    use remaining spin on flywheel (energy imparted by (string + rock) - energy used to wind back (string !rock)) to run generator.
    The only way I know of to burn water either uses pressure and heat we can not create, or requires more energy to be imparted to the reaction than is received back.

  • by Artifakt ( 700173 ) on Sunday August 05, 2007 @06:19PM (#20125233)
    DNA is a late comer. Before that, we think primitive organisms used RNA as a code instead of DNA. We think this is true because the oldest DNA based fossils are the Stromatolites, mats of cyanobacteria which date to about 3 Billion years. From there back to about 3.5 Billion back, the various trace fossils remaining are thought to be mostly RNA based life.
    DNA is an advanced replicator. The sort of DNA found in eubacteria is more advanced (in that it has some additional error correction mechanisms, meaning it does a more reliable job of copying itself. DNA in multicelular organisms is more advanced still - in fact it can be argued that sexual reproduction, putting the reproductive organs deep inside a parent so they are protected from some chemicals and radiation, and many other evolutionary advanced are all about improving copying fidelity.
    Lower mutation probability seems to be something nature is heavily selecting for (which makes sense). Lower mutation probability actually increase the evolution rate (which seems counter-intuitive, but which is just what modern Biologists such as Dawkins will claim, that is lower mutation rate = increased selection rate is the orthodox version of the theory I'm presenting, not some crackpottery. I can go into why this is, but I'd rather people read Gould, Dawkins, and others for themselves and get it from the horse's mouth).
    So if modern DNA evolved from more primitive DNA about 1 Billion years ago and Earliest DNA about 3 Billion years back, what happened before? RNA seems to takes us back to about 3.5 Billion years, so given the age of the earth, we have to squeeze probably at least 5 sequentially more primitive replicators, maybe many more than that, into that first 1/2 billion years that are left. Plus, each step back means sloppier copying and a slower overall evolution rate, so each step is more 'miraculous' than the next. (I'm not claiming an automatically supernatural explanation here, just saying that the probabilities seem to be getting really incredibly unlikely, reaching odds of billions to one and then zooming up into really improbable odds, on a par with all the air molecules in the room just happening to all jump to one side type events, when we talk about the first few steps from inorganic clays with various crystaline microstructures to something a little more like a true self replicating molecule).
    Now this talk about the 'soup' behaving like it's gonna evolve automagically is another thing. When people run experiments with glass globes full of Methane and Ammonia and electrical arcs and UV for energy sources they very quickly get Amino Acids, usually within a few hours, which is where these 'soup' claims start. But when they first did these same experiments the researchers assumed that they would see Proteins within a few weeks or months, and that part just didn't happen. Getting from Amino Acids to self replication turns out to be Quintillions of times or more harder than these early experiments suggested. Saying that self replication might be a mysterious property distributed throughout the 'soup' as a whole is just another way of ignoring how long the actual hard data tells us those odds are.
    Something is fishy as hell with the whole origin of life question, and not just with the Fermi Paradox. Darwin himself knew it - that's why he carefully titled his first book "The Origin of Species" and not "The Origin of Life". By his own writing, he thought he had explained why life, once started, divides up into species and why the fossil record shows species have changed, died out, or been replaced by new one species, but he didn't think he had solved the more ultimate origin problem as well, and in fact thought his theory might pose whole new difficulties in solving it.
    Huxley's related book "On the Origin of Species, Or, The Causes of the Phenomena of Organic Nature", is mostly where people get the idea tha
  • by symbolset ( 646467 ) on Sunday August 05, 2007 @06:39PM (#20125367) Journal

    Creationism is an important aspect of this discussion and shoud not be modded off topic.

    For myself though, I try to see the world as closely as it appears to be, rather than through the interpretations of men. We discuss here things on a cosmic scale perhaps beyond human imagining and I am comfortable with that. I am not comfortable with speculating on the whims and motives of beings divine as I am certain that is beyond my ken.

    Of this I am comfortable though: to describe a thing as being something other than what it clearly is can almost always be considered a slight to its creator. It is beyond me to speculate about why a creator would make the world appear to be one thing and then require his adherents to insist it was another. That sounds to me like a cruel game and even less likely than intelligence as random happenstance.

  • by mark_osmd ( 812581 ) on Sunday August 05, 2007 @07:52PM (#20125841)
    There is a scary possibility, look at our own inability to get fusion to work, oil/chemical energy is ok to just get a civilization started but to go from star to star you at least need fusion. In fact each planet might only get one chance because the first civilization could easily use up all the easy to reach oil and coal. If the first civilization dies off, the next one to come up has no easy to use starter energy to run their technology long enough to even get a shot at researching fusion. For example the hot, jungle like conditions that created our oil and coal might never come again. It's possible that there's is no way to get fusion to work. So everywhere in the universe are lots of civilizations that then have energy crises and either learn to live efficiently (using piddling fission power, wind, and other renewables) or just die off. This makes them much harder to detect. Even without fusion, it might be possible to go from one star to another very slowly via advanced fission propulsion (taking centuries in slow boats to go from one star to the nearest star with robots growing the crew as the ship approaches the target star out of frozen ova or some other even farther out nanotech method) et [] but doing that just clones your power starved civilization on another star and doesn't solve the energy problem. The only thing it really does is reduce the chance that one disaster will wipe out your only planet. Mark
  • Free range humans (Score:3, Interesting)

    by symbolset ( 646467 ) on Sunday August 05, 2007 @08:40PM (#20126077) Journal

    Or at the risk of being "Richard Rank" from Contact, maybe they've solved those problems and yet they still like killing other civilizations just for the sheer joy of it.

    This is one angle I hadn't considered in my post. I'll concede this point. Although farming creatures to kill are a renewable resource, new and different wild game is a sport some individuals in an advanced civilization might enjoy. Extensions of this concept apply, and alien angles beyond what I imagined. Another poster mentioned backups, but I doubt the occupied -> vacant ratio of livable planets is so high that eradication of us as pests is an efficient solution to this problem.

    2) There's energy in the Oort Cloud? I thought it was just a bit of dust flying around.

    Not to be pedantic, but mass is energy. That the Oort cloud is rich in hydrogen for fusion and known to have scattered mountain sized collections of frozen hydrocarbons is just bonus. To get manned craft beyond Saturn we would need fusion power at least, or some other as-yet undiscovered fount of energy. Even for unmanned craft that we send that far we use fission.

    As another poster pointed out, yes, this brings us back to the question of where are they? Perhaps in the coming decades we will come to see that we've already seen them, we just didn't know how to read the signs. Perhaps the noisy phase of social development is brief enough that no culture passed through it close enough for us to see it, in the brief span we've been looking. Perhaps we are alone for now. If we take the obvious step and expand our sphere everywhere we can, we won't always be. Eventually the lines will diverge enough that "we" will be "them". Space is vast, and after Saturn the landmarks are far apart.

    It bothers me that we can't see ion drives in the distance. That must mean the technology is short lived, soon to be surpassed by more efficient means. Otherwise potential alien intelligences would be shifting lunar sized masses with it, and we could see that from a galaxy away.

  • by Lengyel ( 1082385 ) on Sunday August 05, 2007 @09:39PM (#20126403)
    Osame Kinouchi in Persistence solves Fermi Paradox but challenges SETI projects [] has proposed a model of colonization that does not assume that colonization follows a uniform diffusion process. A uniform diffusion process is often tacitly assumed in back-of-the-envelope, extra-terrestrial-free solutions to the Fermi Paradox. Instead of a uniform diffusion process, Kinouchi proposes a model for intergalactic colonization closer to the distribution of cities on the Earth. This is not a simple uniform diffusion process, as shown by the non-uniform distribution of cities, and by the presence of exotic "lost" tribes, whose provincial worldview might prompt them to conclude that there is no global civilization.

    Kinouchi points out that for a wide class of diffusion processes, including simple processes other than uniform diffusion (in which colonization would occur uniformly in every direction), the number of non-visited sites need not decay exponentially with time. Instead, the probability that some site remains uncolonized might follow a power law.

    (He gives the probability that a site might not be visited by time t as P(t) = P_\infty + Ct^{-\theta}.)

    I'll jump to the conclusion: if the colonization of space follows something like a non-uniform, persistent diffusion process, then there will be large regions of space that won't be colonized, away from the colonized areas. Since we haven't heard from extraterrestrials, we can assume we are in one of the large, unvisited regions, and so the nearby candidates for SETI searches are also unlikely to have been visited. (Kinouchi asserts that the Fermi Paradox is "locally" true.) So SETI has to look further than the immediate stellar neighborhood for likely candidates.
  • by Chemicalscum ( 525689 ) on Sunday August 05, 2007 @09:50PM (#20126455) Journal
    There are three current answers to Fermi's Question:

    1. The cosmologist Brandon Carter has produced a calculation based on Bayes theorem that the life span of technological civilizations is less than 10^4 yr. So civilizations don't last long enough to develop instellar travel and the outlook for us is not so good.

    2. That though life may be comparatively widespread in the universe. the evolution of organisms capable of producing a technological civilization is very, very rare. We may be the only one.

    3. They are already here, hiding out in the asteroid belt and on the dark side of the moon observing us. The alien civilization is so advanced an benevolent it does not want to make contact until they think we are sufficiently advanced not to have our civilization damaged by contact. This idea was put forward a few years ago by a group on the internet called the Group of 50 who were fifty signatories to a statement calling for the aliens to contact them by email. They reckoned as internet traffic was channeled through communication satellites that the aliens were monitoring it. No they weren't total nuts, the group was founded by an emeritus U. of Toronto astronomy prof. and consisted faculty, grad students and other interested people mostly from around North America. I don't know if they got an email from them yet (I haven't looked at their site in years, don't know if it still exists), but they had a neat scheme to check out if an email was genuine, not from some nut or hoaxer, they would ask the aliens to set of a small but visible flash on the surface of the moon at some prearranged time.

    Some serious academics to the idea of aliens already here seriously enough to do an infra-red search study of the asteroids. If there was an alien colony on an asteroid it's energy use should cause it to be an infra-red emitter. The result was published in a peer reviewed astronomy journal. The result was negative, oh I guess there not here then.

  • by Simon Carr ( 1788 ) <> on Sunday August 05, 2007 @09:55PM (#20126479) Homepage
    Glad to see everyone has solved the Fermi Paradox just by reminding us that space is big and by quoting Douglas Adams ad nauseum. Guess we can close the book on that one. No Python references for us? I think that would sew it up tight.

    Sarcasm aside this thread has so much supposition about the intelect, ability, advancement, logic and morality of any possible alien life it's mind blowing, and not in a good way. I don't think we can presume to understand an alien intelligence even if it did show up.

    I've read some comments that proposed that if an alien life form advanced enough to actually mobilize the technology to reach us that they would be so intellectually superior that they would have no interest in us, or at least no malevolence towards us because they would be so enlightened. That's a massive guess that puts a lot of faith in the development path of "intelligent" life. If you think of Humanity as a possible median point for cruelty and benevolence (as we often paint ourselves in Sci-Fi), that still leaves a lot of terrifying room for a bad encounter.

    Anyway tl;dr it's a paradox. It's genuinely weird. There's no simple explanation. Space is big, but life should be plentiful if the explanation of abiogenesis holds (local chemicals spontaneously live). It should be plentiful if the explanation of exogenisis holds (space junk has space mold)? Dammit it's just weird!
  • by Saikik ( 1018772 ) on Sunday August 05, 2007 @10:17PM (#20126597)
    Would I be an alien sympathizers if I said I do not envy those races if we are more advanced than we. Imagine what that will do to our 'god complex'.
  • Re:We're right here (Score:5, Interesting)

    by Blakey Rat ( 99501 ) on Monday August 06, 2007 @12:14AM (#20127113)
    The Vikings actually kept decently detailed records, you know. In Jared Diamond's "Collapse" he cites the Viking record that explains why Eric the Red "discovered" Greenland after being kicked out of virtually every other Viking land for killing dozens of people in bar brawls. And that's one of their national heroes.
  • by cburley ( 105664 ) on Monday August 06, 2007 @12:37AM (#20127179) Homepage Journal

    For myself though, I try to see the world as closely as it appears to be, rather than through the interpretations of men. We discuss here things on a cosmic scale perhaps beyond human imagining and I am comfortable with that. I am not comfortable with speculating on the whims and motives of beings divine as I am certain that is beyond my ken.

    But it is rather difficult to "see the world as closely as it appears to be", with disregard for "the interpretations of men", without coming to the conclusion that it, and in fact the whole universe, revolves around you (the observer).

    Of this I am comfortable though: to describe a thing as being something other than what it clearly is can almost always be considered a slight to its creator.

    A good point, but consider going two steps further: how can anyone truly "clearly" see, never mind accurately describe, a creation, if that individual is not the creator — who could be said to have "described" it via his creation?; and, how can the thing created truly "clearly" see (and thus accurately describe) itself, never mind the entirety of the creation of which it is part?

    (There are Biblical, and presumably other religious, statements that raise these same points; they are thousands of years old!)

    It is beyond me to speculate about why a creator would make the world appear to be one thing and then require his adherents to insist it was another. That sounds to me like a cruel game and even less likely than intelligence as random happenstance.

    Start with a safer assumption, which I touched on above: nobody in this world can really "grok" the entirety of the world, never mind the universe. They really can't even understand, or clearly see, themselves. (We still don't really "get" how a dog, a gecko, an ant, or even a paramecium, actually works, never mind why any of them exist.)

    Given that, we really can't reason from how the world/universe "appears" to us, because we don't understand us, and the vast majority of what constitutes said "appearance" consists, for any particular individual, of information obtained "through the interpretations of men".

    That suggests our biggest challenges will involve our "fights" with ourselves and our interactions with others. This shouldn't be surprising, considering that, even in the comparatively-simple world of Newtonian physics, the "N-body problem" is considered very difficult to solve — yet each "body" is obeying very simple and well-known rules, when compared to how any living organism (from a virus on up the so-called evolutionary, and complexity, ladder) behaves.

    Next, is there any truly persuasive evidence that our Creator requires us to insist the world is something other than it appears to be? I'm unaware, offhand, of any evidence that Jesus Christ, or certain other well-known "Men of God", insisted on any such thing, or required their adherents to do so to others.

    That leaves us with a somewhat-less-controversial, but perhaps-even-more-interesting, question: why does religious teaching generally dissuade us from probing, contemplating, and even worshipping the fullness of our physical universe, and instead focus on teaching us how to treat other people, animals, and our environment?

    There's a reasonably scientific answer to this, one that I think becomes more rational the more we learn about our physical universe: the universe may be vast, but it is not, from the point of view of any individual who is subject to religion teachings, consistently important across all of its "components". (I.e. there's insufficient "spooky action at a distance" such that we really need to know what's going on in Andromeda.)

    Simply put, whether

  • Davids vs Goliaths (Score:2, Interesting)

    by Anonymous Coward on Monday August 06, 2007 @02:08AM (#20127487)
    Ben Bova, a major science fiction writer, has a proposed answer to the Fermi Paradox that startw with one of the side-effects of general technological advancement: The average person (of any intelligent species) acquires more and more power to do things. Well, on Earth it is well known that not all persons are emotionally stable, even as adults. Why should an assumption of stability be made for other worlds? Remember that if there is a technological cure for insanity, it is beyond our current technology, and it is reasonable to assume that another species at our technological level will also lack that technological solution. Which means plenty of wackos running around out there with power to do stuff, just like here. And what can one empowered insane person do? How about write a software virus that destructively disables a key technological infrastructure? How about recruit others into a terrorist organization that acquires nuclear weapons and starts a world war? How about create a biological virus that results in a deadly worldwide plague? Bova basically says that after a certain technological level is reached, every global civilization gets murdered from within by some insane individual or group. So nobody ever reaches the stars. Even if some social "cure" is tried, like totalitarian testing/execution of people arbitrarily defined as "insane", likely as not either of three things will happen. (1) They don't catch everyone who wants to destroy civilization. (2) They encourage ordinary folk to resist being part of such a culture, leading to destruction of the civilization. (3) They succeed, but as a result of having clamped down, become a "water empire" [], and end up not wanting to go to the stars.
  • by codeButcher ( 223668 ) on Monday August 06, 2007 @05:01AM (#20128139)

    As we see life here on earth, life is a constant battle - an individual's death provides the nutrients for another to live, and so on in the food chain. Life means growth, which means competition for resources, which boils down to war. The idea of evolution is built on the very foundation of death of the weaker and survival of the fittest (weak and fit defined as by competition). War and violence is a necessary corollary of this process.

    I perhaps don't really have enough imagination to dream up a world that followed a non-violent path to sentience and civilasation, but I would be glad to hear your ideas.

  • Re:The paradox (Score:2, Interesting)

    by tsjaikdus ( 940791 ) on Monday August 06, 2007 @06:46AM (#20128475)
    True. Our EM leakage is not decipherable beyond Pluto. For an outsider far away, we're just some star with a tiny tiny tiny amount of added noise in the radio spectrum. See []
  • by Xtifr ( 1323 ) on Monday August 06, 2007 @08:10AM (#20128775) Homepage
    > Evolution favors a combination of aggressiveness and intelligence.

    Then how do you explain cockroaches, phytoplankton and sponges? What, you think they're "less evolved" than we are? That's nonsense! They've been evolving for just as long (longer, depending on how you measure)--they are extremely evolved! The most populous multicellular creatures on this planet (by sheer volume, not just numerically) are ants and termites. And while some of their behavior may resemble what we call "intelligence", it is clearly hard-wired, not learned. And while ants are usually fairly aggressive, termites are not so much. For a more obvious example, a little closer to home, consider the field mouse, an immensely successful species, but neither intelligent (at least for a mammal) nor aggressive. In fact, aggression is most strongly associated with apex predators [] like that wolf you mentioned. And while apex predators are really cool animals in general, they also tend to be extremely fragile as species.

    I might go so far as to say that the available evidence shows that Evolution (that famous anthropomorphic personification who lives in a house made of giant tortoise shells, decorated with finch feathers) disfavors aggressiveness, and seems to be fairly neutral about the whole notion of intelligence.

    Of course, when it comes to intelligent, technological species, well....we're speculating based on a sample-size of one, which is not enough to form any sort of meaningful conclusions. I think it's fairly safe to say that evolution will favor intelligence when designing intelligent, technological species, but beyond that I hesitate to guess. I also think it will tend to favor hair when designing hairy species. :)
  • Accelerando (Score:3, Interesting)

    by NulDevice ( 186369 ) on Monday August 06, 2007 @09:00AM (#20129083) Homepage
    I like Charlie Stross's solution to the Fermi paradox, as proposed in "Accelerando" - basically that as a civilization becomes more advanced and reliant on technology and bandwidth, they're less willing to leave to go out exploring. Sort of the why-leave-home-all-my-stuff-is-there theory. So we haven't encountered intelligent life because everybody out there decided they were going to stay close to home.
  • by skeptictank ( 841287 ) on Monday August 06, 2007 @10:06AM (#20129565)
    Many of the solar systems that have been discovered have large gas giants so close to the host star that small planets (like Earth) in the habital zones would be kicked from the system. Jupiter is in the just the right orbit to limit the number of large asteroid and comet strikes that happen on our world. Stars much larger than Sol have short lifespans (relative to Sol) and smaller stars tend to be variables and generate flares that would kill Earth life on planets close enough to the star to maintain life.

    Suitable stars with suitable planets for the development of intelligent life maybe very very rare.

  • by Impy the Impiuos Imp ( 442658 ) on Monday August 06, 2007 @11:13AM (#20130315) Journal
    The whole point of the Fermi Paradox is that even if civilizations take a ridiculously long time to travel between stars, and between colonization and sending out their own child colonies, the entire universe (not just one galaxy) should still long since be clogged to the gills.
  • by Khammurabi ( 962376 ) on Monday August 06, 2007 @11:45AM (#20130757)
    If extra-terrestrials do exist out there (which they probably do), the question is more likely "Why would they even bother with us?" Honestly, if they have solved mortality, interstellar travel, and a slew of other issues that it takes to become a space-faring race, why would they be interested in us? Even mild scientific curiosity can be satisfied by scooping up a few of us and dissecting us.

    Reasons to Visit Earth:
    - Humans make fun pets. ("Look, dear! Talking monkeys!")
    - Curious as to what humans taste like.
    - Anal probes are the equivalent of interstellar cow tipping.
    - Human horn is an aphodesiac.

    Reasons Not to Visit Earth:
    - Same reason a level 70 in World of Warcraft avoids starter areas. There's no point.
    - Stupid humans keep wanting the ET's to just solve their problems for them.
    - The last guy that got stranded in Roswell was carved up like a turkey.
    - Same reason why humans don't bother to explain how microwaves work to dolphins. Sure they can talk, but they don't understand a damn word we say.
  • by paladinwannabe2 ( 889776 ) on Monday August 06, 2007 @12:14PM (#20131107)
    You assume aliens would be no more advanced than we are. However, even a thousand years (trivial on the cosmic scale) makes a huge difference in the technological scale. Consider that 1,000 years ago the deadliest fighting force was a man in armor on horseback. A single infantryman today, armed only with basic gear, could take out a hundred knights. A well-equipped squad of 10 could take out a hundred thousand or more- certainly more than enough to break any 10th-century army they fought against. And that's without giving them tanks, ships, or aircraft. That is the difference 1,000 years makes. Our world appears to be billions of years old, and our star one of trillions. Even if there are only 10 other civilizations in our ~10-billion year old galaxy, we would expect at least one of them to be at least a billion years more advanced than us. Saying that we are the most advanced civilization out there is saying we are probably the only civilization out there.

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