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Astrobiology and Sustainability

As the Thanksgiving holiday approaches here in the US, I’m looking at a new paper in the journal Anthropocene that calls the attention of those studying sustainability to the discipline of astrobiology. At work here is a long-term perspective on planetary life that takes into account what a robust technological society can do to affect it. Authors Woodruff Sullivan (University of Washington) and Adam Frank (University of Rochester) make the case that our era may not be the first time “…where the primary agent of causation is knowingly watching it all happen and pondering options for its own future.”

How so? The answer calls for a look at the Drake Equation, the well-known synthesis by Frank Drake of the factors that determine the number of intelligent civilizations in the galaxy. What exactly is the average lifetime of a technological civilization? 500 years? 50,000 years? Much depends upon the answer, for it helps us calculate the likelihood that other civilizations are out there, some of them perhaps making it through the challenges of adapting to technology and using it to spread into the cosmos. A high number would also imply that we too can make it through the tricky transition and hope for a future among the stars.

Sullivan and Frank believe that even if the chances of a technological society emerging are as few as one in 1000 trillion, there will still have been 1000 instances of such societies undergoing transitions like ours in “our local region of the cosmos.” The authors refer to extraterrestrial civilizations as Species with Energy-Intensive Technology (SWEIT) and discuss issues of sustainability that begin with planetary habitability and extend to mass extinctions and their relation to today’s Anthropocene epoch, as well as changes in atmospheric chemistry, comparing what we see today with previous eras of climate alteration, such as the so-called Great Oxidation Event, the dramatic increase in oxygen levels (by a factor of at least 104) that occurred some 2.4 billion years ago.

Out of this comes a suggested research program that models SWEIT evolution and the evolution of the planet on which it arises, using dynamical systems theory as a theoretical methodology. As with our own culture, these ‘trajectories’ (development paths) are tied to the interactions between the species and the planet on which it emerges. From the paper:

Each SWEIT’s history defines a trajectory in a multi-dimensional solution space with axes representing quantities such as energy consumption rates, population and planetary systems forcing from causes both “natural” and driven by the SWEIT itself. Using dynamical systems theory, these trajectories can be mathematically modeled in order to understand, on the astrobiology side, the histories and mean properties of the ensemble of SWEITs, as well as, on the sustainability science side, our own options today to achieve a viable and desirable future.

sustainability_1

Image: Schematic of two classes of trajectories in SWEIT solution space. Red line shows a trajectory representing population collapse. Blue line shows a trajectory representing sustainability. Credit: Michael Osadciw/University of Rochester.

The authors point out that other methodologies could also be called into play, in particular network theory, which may help illuminate the many routes that can lead to system failures. Using these modeling techniques could allow us to explore whether the atmospheric changes our own civilization is seeing are an expected outcome for technological societies based on the likely energy sources being used in the early era of technological development. Rapid changes to Earth systems are, the authors note, not a new phenomenon, but as far as we know, this is the first time where the primary agent of causation is watching it happen.

Sustainability emerges as a subset of the larger frame of habitability. Finding the best pathways forward involves the perspectives of astrobiology and planetary evolution, both of which imply planetary survival but no necessary survival for a particular species. Although we know of no extraterrestrial life forms at this time, this does not stop us from proceeding, because any civilization using energy to work with technology is also generating entropy, a fact that creates feedback effects on the habitability of the home planet that can be modeled.

sustainability2

Image: Plot of human population, total energy consumption and atmospheric CO2 concentration from 10,000 BCE to today as trajectory in SWEIT solution space. Note the coupled increase in all 3 quantities over the last century. Credit: Michael Osadciw/University of Rochester.

Modeling evolutionary paths may help us understand which of these are most likely to point to long-term survival. In this view, our current transition is a phase forced by the evolutionary route we have taken, demanding that we learn how a biosphere adapts once a species with an energy-intensive technology like ours emerges. The authors argue that this perspective “…allows the opportunities and crises occurring along the trajectory of human culture to be seen more broadly as, perhaps, critical junctures facing any species whose activity reaches significant level of feedback on its host planet (whether Earth or another planet).”

The paper is Frank and Sullivan, “Sustainability and the astrobiological perspective: Framing human futures in a planetary context,” Anthropocene Vol. 5 (March 2014), pp. 32-41 (full text). This news release from the University of Washington is helpful, as is this release from the University of Rochester.

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Comments on this entry are closed.

  • RobFlores November 26, 2014, 15:12

    As a commentary to the concept of sustainability I posit.
    Not everyone stands to gain or even wants to participate in the changes due to the advancement of technology. There are a lot of refuse niks out there
    and some have the technological know-how to do a lot of damage. This is my primary worry about the future, some very smart people with dystopian views of the place of humanity, ready to thin the herd dramatically for the
    benefit of “ALL” I agree that the industrialist is who pollutes too much is a blight on the planet, but the damage he causes is a by-product of his ambitions.
    The damage a renegade PHD, with the skills to retask organisms from the microbial-viral world would be much more lethal and direct, with a self-assured world view there is no limit to what he could justify.
    Is stopping this potential adversary part of the question sustainability too?

  • Alex Tolley November 26, 2014, 17:47

    From the paper’s discussion:

    Using dynamical systems theory, these trajectories can be mathematically modeled in order to understand, on the astrobiology side, the histories and mean properties of the ensemble of SWEITs, as well as, on the sustainability science side, our own options today to achieve a viable and desirable future.

    My guess is that this is about as fluffy as it gets. If we replace “dynanical systems theory” with “chaos theory” we can see that this is likely to be a study that generates very little, just as chaos theory had its faddish period that was going to explain everything, but failed to make falsifiable predictions. As far as we know, we are the only SWEIT in existence, or ever has been in existence. We don’t even have other human examples, let alone alien ones. Given how non-deterministic social systems are (no psycho history even in theory) it seems unlikely that we can find quasi-deterministic trajectories for SWEIT evolution.

    @RobFlores – yes that is certainly one possible existential threat to human civilization. One might even argue that this constitutes a “great filter” in front of us as technology affords many such threats, any one of which succeeds will devastate civilization, or bring an end to development with a very heavy authoritarian hand.

  • Rob Henry November 26, 2014, 18:16

    This all presupposes that an ETI stays on its home planet without straying, long after it is able to leave. Either that, or the typical progress from the inception of technological civilisation is much slower than ours has been. If it’s not as stricken by homesickness as us, it will soon become effectively immortal.

    GIVEN that proviso, I think this revels the true danger. Anthropogenic global warming.was always a red herring – a potential for which we noticed in time to alter, if we could only model it sufficiently to that effect. Actually, even if we could and had a plan that we knew could stop it, would we? If, say, the only plan that worked in these better models entailed preventing a billion third world people lifting themselves out of poverty, would we accept it, or would we let things pass a tipping point and hope that a better plan would come to us in a decade or so?

    Anyhow – as I said, AGW is not the true worry. What if we solved it completely, only for the ice age to resume suddenly five thousand years hence, or being struck by a meteorite, or the fertility rate never rebounded from these current lows in any country with a high tech infrastructure? No, to me the true monster is the paradigm approach – that scientists (but not science) deny the existence of (dangers) until they have enough data on them – and for existential risks, we can already reason that it would often be too late.

  • Malcolm Davis November 26, 2014, 19:31

    Perfect Timing for this discussion with Dr. Brian Cox causing a storm of controversy over recent comments about the likely absence of intelligent life other than ours in the Milky Way.

    FOR LAST TIME: I think life is common in universe. We MAY be only civ. in Milky Way. There WILL be other civilisations in univ. #shutupnow— Brian Cox (@ProfBrianCox) October 28, 2014

  • James M Essig November 26, 2014, 22:42

    The number of potential species specific somatotypes and ETI physiologies is huge as is the potential methods they use for space travel and infrastructure design.

    There are an estimated 10 EXP 23 stars in the observable universe that are currently burning nice and bright. Most of these stars will be burning a trillion years from now, while new stars will form.

    Now, imagine the size of a typical grain of salt such as a grain of the famous Morton brand that comes in the familiar dark blue canister from the grocer.

    Now, image 100,000 cubic kilometers of the grains. The number of grains would be about 10 EXP 23. How does covering the entire land area of the United States including all 50 states about 34 feet deep with Morton brand table salt grains sound. Whelp folks! You would then have as many grains as about the number of stars in the observable universe. The number of planets could be 10 times greater in which case would be equal in number to the number of Morton table salt grains in a layer covering the entire United States 340 feet deep. The observable universe is considered to be a tiny portion of our universe.

    We have got an awesome amount of territory to explore and a potentially commensurately rich and huge set of ETI and/or UTI personal species to discover and befriend.

  • Enzo November 26, 2014, 23:03

    Economic and population growth are both strongly promoted worldwide.
    Regarding the former, I’m not even aware of any opposition to the concept, except few individuals considered “fringe”.
    Is there an economic university department studying “steady state economics” ?
    I’m only aware of this organization (not an university):
    http://steadystate.org/
    I had a brief look but I find a bit off-putting that they try to sell their book.
    I mean, I’m sure they need funds but if the cause is important, then it would be in your best interest to make your book available for download.

    In the meantime we are on track for ecosystems obliteration, with wildlife halved in 40 years :
    http://www.newscientist.com/article/dn26290-worlds-wildlife-population-halved-in-just-40-years.html

    Even in relatively protected areas like Australia’s Great Barrier Reef, coral cover has dropped 50% in 27 years :
    http://www.scienceinpublic.com.au/wp-content/uploads/Full-PNAS-paper-for-publication.pdf

    Population might not slow down and plateau at 9 billion as hoped but continue to grow to 12 billion:
    http://www.newscientist.com/article/dn26231-global-population-may-boom-well-beyond-the-year-2050.html

    Ad maiora !

  • NS November 27, 2014, 4:38

    Any society that depends on non-renewable resources is in danger of running out of them eventually. And a society that creates more wastes than it can dispose of may drown in its own garbage (or worse). No matter what the level of technology there is no guarantee that it can keep ahead of these problems. Here on Earth they have already happened to some agricultural societies, seem close to happening to our industrial one, and could even happen to (say) a society that exploits its own stellar system but is unable to obtain significant resources via interstellar travel. The answer? Some combination of intense recycling of materials and a way of dumping heat? I don’t know.

  • DCM November 27, 2014, 5:26

    We just don’t have any knowledge of other civilizations or whether they exist. We can generalize about human behavior, but that’s it. The problem with that is that whatever philosophical trope prevails determines the hypothesis. Currently humans are changing the climate — the same people believe it who know the Earth’s climate has flopped between arctic and tropical for about a million years, most of that time before the majority of humans could even build campfires. The second is the profound self-hate that has gripped the West since World War II that imparts the idea that we’re all wrong and evil and that pessimism is objectivity.
    Something has to force people to shake that off before we can be objective.

  • Al Jackson November 27, 2014, 6:53

    I like this paper , it’s not the first I have seen to math model population biology and population dynamics.
    Have not read with a fine tooth comb … but… have some observations.
    Don’t find enough or hardly much mention on the uncertainty of elements going into the modeling, There has to be error bars on the elements used in the Lotka–Volterra equations 5 and 6, in the paper, dispersions assumed are not stated, probably not estimated.
    Equations 5 and 6 (in the paper) are Lotka–Volterra and nonlinear which leads not only to stable limit cycles and unstable trajectories as in Image 1 above but also to strange attractors which make predictability impossible.
    I love the idea of a quantitate population model for the ‘evolution’ of a civilization but I am hard put to accept that there can be any definitive prediction , especially for a complex technological civilization. There exist ways to quantify the ‘horizon of predictability’ for such modeling (Lyapunov exponents) of nonlinear systems. Knowing such a characterization keeps one sober about modeling the one civilization we have as an empirical point of reference.
    However, I sure welcome quantitate models , I find the qualitative ones interesting philosophical reading but not definitive.

  • Yvan Dutil November 27, 2014, 9:34

    My two cent on this topic:

    http://arxiv.org/pdf/0711.1777

  • Al Jackson November 27, 2014, 11:28

    “My guess is that this is about as fluffy as it gets. If we replace “dynanical systems theory” with “chaos theory” we can see that this is likely to be a study that generates very little, just as chaos theory had its faddish period that was going to explain everything, but failed to make> falsifiable predictions<. "

    This is not true. I can give a concrete examples. Excitement arose over Chaos Theory in the 1980s because 'deterministic chaos' explained the Kirkwood Gap in the asteroid belt at the 3:1 resonance with Jupiter. Chaos is manifested in the eccentricity of orbit in the 3:1 resonance on long time scales. This was not explained until Jack Wisdom and his group at MIT showed that asteroids could be pumped into Mars and Earth crossing orbits so they either were ejected by Mars or the Earth or they hit Mars or the Earth. Not easy to predict which one will but the ensemble of asteroids at this location and any that get into to it will sometimes go into wild orbits and indeed we see this.

    Saturn's moon Hyperion has chaotic rotation due to the 3 to 4 spin orbit resonance between it and Saturn. If one knew Hyperion's shape , rotation and orbit before it was measured one would predict from the nonlinear celestial mechanics that its spin would be chaotic.

    There is other physical processes where knowing Chaos theory is important mainly because it instructs on how far out one can predict a prediction!

  • DCM November 27, 2014, 12:18

    “Rob Henry November 26, 2014 at 18:16
    ………………
    If, say, the only plan that worked in these better models entailed preventing a billion third world people lifting themselves out of poverty, would we accept it, ………
    ……….”

    That IS the plan of the global elite. Whether or not their paradigm is real their plan is to keep billions in poverty and to impoverish and kill off much of the First World in order to be absolute rulers and a medieval type peasantry.
    In reality, the rate of population growth is slowing because as people’s living standard rises they have fewer children. This killing the unborn and old and many in betweens is unnecessary even if the life span is increased.
    The solution all people have always used it to expand AND make more efficient use of the home turf. That’s what we’re about here. That, and, I hope, preserving real freedom.

  • Alex Tolley November 27, 2014, 13:53

    Equations 5 and 6 (in the paper) are Lotka–Volterra and nonlinear which leads not only to stable limit cycles and unstable trajectories as in Image 1 above but also to strange attractors which make predictability impossible.

    For most population ecology use, the cycles are stable.

    @Rob Henry
    If, say, the only plan that worked in these better models entailed preventing a billion third world people lifting themselves out of poverty, would we accept it, or would we let things pass a tipping point and hope that a better plan would come to us in a decade or so?

    You make a good point. Diamond’s “Collapse: How Societies Choose to Fail or Succeed” seems to indicate that collapsed societies could have made sustainable choices, but chose not to. In many respects, this seems to be the case in our industrial civilization. The good news is that he has examples of societies that chose well for sustainability. Unfortunately none of those were democracies IIRC.

  • Rob Flores November 27, 2014, 15:18

    Is there an antagonism between sustainable levels of resource use and
    recycling and the motivation to develop space technologies that enable us
    extract resources from solar system bodies?
    If our civilization becomes specialized in recycling, retasking materials
    and also has only a replacement population growth rate, what would he driving force of space technologies? Exploration by itself is very slow enabler of this technology compared to even Political rivalry (as the accelerated the Lunar Mission time table demonstrates) Right now a few companies are talking developing plans for asteroid resource extraction. Of course this assumes that on the Earth materials recycling is expensive, or that sources still in the earth are uneconomical to extract.

    My opinion is that just because a nation achieves the goal of sustainability is does not follow that any dividend from this will be used
    for more robust space development. Economic incentives are still important even if they are not the most ethical drivers of technology.s

  • DCM November 27, 2014, 19:41

    “Rob Flores November 27, 2014 at 15:18

    Is there an antagonism between sustainable levels of resource use and
    recycling and the motivation to develop space technologies that enable us
    extract resources from solar system bodies?
    ………..”

    Yes.
    Alas, all but a few individuals are driven by the need to survive rather than drawn by curiosity and creativity. Apparently whole cultures can only emphasize the latter under rare conditions that aren’t well understood.
    On the other hand, even the belief that we are safe, well fed, and have a satisfactory social system can stifle the exploration and invention on which our very survival depend.

  • Enzo November 28, 2014, 5:33

    Another article, this time a new one on Scientific American, regarding the new projections for population growth, much worse than expected :
    http://www.scientificamerican.com/article/world-population-will-soar-higher-than-predicted/
    Very depressing .

  • Andrew Palfreyman November 28, 2014, 5:49

    It is likely that crunch time for sustainability is due within a century or two, at the latest. Since we have no world government, and politicians in general cannot be trusted, it behoves us to mobilise for building habitats off-planet as soon as possible. The barrier is launch costs. We need railgun cargo launch ability. We need Skylon, a fully reusable space plane, to get flying for human presence in space. We need to get SPS going, because we can’t wait for fusion. We need to get bases on the Moon, and Mars later. We need a web of lightbeams crisscrossing the solar system for fast efficient travel. Then we can sit back and relax a little.

  • Alex Tolley November 28, 2014, 11:30

    @Andrew – I doubt World government is any panacea. Just look at the conflicts between US federal and state governments. Suppose you had a world government that dictated that the fairest goal was to bring the global population to a standard of living somewhere well below the US. Would developed nations like the US stand for reduced standards of living to meet this sustainability goal? We cannot even wean ourselves off fossil fuels.

    Maybe the only solution is a gamble – risk uncontrolled, growth with a low probability of success at being space faring, or give it up for a sustainable planet. Clarke returned to this theme of exploration vs lotus eating several times. It is Well’s Cabal final line in the movie: “It is the universe or nothing!”
    The difference now is that it may not be a voluntary choice for either faction, but one imposed on the other. I think if you offered the choice of the global population living in reasonable comfort vs increased inequality, high growth with a high risk of a crash, but with a small population being able to live off planet, the choice would be overwhelmingly for the former, and I think rationally so. I hope that the eye of the needle we may need to steer though is sufficiently large to give us a decent shot at becoming space faring.

  • Rob Flores November 28, 2014, 23:51

    Personally I think that while characterizing the equipment and mission designs to mine asteroid is a good intellectual exercise, it seems in practice
    to be premature by a decade or so. We need robotics and molecular assembly tech to develop further for Asteroid mining to compete with Earth based mining. And frankly the recent effor to land on asteroid is not exactly encouraging. I certainly would not invest in such a mining venture today.
    Don’t forget that even if certain critical metals on Earth become prohibitively expensive, it does not necessarily enable space mining. Historically industries find it more efficient to alter their design/operations to enable the use of substitutes to prohibitively expensive materials.

  • DCM November 29, 2014, 5:44

    The best to hope for is continued strife without any world disaster (which includes world government) until there are autonomous off Earth settlements.

  • Alex Tolley November 29, 2014, 14:48

    Historically industries find it more efficient to alter their design/operations to enable the use of substitutes to prohibitively expensive materials.

    A lesson frequently forgotten. I have books on mining the asteroids and the moon (Astronaut geologist, Harrison Schmitt) for platinum to facilitate the hydrogen economy because of the expected shortage of platinum. In reality, the hydrogen economy didn’t take off, use of platinum in fuel cells has become much lower, and we already have substitutes for platinum in fuel cells as well.

    The Club of Rome “Limits to Growth” (1972) report predicting various metal shortages didn’t happen either, (Ehrlich famously lost his bet to Simon) partly due to substitutes.

    It is appropriate that private groups are funding asteroid mining – let them take the technological and market risks. However I was amused that Planetary Resources is crowd funding their first Arkyd telescope to locate suitable candidates (suitably dressed up as a science project). Billionaires unable to fund a $1m space telescope? Is this another example of socializing the risks while keeping the rewards?

  • Astronist November 30, 2014, 11:00

    I have now read this paper. Thanks for referencing it.

    What is one to make of it? It is a very scholarly paper, and mathematically sophisticated. Yet despite its erudition it makes no mention whatsoever of the key issue regarding the sustainability of human (or other) civilisation, i.e. whether or not a large-scale expansion into the Solar System occurs.

    It also treats Species With Energy-Intensive Technology as a single case. This term is never defined, but it seems clear that they’re thinking of a species based primarily on fossil fuels, as we are at present. What happens if and when such a species transitions to nuclear fusion or space solar power is not addressed. Certainly they claim (p.36, col.1, end of 2nd para) that the variables in their model are “not subject to a particular choice or era of technology”. Yet some technologies can be used away from the planet of origin, others cannot. Blurring this distinction is consistent with the authors’ programme of ignoring the possibility of expansion into space, for which they need to be rebuked.

    Stephen A.

  • spaceman December 2, 2014, 0:28

    Paul,

    Thank you for informing us of this interesting article. Just out of curiosity, how are Frank and Sullivan defining our local region of the cosmos? Do they mean just the Milky Way galaxy, the Local Group, or an even larger volume of space? I was just wondering how they went about coming up with the number 1 in 1000 trillion. This is a very small chance of a technological civilization arising, but the more I read about the different components of the Drake Equation and plug in my own estimates, the more I find myself coming to the conclusion that we are almost certainly the only technological civilization in our galaxy. I suspect that all of the values to the right of Fp are all very much lass than 1. For example, the origin of life, Fl, could be a bizarre chemical fluke of epic proportions. If the chance of life arising to begin with is 1 in 10^40,000, for example, than we are probably alone in not just our galaxy, but also the entire observable Universe! Even if life arises to the level of primitive microbes relatively easily, some say that the chances of it progressing beyond that to the multi-cellular level is astonishingly small. What are your estimates for the Drake equation?

  • Paul Gilster December 2, 2014, 9:07

    spaceman writes:

    Thank you for informing us of this interesting article. Just out of curiosity, how are Frank and Sullivan defining our local region of the cosmos? Do they mean just the Milky Way galaxy, the Local Group, or an even larger volume of space? I was just wondering how they went about coming up with the number 1 in 1000 trillion.

    Good question, and it’s one I asked as well. I can’t find what they mean by ‘our local region’ in the paper.

    My estimates of the Drake Equation focus on the lifetime of a technological civilization, which I speculate may be short. But even so, we’re just guessing without further data on the key remaining points. If I had to take a shot at it, I’d say that life is widespread, intelligent life exceedingly rare, and technological civilizations that last rarer still. I always give a figure of 10 active at any one time in the galaxy. Like I say, it’s no more than a guess.

  • ljk December 2, 2014, 12:57

    Enzo said on November 28, 2014 at 5:33:

    “Another article, this time a new one on Scientific American, regarding the new projections for population growth, much worse than expected:

    http://www.scientificamerican.com/article/world-population-will-soar-higher-than-predicted/ Very depressing.”

    How many years did I hear from the “experts” that the human population would somehow level out at a mere 9 billion by 2050 and things would be fine after that.

    Well, when 3 children are born across the planet ever second and the death rate cannot keep up with it, despite our species continued efforts to kill off as many of its rivals both real and perceived at every given opportunity, human growth rates are not going to level off based on a prediction.

    I am also well aware that space colonization is not going to relieve the population pressure on Earth unless there is a mass exodus and that isn’t going to happen any time soon (sorry Interstellar). So what is to be done?

    Earth is a big place, but it is finite both in terms of resources and livable terrain. Unfortunately our species continues to grow and act like we live inside a Dyson Shell (the solid kind); many do not even want to admit for various reasons that we are also affecting our ecosystem despite all the signs.

    If there is going to be space colonization to even start just making sure at least some of our fellow humans are alive somewhere in the Universe, there has to be a much better effort than what the space agencies have been doing for the last few decades. I know private industry is trying but they need more money and resources too and their investors are not going to just keep handing such items over without a return on their efforts. And I also get the feeling these same folks cannot seem to understand or want to see that rockets and spaceships do not always succeed even though we have gotten better at them over the years.

    Again one thing we can do is improve on getting the word out about space and its benefits to our species and the planet Earth overall. I was not exactly heartened by the NPR news I heard this morning on the upcoming Orion test flight: They assume that most people have never even heard of Orion outside the space geek community (look at the title in the linked news item below) and they may sadly be right:

    http://www.npr.org/blogs/thetwo-way/2014/12/02/366832916/nasa-prepares-to-test-new-spacecraft-that-youve-likely-never-heard-of

    The first manned deep space mission test in decades and you would think it might generate a bit more excitement. But NPR is already leading the way with the public assumption this is otherwise and that their listeners are not that savvy to anything outside of politics and sociology and jazz.

    Here is one way to get the public excited about space colonization and exploration in this brief video titled Wanderers:

    http://vimeo.com/108650530

    The creators of this video did in 3 minutes what Interstellar strives to do in 3 hours.

    About the population problem: We had better find some ethical solutions soon or as one of my old professors said about this very issue, nature and frightened governments will find their own methods and they will likely not be ethical or humane.

    And remember, Tuesday is Soylent Green day.

  • Alex Tolley December 2, 2014, 13:46

    @spaceman

    Even if life arises to the level of primitive microbes relatively easily, some say that the chances of it progressing beyond that to the multi-cellular level is astonishingly small.

    At least on Earth, it has been found that the ability to become multicellular is part of the unicellular molecular biology. Which perhaps shouldn’t be surprising, but at least it gets us away from the idea that this evolutionary step was a huge hurdle. We has so many phenomena, and organisms that are colonial, sitting between unicellular and true multi-cellular organisms with specialized cells, that I consider that mult-cellular organisms are likely to be common if they follow the Earth’s pattern for life.

    What we need now is some good data to indicate whether life is common in the universe or not, so that we can end the speculation. We talk about sending probes to sample the plumes on Enceladus, but what exciting science it would be to send a probe to another living world around a star, providing a glimpse of that alien life and sending back biological data from images to molecular biology.

  • Rob Henry December 2, 2014, 22:36

    @ljk, the high frontier MAY be able to alleviate overpopulation through increased resources, but not through direct population transfer. Throughout the first world, fertility is way too low already, and the problem lies entirely where female education is low (ie motherhood = only career path). Unless the solution is for China and the West to pay to send the poorest and least educated Somali and Afghan citizens to work in space, your plan would be useless.

  • Robert G Kennedy III, PE December 3, 2014, 15:56

    Paul, just a minor nit about the second figure cited that you might pass along to the author. 1 exajoule is 1 quintillion joules. Since about 1000 J go into a British thermal unit (Btu), then 1 EJ equals 1 quadrillion Btu (nicknamed “quad” in the energy policy world) more or less. Humanity’s annual primary energy consumption surpassed 500 quads a couple years ago. Therefore the units of the X-axis should be labeled “100s of exajoules” not “100ths”. I’m also amused that I got this copy of /Anthropocene/ by two quite different routes. I guess networking works.

    Thanks again for coming to the Third TVIW in Oak Ridge, Paul, and for your excellent coverage. I hope you enjoyed the Kennedy/Jackson living room at long last. Sorry I did not have time to fix you an Alpha Centauri Sunrise. Next time in Chattanooga, when I’m not so freaking busy…

    Robert

  • Paul Gilster December 3, 2014, 16:50

    Robert Kennedy writes:

    Thanks again for coming to the Third TVIW in Oak Ridge, Paul, and for your excellent coverage. I hope you enjoyed the Kennedy/Jackson living room at long last. Sorry I did not have time to fix you an Alpha Centauri Sunrise. Next time in Chattanooga, when I’m not so freaking busy…

    The Kennedy/Jackson living room was wonderful, especially with the various cats and the one dog wandering about. I’m going to hold you to that Alpha Centauri Sunrise in Chattanooga! Only you have the right touch to make them.

  • Eniac December 3, 2014, 22:52

    Paul, in your speculation on the Drake equation, you, like the authors of this paper (and Drake, I suppose, as well), silently discount the possibility of a civilization expanding into space. One of the likely consequences of such an expansion would be fragmention into multiple civilizations with a combined lifetime that is practically infinite.

    I agree with Astronist that this omission is worthy of rebuke :-)

    Do you have unmentioned reasons to discount the possibility?

  • Paul Gilster December 4, 2014, 10:11

    Eniac, in the back of my mind is my hunch that the lifetime of technological civilizations is short except in rare cases. Multiple civilizations expanding into space is an excellent scenario, but I don’t see how the combined lifetime is necessarily infinite, or practically so. Each of these fragmented civilizations will face the same issues of technological survival. But please don’t take this as advocacy for pessimism. The fact that the issue is so wildly speculative leaves me hopeful that my own hunch about intelligent beings coping with technology is wrong, and that there are ways to get through this ‘filter’ without self-destruction.

  • david lewis December 4, 2014, 11:24

    Sustainability? The biggest hurtle I see to this isn’t technological; it’s psychological. Eleven billion shouldn’t be too difficult to support at a reasonable standard of living, but the path to developing such a sustainable civilization is probably a pretty forlorn hope.

    Take nuclear energy for example. Browse a few websites on the topic and you’ll get an EROEI anywhere from less than 1 to 225. Try to research how dangerous it is and you’ll be vehemently told time and time again that it’ll destroy the world. You might find one or two that explains how it has the lowest death rate per TWH of any energy source.

    Since people tend to assign more credibility to those who are “confident” rather than those who go into a debate with charts and numbers that has little meaning to them, then those who portray it as dangerous and impractical will come out the winner. Hence nuclear energy, which should be well on it’s way to replacing coal, is still an energy source that is often rejected.

    The same applies to our love of warfare. If a leader stands before a people and confidently states that some group is a threat, that they’re the very incarnation of evil, then the people listen. It doesn’t matter that one country has thermonuclear weapon, while the other has little more than a few ancient artillery pieces that should’ve been tossed into the scrapheap long ago. If they’re told over and over, with enough confidence, then people will believe the threat.

    Short of finding some way to demand absolute truth from those who would lead us, whether they be politicians, or CEOs of corporations, or heads of powerful groups like some environmental groups, or those who would just get on some media and bray about some topic they know little about, then I don’t see how we can find a path to a sustainable civilization. There’re just too many conflicting interests: money, power, religion, ideologies ….

    On the bright side, an alien species might be totally different from us psychologically, and might be able to find such a path. One can hope.

  • Robert G Kennedy III, PE December 4, 2014, 15:00

    david lewis December 4, 2014 at 11:24 said:

    Take nuclear energy for example. Browse a few websites on the topic and you’ll get an EROEI anywhere from less than 1 to 225.

    It’s 14 in the West. Frank Kreith (a famous ME professor who wrote the book on heat transfer, and is a world authority on EROEI and sustainability) and I came at this from opposite directions. He thought the EROEI for nukes was about 10, I had estimated 25-30. We happily settled on the geometric mean, 14 (assuming a 40-year lifetime). License extension increases this number in a linear way, so you want to run those nukes as long as possible once they’re built. For comparison, solar PV is rising past 12 with lots of headroom, while windpower has settled about 10-14 depending on the make and model.

    Btw, in case you’re not reading the trade press in the oil patch, forward-looking EROEI for crude oil is down to about 4 or 5. You can estimate the figure by simply dividing the entirety of the world’s crude oil market ($3 trillion annually at today’s depressed prices) by the sum of all drilling / exploration activity (~$700 billion last year). Refined fuel doesn’t magically levitate itself to you; it has to be found, mined, transported, refined, and distributed. A typical refinery consumes one-seventh of its own feedstock just to run itself, and the total “embedded energy” in a gallon of gas is about a liter of that gas. Think of it as a tax. Kreith thinks the minimum viable EROEI for a high technology civilization is 3, so we are not far from the “EROEI cliff”.

    In case you wondered, why isn’t a ratio of 1 viable? the answer is: a ratio of “1” means you put one unit of energy into the ground and all you get back is that one unit. No surplus for anything else like heat for refining, sales to customers, paying off management in the back office or the the investors back home, etc.

    Getting back on topic, this simple analysis illustrates why getting off the planet is a prerequisite for starfaring: the energy requirements are so huge that a single terrestrial environment cannot contain the necessary industrial base.

  • Eniac December 4, 2014, 21:53

    Paul: I suppose the practically infinite lifetime of spreading civilizations depends on them spreading faster than they destroy themselves. In other words, the colonization rate has to be higher than the extinction rate. Whether this is likely to be the case or not we cannot really know, but I am optimistic about it. I feel I have to be. After all, if I am wrong, then there is no future, and I could not stand that.

  • Paul Gilster December 5, 2014, 10:07

    Deep down, Eniac, I am an optimist as well, which means I often find myself at odds with my own hunches!

  • ljk December 5, 2014, 14:59

    For those of you who buy into Physicist J. Richard Gott’s idea, humanity will continue to exist between the next 5,100 years and 7.8 million years:

    http://philsci-archive.pitt.edu/1205/

    Now this could mean our species will go extinct by one of those periods, or it could mean that we just evolve (with technology) into something else that no longer resembles current humanity.

    Or we could always end up this way….

    http://speculativeevolution.wikia.com/wiki/Man_After_Man

  • ljk December 8, 2014, 11:58

    Aliens Are Probably Everywhere, Just Not Anywhere Near Humans

    Written by MADDIE STONE

    December 4, 2014 // 01:20 PM EST

    If there’s intelligent life in the cosmos, it’s probably nowhere we can get to anytime soon. At least that’s the finding of the astrobiologist who, for the first time in decades, has rendered a major update to the key formula scientists use to seek out interstellar life.

    That’d be the Drake equation, which was developed over half a century ago to determine where life might lurk in the universe. Until now, the formulation that promises to pin down the number of intelligent civilizations in the cosmos has suffered one big limitation: There’s been no actual data to constrain most of its parameters.

    All that’s been changing since numbers started coming in from the Kepler mission over the past few years. We now know that small, Earth-sized planets are scattered throughout the galaxy, and that many lie within the habitable zone of a Sun-like star.

    Using the new Kepler data, astrobiologist Amri Wandel did some calculations to estimate the density of life-bearing worlds in our corner of the universe. The exciting news is there are probably millions to billions of biotic planets in the Milky Way.

    But before we start packing our bags, a sobering reality check: Our corner of the cosmos may be dark. Wandel’s math shows the closest life-bearing world is ten to a hundred light years distance from Earth. And that’s just to find a world that harbors single-celled life. The closest intelligent aliens may be thousands of light years further.

    Wandel’s findings, which will be published next year in the International Journal of Astrobiology, were released in pre-print yesterday. He restricted his analysis to Earth-sized planets within their star’s habitable zone—that is, the zone that’s neither too hot nor too cold for Earth-like organisms to potentially evolve.

    Preprint here:

    http://arxiv.org/abs/1412.1302

    Full article here:

    http://motherboard.vice.com/read/alien-life-is-abundant

    Our electromagnetic signals form a bubble of technological “noise” about 200 light years across. Carl Sagan estimated that if there were one million advanced ETI in the Milky Way galaxy, then the nearest one should be about 200 light years from Earth. Therefore the closest alien civilization would just be receiving our first transmissions, if they could even detect them at all since most were not meant for deep space and are very faint. Otherwise we do not readily stand out on a galactic scale.

  • ljk December 8, 2014, 11:59

    Saturday, December 6, 2014

    Burst 2 – Through the Lens of the Drake Equation

    In this short Wow! Signal Burst, Paul Carr talks us through where we are on the seven terms in the Drake Equation, which more about what we don’t know then what we know – so far.

    http://www.wowsignalpodcast.com/2014/12/burst-2-through-lens-of-drake-equation.html

  • Rob Henry December 11, 2014, 18:24

    Robert G Kennedy, I can’t help but notice that low EROEI has its good side. With high EROEI, there is little to stop advanced countries stratifying into a highly productive but tiny elite, and an unneeded underclass for which their is no economic need. A low EROEI economy ensures the need for high routine maintenance, and suddenly these people are employed again and productive as per happened with fracking. Of cause, you can get too much of a good thing…

  • ljk December 30, 2014, 16:27

    Could we find aliens by searching for their VIBRATIONS? £6,000 nanosensor could pick up tiny movements of life on distant planets

    – Tiny sensor was created by researchers in Switzerland and Belgium

    – It uses a nano-sized cantilever to detect motion in living organisms

    – It has already proven successful in detecting human, plant and mice cells

    – Device is just a few microns in length and can hold around 500 bacteria

    – A micron is equal to 1000 nanometres or the thickness of a red blood cell

    By ELLIE ZOLFAGHARIFARD FOR MAILONLINE and AFP

    PUBLISHED: 05:33 EST, 30 December 2014 | UPDATED: 08:06 EST, 30 December 2014

    http://www.dailymail.co.uk/sciencetech/article-2891032/Could-aliens-searching-VIBRATIONS-6-000-nanosensor-pick-tiny-movements-life-distant-planets.html

  • ljk February 26, 2015, 13:32

    Where are they? or What are we?: Thoughts on Astrobiology

    In 1977, Jerry Ehrman of Ohio State’s Big Ear radio telescope observatory detected an unusual signal that was believed to come from the constellation Sagitarrius. A printout of the signal, translated into alphanumeric characters, showed that its ‘signature’ was so different from the incoming signals typically observed, it was assumed to be of extra-terrestrial origin. Ehrman proudly wrote “WOW!” in red ink upon the printout after circling the corresponding signal on the paper, and the name “Wow Signal” has stuck. This same signal has not been detected since.

    However, failure to make “first contact” with an intelligent civilization in this and other instances has not deterred the collective SETI [Search for Extra-Terrestrial Intelligence] projects from continuing with their work, and each successive instance of even a possible alien contact should cause us to reconsider our relation to anthropocentric thinking.

    Full article here:

    http://www.radikaliai.lt/radikaliai/2480-where-are-they-or-what-are-we-thoughts-on-astrobiology