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posted by janrinok on Monday March 03 2014, @01:30AM   Printer-friendly [Skip to comment(s)]
from the its-life-Jim-but-not-as-we-know-it dept.

AnonTechie writes:

"What If We Have Completely Misunderstood Our Place in the Universe ? A Harvard astronomer has a provocative hunch about what happened after the Big Bang. Our universe is about 13 billion years old, and for roughly 3.5 billion of those years, life has been wriggling all over our planet. But what was going on in the universe before that time ? It's possible that there was a period shortly after the Big Bang when the entire universe was teeming with life. Harvard astronomer Avi Loeb calls this period the 'habitable epoch,' and he believes that its existence changes how humans should understand our place in the cosmos. The full article is here"

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  • (Score: -1, Troll) by Anonymous Coward on Monday March 03 2014, @01:48AM

    by Anonymous Coward on Monday March 03 2014, @01:48AM (#9862)

    Thank you for being a friend
    Traveled down the road and back again
    Your heart is true, you're a pal and a cosmonaut.

    And if you threw a party
    Invited everyone you knew
    You would see the biggest gift would be from me
    And the card attached would say, thank you for being a friend.

  • (Score: 5, Insightful) by SuperCharlie on Monday March 03 2014, @01:58AM

    by SuperCharlie (2939) on Monday March 03 2014, @01:58AM (#9866)

    Most people never think about how we have only existed as humans for a blink of an eye in the universe's scale of time. Entire civilizations, planets, and even galaxies teeming with life could have come and gone well before we had our first steps. We tend to be a pretty self-absorbed lot.

    • (Score: 5, Interesting) by mcgrew on Monday March 03 2014, @02:28AM

      by mcgrew (701) <publish@mcgrewbooks.com> on Monday March 03 2014, @02:28AM (#9876) Homepage Journal

      This was a period when solid matter was an anomaly, before most of the elements on the periodic table existed.

      Hard to see how life could existed...

      --
      Free Martian whores! [mcgrewbooks.com]
      • (Score: 3, Interesting) by nking on Monday March 03 2014, @02:36AM

        by nking (1921) on Monday March 03 2014, @02:36AM (#9879)

        I was wondering about this too. He also gives an estimate of about 1 million years for these simple lifeforms (he suggests possibly algae) to evolve before having their planet's environment devastated by global change. Life on Earth took A LOT longer than 1 million years to develop into much of anything, let alone algae (even if life was seeded by asteroids, 1 millions years isn't very long to develop into anything).

      • (Score: 1) by sjames on Monday March 03 2014, @03:52AM

        by sjames (2882) on Monday March 03 2014, @03:52AM (#9894) Journal

        I had the same thought. It seems to me that the process that would produce carbon for life happened later. The bit about water was questionable as well.

      • (Score: 1) by bugamn on Monday March 03 2014, @02:15PM

        by bugamn (1017) on Monday March 03 2014, @02:15PM (#10040)

        Or maybe should we say, "Hard to see how life as we know it could exist"?

      • (Score: 1) by bill_mcgonigle on Tuesday March 04 2014, @04:29PM

        by bill_mcgonigle (1105) on Tuesday March 04 2014, @04:29PM (#10722)

        Hard to see how life could existed...

        Most complex life on Earth depends on iodine - atomic number 59 (as far as I know the highest essential element). Iodine didn't exist in the early universe. Based on the metallicity of stars [arxiv.org], we should be looking about two billions years before Earth to find the earliest life, of our type.

        That's still plenty of time to have many races of Ancients around.

    • (Score: 3, Informative) by evilviper on Monday March 03 2014, @09:44AM

      by evilviper (1760) on Monday March 03 2014, @09:44AM (#9964) Homepage Journal

      It's hard to imagine how intelligent life, like us, could ever be "gone". Even with a nuclear holocaust, thousands of people would crawl out of the ground, a century or so, later, and start out again. Even now, we're seemingly on the verge of colonization of other plants. How long until technology will allow reaching the nearest solar system within a human lifetime?

      If intelligent life has sprung up MILLIONS of times before now... WHERE ARE THEY? Why do our microwave antennas pick up cosmic bacground noise, but no intelligent signals? If they predate us by millions of years, then we should be seeing some signals from up to millions of light-years away. And why isn't there any intelligent life within 100+ light-years of us, who would be seeing our first powerful radio signals by now?

      Not that your premise is correct, though... I expect a large majority of people believe in life outside of earth, and intelligent life, too. Personally, I see overwhelming evidence against the theory. There could be life all over the place, but it seems none of them figured out how to make flashlights or radios... none of them figured out inter-planetary travel and industralization in general, or else they'd be around, and we'd see signs of life on every other solar system...

      --
      Hydrogen cyanide is a delicious and necessary part of the human diet.
      • (Score: 5, Insightful) by TheRaven on Monday March 03 2014, @12:51PM

        by TheRaven (270) on Monday March 03 2014, @12:51PM (#10010) Journal

        There is a difference between 'intelligent' and 'broadcasts RF signals that can be interpreted'. For most of the history of the human race, we've not been transmitting anything. It's possible that a post-nuclear-holocaust society wouldn't either. Even now, there's a trend towards less radiation. The quest for higher data rates involves higher frequency RF, which doesn't propagate as far.

        Contrary to popular SciFi depictions, there's actually very little that we've ever transmitted that would be distinguishable from noise beyond the termination shock. And that's not a matter of insufficiently advanced technology, it's a hard physical limit: if your signal produces less variation in the carrier than the background noise, you can't detect it.

        And there's no guarantee that a species will continue to use RF at all. They may use some other communication mechanism, based on quantum entanglement or some theory that we've not yet discovered, which is not possible to intercept. Being impossible to intercept or block also means it wouldn't interfere, so you'd be able to have a large number of point-to-point links in a single space. We're approaching this with multipath RF, which can easily appear to be noise to anyone who is not one of the endpoints. More complex encoding schemes, even on wavelengths that we can detect, appear even harder to distinguish from noise.

        You assumption isn't that no one outside of Earth figured out radio, it's that no one figured out anything more complex than pumping insane amounts of power through a spark-gap transmitter.

        --
        sudo mod me up
        • (Score: 3, Interesting) by mmcmonster on Monday March 03 2014, @02:10PM

          by mmcmonster (401) on Monday March 03 2014, @02:10PM (#10037)

          The other thought is that due to the rampant energy use current, post-cataclysmic event energy may not be nearly as freely available as it is now.

          How would society evolve now if 10,000 years ago the world's oil, rare earth elements, and easily reachable radioactive element supplies were used up creating a doomsday weapon?

          • (Score: 2) by evilviper on Tuesday March 04 2014, @01:06PM

            by evilviper (1760) on Tuesday March 04 2014, @01:06PM (#10584) Homepage Journal

            post-cataclysmic event energy may not be nearly as freely available as it is now.

            If we have enough sunlight that the planet is not in the worst ice age ever, we have LOTS of power. Mirrors + water + turbines + wire == lots of electricity. Without sunlight, wind power would do well, and keep us from freezing.

            Once you've figured out that whole theory of electromagnetics thing, (and SOMEBODY will remember), it's pretty damn easy to start over from there. Once you know what IS possible, and the basics of what's needed to get there, it doesn't take much effort to start again, and tackle the low-hanging fruit that will save profound amounts of labor right away.

            --
            Hydrogen cyanide is a delicious and necessary part of the human diet.
      • (Score: 4, Interesting) by Open4D on Monday March 03 2014, @02:10PM

        by Open4D (371) Subscriber Badge on Monday March 03 2014, @02:10PM (#10036) Journal

        It's hard to imagine how intelligent life, like us, could ever be "gone". Even with a nuclear holocaust, thousands of people would crawl out of the ground, a century or so, later, and start out again.

        Even accepting that, how successful would these people be, starting out again? My theory is that modern day humankind has been lucky; we had easy access to the raw materials (fertilizers, metals, etc.) and energy that we needed to build ourselves into this fairly advanced civilisation. Those easily accessible materials are gone now (or dispersed & contaminated) - but that's okay because our fairly advanced civilisation is able to do things like extract oil from deep-sea wells (normally) and carry out aeroplane & satellite geological surveys to find new places to mine for all our raw materials.

        But what if all that was lost? I think it would be so much harder for any future human society to boot itself up to our current 21st Century level, that I wouldn't be surprised if it just doesn't happen in the time available (i.e. while the planet remains habitable). It's one reason why we have to be careful not to risk the collapse of our current civilization. (We should make it sustainable, for starters.)

        So to bring it back on topic, I can easily imagine that alien cvilizations could have existed in the past and now be (effectively) gone.

        • (Score: 3, Insightful) by VLM on Monday March 03 2014, @03:08PM

          by VLM (445) Subscriber Badge on Monday March 03 2014, @03:08PM (#10066)

          Don't need worldwide nuke exchange, even a substantial financial impact could be exciting.

          The major domestic coal producers are all basically going bankrupt in the next decade for a bunch of financial and geological reasons. So bail them out for a little while, or just stop burning coal in the USA, or ... ?

          This is reminiscent of the "can't build a saturn V" meme. No, we can't, probably ever again. We might be able to build something bigger and more powerful and more modern, but rolling back the clock is hard.

        • (Score: 1) by SuperCharlie on Monday March 03 2014, @05:46PM

          by SuperCharlie (2939) on Monday March 03 2014, @05:46PM (#10134)

          So to bring it back on topic, I can easily imagine that alien cvilizations could have existed in the past and now be (effectively) gone.

          Im thinking more along the lines of a billion years or more being enough time for a sun to consume a planet, galaxies colliding, planets colliding, etc.. catastrophes on the scale of complete obliteration well before we climbed out of the ooze.

        • (Score: 3, Insightful) by etherscythe on Monday March 03 2014, @06:12PM

          by etherscythe (937) on Monday March 03 2014, @06:12PM (#10143) Journal

          Gun, Germs, and Steel [pbs.org] talked about this very kind of thing - particularly related to why (human) civilization took off in a technology sense in some places, but remains barely above subsistence farming in others. Without the critical availability of certain materials and time-saving techniques that allowed societies to develop specialization and economy of scale, modern chemistry, aerospace engineering, and the internet will never develop. You're back in pretty much the same place if these same resources are used up or destroyed in a major cataclysm.

          --
          "Fake News: anything reported outside of my own personally chosen echo chamber"
        • (Score: 2) by evilviper on Tuesday March 04 2014, @01:25PM

          by evilviper (1760) on Tuesday March 04 2014, @01:25PM (#10592) Homepage Journal

          Those easily accessible materials are gone now (or dispersed & contaminated)

          Iron is "the fourth most common element in the Earth's crust". Silicon (glass) is #2. And unlike aluminum, they're both easily extracted and processed into useful forms with the most primitive of technology (fire). With those two, alone, you could bootstrap electrical power generation in a few weeks, and be putting it to good labor-saving uses (pumping water, heating/cooling, transportation, etc.) in no-time. Iron (or steel) wires wouldn't be as efficient as copper (#26), but they'd still do the job well enough.

          Portable energy for transportation is trickier, but excess electricity can make hydrogen from water, or charge simple batteries. A couple lead plates, or nickel and iron, both in acid, and you've got rechargeable golf-cart batteries after the apocalypse.

          It's the technical knowledge we have now, that early humans lacked. And it's very hard to entirely get rid of such useful knowledge.

          --
          Hydrogen cyanide is a delicious and necessary part of the human diet.
      • (Score: 3, Informative) by Thexalon on Monday March 03 2014, @03:38PM

        by Thexalon (636) on Monday March 03 2014, @03:38PM (#10080)

        It's hard to imagine how intelligent life, like us, could ever be "gone".

        Oh, I can imagine lots of ways we could be done in as a species right now:
        - Out-of-control global warming turns Earth into Venus faster than we can adapt.
        - Large asteroid impact a la the dinosaurs 66 millions years ago.
        - Neutron star or other giant celestial object swats away the entire planet like it's a flea.
        - Yes, nuclear war. Remember, it's not just surviving the initial barrage of nukes (which are now powerful enough that your 60-year-old backyard bomb shelter won't help much), it's having enough supplies underground to manage several centuries with no ill effects, and then enough seeds and enough non-radiated soil and the right atmosphere to come up with food once you reach the surface.
        - Gray goo, as rampaging nanobots destroy everything in their path.
        - Skynet / Matrix, where rampaging sentient artificial intelligence tries to destroy all humans.
        - Virus or bacteria. While often there's enough diversity that at least a few members of a species will make it, sometimes there isn't.
        - Invasion by aliens. (you said "imagine")
        - A religion with an apocalypse story turns out to be right, and some sort of deity / deities kill us all. (Again, you said "imagine") Note that the Norse Ragnarok story does not qualify, since 2 people survive that one to repopulate the world after it's all over.

        You're severely lacking in imagination. I understand why you want to have faith in humanity, but you might be completely wrong.

        --
        The only thing that stops a bad guy with a compiler is a good guy with a compiler.
        • (Score: 2) by evilviper on Tuesday March 04 2014, @01:31PM

          by evilviper (1760) on Tuesday March 04 2014, @01:31PM (#10599) Homepage Journal

          - Out-of-control global warming turns Earth into Venus faster than we can adapt.

          So we survive under-ground. Not too hard. We have glass to allow limited light through for growing plants... solar power would still work, and wind-power would have one hell of a ROI.

          - Large asteroid impact a la the dinosaurs 66 millions years ago.

          Nope. Dinosaurs didn't know how to create bomb shelters, or manage the most basic forms of agriculture and teraforming (eg. shading or using green-houses for plants).

          - Neutron star or other giant celestial object swats away the entire planet like it's a flea.

          In the next couple centuries, I'd expect humanity will have self-sustaining colonies on Mars that would survive the loss of Earth.

          - Virus or bacteria. While often there's enough diversity that at least a few members of a species will make it, sometimes there isn't.

          There are extremely isolated pockets of humanity on earth.

          --
          Hydrogen cyanide is a delicious and necessary part of the human diet.
      • (Score: 3, Insightful) by VLM on Monday March 03 2014, @03:47PM

        by VLM (445) Subscriber Badge on Monday March 03 2014, @03:47PM (#10085)

        From an old telecom engineers perspective, if I'm trying to relay an old fashioned analog microwave carrier 75 miles there is no way my budget, both link budget and economic budget, will permit you to "accidentally" have the SNR margin to detect 10 million lightyears away. Even idiot humans, mere decades after the first radio broadcast, were already pretty good at running near the Shannon limit and optimizing links to darn near the dB. So assuming you'd hear anything other than a long term intentional interstellar broadcast seems a little irrational. Maybe an accident, or maybe something inadvertent like a MASER pumped ion drive which happened to be pointed at us. Maybe. But we are not going to monitor incidental telecoms-grade conversations. The engineering just doesn't work out for anything except some weird intentional stuff.

        Another interesting perspective is an intelligent species could have been sending us a continuous broadcast of rickrolls and goatse from the Andromeda galaxy for the last 2.3 million (or so) years and we're still not going to see them for another 100K (or so) years. Depending on exact geometry. Or "they" could have had a fad of broadcasting to us for 100K or so years, unfortunately 2.6 million years ago, and when their "momentary" fad ended, our ancestors were still working on that whole stone tool thing, so too bad.

        Finally the light cone is only about 14 billion years in radius but at least assuming earthly evolution there's not much to see for the first couple billion. Although the whole universe is at least 78 billion across. So there's an immense fraction of the universe we'll never see, at least using light propagated thru vacuum. Admittedly there's a heck of a lot in our light cone that we could theoretically be expected to see. This does put a bit of a damper on any theoretical warp drive cultures or even substantial sublight cultures as you'd expect a couple billion years would be enough to colonize a large plot of land, and a large plot of land Might result in strange overspill of interstellar comms channels.

        Or perhaps there's IS a perfectly good sublight galaxy wide civilization a mere billion lightyears away, and in a billion years we'll hear all about it.

        http://en.wikipedia.org/wiki/Observable_universe#M isconceptions [wikipedia.org]

        Now if you wanted to really F with an interstellar capable civilization, you'd dump weird things into the sun to create some truly bizarre stellar spectra. We would certainly notice that. That might not be terribly wise. Aside from being wise or not, unfortunately we haven't seen anything that weird.

        I'm forever optimistic that some gamma ray burst or quasar or whatever mystery of the month is just some advanced civilization trying to F with us by putting on a confusing show.

      • (Score: 1) by tangomargarine on Monday March 03 2014, @07:18PM

        by tangomargarine (667) on Monday March 03 2014, @07:18PM (#10164)

        Judging by politics and general human stupidity, they're probably better off staying away...

        --
        "Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
    • (Score: 3, Interesting) by TheLink on Monday March 03 2014, @02:32PM

      by TheLink (332) on Monday March 03 2014, @02:32PM (#10044) Journal
      I think that life is both special and not so special.

      Take consciousness for example. Many people don't seem surprised that they are even conscious at all, and take it for granted. But I find this consciousness thing one of the really weird and amazing things about this universe. If you use "Occam's Razor" isn't there no need for it? Think about it - couldn't you have machines like us, that behave the same manner we do but not experience this conscious phenomena we experience? Why this extra effect? I'm not talking about freewill or information processing self-awareness - I'm talking about the subjective experience of consciousness.

      Maybe you don't experience it but I KNOW that I do experience it for myself! It's one of the only things I can be sure of- everything else could be The Matrix. But I have faith that others do experience it too- I doubt I'd get any proof in my lifetime, but I don't think I am so special. I'm sure other people and many other animals experience this same thing I do.

      But why? Would any math and science in the world explain why we get this experience? Couldn't you build a self-aware robot/replicant/AI that didn't experience this consciousness? Or is there some law in this universe that requires that anything doing that would emergently or magically somehow be conscious? Or is everything in this universe conscious and just differ in their abilities and degree to express/experience stuff? Or does it require specific sort of computation/process - e.g. a quantum parallel simulator recursively simulating itself (which still won't explain stuff, but narrow down what is required)?

      A unique magic little snowflake like the zillions of other unique snowflakes, special and not so special - depending on how you choose to observe it... :)

      Or could a reason be because this universe would otherwise be a lie if we didn't have this consciousness but merely behaved as if we did? ;)
      • (Score: 1) by Woods on Monday March 03 2014, @04:16PM

        by Woods (2726) <woods12@gmail.com> on Monday March 03 2014, @04:16PM (#10097) Journal

        I really want to reply to this, but you managed to already say everything I think about the subject. Sorry I do not have any new input!

        I will say that I have pondered over this many times, but it occurs to me that I will never be able to postulate a reason as to my own consciousness, nor the consciousness of anyone else. Which sounds a lot like solipsism.

        Typically after I think on the subject for a bit, my brain kicks into self-protection mode and turns on my ADD before it begins to melt from any possible realized implications.

      • (Score: 1, Funny) by Anonymous Coward on Monday March 03 2014, @07:19PM

        by Anonymous Coward on Monday March 03 2014, @07:19PM (#10165)

        This is the kind of stuff that keeps me up at night.

        It's also the kind of stuff that I have completely figured out after I eat a handful of funny mushrooms. Unfortunately, all that hard won enlightenment is gone by morning.

  • (Score: 4, Funny) by regift_of_the_gods on Monday March 03 2014, @02:12AM

    by regift_of_the_gods (138) on Monday March 03 2014, @02:12AM (#9874)

    In a protogalaxy far, far away ---dept

  • (Score: 4, Insightful) by nking on Monday March 03 2014, @02:40AM

    by nking (1921) on Monday March 03 2014, @02:40AM (#9880)

    I'm reminded of the quote from Contact:

      "If just one in a million of those stars has planets, and if only one in a million of those has life, and if just one in a million of those has intelligent life, then there are millions of civilizations out there."

    It's an even more incredible idea if the element of time across the history of the universe is added on!

  • (Score: 5, Interesting) by Anonymous Coward on Monday March 03 2014, @03:12AM

    by Anonymous Coward on Monday March 03 2014, @03:12AM (#9884)
    My problem with this concept is that it discusses the 'habitable zone' in terms of temperature, but doesn't mention temperature gradient. TFA says:

    10 to 20 million years after the Big Bang, the universe was still bathed in that warm gas we saw in the CMB, but it had cooled down to a temperature that would keep water liquid no matter where it was relative to its star. The ambient temperature of the universe would provide enough heat to turn an ice giant like Neptune into a water giant. That's why Loeb has dubbed this era the "habitable epoch."

    So the idea is that the entire universe is, say, at ~5C. So there will be a wide band around a given star where the temperature will be suitable for liquid water. So far so good. However, one of the reasons that life exists on Earth is not just the average temperature, but also the temperature gradient. Life is sometimes called 'counter entropic': life represents the formation of order, which seems to contradict thermodynamics, which says entropy must increase. Of course, what's really going on is that the Earth is not a closed system: the sun is pumping energy into the Earth. So even though the entropy of the Earth is decreasing, the entropy of the solar system is still massively increasing as the Sun radiates.

    Another way to think about this is that life is exploiting the local gradient in temperature/energy to actually exist. All of the energy-harvesting organisms on Earth (algae, plants, etc.) are in some way capitalizing on the energy gradient established by the Sun.

    In the limit of having a zero temperature gradient, a system is at equilibrium. You can't extract energy from a system at equilibrium (that would violate thermodynamics, allow for perpetual motion machines, etc.). In this 'habitable epoch' concept, since the background temperature of the universe is so high, the local temperature gradient on any world with liquid water is going to be very small. In other words, such worlds will seem to be in a nearly equilibrium state, which is not favorable for the emergence of complexity.

    In principle, such worlds could have various local temperature gradients (radioactive cooling of the core, day/night cycle of heating, etc.). And perhaps overall this ends up being more favorable for life (because you have so much liquid water, so your probability of life emerging is greater). But I'm still skeptical; I would love to see a more detailed analysis that addresses this issue.

    • (Score: 1, Insightful) by Anonymous Coward on Monday March 03 2014, @03:24AM

      by Anonymous Coward on Monday March 03 2014, @03:24AM (#9887)

      since the background temperature of the universe is so high, the local temperature gradient on any world with liquid water is going to be very small.

      That is only true if the world is floating around in the uniform, high background temperature, but you're never anywhere close to an equilibrium state as you mentioned two paragraphs above. You have a nice, hot star pumping energy into the system.

      • (Score: 2, Insightful) by Anonymous Coward on Monday March 03 2014, @04:09AM

        by Anonymous Coward on Monday March 03 2014, @04:09AM (#9898)
        Yes, but with a high background temperature the available gradients will be smaller ("close to equilibrium"...). That's not favorable for the formation of life...
  • (Score: 4, Interesting) by AsteroidMining on Monday March 03 2014, @03:56AM

    by AsteroidMining (3556) on Monday March 03 2014, @03:56AM (#9896)

    I do not know about the very early universe, but our galaxy started with the Galactic Bulge, which went through a period of star formation about 11 billion years ago, including the formation of high-metallicity stars (and, thus, presumably, planetary systems like ours).

    Any civilizations formed in the bulge would presumably be at least 6 billion years old now, spread throughout the galaxy, and be used to conversations taking thousands of years to get anywhere. They may come calling in 5000 or 10,000 years or so.

  • (Score: 3, Informative) by Ryuugami on Monday March 03 2014, @07:53AM

    by Ryuugami (2925) on Monday March 03 2014, @07:53AM (#9944)

    For an interesting, hard-science-fictional take on this idea, check Stephen Baxter's Xeelee Sequence series of novels. I forget the exact book that had all the details spelled out (maybe another Soylentil will chip in), but I think it was titled "Timelike Infinity" or some such.

    Essentially, the idea presented in the book is that the lower the energy level, the slower the life gets. All the way from a few instants after big bang (high-energy, high-speed quark-based life, think nanoseconds as hours or so) to trillions of years in the future (quantum-fluctuation [or something like that] based life warming up around evaporating black holes, a single thought takes thousands of years). For each energy epoch, the one before it seemed to be too hot to support life, and the one after it was considered as a heat death of the universe.

    I don't know how realistic that is, but it's an interesting concept to ponder about when talking about abundance of life in the universe, both in time and in space.

    --
    If a shit storm's on the horizon, it's good to know far enough ahead you can at least bring along an umbrella. - D.Weber
    • (Score: 1) by WillAdams on Monday March 03 2014, @12:01PM

      by WillAdams (1424) on Monday March 03 2014, @12:01PM (#9996)

      Hal Clement had a couple of stories which used this conceit as well --- unfortunately it's a spoiler to name them, but that's okay, all of his stuff is well-worth reading in a classic retro atomic rockets and chemicals kind-of-way.

    • (Score: 2, Informative) by AsteroidMining on Monday March 03 2014, @03:32PM

      by AsteroidMining (3556) on Monday March 03 2014, @03:32PM (#10075)

      The essential scientific paper on this is "Time without end: Physics and biology in an open universe" by Freeman Dyson [harvard.edu] - alas, all I have is a paper copy. This, later, discussion [astrobites.org] between Dyson and Avi Loeb is also very interesting.

    • (Score: 1) by Woods on Monday March 03 2014, @04:31PM

      by Woods (2726) <woods12@gmail.com> on Monday March 03 2014, @04:31PM (#10103) Journal

      "Essentially, the idea presented in the book is that the lower the energy level, the slower the life gets. All the way from a few instants after big bang (high-energy, high-speed quark-based life, think nanoseconds as hours or so) to trillions of years in the future (quantum-fluctuation [or something like that] based life warming up around evaporating black holes, a single thought takes thousands of years). For each energy epoch, the one before it seemed to be too hot to support life, and the one after it was considered as a heat death of the universe."

      Now THAT is an interesting thought. Wish I could mod up AND post a comment at the same time, but I already commented above. :(

      Humans seem to be stuck on the thought that life must be similar to what we know. Carbon based, in the "Habitable zone", humanoid, etc... When really, we have no idea what it could be, or look like, or even how it interacts with the Universe. What if the intelligent life out there has no sense of sight, but instead uses heat to "see"? i.e. thermal vision. And what if the requirements for this species to live is that they be as far as possible from their star?

      I am sure there have been thousands of books on the subject, but none immediately come to mind, only Star Trek episodes.

  • (Score: 2, Informative) by bitshifter on Monday March 03 2014, @07:55AM

    by bitshifter (2241) on Monday March 03 2014, @07:55AM (#9945)

    Did they go the way of the Dodo?

    "The apparent size and age of the universe suggest that many technologically advanced extraterrestrial civilizations ought to exist.
    However, this hypothesis seems inconsistent with the lack of observational evidence to support it." - from https://en.wikipedia.org/wiki/Fermi_paradox [wikipedia.org]

    • (Score: 5, Insightful) by AsteroidMining on Monday March 03 2014, @03:06PM

      by AsteroidMining (3556) on Monday March 03 2014, @03:06PM (#10064)

      I do not regard such statements as at all conclusive. If you want a counterexample, there is the 511 keV gamma ray line coming from the Galactic bulge (a clear signature, indeed the only clear signature, of matter-antimatter annihilation, which could imply a large scale use of either antimatter or non-stellar hydrogen fusion). This line has no generally accepted astrophysical explanation; if you assume that it is the leakage from power generation from an advanced civilization, you get a Kardashev number of about 2.7, i.e., a close to K III civilization.

      There is no shortage of other astrophysical oddities that could be a signature of some large scale civilization, but such explanations are rarely considered (yes, I really need to write this one up). I thus consider statements (as in that wikipedia article) as basically circular reasoning (as intelligent life is generally not considered to be a possible solution for puzzles in astrophysics, to say that puzzles in astrophysics do not reveal signs of intelligent life is just to confirm the initial bias, not to add more information). There is also the issue that it seems dangerous to rely on a specific hypothesis for what the signature of a truly advanced civilization would be (if, for example, they make massive use of either hydrogen fusion or antimatter, they do not need to build Dyson spheres). I prefer to assume that

      "any sufficiently advanced civilization is indistinguishable from astrophysics"

      and see where that leads. That line of reasoning, far from being ruled out, has hardly been touched.

      • (Score: 1) by bitshifter on Monday March 03 2014, @03:26PM

        by bitshifter (2241) on Monday March 03 2014, @03:26PM (#10070)

        I find your response very interesting.
        I agree that we may simply not recognize evidence of other civilizations.

        I did not mean to sound conclusive.
        I quoted this since the question seems appropriate - if there have been countless civilizations before, where have they disappeared?
        Or, as you say, they are there, just ignorant/unaware/not interested of us, or maybe just stuck at a technological level that does not allow space travel.

        Thanks for the interesting response.
        I wish I could mod you up.

        • (Score: 3, Interesting) by AsteroidMining on Monday March 03 2014, @03:52PM

          by AsteroidMining (3556) on Monday March 03 2014, @03:52PM (#10087)

          Or, as you say, they are there, just ignorant/unaware/not interested of us, or maybe just stuck at a technological level that does not allow space travel.

          If there is any galactic civilization (bulge or disk) that is order 5 - 6 billion years old, it would be reasonable to assume that they have knowledge of every star in its galaxy, with its planets and their biological potential (as that information would take a small fraction of billion years to acquire). My suspicion is that waiting 10,000 years or so (which is next-to-nothing to a multibillion year old civilization) to contact new-comers would help weed out the "flash-in-the-pans," and save wasted effort. Given that our civilization is all of 5000 years old, that may give us still a little while to wait. Under this hypothesis, there is presumably some sort of alien monitor here in the solar system, which we might be able to find, as in Arthur Clarke's "The Sentinel" and (of course) "2001," although that may be hard or even beyond our abilities, as it may not want to be found.

          • (Score: 1) by bitshifter on Monday March 03 2014, @04:01PM

            by bitshifter (2241) on Monday March 03 2014, @04:01PM (#10092)

            Well, if you follow the line of "Sentinel" (and "2001", of course), then this "monitor" will be made hard to find on purpose, as you say, to ensure that the finder is worthy :)
            On the other hand, there is now a bubble of radio transmissions with a radius of 100 light years, surrounding the solar system, and growing.
            Somebody is bound to notice, sooner or later.

            • (Score: 3, Interesting) by AsteroidMining on Monday March 03 2014, @04:20PM

              by AsteroidMining (3556) on Monday March 03 2014, @04:20PM (#10098)

              Yes.

              As for "hard to find," consider trying to find something like this - a probe made of condensed quark matter placed at the center of the Earth, looking for signs of neutrino production from nuclear power (we now generate lots) and communicating back to HQ by beamed neutrinos (condensed quark matter is basically opaque to neutrinos, and so would make neutrino communication possible). And, that is just something I can come up with. I would expect a multi-billion year old civilization to do substantially better.

              • (Score: 1) by Woods on Monday March 03 2014, @05:16PM

                by Woods (2726) <woods12@gmail.com> on Monday March 03 2014, @05:16PM (#10120) Journal

                Communication via neutrino emission, how very clever. Apparently, some American scientists have already started on this, and have successfully sent a short message "Neutrino" through 237 meters (2.2 football fields) of bedrock.

                Though, the method requires a particle accelerator, and a massive detector, I am sure eventually we will figure out how to get it whittled down to something much more manageable.

              • (Score: 1) by bitshifter on Monday March 03 2014, @05:26PM

                by bitshifter (2241) on Monday March 03 2014, @05:26PM (#10123)

                OK. So assuming that assuming neutrinos travel at the speed of light, the bubble of neutrinos has a radius of 69 light years, from the time of the the first atomic tests...

          • (Score: 2) by Grishnakh on Monday March 03 2014, @05:39PM

            by Grishnakh (2831) on Monday March 03 2014, @05:39PM (#10131)

            5000 years? Last I heard, we humans started using agriculture around 8000 years ago.

            Why wait a specific length of time anyway? Different civilizations will develop at different rates, surely. The Star Trek concept of waiting until a civilization develops warp drive seems to be a pretty good marker for "ready for first contact". (Of course, we don't know if warp drive is even possible, so maybe the ETs look for some other marker that we don't even know about because we haven't invented it yet.)

            It's too bad that our civilization is most likely one of those "flash in the pan" types you mention, and seems to be regressing rather than progressing. Just look at Windows 8 for proof.

            • (Score: 1) by AsteroidMining on Monday March 03 2014, @06:30PM

              by AsteroidMining (3556) on Monday March 03 2014, @06:30PM (#10147)

              Why wait a specific length of time anyway?

              Well, the entities interested in new civilization anthropology (or whatever bin it falls under) might be, say, in the galactic bulge, or 15,000 light years away. Or they might be "merely" a few 1000 light years away. We have no way of knowing.

              It seems to me that one crucial question here is whether the speed of light is a true limit. If so, a galactic civilization will move slowly. No matter how fine the wheels grind, no matter where they are, they will grind exceedingly slow.

              Conversely, if c is not a barrier, they presumably know all about us, and are waiting their time for their own reasons. (They, of course, would have experience in these matters, about things like when would be a good time to intervene, etc.) Either way, 5000 or 8000, that number of years is just not likely to seem like a significant delay to a billion+ year old galactic civilization.

              In consequence, I do not see how a delay in contact since the founding of our civilization (however that is defined) is any sort of proof of the non-existance of a multi-billion year galactic civilization.

              • (Score: 2) by Grishnakh on Monday March 03 2014, @06:50PM

                by Grishnakh (2831) on Monday March 03 2014, @06:50PM (#10155)

                It seems to me that one crucial question here is whether the speed of light is a true limit. If so, a galactic civilization will move slowly. No matter how fine the wheels grind, no matter where they are, they will grind exceedingly slow.

                I'm not so sure about this. It seems to me that if it is a true limit, there simply can't be a such thing as an galactic (or worse, intergalactic) civilization. You could have a civilization that spawns many colonies, but a "civilization" implies that all parts of that society are able to communicate, and thus function more-or-less as one. For instance, suppose that we humans built a big generation ship and sent a bunch of people out to Alpha Centauri to start a colony. We can exchange little bits of information from them, which is years old by the time it gets to either side, but we're really now two separate civilizations, not one. Instead of Alpha Centauri, make it a one-way wormhole to the Delta Quadrant; we could still communicate with them (maybe), but the latency will be so ridiculously long that we effectively have no contact. We're no longer a single civilization.

                I think the only way you can call yourself a "civilization" is if you have communications with reasonable speed; the slower they are, the more the whole "civilization" idea breaks down.

                In consequence, I do not see how a delay in contact since the founding of our civilization (however that is defined) is any sort of proof of the non-existance of a multi-billion year galactic civilization.

                Well of course. I was just quibbling about the age of our civilization. They probably have a Prime Directive. It doesn't take a genius to figure out the problems inherent in contacting primitive goat-herders and showing them advanced technology.

                • (Score: 2, Interesting) by AsteroidMining on Monday March 03 2014, @07:05PM

                  by AsteroidMining (3556) on Monday March 03 2014, @07:05PM (#10158)

                  I assume that a very long lived civilization will also contain very long lived entities. Suppose they have a lifespan of 10^9 years, then spending 100,000 years to get somewhere and come back is comparable to one of us spending 3 days on a trip to LA. The British had a global empire (tougher to do than a civilization) at a time when travel times were months (yes, they lost the US part of it, but kept the rest, at least until communications sped up) and, of course, many civilizations (such as the Chinese) certainly existed at a time when the vast majority of their inhabitants never left their home village.

                  • (Score: 2) by Grishnakh on Monday March 03 2014, @07:38PM

                    by Grishnakh (2831) on Monday March 03 2014, @07:38PM (#10176)

                    Yes, I suppose the ultra-long lifespan thing would make it more feasible. I guess it's pretty hard to think about in human terms, because the idea of waiting even 100 years for a response to a query seems pretty ridiculous even if we had 200+-year lifespans, just because of the speed of our thinking. But remember, it's not just lifespans, it's the speed at which your daily events take place: when the British had to deal with the American colonies declaring independence, travel time was probably only a couple of weeks. It's not like King George had to wait years or decades to learn enough information to decide whether to send troops or not; he had his answer in a month or two. It's still a long time, but not so long you've moved on to other matters and lost interest in the issue.

    • (Score: 3, Funny) by Grishnakh on Monday March 03 2014, @05:31PM

      by Grishnakh (2831) on Monday March 03 2014, @05:31PM (#10128)

      Have you forgotten about all the UFO sightings, and the incident in Roswell? They've been visiting us and observing us.

      However, have you noticed that no one claims to have seen a UFO in recent years, or have been abducted? There was a big rash of that activity in the mid-to-late 20th century, and then if fizzled out.

      The answer is simple: the aliens came and observed us, and decided after a while that we're a bunch of assholes not worth their time. So they've left, and likely posted beacons outside our solar system warning other interstellar travelers to avoid us.

  • (Score: 1) by Boxzy on Monday March 03 2014, @10:30PM

    by Boxzy (742) on Monday March 03 2014, @10:30PM (#10289) Journal

    allows lots of things many other planets 'atmospheres' do not. Water planets would find it difficult to support any kind of industry, chlorine atmospheres would find it difficult to support electronics, there are many combinations that would support intelligent life whose inhabitants would find radio signals an extreme challenge.

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