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Habitable exoplanets are bad news for humanity

Last week, scientists announced the discovery of Kepler-186f, a planet 492 light years away in the Cygnus constellation. Kepler-186f is special because it marks the first planet almost exactly the same…

Let’s hope it’s barren. NASA Ames/SETI Institute/JPL-CalTech, CC BY

Last week, scientists announced the discovery of Kepler-186f, a planet 492 light years away in the Cygnus constellation. Kepler-186f is special because it marks the first planet almost exactly the same size as Earth orbiting in the “habitable zone” – the distance from a star in which we might expect liquid water, and perhaps life.

What did not make the news, however, is that this discovery also slightly increases how much credence we give to the possibility of near-term human extinction. This is because of a concept known as the Great Filter.

The Great Filter is an argument that attempts to resolve the Fermi Paradox: why have we not found aliens, despite the existence of hundreds of billions of solar systems in our galactic neighbourhood in which life might evolve? As the namesake physicist Enrico Fermi noted, it seems rather extraordinary that not a single extraterrestrial signal or engineering project has been detected (UFO conspiracy theorists notwithstanding).

This apparent absence of thriving extraterrestrial civilisations suggests that at least one of the steps from humble planet to interstellar civilisation is exceedingly unlikely. The absence could be caused because either intelligent life is extremely rare or intelligent life has a tendency to go extinct. This bottleneck for the emergence of alien civilisations from any one of the many billions of planets is referred to as the Great Filter.

Are we alone?

What exactly is causing this bottleneck has been the subject of debate for more than 50 years. Explanations could include a paucity of Earth-like planets or self-replicating molecules. Other possibilities could be an improbable jump from simple prokaryotic life (cells without specialised parts) to more complex eukaryotic life – after all, this transition took well over a billion years on Earth.

Proponents of this “Rare Earth” hypothesis also argue that the evolution of complex life requires an exceedingly large number of perfect conditions. In addition to Earth being in the habitable zone of the sun, our star must be far enough away from the galactic centre to avoid destructive radiation, our gas giants must be massive enough to sweep asteroids from Earth’s trajectory, and our unusually large moon stabilises the axial tilt that gives us different seasons.

These are just a few prerequisites for complex life. The emergence of symbolic language, tools and intelligence could require other such “perfect conditions” as well.

Or is the filter ahead of us?

While emergence of intelligent life could be rare, the silence could also be the result of intelligent life emerging frequently but subsequently failing to survive for long. Might every sufficiently advanced civilisation stumble across a suicidal technology or unsustainable trajectory? We know that a Great Filter prevents the emergence of prosperous interstellar civilisations, but we don’t know whether or not it lies in humanity’s past or awaits us in the future.

For 200,000 years humanity has survived supervolcanoes, asteroid impacts, and naturally occurring pandemics. But our track record of survival is limited to just a few decades in the presence of nuclear weaponry. And we have no track record at all of surviving many of the radically novel technologies that are likely to arrive this century.

Esteemed scientists such as Astronomer Royal Martin Rees at the Cambridge Centre for the Study of Existential Risk point to advances in biotechnology as being potentially catastrophic. Others such as Stephen Hawking, Max Tegmark and Stuart Russell, also with the Cambridge Centre, have expressed serious concern about the exotic but understudied possibility of machine superintelligence.

Let’s hope Kepler-186f is barren

When the Fermi Paradox was initially proposed, it was thought that planets themselves were rare. Since then, however, the tools of astronomy have revealed the existence of hundreds of exoplanets. That just seems to be the tip of the iceberg.

But each new discovery of an Earth-like planet in the habitable zone, such as Kepler-186f, makes it less plausible that there are simply no planets aside from Earth that might support life. The Great Filter is thus more likely to be lurking in the path between habitable planet and flourishing civilisation.

If Kepler-186f is teeming with intelligent life, then that would be really bad news for humanity. For that fact would push back the Great Filter’s position further into the technological stages of a civilisation’s development. We might then expect that catastrophe awaits both our extraterrestrial companions and ourselves.

In the case of Kepler-186f, we still have many reasons to think intelligent life might not emerge. The atmosphere might be too thin to prevent freezing, or the planet might be tidally locked, causing a relatively static environment. Discovery of these hostile conditions should be cause for celebration. As philosopher Nick Bostrom once said:

The silence of the night sky is golden … in the search for extraterrestrial life, no news is good news. It promises a potentially great future for humanity.

Join the conversation

64 Comments sorted by

  1. Steven Crook

    Programmer and software designer at Currently resting

    I'm not that pessimistic. If that planet has intelligent life and they're roughly at the same level of development as us, we've still got a long wait for radio signals to reach us.

    The Drake equation is cause for optimism IMO. There are plenty of planets out there some may be a long way away, but the idea that there's not intelligent life elsewhere in the galaxy seems implausible given the number of stars and the planets orbiting them.

    The idea that life (intelligent or otherwise) is a rare or non-existent thing in the galaxy appears to be rooted in the creationist assumption that we're special in some way.

    If there's dark matter and dark energy, is there perhaps also dark life? These are interesting times, and in a good way...

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    1. airbag moments

      logged in via Twitter

      In reply to Steven Crook

      I think there's intelligent life all over the place. But it's either self-annihilating or too far away to matter due to light speed limitations.

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    2. Steven Crook

      Programmer and software designer at Currently resting

      In reply to airbag moments

      I think that the most depressing part of the Fermi paradox is that, probably, it's telling us that the speed of light is a hard limit.

      So it's generation ships or nothing...

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    3. Hannibal Lamb

      logged in via Facebook

      In reply to Steven Crook

      I agree with Dr. Kaku and his theory of species transference from one level to the next. Type 1, 2, 3. Transference from type 0 to type 1 is dangerous. Its like a teenager becoming an adult. Its stressful for us to find our place, we rebel, and might make seriously bad choices that can ruin our lives before they begin. Same thing as a species. We use things like the hadron collider when we have no idea what it will really do. We have theories and carefully equated guesses as to what will happen but we have no real idea what it will do. Who is to say a young species tries and experiment in weather seeding and destroys themselves through droughts. Or goes to war with a unknown weapon and dies off.

      And as for the Drake equation i do agree with it as well. Scatter trillions of planets over the verse and sooner or later life is going to pop up. The question is what type. Intelligent? Moral?

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    4. Hannibal Lamb

      logged in via Facebook

      In reply to airbag moments

      I dont think they travel via light speed. Wormhole travel, or bending space/time is more likely. Or they could be neighbors in another dimension and have figured out how to simply "step over" to our side. Light speed is to limited as is our understanding of the universe and its mechanics.

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  2. Mark D. Roberts

    failure

    I think that the transition from inanimate matter to life is so unlikely that it is not worthwhile thinking about other life in our galaxy.

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    1. Steven Crook

      Programmer and software designer at Currently resting

      In reply to Mark D. Roberts

      But that's the whole point of the Drake equation. With hundreds of billions of stars to choose from intelligent life doesn't have to be very likely, and there's still be plenty of it.

      Of course we may never know about it because we're too far away. But even then, I think it's worthwhile knowing because it puts us and our planet in some sort of perspective.

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    2. Tim Benham

      Student of Statistics

      In reply to airbag moments

      > We know it happened at least once.

      So what? That is consistent with its happening exactly once.

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    3. Steve Griffin

      logged in via Facebook

      In reply to Mark D. Roberts

      If DNA is indeed formed in nebulae then "life" could be everywhere and seeded from such clouds. Does DNA, in and of itself, qualify as life? What ultimate form that DNA adopts depends deeply on the environment in which it finds itself so planets may not necessarily be the 1st choice for "life" to exist anyway. I suspect life gets a start on many worlds but survives only a fraction of them. The fact we, as a species, are about to allow a bunch of greedy money grubbers to destroy us, without so much as a fight, says it all.

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    4. Thomas Goodey

      Researcher

      In reply to Steve Griffin

      If... that's a very big "if". Who said that DNA was formed in nebulae?

      Stop dragging left-wing propaganda into discussions that are about something else entirely!

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    5. Steve Griffin

      logged in via Facebook

      In reply to Thomas Goodey

      With researchers like you who needs politicians?

      Re' DNA: Organic molecules have been detected in space so I don't see any reason not to surmise that DNA may originate there as well.

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    6. Thomas Goodey

      Researcher

      In reply to Steve Griffin

      We need politicians, for fear of something worse.

      The term "organic molecules" is a very wide one, and basically means any molecule including carbon that is not generally accepted by tradition as being inorganic (such as CO2). DNA is an extremely complicated substance, and while anyone is of course free to surmise that it is present in space, such speculations are very wild indeed, since there is no evidence whatever of such complex compounds floating about out there.

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    7. Hannibal Lamb

      logged in via Facebook

      In reply to Mark D. Roberts

      Thats kind of silly to say. If i flip coins all day, every day for years at a shot glass across a gymnasium sooner or later im going to put a coin right into the shot glass. Its simple odds. With an ever expanding universe sooner or later another species is going to pop up with intelligence.

      And the truth be told the Fermi Paradox is jumping to conclusions. For all we know were in the boondocks of the universe. A very new, by measure of the whole picture, of the universe. You have to look at us as a species. We have only been alive on this planet for a very very very short time. Basically our species was a human, we would still be a fetus in the last trimester. We have just begun going to other planets. Not including our moon which im sure for other species is just simple step away. We need to start looking at this from a more humble perspective, not the all knowing all seeing chosen species view point many have. We need to be calm. When we are ready, they will show up.

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  3. Stephen Pritchard

    Researcher, cognitive science

    I would argue that ants are not really aware of humans.

    Similarly, it could be that the residue of alien activity is all around us, but we are simply not intelligent enough to identify and comprehend it. After all, the universe is teeming with higgs-bosons, but we only just verified that they exist at all.

    For all we know, we might be analogous to neurons in an interstellar alien brain. Do neurons know about the brain that they comprise?

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    1. Steven Crook

      Programmer and software designer at Currently resting

      In reply to Stephen Pritchard

      Yup, there's a lot we don't know and the galaxy is huge. Perhaps we'll never know, but we made the first step and started looking...

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  4. Thomas Goodey

    Researcher

    The methodological thinking behind this article is sort of comical. I understand the thrust, but it doesn't amount to anything that should make us conclude that actual facts about the universe are "bad news" or "good news". They are just facts about the world.

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  5. Michael Thomas

    logged in via Facebook

    Fermi Paradox: This can be very bad news.
    It is also well within a possibility that no one wants to venture into.
    That a old civilization, possibility of being Millions of years old has ingrained in them by a Darwinian survival fear of other civilizations. In fact, to the point of Xenophobia. That to remain safe, destroy any civilization before a threat develops.
    Think about it. Some race in the distance past, ventures into deep space. They encounter another civilization, a war develops that leaves the surviving species nearly destroyed and the other extinct.
    How do you think this would effect the surviving species. It just might hard wire said race with a Darwinian Xenophobia. "KILL ANYTHING NOT US" might be their calling card.

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  6. Zoltán Sándor

    logged in via Facebook

    Attenborough said:
    "I think that we’ve stopped evolving. ... We stopped natural selection as soon as we started being able to rear 95–99 per cent of our babies that are born. We are the only species to have put a halt to natural selection, of its own free will, as it were. ... Stopping natural selection is not as important, or as depressing, as it might sound – because our evolutionary process is now cultural."
    Source: http://www.radiotimes.com/news/2013-09-09/david-attenborough-i-dont-ever-want-to-stop-work

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    1. Thomas Goodey

      Researcher

      In reply to Zoltán Sándor

      No, that is not true. Human physical evolution has not stopped. It may not be going the way you or I would like it to, but it has not stopped, because it can't. People of some heritable types reproduce more than people of other heritable types, so the former types will be selected for. This process cannot be avoided.

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    2. Thomas Goodey

      Researcher

      In reply to Zoltán Sándor

      Apart from being stupidly patronizing, your comment is too vague to be worth replying to, really... but anyway:

      The fact that we don't have a very high rate of infant mortality does not mean that evolution has stopped, because it can't stop. It means that death of children is no longer the prime driver of evolution, sure. But still, there are any number of reasons why Person A having genotype 1 will produce more descendants that in their turn reproduce, than Person B having genotype 2. This will…

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    3. Zoltán Sándor

      logged in via Facebook

      In reply to Thomas Goodey

      Wise researcher, yes, that's it evolution, when the natural selection works. But we cut it out (made by our technical civilisation and the medical sciences). Allways more the harmful mutation, than the favourable ones. The disadvantages remain (because the natural selection do not works). And the disadvantages expand (multiply) in the populations.
      You must learn some more, and You must think again.

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    4. Thomas Goodey

      Researcher

      In reply to Zoltán Sándor

      You don't understand the first principles. What I described is exactly how natural selection continues to work today. It would still work even if there were no child mortality at all. You speak of "harmful mutations", but if they survive they are, by very definition, good mutations. You say "the disadvantages expand (multiply) in the population", but no, if they do that, then by definition they are advantages, not disadvantages. Whatever multiplies in the population is a pro-survival mutation, obviously.

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    5. Zoltán Sándor

      logged in via Facebook

      In reply to Thomas Goodey

      What do You think - this is evolution or devolution?

      In Hungary, grows drastically the number of diabetic children. Between 1992 and 2012 the type 1 diabetes grew from 9 to 18 from among 100 thousand children.
      Source: http://www.origo.hu/egeszseg/20120405-naponta-7-magyar-cukorbeteget-amputalnak.html
      The censorship was inattentive! Usable data were published. Calculable, that all Hungarian children will be type 1 diabetes after ~ 250 years (if this rate remains constant). But this is only…

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    6. Thomas Goodey

      Researcher

      In reply to Zoltán Sándor

      Modern science does not recognize the concept of "devolution" as opposed to "evolution". It's all called "evolution". If the evolutionary disadvantages of diabetes are reduced or disappear, yes, hereditary diabetes will become more common in the population. This would be an example of evolution at work.

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    7. Thomas Goodey

      Researcher

      In reply to Zoltán Sándor

      Perhaps so - as a result of the process of evolution. The SA paper you quote itself says "From a biological perspective, there is no such thing as devolution. All changes in the gene frequencies of populations--and quite often in the traits those genes influence--are by definition evolutionary changes. "

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    8. Tim Benham

      Student of Statistics

      In reply to Zoltán Sándor

      > We stopped natural selection as soon as we started being able to rear 95–99 per cent of our babies that are born.

      Natural selection is about changes in gene frequencies, not the proportion of babies who are reared. Attenborough must think infant mortality is the only selection pressure. He is wrong.

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    9. Thomas Goodey

      Researcher

      In reply to Tim Benham

      Of course. Natural selection cannot be avoided, because certain inherited characteristics inevitably lead to some of the organisms in the population leaving more fertile descendants than others.

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    10. Zoltán Sándor

      logged in via Facebook

      In reply to Tim Benham

      Natural selection is not the changes in gene frequencies. You are wrong (mutations are the changes).

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    11. Zoltán Sándor

      logged in via Facebook

      In reply to Thomas Goodey

      Wrong. Really You must learn some more, and You must think again. We are not some of the organisms, we are humans and we have medical sciences. But the correction of the genetic mistakes yet only a distant aim. http://www.cell.com/trends/genetics/abstract/S0168-9525(12)00158-8
      "New developments in genetics, anthropology, and neurobiology predict that a very large number of genes underlie our intellectual and emotional abilities, making these abilities genetically surprisingly fragile."
      And our physical health also fragile.

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  7. Eric Blankenburg

    logged in via Facebook

    The Fermi Paradox is not a paradox at all.

    We live in the middle of nowhere. Our solar system is not in the center of the galaxy (where most of the stars are). It's not even in one of the three main spiral arms of the galaxy. We live in a spur off of one of the main arms.

    There are somewhere between 200 billion and 400 billion stars in our galaxy.

    We have only been broadcasting television for about 50 years. There are only 1,850 stars within 50 light years of earth. Radio signals will dissipate…

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    1. Thomas Goodey

      Researcher

      In reply to Eric Blankenburg

      In my opinion, if advanced civilizations communicate electromagnetically at all, they will do so with tight light-frequency beams, not long radio waves.

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    2. Tim Benham

      Student of Statistics

      In reply to Eric Blankenburg

      You seem to be missing much of the Fermi argument. It isn't just a lack of radio signals, it is a lack of anything. An alien intelligence many millions of years old would have had enough time to colonize the galaxy and put collector spheres around most of the stars.

      Maybe they all decide that isn't a good thing to do and they'll let all that energy go to waste. Another thing they could do is send a probe here. You assume that they would take no interest in Earth until they received our radio signals, but they have had plenty of time to construct telescopes that could image planets like Earth directly. Atmospheric oxygen, surface water, red edge, seasonal changes etc, pretty exciting exoplanet huh?

      > Even if someone did broadcast a signal directly at us, we would have to to be listening in the exact direction the signal came from, on the exact frequency they used

      I'm pretty sure radio receivers don't work on exact frequencies.

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    3. Steven Crook

      Programmer and software designer at Currently resting

      In reply to Tim Benham

      Lets take us as an example. We cannot travel to planets in our own solar system yet. How long will it be before we're in a position to build a ship capable of travelling to another solar system?

      The Fermi paradox only makes sense if its easy to get out and colonise the galaxy.

      What if that's the really really hard thing to do? So hard that, so far, no-one has done it.

      What if when a civilisation has advanced sufficiently far enough to get out of their solar system, they can only do it at speeds below light speed.

      What if when a civilisation has advanced sufficiently far enough to get out of their solar system they have lost the urge for colonisation/conquest and are content to explore and document?

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    4. Tim Benham

      Student of Statistics

      In reply to Steven Crook

      > We cannot travel to planets in our own solar system yet.

      We could if we wanted to. Probes have been sent to the vicinity of every planet in the solar system. If extravagant national vanity projects were still popular in the West then we would have landed a man on Mars by now.

      > What if that's the really really hard thing to do?

      Why would it be very hard to do? We have already sent artifacts beyond our solar system and we have had the capacity for inter-planetary flight for only about 50 years. Do you think the next 500 or 5,000 or 5,000,000 years of technological progress will not permit much greater feats? It is unlikely that the interstellar live export trade will ever be economically viable, but machines will soon be more capable than biological organisms.

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  8. Iam Strange

    logged in via Facebook

    Rather facetious approach to a very weighty issue. Let's hope that a planet doesn't have life because one interpretation of one hypothesis implies that life on Earth is doomed. While the existence of life may not be unique, each variety of life surely would be. Believing that Earth (and humanity specifically) must adhere to some set rule of the Great Filter has the author shaking in his boots, yet who is to say we cannot overcome such problems? We've had radio communication for barely more than 100…

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    1. Mike Lane

      retired computer services manager (amongst lots of other things)

      In reply to Iam Strange

      "Being at the right time/distance/development to communicate is another."
      I agree with this. I suspect that throughout history mankind has thought of itself as being an "advanced civilisation". However, another, distant, civilisation has only to be, say, a couple of hundred years behind ours for the inhabitants to be unable to travel by steam power, let alone to worry whether there is life on another planet.
      However, if the inhabitants are a couple of hundred years ahead of us they may have discovered ways to suspend animation - and be on their way!

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  9. Mark Mahin

    logged in via Facebook

    I find this reasoning to be unconvincing. The so-called Great Filter could be many different factors, and none of them necessarily imply anything about the lifespan of our civilization. The most likely reason why "they" are not here is the extreme slowness of interstellar travel, and also the unlikelihood that extraterrestrials would be ultra-expansionist types who would want to "take over the galaxy" in any way similar to what we imagine (with our imperialistic mindsets). See my blog post below, entitled "No, Habitable Planets Are Not Bad News for Humanity."
    :
    http://futureandcosmos.blogspot.com/2014/04/no-habitable-planets-are-not-bad-news.html

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  10. Robert Walker

    logged in via Facebook

    There is another possibility. We might be the very first ET to evolve in our galaxy. That is unlikely if life evolved from scratch in our solar system. But there's one line of evidence, that suggests life might have evolved first about 10 billion years ago, and got transferred to our solar system probably during formation - maybe an exoplanet with life on it passed through our solar system during the formation of the planets or a bit later during the early heavy bombardment.

    If so, then it might…

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  11. Daniel Felix

    logged in via Facebook

    Two opposing perspectives:

    Equating intelligence with self-awareness and the ability to construct technological marvells may be shortsighted. Perhaps organisms such as microbes are the most 'intelligent' in the grand scheme of things as they have evolved into a niche that will allow them to exist far into the future.

    But then what of the finite life span of the sun and earth? Microbes have no solution for circumventing that hurdle. Humans with our technological solutions, however, are now able to launch rockets out beyond the solar system. Perhaps that is all we are good for: launching an ark of microbes into space as emissaries from earth, and awaiting our eventual extinction.

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  12. Florence Leroy

    logged in via Facebook

    What I always find very strange when hearing/reading people talking about alien life, and limiting also, is that we base our understanding of what life is on what we experience here on Earth. Oxygen? Methane? Water? " Perfect conditions"? What is 'life' could be developed that didn't need any of that? Ok, we have to start somewhere. On what we know now. But we see so many theories coming and going through the years. What we know now could be refuted tomorrow.
    Anyway. My point is maybe there is life already out there, but we are just not looking using the right criteria…

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  13. Cristian Chidesa

    logged in via Facebook

    So many Earth-Like planets in our galaxy and no sign of intelligent life detected yet by our radio telescopes. But when we remember the dangers, rare at our time scale but deadly real, which exist in our galaxy (asteroids, comets, neutron stars, supernovae, black holes, supermassive black holes, etc), we might envision the possibility that any advanced civilization would decide at some moment during its evolution to build its own artificial worlds, fully controllable and perfectly autonomous in cosmos…

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  14. Tim Benham

    Student of Statistics

    > The atmosphere might be too thin to prevent freezing

    Or its "atmosphere" might be over 1,000 bars of hydrogen and volatiles.

    > If Kepler-186f is teeming with intelligent life, then that would be really bad news for humanity.

    If Kepler-186f is teeming with intelligent life, the SETI people should all buy lottery tickets because their luck is certainly in. Actually I don't think you can draw that conclusion until you hear what they have to say. Perhaps they will preach the gospel of cosmic Juche and explain how they, like millions of other civilizations, have spent the last billion years in peaceful co-existence by following its principles of civilizational humility, self-reliance, independence and non-interference.

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  15. Mike Alexander

    logged in via Facebook

    I don't see the need for any filter. For he it seems unlikely that any advanced civilization would be interested in exploring other worlds for more than a relatively short period of time when they would visit a relatively small number of planets. Advanced civilizations could appear all the time, but unless there was one very nearby who just happened to occupy this window right *now*, we would never see *any* evidence of alien civilizations.

    As for why there is a window that seems obvious. Today…

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    1. Thomas Goodey

      Researcher

      In reply to Mike Alexander

      Having long ago abandoned all that once was physically human, of what interest would other beings like those we once were be?

      Well, to steal what they've got, I suppose. Soft targets!

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  16. Alan Kohn

    Retired

    Intelligent life is competitive and therefore self destructive.

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    1. Thomas Goodey

      Researcher

      In reply to Alan Kohn

      You could have left out the word "intelligent" there... All life is competitive and therefore self-destructive. But the self-destruction need not become terminal. It is essentially creative destruction.

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  17. Hannibal Lamb

    logged in via Facebook

    It could also be that civilizations dont broadcast their crap into space like humans. Technically our race is like the guy on the bus blasting his music on his phone full volume and yelling over it talking to his GF. Another theory is they are here already and since we are a fetal species yet to develop any defenses against far superior civilizations we have been "cut off" from a more bustling commonwealth of species. Putting us into a large government of superior races would be like putting a 3 year old on the play ground with rugby players. Gonna have a bad time. We would be exploited or worse.

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  18. Chris Fredlake

    Research Scientist

    How much consideration has anyone given to economics? It would seem to consume an inordinate amount of a civilizations resources to achieve routine interplanetary travel even within a solar system. What would be the return on that investment? To the extent we are willing to think that human civilization is typical, we evolve culturally to spend most of our national wealth on social safety nets and other social programs. We really don't spend much of our GDP on exploration of space because their is little to be gained economically. Why would that be different from most civilizations (other than some doomsday scenarios or the discovery of some free energy source)?

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    1. Thomas Goodey

      Researcher

      In reply to Chris Fredlake

      You are assuming that the cultural, technological, and economic circumstances of 2014 will persist throughout eternity and will hold for all races in the entire galaxy. How do you know that our future cultural evolution won't be in the direction of gassing all the unproductive poor people and devoting half our GNP to space travel for religious reasons? You have no idea what conditions will be like many centuries from now, even on Earth. And what about technological advances? By the way, energy isn't the problem; reaction is.

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  19. Andy Welch

    logged in via Facebook

    This has a history.
    My immediate reaction to this is that it is an infatuation.
    The history of anxiety and risk is the history of the modern world.
    Here we have astrophysicists - the best in their fields - unaware of the degree to which they are influenced by the prevailing negative currents in our culture. In the same way that Climate alarmists are unaware of the cultural history of doom scenarios, it is no more surprising that physicists aren't particularly socio-politically savvy. If I was reading…

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  20. Jaakko Vähänen

    logged in via Facebook

    Correct me if I'm wrong - and sorry if this has been brought up already, didn't have the patience to read all the comments - but: let's say we did find intelligent life on Kepler-186f. Wouldn't that prove that the whole Great Filter theory is a load of bull?

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  21. Albert Rogers

    logged in via Facebook

    I have an alternative explanation to the Fermi Paradox. If life essentially needs a planet with water, the dominant, most intelligent life form is probably like our cetaceans, and has no great interest in anything beyond its atmosphere. For all we know, dolphins and whales may have purely intellectual cultures needing no artifacts, and strongly associated with their dual ability to "see" things with their eyes or their sonar.

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