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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 UncleWilly ( 1128141 ) * <<UncleWilly07> <at> <gmail.com>> on Sunday August 05, 2007 @10:20AM (#20121569)
    o Far away in space
    o Far away in time
    o Far away in space and time
    o Hollywood
    • by smallfries ( 601545 ) on Sunday August 05, 2007 @11:09AM (#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 [slashdot.org] describes it well.
      • by 1u3hr ( 530656 ) on Sunday August 05, 2007 @02:00PM (#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 [fnal.gov], very interesting despite being a PS file with the ugly bitmapped TeX font.

      • Re: (Score:3, Interesting)

        by Saikik ( 1018772 )
        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.
        • Re: (Score:3, Funny)

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

          Christ, I hope not. Once the alien civilizations "grow up" we'd quickly become the idiot savants of the galaxy. Sure we will have split the atom, manipulated our genes, and developed FTL travel, but we will probably still entertain ourselves with reruns of Bret Michael's Rock of Love, burn down our cities when sports teams win championships, and get our "news" from Bill O'Reilly IV.
      • by AndersOSU ( 873247 ) on Monday August 06, 2007 @07:17AM (#20128813)

        our galaxy was not conducive to intelligent until recently
        Sounds like a twisted version of the anthropic principle.

        The reason the Fermi Paradox is interesting is that "recent" in astronomical terms is a long, long time in even geological terms. Even if what you say were true, there would have been many times the incubation period for intelligent life to develop between then and now, and we still should have seen something by now.
    • We're right here (Score:5, Interesting)

      by symbolset ( 646467 ) on Sunday August 05, 2007 @12:02PM (#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.

      • by Enoxice ( 993945 ) on Sunday August 05, 2007 @12:39PM (#20123061) Journal
        Or, perhaps, they'd come To Serve Man [imdb.com]...
      • Re: (Score:3, Informative)

        If we're the aliens we're looking for, then maybe the theory of Dyson Spheres [wikipedia.org] applies to Earth. Only we live on the outside of the sphere instead of inside. Perhaps we are the one's we're looking for.
      • by Blakey Rat ( 99501 ) on Sunday August 05, 2007 @01:56PM (#20123797)
        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.

        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. Vikings were filthy rich at one point in history, and had everything they could possibly want (or could get it just by making threats), and yet that didn't stop them from slaughtering others and themselves on a regular basis. Who even knows? It's so hypothetical, we can't even speculate.

        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?

        1) Because you're fighting for some reason other than lack of resources. As another example, look at the planet Krikket in the last couple books in the Hitchhiker's Guide. They seemed to have everything they wanted, and yet they still engaged in a campaign to destroy everybody else just so they could be alone in the universe. True, it's a comedy, but you're making a lot of assumptions about the nature of conflict here that don't necessarily hold true.

        I do agree with you that the V scenario, where the aliens come to steal food and water, is pretty stupid.

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

        Why travel all the way to another star just for that since those things are doubtless abundant where you came from?

        Because the resource "people to kill" may not be abundant where they come from.

        The real point is that we simply don't know the answer to any of this. ETs could be so different from us that we don't even recognize them (maybe we've already had contact, but they move so slow that we didn't notice.) They could have motivations entirely different than any that apply to us.
        • Re: (Score:3, Insightful)

          by Stephen Ma ( 163056 )
          There's energy in the Oort Cloud?

          Should be lots of deuterium there.

        • Free range humans (Score:3, Interesting)

          by symbolset ( 646467 )

          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 back

        • 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 ta
      • by SlayerDave ( 555409 ) <elddm1@gma i l . com> on Sunday August 05, 2007 @03:05PM (#20124295) Homepage

        we are the alien life forms we're looking for...

        I'm not the droid I'm looking for.

      • Re:We're right here (Score:5, Interesting)

        by Stephen Ma ( 163056 ) on Sunday August 05, 2007 @03:07PM (#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?

    • Re: (Score:3, Interesting)

      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. T

  • by KingSkippus ( 799657 ) * on Sunday August 05, 2007 @10:20AM (#20121571) Homepage Journal

    In the immortal words of Douglas Adams, "Space is big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space."

    The problem isn't that there isn't anyone else out there. With so many billions of stars and planets, the odds that there are other intelligent beings out there are astronomically large. (Pun slightly intended.) The problem is that the distances required to travel to reach them and also astronomically large, and the odds that there is life on any given planet are infinitesimally small.

    I always put this thought experiment before people: If you had a spaceship that could instantly take you to anywhere in the universe, where would you go?

    Sure, you'd probably drop by a few nebulae and stars and even planets, but after you've seen a few, where to then? You could travel to other planets for lifetimes and still not run across intelligent life on other planets. It's not that truly interesting things aren't out there, it's just that the universe isn't very conducive to producing life-bearing planets. Sure, with so vastly many planets, it will happen (and obviously has), but finding life out there is like finding a needle in a haystack, and we're just now starting to be able to see the haystack.

    Further complicating matters is that we don't have spaceships that can instantly take us anywhere in the universe, and according to the laws of physics as we know them, it's likely that other intelligent beings don't either. Maybe they have travelled lifetimes and they just haven't run across us yet.

    So be patient, my fellow humans, it may take a few million (or even billion) more years. After all, it's more than just a trip down the road to the chemist, and something that cool will probably be worth the wait.

    • by Anonymous Coward
      A fungus doesn't need to travel fast to eat your bread. Actually it doesn't travel at all and gets the job done after a few weeks. Space colonization is the same process on a larger scale.
      • Re: (Score:2, Funny)

        by Anonymous Coward
        >A fungus doesn't need to travel fast to eat your bread. Actually it doesn't travel at all and gets the job done after a few weeks. Space colonization is the same process on a larger scale.

        I'm not sure how sending fungi into space to find alien bread to consume is going to be useful to anyone besides the fungi.
    • The paradox (Score:2, Insightful)

      by aepervius ( 535155 )
      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. But we see nothing.

      IMHO a simple way to resolve the paradox is that no species has the raw material or the scientific knowledge to ever send self reproducing probe to explore the galaxy. We might not be alone but we will never meet each other and stay in our small island of life.
      • Re:The paradox (Score:5, Interesting)

        by thegnu ( 557446 ) <(moc.liamg) (ta) (ungeht)> on Sunday August 05, 2007 @11:01AM (#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.
        • Re:The paradox (Score:4, Interesting)

          by TheRaven64 ( 641858 ) on Sunday August 05, 2007 @12:16PM (#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 Plutonite ( 999141 ) on Sunday August 05, 2007 @12:41PM (#20123087)

          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.
          You have a girlfriend, and she points out insightful things about space exploration stories on slashdot and knows what a hydrogen-based signal is? Your existence is less probable than that of the aliens :)
      • Re:The paradox (Score:5, Insightful)

        by NtroP ( 649992 ) on Sunday August 05, 2007 @11:54AM (#20122613)

        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. But we see nothing.

        I was talking about this with a coworker a few weeks back and realized something. Back when radio was first discovered they used *huge* transmitters to transmit a small amount of data a short distance because their receivers were so crude. Later receivers were vastly improved and you could use much lower power to send much more data. Soon we had over the air TV that had a phenomenal amount of data flowing through the air, but, to not encroach on competing channels in adjacent areas, the signal strength was reduced again.

        Skip forward to today and we are using cable (very little "signal" escapes) and fiber-optics (no signal escapes) to send even more data back and forth. So, in a few years time we've gone from a very noisy planet with out much to say, to a much less noisy planet with much more to say.

        I think it is inevitable, simply from an efficiency perspective, that we will be using more and more "tight-band" communication methods in the future (quantum entanglement?). It seems intuitive that the more advanced a civilization gets the more efficient it will strive to be. The more efficient it is, the less noise will be wasted into space (especially compared to the natural noises of the planet, like lightning, aurora, etc.)

        Look how much more efficient we've become in just a hundred years. If this is indicative of other civilizations, then the window of opportunity for eavesdropping on them is extremely small. And that's assuming that they are remotely like us and not building their civilization at the bottom of their ocean or are just so different from us that we wouldn't even recognize them as life.

        As far as colonizing the stars goes, barring some way of FTL (or instant) travel and communication, I think we will never move beyond our own solar system in our current physical form. I think we will have figured out how to lose our bodies and move our consciousness into "the machine" before then. Once that happens, there will be no need for maintaining the human race in a biological form at all since "reproduction" can occur in solid-state. Once we've reached that stage, being effectively immortal, we might be willing to entertain the thought of physically traveling to other stars, but there will be no need to colonize them, they can be virtualized. But then again, we could virtualize the whole trip anyway.

        Either way, that step in technology would almost guarantee a very efficient system that would need to produce almost no waste products. With no need for maintaining and supporting physical bodies, all of the energy required to sustain physical life will not be needed. No more growing and shipping crops. No more energy wasted in physical travel. In fact, very little need for ever physically moving anything, from then on. This would make most of our civilization a "static" construct. At that point, unless we were purposely broadcasting for neighbors, who'd ever hear us?

      • Re: (Score:3, Interesting)

        by gobbo ( 567674 )

        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 para

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

          by Doug Merritt ( 3550 ) <doug AT remarque DOT org> on Sunday August 05, 2007 @11:17PM (#20127121) Homepage Journal

          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?

          Even more irksome is when people make sweeping statements about things supposedly missing from science fiction that has in fact been extremelyv thoroughly explored over the decades.

          (And trying to be slippery by qualifying with "run-of-the-mill" doesn't help, since that amounts to a circular reference -- if a story does address non-radio-signal communication, then it doesn't count???)

          Even in the earliest "space opera" stories (e.g. E. E. "Doc" Smith and his cohorts) in the 1930's outright assumed that advanced civilizations would use telepathy, tachyonic communication, etc., and it was not rare even then to suggest that they had more or less forgotten about ordinary radio waves as hopelessly antiquated.

          Decades ago there was one particularly amusing story (author and title forgotten, alas) with a series of vignettes, each suggesting a different and clever explanation for the Fermi Paradox e.g. one civilization was trying hard to communicate with Earth in particular, but they kept assuming that their data rate of e.g. one bit per year was too fast, so they kept slowing the rate down.

          A very funny story (which I think is actually available online, these days) talks about the incomprehensibility, to members of a far-flung multi-species galactic civilization, of Earth having beings that "thought with meat", as opposed to every other galactically-known species that had brains of plasma or electronic etc. nature than were otherwise known. (This was not directly about SETI issues, but such are strongly implied.)

          The ultimate problem is not a lack of imagination -- many, many exotic notions of ET communication have been considered -- but rather that the exotic modes are not pragmatic. If ET's communicate with tachyons, well, alas, we don't even know for sure whether tachyons exist or not, let alone how to try to receive them from ET's.

          Interesting recent example: in quite recent years, it turns out that there is a previously-unnoticed theoretical prediction from quite orthodox physics, that photons can carry, not just their intrinsic spin of 1, but also an arbitrary number of additional units of angular momentum. This seems to be little-known, so far, and no one knows how to either produce or to detect that additional angular momentum in photons.

          Nonetheless, many people immediately speculated about 2 things: whether cosmological events may produce such photons, and whether ET's might produce such photons.

          Failure of imagination is not the problem. The problem is the pragmatics of turning imagination into a realizable experiment.

          You complain about the failure of the imagination of SF writers, futurists, etc, but what that says to me is that you are unaware of the rich imagination long ago represented by such people.

          Perhaps the problem is merely that you read only "run of the mill" or mediocre fiction and futurism, hmm?

    • It's not just a good idea, it's the law.
    • There are several other possibilities. We could find ETIs by:

      1. Observing their effects on the galaxy
      2. Observing their communications
      3. Observing them directly

      For observing their effects on the galaxy, perhaps the ETIs make changes which are too small to detect on the scales we can currently resolve. Or maybe they don't need to make such changes to advance their society.

      For observing their communications, perhaps their communications are too weak to reach us above the background noise, or they used broa

    • Re: (Score:3, Insightful)

      by idesofmarch ( 730937 )
      The Fermi paradox has an answer to your thought expirement. The universe is also mind-boggingly old. Furthermore, the Earth is a relatively new planet, meaning there have been billions of years for intelligences to develop before Earth was even around. The Milky Way, on the other hand, is relatively old, meaning that even within the confines of our own galaxy, there should have been plenty of older civilizations.

      Now, think of it in a new way. Suppose you were a civilization that just developed space t

      • 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 yards
    • With so many billions of stars and planets, the odds that there are other intelligent beings out there are astronomically large. (Pun slightly intended.)

      That's the Sagan argument. Unfortunately, the fact that we exist tells us absolutely nothing about how probably intelligent life is or isn't (see: anthropic principle). Sagan's argument doesn't address the fundamental Fermi problem.

      The problem is that the distances required to travel to reach them and also astronomically large, and the odds that there is life on any given planet are infinitesimally small.

      True, but the amount of time that's passed until us showing up is also astronomically large. It only takes one race with an expansion desire to fill up the galaxy at sublight speeds around 1 to 10 million years (via geometric expansion). Even if it took 100 million years, that's still a blip in the life of the galaxy. At the very least, someone should have sent out self replicating probes by now. By we've seen absolutely nothing.

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

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

        What an extremely narrow and self-centered view of the universe.

        First of all "extremely improbable" when talking about something the size of the universe means that even if life in a given star system had a 1 in 1 million chance of ever developing (I'd call that "extremely improbable"), that's still 5,000 systems in our galaxy alone that will develop life someday, or already have. For a 1 in 1 billion chance, that's still 500 star systems. And there are up to 500 billion galaxies in the universe. Even if only 1 out of every billion star systems will support life - or perhaps 1 out of every 5 billion planets - that would still mean there could be trillions of life-supporting star systems in the universe. Given that there are not one, but two planets in our system that are capable of supporting life (Earth and Mars), both of which may have actually supported life, it's certainly no stretch to think there are at least this many planets out there that could support life and that at least some of them are actually doing so.

        It's all too easy to draw conclusions for the entire universe based on observations of your local area. People do it not just when thinking of extra terrestrials but even when thinking of other people and cultures on our own planet. There's a tendency to think that the way we do things is just the way that things should be done. But there are many ways life can develop, many ways life can be supported, and many, many planets that are much too far away for us to observe or for them to observe us. It's foolish to think that we are alone simply because we have not observed any other intelligent life in the few hundred years we've been looking.

        Maybe other life forms have sent out self replicating probes. Why would we have necessarily noticed?
      • 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 k

  • by Anonymous Coward on Sunday August 05, 2007 @10:23AM (#20121613)
    This is it folks, this planet is all there is. God only created life here on earth.
  • Time to give up... (Score:3, Insightful)

    by g0dsp33d ( 849253 ) on Sunday August 05, 2007 @10:24AM (#20121621)
    So we've used a few hundred years of technology for almost a hundred years to look for signs of life in a (nearly?) infinite universe and not found anything. Must mean its not there.

    Considering the state of terrestrial intelligence, maybe any ETIs have realized that broadcasting attack coordinates into space may not be such a great idea?
    • by h4rm0ny ( 722443 ) on Sunday August 05, 2007 @10:35AM (#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.
      • Re: (Score:2, Interesting)

        by Trevin ( 570491 )
        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?
    • So we've used a few hundred years of technology for almost a hundred years to look for signs of life in a (nearly?) infinite universe and not found anything. Must mean its not there.

      The point isn't that we haven't found them, the point is that nothing has found this planet. And that should've happened a long time ago, either by a race expanding at a geometric rate (even at sublight speeds), or by a self-replicating probe. A billion years is a long time.

  • by Joe The Dragon ( 967727 ) on Sunday August 05, 2007 @10:24AM (#20121627)
    and the Extra Terrestrial Intelligence that we know about has been covered up.
  • by FlyByPC ( 841016 ) on Sunday August 05, 2007 @10:26AM (#20121647) Homepage
    Steven Hawking's comment (about how the history of advanced civilizations on Earth meeting less-developed civilizations has generally not gone well for the less-developed ones) would seem to apply here. Hopefully, any civilization advanced enough to not blow itself to pieces before developing interstellar transport capability would be reasonably benign -- but can we afford the risk? If a civilization has the wherewithal to visit other star systems, they are at the very least many years beyond where we are, both technologically and economically.

    Maybe we should be glad if we're too insignificant to be noticed just yet. (We certainly don't have our act together, at any rate.)
    • Re: (Score:2, Interesting)

      by Stefanwulf ( 1032430 )
      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 te
    • in less than 20 years we will have the technology to detect life on other planets, what are the chances that a technologically advanced civilization capable of going into space wouldn't have the technology to find our life with or without us being significant or not? chances are if they are still around they are far more advanced than us [assuming they are space capable etc.] and would find it a trivial problem to find species like ourselves. but you are probably correct in that this being true, they eith
    • Yes, and maybe we are alone because ... that's what they want.

      Currently, our cultures and our societies are typically humans, and if one day a "superior" civilization, coming from another star, goes on Earth, what would happen?

      We will try to mimic them. Currently, our research and development are going into all the directions, because we don't know where to search. If a lab can look at what an UFO looks like, what do you think they will try to do? To copy it. Or to ask for the ETs to answer the questions we
    • Hopefully, any civilization advanced enough to not blow itself to pieces before developing interstellar transport capability would be reasonably benign ...

      Why would showing restraint with respect to interactions with your own species mean you would show similar restraint when interacting with other species? Wolves can show much restraint to other wolves, but little to other species.

      Evolution favors a combination of aggressiveness and intelligence. Losing either quality will make you vulnerable to tho
      • > 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",
  • by dgtangman ( 140663 ) on Sunday August 05, 2007 @10:29AM (#20121683)
    Anyone remember who first noted that the best evidence for intelligent life in the universe is that they haven't contacted us?
  • They set up shop on the far side of the moon and launch interstellar spaceflights from there. That's why. Didn't you see that in Star Trek IV [imdb.com] when Kirk and the gang used the moon to hide their warp signature from the Vulcans as their ship headed off towards the sun to travel back to the future?
  • ...but they are way too smart to talk to strangers!
  • by originalhack ( 142366 ) on Sunday August 05, 2007 @10:39AM (#20121771)
    We've been unable to make our presence known by radio until less than 100 years ago.

    We can get humans to the moon, but not to the next planet.

    The universe is vast even compared to our oceans and we lose people in our oceans all the time. Why would we think a space probe would be noticed by someone?

    Now, our technology will improve and some of the above statements may change rapidly. But, the chances of our using some of those technologies to destroy ourselves seem to be accelerating as well. Perhaps the missing part of the model is that other civilizations always blow themselves up within a few hundred years of their first communication attempts or steps off their planets.

    We probably will.
  • CSI quote (Score:3, Insightful)

    by wizardforce ( 1005805 ) on Sunday August 05, 2007 @10:42AM (#20121805) Journal
    reminds me of a quote Grissom had on CSI about aliens: "I am sure if there is something out there looking down on us from somewhere else in the universe, they're wise enough to stay away from us."
  • by Jasin Natael ( 14968 ) on Sunday August 05, 2007 @10:43AM (#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 nick_davison ( 217681 ) on Sunday August 05, 2007 @10:43AM (#20121819)
    Assuming they're smart enough to create signals that we can detect, they can most likely detect ours too.

    Complex life on this planet has been going on for hundreds of millions of years and yet it's only in the last hundred or so that we've been able to look out with anything more than enhancements of our natural senses. This implies that the odds of a second species being at exactly the same point tiny. Most likely, if they're sending things we can read, they got there a long way before us and are quite a bit smarter.

    Assuming they're quite a bit smarter, one look at the crap our radiowaves are sharing with the universe - infomercials, reality TV and our politics/wars - and I'd imagine pretty much any higher civilization would be embarrassed enough about us to screen their signature and make damn sure those idiotic hairless apes don't go and screw their part of the galaxy up too.

    So, the answer to the paradox: There's most likely higher intelligence out there. And, because it's higher, it's most likely embarrassed to hell and back by us and screening itself from us. Problem solved.
    • Re: (Score:3, Insightful)

      by joto ( 134244 )

      I don't see why they would be embarrassed. When a baby craps in his pants, are you embarassed for the baby? When you see dogs marking their territories with pee, and humping human legs, are you embarrassed about the dog? Rabbits puke their partially digested food, and eats it again. Cows do the same, but unlike rabbits, the food never exits their mouth. Fleas puts their eggs in horse-shit. Are you embarrassed about that? When you see a blue-green algae in the microscope using it's flagella to swim towards t

  • Better Off. (Score:5, Insightful)

    by bmo ( 77928 ) on Sunday August 05, 2007 @10:44AM (#20121823)
    Any space-faring race that makes it here will be technologically advanced by far.

    We're technologically advanced over all the other creatures here on Earth. We eat them.

    --
    BMO
  • by IBBoard ( 1128019 ) on Sunday August 05, 2007 @10:45AM (#20121839) Homepage
    Maybe they are out there, trying to communicate with us, but they're using MSN Messenger and have the same bad grammar as half of the other people who use it?

    "hello earthling.we want to know you know about us.info is important!!!!!"
  • Radio waves.. (Score:5, Insightful)

    by Mascot ( 120795 ) on Sunday August 05, 2007 @10:50AM (#20121879)
    I always found it puzzling that the brightest minds seem to feel there's a fair percentage chance we'll find sign of extraterrestrial intelligence from radio waves. Granted, they're a lot more clever than me, so hopefully they have good reasons.

    My view though...

    Our civilization is in its technological infancy, and even we find radio rather slow and limiting. I can't imagine us leaving much of a radio footprint in another hundred years, especially not leaking it with omnidirectional broadcasting.

    Imagining the same being the case of another civilization, we're trying to listen in on broadcasts from a time window of two hundred years or so, and we've been listening for a couple of decades. In a context where being off by a million years wouldn't be too bad, the odds strike me as fairly infinitesimal even if assuming thousands of civilizations located cosmically nearby.

    Doesn't hurt to try, mind. It's not like we have a lot of other options open to us currently.
  • The truth is oil was discovered on the new planets. And they had a different religion. They will find us next.
  • by account_deleted ( 4530225 ) on Sunday August 05, 2007 @10:52AM (#20121901)
    Comment removed based on user account deletion
  • We have not had electronics for very long. We have just become able to communicate across the planet at any kind of speed.
  • by Hej ( 626547 ) on Sunday August 05, 2007 @10:58AM (#20121955)
    I found a video from these guys to be rather interesting, if not somewhat convincing: http://http//www.disclosureproject.org/ [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: http://www.netro.ca/disclosure/npccmenu.htm [netro.ca]
  • the leader of the fifth invader force speaking to the commander in chief...

    Answer here [morgan.edu]

    "They're made out of meat, Sir."
  • by Mr. Slippery ( 47854 ) <tms&infamous,net> on Sunday August 05, 2007 @11:07AM (#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 [faqs.org] 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?

    • Re: (Score:3, Insightful)

      by pclminion ( 145572 )

      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.

      That statement boggles the mind. You're assuming, from a human context, that no living thing in the ENTIRE UNIVERSE would EVER want to engage in space travel. Head swollen a bit?

      For that matter, you assume that

    • Wrong question (Score:3, Insightful)

      by Tony ( 765 )
      Why go anywhere else?

      Why *not* go anywhere else?

      First, there's a danger in keeping all your genetic eggs in one basket. Secondly, I don't know about you, but I have a strong yen to stride among the stars. I do know there are many like me. Why climb everest? Why colonize the moon? Or Mars? Why *not* travel to the far reaches of the universe?

      Humans are, by and large, creatures with a great curiosity. In the face of a utopia, I'd hope that at least some would wish to explore, and perhaps settle, the great unkn
    • Re: (Score:3, Informative)

      Why go anywhere else? ... They're working on stellar engineering, of course, so there's no worry about their sun going nova

      Well, there's the answer right there and you hand-wave it away. Unless you have an awesome supply of non-stellar hydrogen nearby or physics works differently than we know, suns burn out.
  • by BeerGood ( 561775 ) on Sunday August 05, 2007 @11:07AM (#20122065)
    Even if there was proof of ETI our governments would cover it up. Is it really a paradox if we have no chance of obtaining proof?
  • by ofcourseyouare ( 965770 ) * on Sunday August 05, 2007 @11:09AM (#20122093)
    One piece of wild speculation on why we haven't accidentally picked up any TV or radio broadcasts from ET...

    At this point in time TV and radio is rapidly being usurped by interactive media, most of which currently travels along cables and would of course be undetectable from other planets. As for wireless internet, the power of a wireless LAN router is obviously far less strong than say a TV signal broadcast from a TV tower. And future wireless broadband signals would presumably also be local and low-powered, because it's more efficient that way. (Guesswork, of course).

    Of course traditional high-powered TV and radio broadcasts aren't dead yet, but in say 100 years it's pretty easy to imagine that they they might be. (Or not -- I know this is all speculation)

    So, IF (huge if) other civilisations follwed this path, this might be a possible reason why we don't see or hear their broadcasts -- because like us their high-powered broadcast media only existed for a short time, and were soon replaced by more efficient low-powered interactive media

    All wildly speculative I know.
  • by kypper ( 446750 ) on Sunday August 05, 2007 @11:34AM (#20122373)
    The Universe Song

    Whenever life gets you down, Mrs. Brown,
    and things seem hard or tough.
    and people are stupid, obnoxious or daft,
    and you feel that you've had quite enough...

    Just remember that your standing on a planet that's evolving,
    and revolving at nine hundred miles an hour.
    That's orbiting at ninety miles a second, so it's reckoned,
    the sun that is the source of all our power.
    The sun and you and me, and all the stars that we can see,
    are moving at a million miles a day.
    in an outer spiral-arm at forty thousand miles an hour
    of the galaxy we call the Milky Way.

    Our galaxy itself contains a hundred billion stars,
    it's a hundred thousand light years side to side.
    It bulges in the middle, sixteen thousand light years thick,
    but out by us it's just three thousand light years wide.
    We're thirty thousand light years from galactic central point,
    we go 'round every two hundred million years.
    And our galaxy is only one of millions of billions,
    in this amazing and expanding universe.

    The universe itself keeps on expanding and expanding,
    in all of the directions it can whiz.
    As fast as it can go, that's the speed of light you know;
    twelve million miles a minute, that's the fastest speed there is.
    So remember when your feeling very small and insecure,
    how amazingly unlikely is your birth,
    and pray that there's intelligent life somewhere up in space,
    'cause there's bugger-all down here on earth!
  • by Mystery00 ( 1100379 ) on Sunday August 05, 2007 @11:45AM (#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 localman ( 111171 ) on Sunday August 05, 2007 @12:40PM (#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.

    Cheers.
  • by Sigfried ( 779148 ) on Sunday August 05, 2007 @12:57PM (#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.
    • Re: (Score:3, Interesting)

      by Lengyel ( 1082385 )
      Osame Kinouchi in Persistence solves Fermi Paradox but challenges SETI projects [arxiv.org] 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
  • by geckoFeet ( 139137 ) <gecko@dustyfeet.com> on Sunday August 05, 2007 @03:05PM (#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.
  • by Simon Carr ( 1788 ) <slashdot.org@simoncarr.com> on Sunday August 05, 2007 @08:55PM (#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!
  • Accelerando (Score:3, Interesting)

    by NulDevice ( 186369 ) on Monday August 06, 2007 @08:00AM (#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 taradfong ( 311185 ) * on Monday August 06, 2007 @12:04PM (#20131611) Homepage Journal
    Funny how God is the last explanation anyone is willing to entertain regardless of how much a stretch the alternative is.

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