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Fermi Paradox Predicting Humankind's Future?

Posted by ScuttleMonkey on Mon Feb 19, 2007 11:31 AM
from the magic-eight-ball dept.
An anonymous reader writes "The Fermi paradox says that if extraterrestrial civilizations exist, at least one of them should have colonized the entire galaxy by now. But since there is no evidence of this, humankind must be the only intelligent life in the galaxy. The Space Review has an article on how the Fermi paradox can be applied to human civilization. It says that, like the extraterrestrials, humans have three choices: colonize the galaxy, remain on Earth, or become extinct."
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  • More likely (Score:5, Interesting)

    by Maxo-Texas (864189) on Monday February 19 2007, @11:36AM (#18068106)
    The speed of light is a real and unbreakable rule as a result nothing more than 4 or 5 light years away is reachable.

    Sure- you *might* be able to theoretically build a ship that could go further but all politics is local. Look at our politics- could we gather the will to build a 10 trillion dollar multi-generation star ship?

    I think civ's do okay, never get off the planet the started on, and eventually die out from lack of resources, some kind of self destruction, or being wiped out by an external event.
    • Re:More likely (Score:5, Interesting)

      by peragrin (659227) on Monday February 19 2007, @11:42AM (#18068184)
      While the speed of light may be constant it doesn't mean there aren't other ways around the problem.

      Let's figure out how first.

      Besides why would an alien race need the whole galaxy? A small section would do. Even so they could have died out millions of years ago. Or we could be the first advanced race and as we reach out amoung the stars we shall find other less advanced races.

      • by Anonymous Coward on Monday February 19 2007, @11:46AM (#18068236)

        we could be the first advanced race and as we reach out amoung the stars we shall find other less advanced races.
        ... Lord help them
      • Re:More likely (Score:5, Insightful)

        by SatanicPuppy (611928) * <Satanicpuppy@@@gmail...com> on Monday February 19 2007, @11:55AM (#18068362) Journal
        Well, it's a population pressure thing. If there is no limit to your expansion, you'll expand to your limit.

        Not that I don't think Fermi is full of it. All the "There can be no intelligent life if they haven't already a) been found by us or b) taken over the galaxy, theories are pretty foolish. There could be intelligent life inside 10 light years from us, and we wouldn't know it now; hell, we could be living on a planet seeded with life by an advanced society and we wouldn't know it...Maybe the dinosaurs were killed off by an automated terraformer. =P

        Basic probability also suggests that it is extremely unlikely that we are an isolated occurrence...You'd have to buy into Creationism to think that such as we could never have happened anywhere else.
        • Re:More likely (Score:5, Insightful)

          by Cerberus7 (66071) on Monday February 19 2007, @12:02PM (#18068466)
          Extremely unlikely also means it's possible. We might very well be the first intelligent life to emerge in this galaxy. We might be the first in the universe. Extremely unlikely doesn't mean impossible. If we are, God help the younger species; the humans are coming.
          • Re:More likely (Score:5, Insightful)

            by broller (74249) on Monday February 19 2007, @12:13PM (#18068596)
            They've had 10 billion years to visit us.

            Sure, if you are only looking for life. If you are looking for intelligent life, the chances are much smaller.

            If they were here in the first 99% of those 10 billion years, they would have missed us. We may be marked as a "potential revisit" but the likelihood of any existing lifeforms knowing that we are here is very small. The likelihood of us knowing that THEY are around is even smaller.

            If the number of potentially viable planets is of any meaningful size, we could be one of a billion planets out there that they plan to eventually come back to.

            • by Vampo (771827) on Monday February 19 2007, @01:02PM (#18069396)
              We may be marked as a "potential revisit"

              I believe the correct term is "Mostly Harmless"
            • by jc42 (318812) on Monday February 19 2007, @01:21PM (#18069680) Homepage Journal
              If they were here in the first 99% of those 10 billion years, they would have missed us. We may be marked as a "potential revisit" but the likelihood of any existing lifeforms knowing that we are here is very small.

              Actually, if they are living (or have automated monitors) within a radius of roughly 80 light years, they know we're here. We've been broadcasting our presence via radio waves for about that long now, and our broadcasts are unmistakably "intelligently designed".

              Of course, it just might be that the speed of light is a hard upper bound that can't be violated in our universe. In that case, we might still have some time before visitors come calling.

              Our best bet is to continue scanning the skies for possible incoming messages (which might or might not be addressed to us).

              And hope it's not just spam ...

              • by Mex (191941) on Monday February 19 2007, @02:07PM (#18070404) Homepage
                Hello,

                My name is Blorgflog Fleeberblox from the Indurian colony of Aran. After current civil war between Xzixi faction and Xlfrixi government, my father, General Zobb escaped with a 10,000 trillion credit box...
              • Re:More likely (Score:5, Insightful)

                by fyngyrz (762201) * on Monday February 19 2007, @02:01PM (#18070292) Homepage Journal
                The Fermi Paradox is that if they were here any time in the last 500 million years or so, thay would have colonised the place

                Presumes:

                • Earth is the right distance from the sun
                • Earth has the right atmosphere
                • Earth has the right gravity
                • Earth doesn't have something common, which is toxic to them
                • Earth is somewhere they want to be (a spiral arm in the boonies)
                • Earth wasn't colonized, and we are it
                • Earth wasn't colonized, and dolphins (or something else, maybe cats or fleas) are the remains of it
                • Earth wasn't colonized, and they died out due to lack of vigor
                • Earth wasn't colonized, and they died out as a result of an asteroid, etc
                • Earth wasn't colonized, and someone else came along and took exception to it, and wiped them out
                • Aliens are interested in colonization (because we are - but that may not follow)

                ...and those are just off the top of my head. Just because you're qualified to push formulas around, doesn't mean you're an authority on aliens, for crying out loud. Some people - and clearly, Fermi was one - can't think their way out of a paper bag when they step outside their speciality.

          • Re:More likely (Score:5, Insightful)

            by squiggleslash (241428) on Monday February 19 2007, @12:14PM (#18068606) Homepage Journal

            They've actually had about 50,000 years to visit us, less if you only want to count "recorded history". Indeed, any visits done 50,000 years ago would have been to a group of "intelligent" primates who, in all probability, would have had great difficulty in having the contextual skills needed to show intelligence to the visitors.

            So, Fermi's paradox is that something impossible is expected of aliens civilizations, that we have no way to tell has happened. And this is taken seriously, why?

            • Re:More likely (Score:4, Interesting)

              by quadelirus (694946) on Monday February 19 2007, @12:58PM (#18069312)
              I don't think Fermi is talking about mere visits, but colonization. If so, we wouldn't have to worry about them missing us, because if they had come, they would have stayed. To quote the wikipedia article: "The second cornerstone of the Fermi paradox is a rejoinder to the argument by scale: given intelligent life's ability to overcome scarcity, and its tendency to colonize new habitats, it seems likely that any advanced civilization would seek out new resources and colonize first their star system, and then surrounding star systems. As there is no evidence on Earth or anywhere else of attempted alien colonization after 13 billion years of the universe's history, either intelligent life is rare or assumptions about the general behavior of intelligent species are flawed."
              • Re:More likely (Score:5, Interesting)

                by SnowZero (92219) on Monday February 19 2007, @02:09PM (#18070436)
                I dunno, if I were an alien race, and had the choice of colonizing solar systems where the best planet was:
                (1) Teeming with constrantly mutating alien bacteria
                (2) Lifeless and ready for terraforming

                I know which one I would choose. Seriously, why risk alien disease when there are so many "clean" places to choose from? If you were looking for a cave to sleep in, would you choose the empty one or the one with animals already in it? Unless space travel is instant, I really don't see a race ever expanding fast enough to need to use every planet. Besides, it is selfish to think alien life is "as we know it" and would even care about our planet; If they aren't water-based our planet could seem like the same kind of hell that Venus seems to us.
          • Re:More likely (Score:5, Insightful)

            by SatanicPuppy (611928) * <Satanicpuppy@@@gmail...com> on Monday February 19 2007, @12:16PM (#18068644) Journal
            Sure, but they could also have colonized the whole galaxy, then devolved and died off in the same period. Or they could just have skipped us because they like metal-rich planets in the liquid water zone with an atmosphere that's primarily methane, or any number of possible scenarios.

            The point is, unless they set up an "Alien Burger" on the moon with a sign forty miles on a side, we'd never know they were around. Omni-directional radio of terrestrial origin has very little chance of ever being received in another solar system.

            There is also the whole "What are the odds of intelligent live evolving at all?" question. It may be that, despite the age of the universe, the conditions for intelligent life took a long time to come together. Or that the process of evolution tends to take a while to produce a space faring civilization.

            There are way too many variables to just automatically say, "If it were going to happen, it would already have happened."
            • Re:More likely (Score:5, Informative)

              by jc42 (318812) on Monday February 19 2007, @01:55PM (#18070200) Homepage Journal
              Omni-directional radio of terrestrial origin has very little chance of ever being received in another solar system.

              Not nearly correct. Google for "Eavesdropping The Radio Signature of the Earth", the title of an article by W.T. Sullivan and C Wetherill in the Jan 27, 1978 issue of Science. You'll get links to a number of cached copies of it online, and also some discussions.

              One of the hits is to a NASA article [nasa.gov] on the same topic with updated info and some pretty graphs. It also contains the comment "On a cosmically infinitesimal time scale, Earth has indeed become a very bright planet, outshining the Sun by orders of magnitude in certain narrow frequency ranges."

              The general idea is that, first, our radio/TV/radar broadcasts aren't omni-directional; from the start our broadcasts have used antennas that broadcast most of their energy horizontally. The resulting 2-dimensional dispersion pattern reaches much farther than an omni-directional signal of the same energy would. Over time, each broadcast station does send in all directions, but from any one direction, the station appears to fade in and then fade out some minutes later, twice a day. The frequency is doppler-shifted due to the Earth's rotation, and also varies over a year due to our orbit around the sun.

              And, second, with our own technology, we could detect the most powerful our own broadcasts from anywhere within the sphere that they've reached. This was the basic question in the Science article. But they also addressed a more interesting question: Assuming our own technology, and the ability to measure the signal's spectrum but not decipher program content, what could be deduced about the senders? The results were quite impressive.

              Figuring out which star system the signals come from was trivial (to an astronomer). After a year or so of data collection, the planet's orbit would be known, as would the planet's size. The presence of a large satellite (including its orbit and approximate mass) would also be known. It would be clear that the senders are primarily active during the daytime and early evening.

              Further study would generate a rough map of all the broadcast stations. They would be concentrated in narrow bands separating two different sorts of terrain. From the planet's orbit and the sun's brightness, the conclusion would be that the planet is roughly 3/4 water and 1/4 land, and we live on land, primarily along the coasts.

              Even more study would determine from spectrum details that there were several different kinds of technology in use to generate the broadcasts, and each kind of equipment was distributed across patches of land that we might call "nations", with some kinds of hardware used by nations not close to each other, implying long-distance technological sharing among coalitions of nations.

              It was interesting reading 30 years ago. (But I do remember thinking that it might be a good thing if the actual program content couldn't be decoded. ;-)

            • Re:More likely (Score:5, Insightful)

              by ArcherB (796902) * on Monday February 19 2007, @12:38PM (#18069002) Journal
              Hit a nerve, I see.

              Yes. I take it personally when my belief system is used as a synonym for stupid, ignorant or "intellectually backwards". Just as, say a Muslim would takes it personally when Islam is equated to terrorism, or sci-fi fan is equated with "Trekker" (or Trekki, if forget which). I can usually take someone hitting a nerve in stride, but that nerve has been rubbed raw.

              The reason I say you'd have to buy into Creationism, is because in Creationism, God created man, and no other species. That would be the only explanation for how an intelligent species could exist without there being the possibility for other intelligent species.

              Well, there is nothing that says we are not the first intelligent species in the universe. I agree that it is HIGHLY unlikely, but someone has to be the first. Also don't assume that everyone who believes that God created man believes that God stopped there.

              It's not that Creationists lack common sense. It's that they are so rabid about anything that might possibly in some world conceivably be a challenge to their beliefs, that they refuse to accept anything outside their little book. If they were open-minded at all, they wouldn't be pure Creationists. Just that simple.

              There are "jihadis" that are even more rabid in their beliefs, but to say that all Muslims are equally closed minded is just as offensive as your argument. Don't get me wrong, I don't think you mean any disrespect, but stereotyping religions is no different using stereotypes as a basis for racism.

                  • Re:More likely (Score:5, Informative)

                    by spun (1352) <loverevolutionar ... om minus painter> on Monday February 19 2007, @02:15PM (#18070550) Journal
                    See? This is the kind of craziness I'm talking about. You have entered into an infinite regress. Where does this thing outside space and time come from? Either it arises from something else, or it is eternally present, or it is self created. If it arises from something else, nothing is answered, we just have added another layer to the question. If it is eternal or self created, why could the universe itself, which must be less complicated than any proposed creator, not also be eternal or self creating?

                    This is so ridiculous and illogical: you posit that something as complex as the universe needs a creator, you posit a creator that must be more complex than its creation, and then you say that creator itself is not created by somethign else. Please try to see how insane this sounds to those of us who have not been infected by your mental virus.

                    There is no responsibility that comes from being in a created universe. Just because somethin gcreated you does not put that thing in a superior position over you. It is in no position to dictate responsibility to you, to say that it is is another of those completely illogical things religion would have you believe.

                    There is no lack of responsibility that comes from being without a creator. All real responsibility is a form of enlightened self interest. I don't need a creator to tell me to be responsible. If being responsible makes sense, I am perfectly capable of figuring that out on my own. Turns out it does make sense, creator or no.

                    Whether or not there is a creator is a question that is completely seperate from the question of whether religion is a form of insanity. If there is a creator, it sure has done a piss-poor job of communicating its intentions in unambiguous ways to it's creations. Until said creator makes itself and its intentions known to me in a way that can't be faked by mentally damaged humans, the question of whether or not there is a creator is utterly meaningless.

                    The question of the impact of religious insanity on human well being, however, is an important one that can be answered.
        • by SirWhoopass (108232) on Monday February 19 2007, @12:08PM (#18068526)

          It is very easy for humans to ramp up to 10 offspring for 2 parents.
          You must not have children of your own.

            • Re:More likely (Score:5, Insightful)

              by SirWhoopass (108232) on Monday February 19 2007, @12:52PM (#18069216)
              I don't know if government is anti-procreation as much as people expectations of what a minimum lifestyle is. I suppose that counts as society.

              I have a two-bedroom, one-bathroom post-war rambler, about 900 square foot foundation. The family that built this house raised six children in it in the 1950s and 1960s. Today, I am constantly asked when I will buy a bigger house because I have one child.

              Could a "typical" family have six to ten children today? Certainly. Would they all have DVD players, attend summer soccer camp, college funds, and the latest fashions? No.
    • Re:More likely (Score:5, Interesting)

      by AJWM (19027) on Monday February 19 2007, @11:49AM (#18068274) Homepage
      The speed of light is a real and unbreakable rule as a result nothing more than 4 or 5 light years away is reachable.

      The Fermi Paradox assumes the light-speed limit.

      There are an awful lot of hidden assumptions in your bald statement that the speed of light automatically limits travel to a range of 4 or 5 ly. Why not 3, or 6, or 10? It doesn't take much to allow for hops from one star to the next, and if you've got the tech to build starships, you've got the tech to colonize a star system that doesn't have Earthlike planets. (Ie space colonies, not terraforming - although the latter may also be possible.)

      I think civ's do okay, never get off the planet the started on, and eventually die out from lack of resources,

      Quite likely a civilization that never gets off its home planet will eventually run out of resources. But there are resources aplenty for those that take that first step. That's why people talk about He3 mining, solar powersats, mining asteroids, etc. Remember O'Neill's question: "Is the surface of a planet the right place for an expanding industrial civilization?" The answer is "no".
      • by squiggleslash (241428) on Monday February 19 2007, @11:58AM (#18068392) Homepage Journal

        The Fermi Paradox assumes the light-speed limit.

        If it does, I can't see how it'd ever be right, given the fact the universe is still expanding. No civilization can ever populate the entire universe with slower than light travel.

        There are an awful lot of hidden assumptions in your bald statement that the speed of light automatically limits travel to a range of 4 or 5 ly.

        Could be that more than 4-5 light years makes travel a little... hairy. I mean, people start to ...wig-out at those kinds of distances. There's a lot of distance to cover, with a lot of dangerous particles flying in the same space, so it's safe to say the further you go the more... close shaves you'll have!

        Har har har I kill myself.

      • Re:More likely (Score:5, Interesting)

        by SatanicPuppy (611928) * <Satanicpuppy@@@gmail...com> on Monday February 19 2007, @11:59AM (#18068416) Journal
        The problem is, expansion is driven by population pressure. The kind of space travel you're theorizing wouldn't do a damn thing to relieve local population pressure, so it would be more of a sort of species level masturbation, to send out ships to make colonies that are so far away that you'd never be able to engage in any sort of trade or cultural exchange.
    • Re:More likely (Score:5, Informative)

      by aditi (707829) on Monday February 19 2007, @12:03PM (#18068484)
      "The speed of light is a real and unbreakable rule as a result nothing more than 4 or 5 light years away is reachable."

      An insertion here about relativity: if the ship were traveling fast enough, you mightn't need several generations just for 4-5 years. Because of relativistic time dilation, the astronauts in the spaceship would feel considerably less time elapse, while the journey would seem to take decades to everyone on earth. The question then becomes whether people would be willing to spend trillions of dollars on something only their children and grandchildren would see.
      • Re:More likely (Score:5, Informative)

        by Maxo-Texas (864189) on Monday February 19 2007, @12:14PM (#18068604)
        You are correct... some interesting comments here http://math.ucr.edu/home/baez/physics/Relativity/S R/rocket.html [ucr.edu] From the article, for 1g acceleration: Distance Location On Ship Time.
        4.3 ly nearest star 3.6 years
        27 ly Vega 6.6 years
        30,000 ly Center of our galaxy 20 years
        2,000,000 ly Andromeda galaxy 28 years
        • Re:More likely (Score:4, Interesting)

          by rudy_wayne (414635) on Monday February 19 2007, @01:20PM (#18069668)
          There's more to this problem than just the issue of time. What if intelligent life exists in another galaxy (We have now identified more than 100,000 other galaxies in the universe.)

          http://math.ucr.edu/home/baez/physics/Relativity/S R/rocket.html [ucr.edu]

          According to the calculations in that article, using 1g acceleration someone from Andromeda (2 million light years) could reach us with only 28 years passing on board their ship. Sounds nice. Outside the ship, however, millions of years would have passed, which means that the visiting aliens would have had to leave their home planet before there was any human life on earth in order to arrive today.

          Also, the fuel requirement, assuming 100% efficiency, is 4000 tons of fuel for every 1 kilogram of ship weight. And that's only if the visiting aliens want to go sailing past us. If they want to stop and visit, they have to start slowing down at the half-way point of the journey, which means:

          1. They have to know exactly where they are going so that they know when to start slowing down. Coming from Andromeda, how would they even know that earth would be a desirable destination?

          2. It greatly increases the fuel requirement -- 4 thousand million tons of fuel per kilogram of ship weight.

    • by quokkapox (847798) <quokkapox@gmail.com> on Monday February 19 2007, @01:22PM (#18069690)

      I think the answer to the Fermi paradox is this:

      Once a civilization has derived the laws of physics and chemistry to sufficient precision and certainty, there is no longer any pressing need to pursue direct observation of extraterrestrial intelligence. You can simply assume that it exists, based on your local knowledge.

      We are reaching this same point with our knowledge of biology; everywhere we look on Earth, we find life. Simply confirming the existence of microbial life on Mars would make it a bit less urgent to get all the way to Europa and verify that it's there too. If we did make it to Europa to confirm that life has evolved there as well, I'd be reasonably comfortable making the prediction that life exists pretty much everywhere else in the galaxy.

      If there's no reason to doubt life elsewhere in the galaxy, there's probably intelligent life too. So why worry about going there and confirming something by direct observation, when there's a 99.999% probability that it's true? It makes more sense to stick around here for now and simulate what they're like instead of going there and seeing it directly.

      Once we have learned how to just simulate the biochemistry of Europa with high enough fidelity, there's no longer any pressing need to go there, is there? If we make it that far and our simulations and models indicate the presence of life on extrasolar planets, that's good enough for me.

      In other words, the reason the aliens haven't bothered to travel here, land, and say "take me to your leader" is because they know what would happen already. It doesn't matter what we are actually like. It doesn't matter what they're actually like either, because we can imagine them now and we will be able to simulate them soon enough.

      The reason we don't run into aliens is because we can imagine and simulate them and they can imagine and simulate us and there's no point in actually confronting each other expensively IRL.

    • Re:More likely (Score:5, Insightful)

      by Dogtanian (588974) on Monday February 19 2007, @01:38PM (#18069922) Homepage

      The speed of light is a real and unbreakable rule as a result nothing more than 4 or 5 light years away is reachable.

      There are at least two major issues with extra-terrestrial intelligence.

      Let's assume that they evolved independently of us. It is often said that- by the sheer number of star systems- that there are likely to be a very large number of potentially life-supporting planets elsewhere in the universe. Let's assume that this is correct, and further that life may have evolved on a proportion of them.

      Thus, the reasonable conclusion is that there is life "out there". Fair enough. Now; consider the timescale of the evolution of intelligent life on Earth. Very simple bacterial/single-cell type stuff for a large portion of that time. Moderately-intelligent creatures (dinosaurs, birds, etc...) evolving at slow speed for a very long time. Then- on the cliched "24-hour-evolutionary-scale"- mankind, the only organism likely to get anywhere near space-travel- appears at "five-to-midnight".

      Furthermore, although Homo Sapiens in their modern form have been around for 200,000 years, most of the progress made towards space travel hasn't been even; it's been very skewed towards the present day. Technological sophistication has been growing ever-faster, on a pretty-much-exponential scale; how much modern technology has been developed in the past 100 years (a lot)- how fast has computer technology developed in the past *30* years (an incredible amount- by many orders of magnitude(*).

      It doesn't take a genius to see where this is going. Around 10 years ago, I figured out by myself (**) that the next 1000 (if not closer to 100) years are likely to see more significant and fundamental changes in the nature of the human race than those since the dawn of human-like-intelligence.

      My point being this:- Yes, there may be many planets/systems out there capable of evolving and supporting life, and possibly many with life as we speak. However, if we assume that the evolution of life (and technology) follows broadly the same pattern elsewhere as it does on Earth, (very slow for a very long time, then an incredibly sudden surge in intelligence/development), then...

      Unless intelligent evolution (and its inevitable offshoot, technology) has independently reached the same "explosive" stage on one of those other worlds at *exactly* at the same time it has on earth (i.e. around the present day), they'll either be way behind us (at best.. primitive man? monkeys? horses?) or so far ahead of us that it's unlikely we can even speculate on where they'll have reached.

      Remember; our recent technological evolution has been very sudden relative to the timescale of mankind's evolution. In turn, mankind's evolution has been a sudden event relative to the history of life on the planet.

      So, the chances of independently-evolved life elsewhere having reached a comparable stage to us is similar to the chances of two independently-set 24-hour clocks purely coincidentally reading the same time to within a small fraction of a second. If they're more than a few seconds behind, they're nowhere near achieving space travel.... if they're more than a few seconds ahead, they're likely gods, as far as we're likely to be able to comprehend them.

      That's assuming they haven't made a fatal mistake as they progress on their exponential evolutionary/technological curve. As with mankind, by the time they've developed space travel, it's likely that they'll be developing sciences and technologies that have the ability (if not used carefully and responsibly), to wipe them out completely. If they're anything like us, their technological evolution will not be matched by social evolution, and there will be great danger that around the time of (shortly before or after) developing space travel, that they'll put a foot wrong and wipe themselves out.

      Back to the parent comment; if the alien intelligence has survived, and is more

      • by Smallpond (221300) on Monday February 19 2007, @12:14PM (#18068614) Homepage Journal
        If you live in a typical suburban neighborhood, there are at least 200 houses within a 30-minute walk. How many have you visited? How many would you visit if it took the entire output of your civilization for 10 years in order to visit?

        Anyway, amongst the nearest alien species this is called the "Brakloo'tj Paradox".
  • Only two choices. (Score:5, Interesting)

    by AJWM (19027) on Monday February 19 2007, @11:36AM (#18068114) Homepage
    "Remain on Earth" and "become extinct" are not distinct choices. As Heinlein and numerous others have put it, the Earth is too small and fragile a basket for humanity to keep all its eggs in.

    It's not so much a matter of "if" but of "when". Ask the dinosaurs.

    • Re:Only two choices. (Score:4, Interesting)

      by flyingsquid (813711) on Monday February 19 2007, @11:53AM (#18068334)
      The dinosaur argument doesn't hold water. Turtles, salamanders, crocodiles and pike all survived the extinction, and none of them had, to my knowledge, any kind of a space program. What killed the dinosaurs was that they had high food requirements- being large and warm blooded- didn't have the ability to store food, and then the ecosystem collapsed. We, on the other hand, do have the ability to anticipate asteroid impacts and store food.


      The best way to survive a Chicxulub-style impact is the Dr. Strangelove model. Get an underground complex to ride out the initial fallout of red-hot debris, have a nuclear reactor for power, some parkas for ventures outside into the cold, food to survive for 10-100 years, a force to defend it from looters, and store up the machinery needed to start reestablishing an industrial civilization when things have recovered. It wouldn't even have to be a terribly large population, since you could have a bank full of ten thousand frozen embryos to maintain adequate genetic diversity.

      Concievably there are threats where a space program is the logical answer- say, the sun goes supernova- but an asteroid impact just isn't one of them.

  • by Viol8 (599362) on Monday February 19 2007, @11:43AM (#18068212)
    Any intelligence advanced enough to reach Earth from another star system (or dimension?) would easily be able to disguise their presence so we couldn't see them but they could still study us. Just because aliens might exist doesn't mean they'd want to interact with us - thats taking a very human centred view of their motives. For all we know they could view us as barely above pond life in the scale of celestial intelligences and so interaction with us for them would be like us trying to have an interesting and meaningful conversation with an insect - a waste of time and effort.
  • by twifosp (532320) on Monday February 19 2007, @11:50AM (#18068280)
    The math used in the paradox is flawed. It only contains a linear probability using only one variable: quantity. Wikipedia states that there are an estimated 250 billion visible stars in the milky way and 70 sextillion in the visible universe. What it does not take into consideration is time. For every lightyear of distance a potential life carrying solar system away from Earth is, a year is subtracted from the amount of time it took that potential system to reach space maturity.

    In other words, it has taken primates some-odd half a million years to evolve into humans capable of inventing devices that can decipher energy waves from space. It has taken the Earth some 200 million years (from early life to humans) to evolve life on this scale. Assuming other planets have roughly the same time scale, we can only assume those planets inside a 200 (give or take a 100) million lightyear radius contains no life.

    The paradox with the paradox is as follows: Earth contains intelligent life. Earth has not colonized the galaxy. Earth's evidence in space only reaches back into the 1930s when the very first signals were sent into space.

    • by mcvos (645701) on Monday February 19 2007, @12:26PM (#18068840)

      In other words, it has taken primates some-odd half a million years to evolve into humans capable of inventing devices that can decipher energy waves from space. It has taken the Earth some 200 million years (from early life to humans) to evolve life on this scale. Assuming other planets have roughly the same time scale, we can only assume those planets inside a 200 (give or take a 100) million lightyear radius contains no life.

      You're forgetting the age of the earth and the age of the universe. The universe was already over 10 billion years old before earth came into existence. Even if every other earth-like planet really needs at least 4.5 billion years too evolve an advanced civilisation, I still don't see why such a planet couldn't have formed one or two billion years before earth has.

      The odds are really simple: if the evolution of intelligent civilisations is likely, then some of those must have a multi-million year headstart on us. Why aren't they here? The possibilities are limited:

      • Our evolution is sufficiently unlikely that we are one of the first (someone has to be, after all),
      • It's completely impossible to colonise other solar systems,
      • Advanced civilisations that are aggressive enough to colonise space are too aggressive to not wipe themselves out before they get there,
      • Somebody is protecting us/has quarantined us/is keeping us isolated for whatever reason.

      Could be there's a few other options, but basically they all boil down to: we're incredibly lucky, or we're doomed.

  • by Jerf (17166) on Monday February 19 2007, @11:50AM (#18068286) Journal
    For what I consider a much better treatment of this topic, see: The Great Filter - Are We Almost Past It? [gmu.edu]

    This stuff is a big deal, and the Great Filter paper actually manages to draw some useful concrete conclusions from the question, or at least useful concrete questions.

    Also related, albeit a little more tangentially, is "Are You Living In A Computer Simulation? [simulation-argument.com]". "We're in a simulation and there are no extraterrestrials in the simulation" must be considered one of the leading possible answers. (I'm not advocating it either way, I don't have an answer. Nor do I consider this post anywhere near a complete list, just some relevant pointers.)
  • by radtea (464814) on Monday February 19 2007, @11:52AM (#18068302)
    Webb's 50th solution is the one that he believes is the most likely. Unfortunately for extraterrestrial enthusiasts, the solution is depressingly pessimistic: "...the only resolution of the Fermi paradox that makes sense to me--is that we are alone." Webb's preferred solution is highly controversial, but it satisfies Ockham's razor; out of all the Fermi paradox explanations, it is the simplest one. On the other hand, the solution is only as good as the evidence it is based on. New evidence could lead to a different solution to the paradox.

    Fermi's Paradox isn't really a paradox, it's a question: "Where are they?" One possible answer is, "They don't exist." It seems probable that as we explore the galaxy we will find life everywhere, and intelligence nowhere.

    The evidence for this is very strong. For one, there is the fact that we see no evidence for them at all. For two, life on Earth shows us that the kind of intelligence that builds spacecraft is extremely unlikely to evolve.

    Evolution routinely produces some complicated solutions to common problems over and over again. The eye has (probably) evolved many, many times. Wings have certainly done so, as have fins. Everything we know about natural history on Earth tells us that evolution by variation and natural selection will produce the same solution to the same problem with very high reliability. This is even true of things like extra vertebra in the necks of some Central American lizard: there are a couple of species that have this feature, and previously they were thought to have a recent common ancestor. Gene sequencing shows this is not the case--it is merely a result of common evolutionary pressures on similar forms having similar results.

    Human intelligence, on the other hand, seems to be something of an evolutionary fluke. Our ancestors were a marginal species of mediocre tool users for hundreds of thousands of years before we suddenly started on our current course about fifty thousand years ago, with the Upper Paleolithic Revolution. If intelligence was even just ten times harder to evolve than eyes and wings, it would have occurred more than once in the entire history of the Earth.

    Until someone comes up with a compelling account as to why human-style (i.e. machine-building, empire-building, world-colonizing) intelligence should be anything other than incredibly rare, there really isn't any other reasonable answer to Fermi's Question.
  • by dpbsmith (263124) on Monday February 19 2007, @12:21PM (#18068762) Homepage
    Clearly, then, humankind has the right, nay the obligation to expand throughout the universe.

    We should terraform any planets that are not already Earthlike, use the energy of however many stars it takes to achieve our goals, and find some black hole into which to pitch any planets that become inconveniently polluted.

    Any semi-intelligent life we encounter along the way will obviously be inferior, since it has not colonized the universe first. If it gets in our way (or even if it doesn't) we should trample it under our jackboots, but only if necessary. Whenever possible we should altruistically force them to accept the inestimable benefits of the English language, democracy, and McDonald's hamburgers.
  • by unfortunateson (527551) on Monday February 19 2007, @12:47PM (#18069142) Journal
    1) "Accelerando" by Charles Stross: Civs advanced enough to create computing will shortly turn all of their available power (the sun) into shells of 'computronium', each operating off the waste heat of the one inside it. With nearly infinite virtual worlds at your disposal, why go anywhere else?

    2) "Berserker" by Fred Saberhagen: There are civs out there, but they're really, really quite to avoid being noticed by fleets of robotic intelligences sworn on eliminating all biological intelligences

    3) "Quaarantine" by Greg Egan: We're cut off from the rest of the galaxy until we prove ourselves. What we're seeing of the sky is cleverly only showing what they want us to see.

    I'm a bit of a fan of the "We're living in a computer simulation" theory too: since in the future there will be enough computing power to simulate a huge number of realities, the odds are greater that this is a simulation than that it isn't. It would also explain why socks disappear from the dryer, my car keys aren't where I left them, voting irregularities, etc.: Microsoft has got its hand in the kernel somewhere.
  • As we can ALREADY see, some mechanism is at least in humans reducing population growth in the parts of the population that have reached a certain level of social safety: Most developed nations are seeing sub-replacement level birth rates. In countries who have not yet reached this stage, we are seeing mass deaths and low life expectancies. And it's worth noting that this is not cultural either - immigrants moving to developed countries typically adapt to the host nations birth rate patterns within 1-3 generations.

    So a simple possible answer to the Fermi paradox is that this is an inherent biological mechanism and that in any population that grows to fill its biological niche, birth rates will sooner or later drop until an equilibrium is reached, and this is likely to happen before there is significant pressure to colonize the nearby solar system or stars. While that would leave visits to other planets still reasonably likely, and perhaps even small "local" colonies, without an expanding population and diminishing resources driving prices up, pure economics would dramatically slow down the tempo of any colonization effort to what private individuals could afford and would want to try.

    Look at how long Europeans had the capability to reach America before the wave of colonization started, for example. This was a set of cultures that were aggressive and expansionist. Assume the drive to start colonization gets successively less likely as the cost of doing so goes up and the immediate benefit of doing so drops. Once it takes more than a lifetime for economic value to be derived from a colony due to travel time even at light speed, the motivation for pushing for it dramatically reduces for most individuals (look at how hard it is getting people to even sacrifice spending today vs. getting a good pension until they're getting to a certain age, not to consider getting people to sacrifice now for the benefit of their children).

    Even with dramatic population growth, a colony would either have to bring economic value (in the form of resources) OR cost little enough in terms of resources to initiate and transfer colonists to than leaving the people the colony would have been made up of in place for a long enough amount of time to make giving up those resources seem prudent. If improvements in how we exploit various resources keep improving, that in itself might put a significant damper on any colonization efforts.

    That leaves us with possibly the odd colony here and there or the odd probe. Small colonies would face high odds of dying off, and would be unlikely to be established far away - presumably nearby stars would be targeted. Unless these colonies then enter an aggressive expansionist phase, and either had the technology to pull it off (provide resources for itself) or had the fortune of finding a location that provides abundant resources, it would take a lot of time before such a colony could produce offshoots further away. Chances are they'd grow to fill their new solar system first, and run into the same hypothetical growth reductions as we're currently seeing with developed countries on earth.

    That leaves radio. Why haven't we heard radio chatter? Stephen Baxter suggested a simple solution in the novel "Space": IF there are aliens out there, we might not want to make a big fuss about our existence, and also, a civilization may simply grow past broadcasting (That book does also, btw. pose an alternative explanation for the Fermi paradox, but stating it here would be a huge spoiler - it's a good read). We might already be nearing the time where we'll "go silent", as technological advance continues. Given the number of possible stars, how short time we've been listening, and how short periods potential civilizations may broadcast, it's very possible that there just aren't enough civilizations at the right stage of development that their radio chatter happened to intersect with the time periods we are currently monitoring. We may for that

    • NOT being honest! (Score:5, Interesting)

      by ScentCone (795499) on Monday February 19 2007, @11:58AM (#18068406)
      we're too small minded to colonise the galaxy

      We weren't too small minded to risk lives hiking over mountain ranges or floating in very-likely-to-sink boats across open ocean to other continents, remember? Primitive Asians floating across the Pacific to populate South America or hoofing it in across the northern straights were taking on something at least as dicey as we currently see activities in space. Villages wiped each other out, disease killed off whole tribes - all of the stuff that people say would keep us from colonizing elsewhere. Sure, some of those efforts would fail - just as they have for tens of thousands of years. But some will succeed, too.

      we use our resources to make trivial things that amuse us for a short period of time (ipod, iphone, etc)

      That's because we evolved from, and still are short-lived primates. Our brains were wired to deal with much more short-term issues. Planning through the coming weather change is about as far as we ever needed to go, mentally. Only some people have the wiring to do big picture stuff... and guess what: they tend to get jobs doing big picture stuff. As for trivial things like iPods: you'd rather have a society with somewhat better antibiotics, but completely absent all of the things that make life a pleasure? The iPod is just a newer take on cave painting and tribal dancing. The fact that we evolved into creatures that put handprints on walls and invent group songs to sing doesn't mean we can't also do things like invent solar cells, fly transplant organs through the air to another city where they're needed, or manage to live past 25. Being productive, inventive, and joyous are not mutually exclusive - they're interdependent.

      rather than doing useful things (cure diseases, etc).

      I'm sorry to hear that you died of Polio. Or was it Smallpox? Or maybe spoiled food because we haven't invented refridgeration yet. Anyway, sorry you died.
      • Re:Fermi paradox (Score:4, Insightful)

        by mcvos (645701) on Monday February 19 2007, @12:09PM (#18068542)

        I agree with this parent post. It's pretty silly to assume that "if spacefaring civilizations exist, they should have colonized the ENTIRE galaxy by now." What about evolution time? Time to develop technology? Time to establish colonies? etc etc etc...

        If another civilization was even dramatically ahead of ours with regards to technology, they could have started, what, 10,000 years ago? 20? Think that's enough time to colonize THE ENTIRE GALAXY??? Come on...

        Think 20 million years. Or 200. Or billions, even. 10,000 years is not being dramatically ahead, that's being barely older than we are.

        Consider the enormous timescale of evolution. Earth has existed for about 4.6 billion years. Compared to that, a few million years is nothing. What if the meteor that killed the dinosaurs had arrived a few million years earlier? Or later? Why did evolution take a billion years to get cells past the prokariotic stage? Could that have happened a few million years faster? Or is that step so unlikely that most planets never make it?

        Furthermore, consider the age of the universe. The universe is about 3 times as old as the earth. Why couldn't an earth-like planet have appeared 5 or 6 billion years ago? There are good reasons why such a planet can't have appeared 14 billion years ago, but what about 7? That'd give any civilisation arrising on that planet an immediate 2 billion year headstart on us.

        Is that enough to conquer the galaxy? If it isn't, nothing is.

      • Re:Fermi paradox (Score:5, Interesting)

        by Pedrito (94783) on Monday February 19 2007, @12:18PM (#18068678) Homepage
        I agree with this parent post. It's pretty silly to assume that "if space faring civilizations exist, they should have colonized the ENTIRE galaxy by now." What about evolution time? Time to develop technology? Time to establish colonies? etc etc etc.

        Actually, the Fermi Paradox takes all that into consideration. The time to colonize the galaxy, once a species has become space faring is minuscule in comparison to evolution. The paradox is based on the idea that the space faring civilization will colonize the galaxy before other species have a chance to evolve and the probability of two space faring civilizations existing at the same time is incredibly low.

        If another civilization were to have started colonizing the galaxy, it's unlikely it would have been in the time periods you point out, 10,000, 20,000 years ago. It's more likely they would have begun tens to hundreds of millions of years ago, and yes, that is enough time to colonize the entire galaxy.

        The Earth is believed to be about 4.6 billion years old. Life emerged in the first few hundred million years, probably around 4 billion years ago. Multicellular life sprung up around 1 billion years ago. Mammals have been around for about 200 million years. Homosapiens started out, probably around 200 million years ago. Now, let's say that instead of taking 3 billion years to go from single cell to multi-cell, it only took 2.5 billion years. That's a 500 million year head start. And there's no reason to think that's impossible. It's believed that the evolution of multi-cell was likely a fluke and not necessarily a forgone conclusion, largely because it took so long to show up. So that "fluke" could have probably happened any time after single-celled life began (well, any time after the first few hundred million years of it, at least).

        Also, intelligence isn't necessarily a forgone conclusion of evolution. Dinosaurs had a lot more time to evolve than we have and they never developed our kind of intelligence. So let's say an animal in the dinosaur period had developed intelligence. That was over 65 million years ago. Plenty of time to colonize the galaxy.

        The time to colonize the galaxy would, with only modest technological advancement from where we are now, would probably be a few million years. A very thin line on the timeline of evolution.
      • by ZachPruckowski (918562) <zachary.pruckowski@gmail.com> on Monday February 19 2007, @12:12PM (#18068588)
        For some reason, they don't take orders from somebody on Slashdot with a 900k+ user ID.

        Does that imply that there exists a person on Slashdot with a sufficiently low UID to give orders to NASA?
        • by DG (989) on Monday February 19 2007, @01:13PM (#18069534) Homepage Journal
          Slashdot Low User ID Operations Order 001

          1. SITUATION: the Fermi Paradox compels us to populate the Galaxy or become extinct.

          2. MISSION: NASA will design, test, build, staff, and deploy a fleet of interstellar colony ships for the purposes of populating the galaxy.

          3. EXECUTION: This mission will take place in 6 phases:

          a. Design a colony ship;

          b. Test the colony ship;

          c. Build a fleet of colony ships;

          d. Staff and populate the colony ships with suitable colonists;

          e. Deploy the fleet; and

          f. Monitor the colonies and provide support as appropriate.

          4. SERVICE SUPPORT

          a. Funding: no change.

          5. COMMAND AND SIGNALS: no change.

          There! Let's see if that works.

          DG
      • by Smallpond (221300) on Monday February 19 2007, @12:31PM (#18068894) Homepage Journal
        By far the most successful animal species on Earth is the ant. They have exactly the type of determination that you describe. Imagine a technologically advanced species with similar attitude - every individual has a pre-determined role supporting the species plan of conquering every available planet. As for revolts and warfare, there is plenty of war between different ants. Hasn't prevented them from becoming the dominant type, on the order of 1/4 - 1/3 of the total animal biomass.