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Thread: One Fermi Paradox Explanation

  1. #31
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    Quote Originally Posted by Colin Robinson View Post
    A Bracewell probe, i.e. a probe designed to communicate with other civilisations, is an interesting concept... but apart from the cost of send out the probes, such a project would get the same objections as projects to send out radio messages. Some would argue that it isn't sensible to advertise our presence to beings whose intentions and capabilities are unknown to us...
    Unlike a direct line signal--it could announce its arrival after coming in from another direction. Looping around a more distant star.

  2. #32
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    Quote Originally Posted by swampyankee View Post
    c) they checkup on Earth every 20,000,000 years, and we're not due for another 19 million.
    Who is "they"?
    Are you assuming _all_ species in the galaxy agreed or conspired to avoid Earth for millions of years? Highly unlikely.
    I cant get 20 relatives on a family get together to agree on politics, much less colonizing other planets.

    Unless there is an alien kingdom or empire of millions of worlds ruled by an emperor who commanded all the planets to avoid Earth specifically, I dont see any alien Illuminati or
    Masonic lodge creating a quarentine around Earth.

  3. #33
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    A problem I see with the article is our Solar System which is the only observational evidence we have for a heating/cooling problem. From that one sample we may conclude that 1/3 of initially habitable planets stay habitable. It may be 1/2 since Venus is within our circumstellar habitable zone but a couple of estimates exclude Mars.
    The Fermi paradox as expressed in the Drake equation has "the fraction of planets with life that actually go on to develop intelligent life". The authors have a good idea that influences that fraction. How much is unknown rather than their "rarely" assumption leading to a tiny fraction because we have no evidence of alien life.

  4. #34
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    Quote Originally Posted by Gomar View Post
    Who is "they"?
    Are you assuming _all_ species in the galaxy agreed or conspired to avoid Earth for millions of years? Highly unlikely.
    I cant get 20 relatives on a family get together to agree on politics, much less colonizing other planets.

    Unless there is an alien kingdom or empire of millions of worlds ruled by an emperor who commanded all the planets to avoid Earth specifically, I dont see any alien Illuminati or
    Masonic lodge creating a quarentine around Earth.
    Or, just one alien society that doesn't check back very often. Not quarantined, just ignored.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright
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    ET doesn't want to go on double-secret probation...

  6. #36
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    Quote Originally Posted by Gomar View Post
    Who is "they"?
    Are you assuming _all_ species in the galaxy agreed or conspired to avoid Earth for millions of years? Highly unlikely.
    I cant get 20 relatives on a family get together to agree on politics, much less colonizing other planets.

    Unless there is an alien kingdom or empire of millions of worlds ruled by an emperor who commanded all the planets to avoid Earth specifically, I dont see any alien Illuminati or
    Masonic lodge creating a quarentine around Earth.
    If "all the species" amounts to one or less (besides us), then it is entirely possible.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright
    "It is the duty of the writers to seduce me into suspending my disbelief!" Paul Beardsley

  7. #37
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    Quote Originally Posted by Colin Robinson View Post
    One should really speak of the "Fermi-Hart paradox". Or the "Fermi-Hart question", if you think the word paradox is inappropriate. Fermi made a remark based on some quick calculations. Michael Hart published a paper in a journal about why the question should be taken seriously. The "assumptions" are basically two:

    1. Comparable forms of life are likely to appear on comparable planets.
    2. Interstellar colonisation will be feasible and attractive to our descendants.

    The point is not that we know these propositions to be true, but that they are plausible enough to consider what the consequences would be if they were true. In fact, Hart argues that they cannot both be true, since otherwise Earth would have been colonised already by beings comparable to humans, who evolved on a planet comparable to Earth, but (in geological terms) just slightly older.
    This is what most people miss about the Fermi conundrum (or, as you suggest, the Fermi-Hart question). The question isn't 'why haven't we made contact with them', it is, 'why aren't we them?' If a civilision had colonised the galaxy we already would be part of it. In ten million years I sincerely expect that the Milky Way Galaxy will be populated throughout by our mind-children; if this isn't on the cards, we really need to find out why - the answer might kill us.
    Last edited by eburacum45; 2017-Feb-13 at 09:57 PM.

  8. #38
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    1. Comparable forms of life are likely to appear on comparable planets.
    2. Interstellar colonisation will be feasible and attractive to our descendants.

    Hart argues that they cannot both be true, since otherwise Earth would have been colonised already by beings comparable to humans, who evolved on a planet comparable to Earth, but (in geological terms) just slightly older.
    Hart may be right, but who knows? I have no problem with both being true (aside from the "feasible" part). My own thoughts lead me to believe that finding other earth-like planets is quite likely, but moving humans there would expose them to the environmental hazards present that naturally evolve independently upon each E-L planet. These planets have evolved for billions of years, they are not "The" Earth, similar in many ways, just not similar enough to live unhindered imho. The sci-fi world does prefer their explorers to just land on or transport to a planet where no biohazard protection is worn in most all instances. I can't see that happening, we best take care of this earth like planet ;-)

  9. #39
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    Quote Originally Posted by eburacum45 View Post
    This is what most people miss about the Fermi conundrum (or, as you suggest, the Fermi-Hart question). The question isn't 'why haven't we made contact with them', it is, 'why aren't we them?' If a civilision had colonised the galaxy we already would be part of it. In ten million years I sincerely expect that the Milky Way Galaxy will be populated throughout by our mind-children; if this isn't on the cards, we really need to find out why - the answer might kill us.
    Is populating the entire galaxy in their nature? Is it a cultural or instinctive drive that would be maintained over millions of years? Could they have found alternatives? Do they share the same environmental needs as us, ensuring that they'd use our planet as their new home? Would they avoid an already life-bearing planet as a potential source of ecological contamination?
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright
    "It is the duty of the writers to seduce me into suspending my disbelief!" Paul Beardsley

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    If dinosaurs evolved intelligence, what would their society use for fossil fuels??

    Ahem. My apologies.... as to the matter at hand....

    I think people underestimate the *time* component of the Fermi Paradox. How long does an intelligent civilization exist? That answer is as much of an unknown as many of the other components of the equation. There could have been 100,000 intelligent civilizations in the history of the Milky Way each existing for 50,000 years and still the Milky Way would have no intelligent life for over half its existence. So maybe our planet was bombarded with alien radio waves off and on for the past 4 billion years (give or take) and we just happen to be living in an "off" period.

  11. #41
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    Quote Originally Posted by Red5 View Post
    If dinosaurs evolved intelligence, what would their society use for fossil fuels??

    Ahem. My apologies.... as to the matter at hand....

    I think people underestimate the *time* component of the Fermi Paradox. How long does an intelligent civilization exist? That answer is as much of an unknown as many of the other components of the equation. There could have been 100,000 intelligent civilizations in the history of the Milky Way each existing for 50,000 years and still the Milky Way would have no intelligent life for over half its existence.
    Yes, that's a valid point. Michael Hart's argument is based on the idea that once technology reaches a certain level it will enable a civilisation to continue (and expand) over geological time. Maybe that's not what happens. Maybe every development in technology brings not only new opportunities but also new dangers...

    So maybe our planet was bombarded with alien radio waves off and on for the past 4 billion years (give or take) and we just happen to be living in an "off" period.
    Last edited by Colin Robinson; 2017-Feb-14 at 08:30 PM.

  12. #42
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    This is worth discussing in some detail.
    Quote Originally Posted by Noclevername View Post
    Is populating the entire galaxy in their nature?
    An interesting question. If significant numbers of different civilisations have emerged over the last thirteen billion years, then there could be a wide range of different 'natures', natural behaviours, to chose from. I think it is more complex that that, though - a sufficiently advanced civilisation would have the capacity to direct, or change, its range of natural behaviours, and it is possible that all advanced civilisations (or maybe just all advanced expansive civilisations), will converge on a particular set of behaviours.

    Is it a cultural or instinctive drive that would be maintained over millions of years?
    I tend to think of it as a voluntarily adopted cultural goal - or possibly a programmed behaviour in post-biological entities. One advantage of establishing a widespread, or galaxy-wide, civilisation is that other potential rivals or enemies are subsumed or inhibited. Alternately, diversity could be a goal in itself.
    Could they have found alternatives?
    Given a large set of different civilisations over billions of years, some or may would- but would all of them?
    Do they share the same environmental needs as us, ensuring that they'd use our planet as their new home?
    An advanced galactic civilisation might be reasonably expected adapt themselves to a wide range of environments. A civilisation that was not adaptable in this way might be more dangerous- if they couldn't interact with our biology they might reasonably decide to inhibit it in some way.
    Would they avoid an already life-bearing planet as a potential source of ecological contamination?
    Or would they sterilise it?
    Even if they placed our world under quarantine millions, or billions, of years ago, would every faction in their civilisation agree to observe that quarantine forever?
    Last edited by eburacum45; 2017-Feb-14 at 10:36 PM.

  13. #43
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    Quote Originally Posted by eburacum45 View Post
    If significant numbers of different civilisations have emerged over the last thirteen billion years, then there could be a wide range of different 'natures', natural behaviours, to chose from. I think it is more complex that that, though - a sufficiently advanced civilisation would have the capacity to direct, or change, its range of natural behaviours, and it is possible that all advanced civilisations (or maybe just all advanced expansive civilisations), will converge on a particular set of behaviours.
    Interesting! (Significant numbers being a subjective term, of course.)

    I tend to think of it as a voluntarily adopted cultural goal - or possibly a programmed behaviour in post-biological entities. One advantage of establishing a widespread, or galaxy-wide, civilisation is that other potential rivals or enemies are subsumed or inhibited. Alternately, diversity could be a goal in itself.
    Possibly. I can't buy the "we might have enemies someday, maybe, somewhere" reasoning as a driver for Galactic colonization, as there are easier ways to prevent foes from arising. Berserker Von Neumanns, for example.

    Given a large set of different civilisations over billions of years, some or may would- but would all of them?
    Right. And how far would they expand before giving up/changing their goals/evolving away from expansion?

    An advanced galactic civilisation might be reasonably expected adapt themselves to a wide range of environments. A civilisation that was not adaptable in this way might be more dangerous- if they couldn't interact with our biology they might reasonably decide to inhibit it in some way.
    Or would they sterilise it?
    Maybe. Or, it might just not be worth the candle. They could have less use for planets altogether if they are frequent Galactic travelers.

    Even if they placed our world under quarantine millions, or billions, of years ago, would every faction in their civilisation agree to observe that quarantine forever?
    They might have enforced the quarantine by engineering themselves to have a strong instinctive avoidance factor for alien life or planetary settlement, for their own safety; they'd only be at home in places they'd made themselves, like termites in their mounds. If anyone suggested living on a planet, they'd all be like, "why would you want to do that?"
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright
    "It is the duty of the writers to seduce me into suspending my disbelief!" Paul Beardsley

  14. #44
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    Quote Originally Posted by eburacum45 View Post
    This is worth discussing in some detail.

    An interesting question. If significant numbers of different civilisations have emerged over the last thirteen billion years, then there could be a wide range of different 'natures', natural behaviours, to chose from. I think it is more complex that that, though - a sufficiently advanced civilisation would have the capacity to direct, or change, its range of natural behaviours, and it is possible that all advanced civilisations (or maybe just all advanced expansive civilisations), will converge on a particular set of behaviours.
    I agree that is conceivable. It would resemble convergent evolution, except that it would be happening at the level of cultural evolution. If so, what sort of behaviours would these civilisations converge on?

    I tend to think of it as a voluntarily adopted cultural goal - or possibly a programmed behaviour in post-biological entities. One advantage of establishing a widespread, or galaxy-wide, civilisation is that other potential rivals or enemies are subsumed or inhibited.
    One disadvantage of establishing colonies in a generation or two your colonists may become your enemies. I'm thinking about what happened to the Macedonian empire after the death of Alexander the Great...

    Alternately, diversity could be a goal in itself.
    Which could be a reason for minimising intervention in already-inhabited worlds...

    Given a large set of different civilisations over billions of years, some or may would- but would all of them?
    An advanced galactic civilisation might be reasonably expected adapt themselves to a wide range of environments. A civilisation that was not adaptable in this way might be more dangerous- if they couldn't interact with our biology they might reasonably decide to inhibit it in some way.
    Or would they sterilise it?
    Not if they valued diversity, presumably?

    Even if they placed our world under quarantine millions, or billions, of years ago, would every faction in their civilisation agree to observe that quarantine forever?
    If your earlier suggestion is true that advanced civilisations converge on a particular set of behaviours wouldn't that also imply a convergence of the behaviour of different factions within a civilisation?

  15. #45
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    Quote Originally Posted by Noclevername View Post
    So I can't see any viable purpose for spreading to the entire galaxy.
    Much as there was no viable purpose in coming down out of the trees, leaving Africa, or crossing the Bering Strait. Just as there is no viable purpose in climbing mount Everest, landing on the moon, or collecting stamps.

    It's what we do. It's who we are.

  16. #46
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    Quote Originally Posted by Eclogite View Post
    Much as there was no viable purpose in coming down out of the trees, leaving Africa, or crossing the Bering Strait. Just as there is no viable purpose in climbing mount Everest, landing on the moon, or collecting stamps.

    It's what we do. It's who we are.
    What WE do. WE are not the subject here.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright
    "It is the duty of the writers to seduce me into suspending my disbelief!" Paul Beardsley

  17. #47
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    Quote Originally Posted by Noclevername View Post
    What WE do. WE are not the subject here.
    Except that the Fermi-Hart argument makes a working assumption that other intelligent, technological species in the galaxy would be something like our own species, at least in the sense that they would have a powerful tendency to explore and expand...

    Quote Originally Posted by Eclogite View Post
    Much as there was no viable purpose in coming down out of the trees, leaving Africa, or crossing the Bering Strait. Just as there is no viable purpose in climbing mount Everest, landing on the moon, or collecting stamps.

    It's what we do. It's who we are.
    There are other things we humans also do, and have done throughout history. For instance, we fight each other a lot...

    The very technologies that make interstellar colonisation seem almost feasible — rockets and nuclear power — were born out of our most destructive war so far... The first rocket to leave Earth's atmosphere was the V2, and it wasn't on a mission to the Moon... Fermi is not remembered only for the "Fermi paradox", he also led the team that made the first atomic bombs...

    There are projected technologies, consistent with known laws of physics, which might make may interstellar colonisation a real possibility, e.g. nuclear pulse propulsion; or production and storage of anti-matter on such a scale that it could be used as fuel. BUT, either of these technologies would have obvious military applications too... To use them without destroying or devastating our own species, we as humans will have to change what we do, and perhaps who we are, in the sense that we'll have to become a lot less warlike, a lot less aggressive...

    If we did change in such a way, would we still have the same inclination to colonise new worlds?
    Last edited by Colin Robinson; 2017-Feb-15 at 08:52 AM.

  18. #48
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    Quote Originally Posted by Eclogite View Post
    Much as there was no viable purpose in coming down out of the trees, leaving Africa, or crossing the Bering Strait.
    There are in fact quite tangible purposes to those actions. Coming out of the trees was an evolutionary adaptation to a change in environment. The rest were the results of searches for resources.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright
    "It is the duty of the writers to seduce me into suspending my disbelief!" Paul Beardsley

  19. #49
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    Quote Originally Posted by Noclevername View Post
    What WE do. WE are not the subject here.
    Expansion into new territory is scarcely a solely human trait. A great many species are known to do this, when it is to their advantage to do so. Being such a widespread phenomenon in living things, it doesn't appear unreasonable that the drive to territorially expand should apply to many other forms of intelligent life in the universe.

    If preserving diversity of life were a goal of such beings, as it has begun to be with us, they could leave certain areas alone, within a general wave of expansion. If Earth is part of such a preserve, it could explain how a galactic-wide civilization could exist around us, without our being a part of it, or at least aware of its existence.

    Cultural and technical development seems to confer evolutionary advantages-- survival advantages -- why else would it have begun and persisted? A disease epidemic could have driven humans to extinction a couple of million years ago, confined as they were to a relatively small area, and lacking medical science or even an idea of how disease spread. Territorial expansion came first, and reduced this threat. Later came better and better understanding of disease and how to control it. Each innovation made extinction a more remote possibility.

    When travel became easier, so did the spread of disease, but with it came medical science, which worked to counter illness. The point is this-- as civilization advanced, every problem was accompanied by a potential solution. Looking ahead, when we have persisted as a civilization, long enough to encounter an asteroid with Earth's name on it, we'll have likely perfected the means of coping with the danger.

    Adaptation, as a means of securing survival advantage, is clearly generalized in living things, so, it seems, would intelligent adaptation, the essence of civilization, in other intelligent life in the universe.
    Last edited by Ross 54; 2017-Feb-15 at 05:39 PM.

  20. #50
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    Quote Originally Posted by Spacedude View Post
    CJSF, here is the meat as stated at the site ;

    Summary:
    "The universe is probably filled with habitable planets, so many scientists think it should be teeming with aliens. But life on other planets would likely be brief and become extinct very quickly, say astrobiologists. In research aiming to understand how life might develop, the scientists realized new life would commonly die out due to runaway heating or cooling on their fledgling planets."


    Well, according to recent claims our Earth has gone through "runaway heating or cooling" during it's long period (~ 4 billion years) of simple microbial life before more complex life evolved. This includes 2 snowball earth epochs as well as multiple periodic catastrophic disruptions. No doubt that most planets don't have ideal conditions as seen in our own solar system, but even if 0.001%* of planets do end up Earth-like then that's still plenty of them out there to allow intelligent beings to evolve.

    * a reasonable number pulled out of my...hat.
    And by the same token 99.9% of all species that have ever existed on Earth have gone extinct..... While common theory posits that becoming technologically advanced enables a species to prevent it's own extinction, there are a myriad of ways in which it can hasten, perhaps guarantee, the species demise. The toll civilization has upon the enviroment, from pollution to climate changes, War on a scale nature never intended, self created disasters, genetic tampering gone awry, depletion of natural resources (such as oil/gas for us) before more viable alternatives can be implemented ect.

  21. #51
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    Quote Originally Posted by Gomar View Post
    Who is "they"?
    Are you assuming _all_ species in the galaxy agreed or conspired to avoid Earth for millions of years? Highly unlikely.
    I cant get 20 relatives on a family get together to agree on politics, much less colonizing other planets.

    Unless there is an alien kingdom or empire of millions of worlds ruled by an emperor who commanded all the planets to avoid Earth specifically, I dont see any alien Illuminati or
    Masonic lodge creating a quarentine around Earth.
    No vast empire. Just one space traveling group, which just doesn't care very much. Travel is hard, expensive and the coach cabins are cramped. I

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