Eben Rose

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How can we surmise that chemical evolution may lead to Earth-referenced attributes of life as if it is a universal law?

Our experience with life and intelligence is wholly Earth-referenced, yet SETI and the discipline of astrobiology assert that life-as-we-know-it is unquestionably "out there". Why? Is it a reasonable assumption that chemical evolution inevitably leads to "us-like" properties wherever conditions are "just right'? How restrictive is the notion of "just right" conditions? Wouldn't such conditions need to be EXACTLY like Earth's historical conditions in order to arrive at Earthlike outcomes?

Taken at the level of molecular organization and building up from there, the probabilities of generating a bacterium, even given Earthlike initial conditions of, say, 4 billion years ago, are beyond astronomical. A probability distribution is associated with each stage of synthesis along the evolutionary path, and these are affected, too, by ever changing and largely unpredictable externalities, such as irradiation and impacts. The outcome of these probabilities then provide the prior conditions that affect the shape of the next probability distribution. All of these compounded probabilities have been integrated over geological timescales to arrive at Earth's version of life. How could recognizably similar outcomes be extrapolated to the integrated histories of chemical synthesis taking place on other worlds?

Indeed there are huge numbers of stars and galaxies in the vast universe, and we have all been lured by the numbers game that turns the even the minutest probability into an inevitability. But we should always temper our searches for ET to that vastly smaller part of the universe that is in any way accessible to us from our own spacetime well. At some scope of distance, the search for ET crosses the boundary into cosmology with contact across times and parallel universes that are not part of the ET search.

SETI and astrobiology proffer deterministic metaphysics of inevitable life within our accessible universe as if it is science. Is it science or just wishful thinking?

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    Jun 12 2012: My comment is in regard to Universal Law;
    specifically 6:30-7:00 minutes through when Seth Shostak lays down his mathematical probability of the non-existence of "our""miracle" Theory.
    A Galileo, a Pascal, a Newton, William Herschel, Charles Babbage, Samuel Morse, Charles Darwin's "Origin of Species" (which is a mis-interpretation of Thales first principles), which predates all others;
    leading to a Graham Bell, Nikola Tesla, Marconi, Sputnik, ARPA, Atari, and Tim Berners-Lee whom, somehow, were a simplified and universal series of evolutionary thinkers and events which can be attributed chemically, contributed to the SETI AIM;
    that others, who are believed to have followed even a remotely similar existence, who are out ...there; signaling

    In itself proves Mr. Shostak's belief in the "Miracle" Seth is a Believer!
  • Van Le

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    Jun 9 2012: well the fact is the universe has been around longer than planets like the earth. Given the universe is 10billion years older than the earth, i am sure it would have somewhere spawned planets like earth billions of years before this planet even existed. Given the low probability of protein forming, well, its happened once in 1 billion years (time it took for first simple cells to form) in earth conditions, so we know it must have occured at least a few more times in 10 billion years before the earth has even existed. Given the number of earth like planets out there each Billion years there is a chance of prokaryotes forming. If it did happen and then that civilization is billions of years more advanced than us, they probably have control over space and time, i doubt they would have any interest in a noob civilisation like ours. Instead they would probably be not wanting to wait a billion years for an evolutionary event to take place, instead they might just be dumping cells here and there and watching the result or having their machines do it. So if this is happenening theres alot more life out there :) rather than aliens just leaving it to chance. :)) So cmon, if you were the most advanced civilisation in the universe, what else would you be doing? Playing God of course :)
    • P C

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      Jun 10 2012: I think it's safe to say that all life forms in the universe evolved on aat least 2nd generation stars. This will naturally push forward the initial stages of life to a point far enough that a 1st generation star would have needed to go through all stages of stellar evolution.

      Life on Earth was nearly wiped out 2 or 3 times, which delayed our development but also diversified life.
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      Jun 10 2012: Our Earth history produced Julius Caesar, but we would not so easily accept that, given "Earthlike conditions", other worlds in the universe would, with any probability, produce Caesar. This is not how history works. History is not rule-governed in any way but in that which can predict the most general of outcomes.

      Prokaryotes are highly derived levels of organization that cannot be predicted from polypeptides or from properly folded proteins. Or can they? Somewhere between the easily dismissible expectation that Caesar would appear at least one other time in the vast population of "Earthlike" planets in the universe, and the expectation of prokaryotes emerging on another world from prebiotic precursors, just as it did on Earth, lies the intersection between deterministic processes that give SETI its modus operandi and stochastic processes that mark one-of-a-kind historical trajectories. Where is this boundary?
  • Jun 7 2012: You lost me right there when you said

    QUOTE: yet SETI and the discipline of astrobiology assert that life-as-we-know-it is unquestionably "out there".

    The word "unquestionably" made me think that the whole basis of your "idea" is questionable. Some time ago I read lots of things about the possibilities of life in other planets. All those, some written by people on SETI, talked about the difficulty we might have since we could not expect that life would be as the life we see on earth. Unless you used too wide a definition for "life as we know it," I think you built yourself a straw-man to fight against.

    Be well.
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      Jun 7 2012: Central to the work of SETI is the Drake Equation: N = R* • fp • ne • fl • fi • fc • L

      N = The number of civilizations in The Milky Way Galaxy whose electromagnetic emissions are detectable.
      R* =The rate of formation of stars suitable for the development of intelligent life.
      fp = The fraction of those stars with planetary systems.
      ne = The number of planets, per solar system, with an environment suitable for life.
      fl = The fraction of suitable planets on which life actually appears.
      fi = The fraction of life bearing planets on which intelligent life emerges.
      fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.
      L = The length of time such civilizations release detectable signals into space.

      Factor fl can incorporate a permissive definition of life, such as those experimental products of Martin Hanczyc, but factors fi and fc are highly restrictive and speak to a very self-referenced version of intelligence and civilization.

      As Claudio Maccone, a member of the Permanent Study Group of SETI, wrote in a 2010 paper in reference to factor fc above, that ET will have done “…just as we have done since 1900, when Marconi started the transatlantic transmissions” (p. 1367). His portrayal of the Drake Equation in this paper presents the singular Earth example as one in a population of “us-like” variants for which “us-like” is defined as the center.

      My question, differently posed, is upon what basis SETI can derive a probability distribution function (pdf) from one data point.
      • Jun 9 2012: Eben,

        You only complicated your straw-man. I do not see how or why the existence of an equation that tells us the kinds of factors necessary to calculate how many civilizations might be out there that could communicate with us, automatically means that the equation implies that this is inevitable. If instead of unknown-factors it had constants, then I would incline towards believing that your cartoon has any resemblance with reality. Everything I have read from SETI/astrobiology, indicates that they are very conscious that those factors have their problems. Lots of research to try and figure them out. Thus, they know that they can't derive a distribution out of one sample.

        Whatever Maccone presented does not mean that he thinks that he can put a precise number to represent that factor, that he presented our own planet does not mean that he imagines ET as being life-as-we-know-it, unless he were using quite a wide definition for life-as-we-know-it, and then there would be nothing wrong with that. There is nothing wrong with using a Marconi metaphor either. I bet that if we read carefully what the guy has published we would not end with this cartoon of yours.

        Be well.
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          Jun 9 2012: Okay, then, let me put this question another way that uses another example so that hopefully you see that it is not a straw man but is indeed the crux of the argument.

          Winged flight, as one extant property of Earth's biosphere, is shared by insects, most birds, and some mammals. One may suggest that flight is an emergent property that would inevitably rise in the biosphere, i.e., if not by insects then by birds or mammals. On closer examination there is less of a convergence of evolution at play if one considers that birds and mammals may have perfected flight in large part because flying insects were ready prey. The point here, though, is whether we can say that organic matter, if given enough time to evolve, will inevitably (or at least with a high probability) lead to winged flight.

          Winged flight is one property of our extant biosphere. The human version (or, more specifically, SETI's version) of intelligence is another such property. My question is whether any such highly derived property as winged flight, human-styled intelligence, or for that matter, leaves, internal digestion, predator-prey relations, etc., are all simply what happens when (to quote SETIan Jill Tater in her TED Prize speech) "...a primordial mixture of hydrogen and helium evolve so long that it begins to ask where it came from." All of these 'emergent' properties are present in Earth's biosphere. We see them. We recognize them. We identify with them. On what basis can we claim that any one of these self-identified attributes is an inevitable consequence of chemical evolution in any other possible world than the one that we know?

          Consider Neil DeG Tyson's take on it: we are some >98% similar in DNA to chimps (other estimates are ~95%). These are our closest relatives, also evolving 4 B yrs under identical conditions, but we can barely access chimp intelligence face-to-face. SETI & Shostak see this narrowly defined emergent property of "us-like" intelligence as probable in the cosmos. Why?
        • P C

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          Jun 10 2012: Eben, perhaps another reason why we have such assumptions within the Drake Equation is that this would represent the main kind of intelligent civilization that we best understand. Given your Ph.D., have you considered asking Drake himself?
      • Jun 10 2012: Eber,

        Now you got me completely flabbergasted. Your winged flight seems to have a fundamental philosophical fault. I know you just made it up. That is not the problem. The problem is that you are saying: "suppose that flight in animals other than insects was pushed by flying insects, thus non-independent of the first flying shit." Well, you might as well be saying "suppose that winged flight will only arise under the proper circumstances." Well, nothing incompatible with that and "winged flight might be an emerging property of life on Earth" as long as you subscribe to this property being able to emerge "given the proper circumstances." This is quite clearly all right. Under your imagined scenario winged flight would be unknown without the flying insects. How is that different to "... a subset of planets bearing life might develop intelligent life, and a subset of these planets might have such life developing technologies ...." We don't expect every animal to evolve into winged life. We don't expect every life-bearing planet to evolve intelligent life, and so on.

        So, again, quite the straw-man. That some researchers might be inclined to think that it might be "inevitable," given the incredible number of planets out there, is not a problem. They have their reasons. Without reading and understanding those reasons, while presenting the whole thing as if research was based on certainty that "life-as-we-know-it" evolves "inevitably" out there is a straw-man. Example: I don't see how "a primordial mixture of hydrogen and helium" could be "life-as-we-know-it." So, why would you use those words (life-as-we-know-it) if not for rhetorical effect?

        Be well.
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          Jun 11 2012: I wonder what you would propose is the "real" question to ask that is not, as you say, a straw man. SETI absorbs a great deal of metaphysics in the theory that sustains its quest. The title of Shostak's talk is that ET is 'probably' out there. My question-- and I leave it as an open question-- is where the boundary lies between reasonable and unreasonable expectations that Earth's historical outcome of emergent properties could be repeated elsewhere not only possibly, but 'probably'. With one historical outcome to draw from, how do Shostak or other SETIans proclaim that ET is 'probable'?

          I have read and understood the literature of those researchers who you cite are inclined to think that such an emergent property as "us-like" intelligence is probable, if not inevitable. This was the topic of my dissertation and remains a problem for which I am deeply engaged in finding a reasonable answer. Some properties, such a rudimentary replication, spontaneous formation of coacervates, peptide formation, etc. have been demonstrated in labs under controlled conditions. But on the other side of the coin we have on Earth a highly derived, highly evolved set of properties that we associate with our own existence that have indeed emerged in the natural biosphere. It does not help us much to say that the emergence of such properties is thermodynamically permissible. The question -- and it is not a straw man -- is what law (perhaps a kinetic law) necessarily directs the trajectory of evolution toward the "us-like" emergent properties that are SETI's target in any other world than the one we know.

          We would not so confidently say that, among the billions of Earth-like planets in the galaxy, that surely another besides Earth will have Spanish-speaking inhabitants. But why not? It happened on Earth naturally, after all; it is thermodynamically permissible.

          Please tell me why is this a ridiculous argument, but seeking other 'technological civilizations' is not ridiculous?
      • Jun 12 2012: Eben,

        You keep insisting on building up your straw-man. Look at this and this only for now:

        You say: "is what law (perhaps a kinetic law) necessarily directs the trajectory of evolution toward the "us-like" emergent properties that are SETI's target in any other world than the one we know."

        This is an awful and obvious straw-man.
        1. SETI is not saying that life elsewhere will be like life on earth. I know, I have read some papers, and actually, they seem rather intense on the idea of finding life that does not look like life-as-we-know-it.
        2. SETI is not saying that there being life, it will necessarily evolve properties like those that evolved here. Remember I talked about subsets of subsets at all? Do you know what "subset" means? Do you understand that the equation you mentioned above is about subsets, and not about laws that necessarily blah, blah, blah?
        3. You use "emerging property" as if it means some kind of magic. Like speaking Spanish. SETI is interested in studying what makes intelligence in order to figure out the possibilities for such a thing to evolve. For now they assume that it is happening, but nowhere do they suggest that it will arise in the very same way it arose here. They might be hopeful, but that's different to saying that everywhere it will happen by some inevitable law.
        4. Life and our intelligence are not just "thermodynamically permissive," but thermodynamically driven. As much as you might think that intelligence is an "emerging property" (meaning some kind of magic?), intelligence arises from compounded properties of life. That does not mean that it will necessarily evolve to a technology-producing state, but it does mean that there is nothing magical about it, and thus it might occur elsewhere.
        5. Your comparison to Spanish is a gross equivocation fallacy. Which makes your straw-man even worse.

        Clear so far?
      • Jun 12 2012: Eben,

        To finish my interaction with you, given that you love compounding your fallacies. Had you said something like "I don't think that intelligence has any probability to appear anywhere else, and thus SETI is a waste of time." I would have said that you are entitled to your opinion. Maybe I would have argued about how and why you think so. However, you accuse the SETI and astrobiology programs of an absolutist position whereby intelligence and technology will evolve necessarily everywhere where life arises to the point that both life and intelligence will be, for sure, "as-we-know-it." You transform half their sentences into a meaning that they don't have. Example, your accusation about "as-we-know-it" would hardly survive a second look if you paid attention to such phrasing as "primordial mixture of helium and hydrogen."

        Thus, you come across as irremediably ignorant, proud to be so. You show some poor, if convoluted, thinking. Seems like you hold a stubborn position regardless of evidence against it. I have no idea how you are approaching your research on the origins of life, but seems like your understanding of anything SETI, astrobiology, intelligence, life, set theory, and thermodynamics, is rather shallow. Seems like your reading of other's people research reduces to their TED talks, while ignoring anything else.

        I might be wrong, but that's exactly how you have come across this far. So, have a good conversation. I don't think that I can interact much more with you.
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          Jun 22 2012: I have contacted the TED officials to referee your comments. I had hoped in starting this conversation that I could gather others' insight into the boundary between deterministic processes that are predictable from physical laws and historical outcomes that are affected by stochastic processes that confound prediction of specific outcomes. Set theory does not illuminate nor solve this dilemma, and since this is the question I posed in this conversation string, it is not a straw man despite your entreaties.

          Perhaps you have some insight to offer– certainly you have a strong opinion– but I think the purpose of these discussions are to offer suggestions and insight and to gain insight from others, not to bully and insult others.
  • P C

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    Jun 7 2012: To answer the OP, the reason why astrobiology seems to be universal is because of stellar evolution.

    Here's a quick YouTube video to explain element formation: http://www.youtube.com/watch?v=uKqvjEE0wFg
    Here's a Wikipedia article on stellar evolution: http://en.wikipedia.org/wiki/Stellar_evolution
    Here's an image of a mature star's core: http://upload.wikimedia.org/wikipedia/commons/3/37/Evolved_star_fusion_shells.svg

    Look at the image of the mature star then consider how the elements form when it explodes from the inside-out. The mass composition of all living creatures perfectly corresponds to this relationship. Since stellar evolution is fairly well understood, and since we can measure the population distribution (i.e. Bell Curve) of stars in the universe by mass, we have a pretty good understanding of the likelihood that these elements will exist elsewhere in the universe.

    So what about the "evidence"?

    1. If a star explodes, then the concentric shells in the core of a star will probably likewise exist outside of where it once stood. Hence why the inner planets contain iron cores and why there's so much water in comets and in the Oort Cloud. The formation of elements by way of stellar evolution seems to be universal.

    2. If we find elements beyond helium in the dust around a young star, we can probably conclude that we're looking at a 2nd generation star, and that all of the necesary building blocks of life are in the planetary disc.

    3. Carbon is one of the most prolific compounds for forming elements. Nealry 90% of all known compounds contain carbon.

    4. RNA/DNA is made of amino acids. Amino acids (made of carbon) have been found in asteroids and comets.

    Considering all of these pieces of evidence, it isn't too much of a stretch to induce that life can exist elsewhere. The question isn't whether we'll find life, but whether we'll find intelligent life.
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      Jun 7 2012: It is too much of a stretch.

      Stellar processes that produce elements approximating the Redfield ratio and lower T processes that generate amino acids are not the kink point of the problem. The problem is how amino acids and other building blocks organize into properly folded and functional proteins, and then how those proteins become protein complexes, those complexes become coded in genetics, etc. Contemporary research has gained some insight into how nature gets around the Levinthal Paradox, for example, but there remains a huge gap of understanding in how organic building blocks evolved on Earth (or evolve in any case) into anything we currently describe as "life".

      Theories abound and I see progress in such theoretical discussion. But we are far from discerning a law of nature that governs organic matter evolution leading to anything we might call "life". Such a law may not exist at all. What we see as life is the outcome of billions of years of co-evolution of Earth and organic matter, and this may be much more about concatenate probabilities than about providence or first principles. To clarify the question, what is the basis for assuming that chemical evolution (e.g., from amino acid, lipid, and simple sugar precursors) inevitably leads to an autonomous organism in any other possible world?
      • P C

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        Jun 7 2012: Give it time. Moden geology just went through its major revolution with Plate Tectonic Theory back in the 70's. Biology is still parsing out the discoveries made from the Human Genome Project. The field has only just begun sequencing other species. There is a recent TED talk about discovering whole new sections of our DNA whose role we don't understand. It will take a few more decades to understand what particular sequences mean. If Ray Kurzweil is correct that genetic information is a highly iterative process, then life may not be as complex as first appears.

        You seem to have two questions nested into one. What is the basis for having particular assumptions and what is the process by which chemica evolution leads to autonomous organisms.

        Your first question is philosophical. The answer to me seems to be in two areas. Through methodological naturalism, we can postulate that since life exists, the only explanation must be a natural one. And secondly, via Francis Bacon's "Novum Organum", which gives us empricism, we strive to avoid any bias (idol) which rejects exceptionalism. Since life is made of naturally occurring materials widely available in the universe, perhaps life is generalizable.

        As for the second. No one knows yet. As mentioned previously, the field of genetics is still in its infancy. As you say, hypotheses abound. It seems to me that the cornerstone of life is the ability to duplicate genetic information, which would point to the mechanism behind doing that, as being the most important advance. Maybe viruses played a role that we don't yet understand. Did they evolve before or after prokaryotes? Are certain features of the DNA/RNA replication process actually symbiotic viruses? Did viruses fuse together two symbiotic organisms into one? What would happen if you throw random amino acids at such a replicator mechanism? Since prokaryotes developed fairly quickly, might we conjecture the mechanism is simple?
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          Jun 7 2012: The 2008 NASA Astrobiology Road Map poses as one of its central questions, "How does life form [in the universe]?" The choice of present tense "does" suggests that this is an ongoing process as if driven by some universal law that is known to exist but has yet to be discovered or described. This seems to be your position in the comment above. But there is a huge gap between the permissive definition of life as cited, e.g., in the TED talk by Martin Hanczyc on the one hand, and SETI style searches for ET on the other.

          The degree to which historical trajectories are seen as law-driven depends greatly on the permissiveness or restrictiveness of the outcome predicted by the governing law. Our law-based knowledge of chemistry allows us to experiment in the manner of Martin Hanczyc and can permit a statement like "how does life from?" But the exact behaviors and outcomes of even Hanczyc's simple systems must be realized through experiment to see what actually happens. It turned out in his case that the same experiment run different times yielded different results. The rules of thermodynamics permit such differing outcomes, but the messiness of kinetics makes prediction of these outcomes even at this simple scale very difficult.

          The now-famous Drake Equation that is employed by SETI, on the other hand, stacks seven probabilities as prior conditions, starting with the fraction of stars that have planets and ending with the fraction of such planets with “intelligent civilizations” that are capable of communicating across interstellar distances electromagnetically and that are indeed doing so within our frame of perception. This is a highly restrictive outcome and one that is not predicted by thermodynamics. Indeed what the Drake Equation assumes is that our own history of development is inevitable (i.e. law-driven) in a sense that is restrictive enough for us to recognize it.

          Is SETI– or any of us– prepared for the sobering empirical result that we may indeed be alone?
      • P C

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        Jun 7 2012: Seeing your profile background, it would seem that this is the pinnacle question of your profession. One that you are uniquely suited to answer in that you can identify features of the early Earth environment that biologists can use to limit their range of possible conditions. Developing high precision geochemical maps in reverse time doesn't sound easy. You'd probably need to gather more sample data points than normal since you'd be looking for trace elements and ideally patterns. Sadly we ultimately may never find the answer given the dynamic nature of the plates.

        You're right that we're grasping at straws here because we really don't know, and are just making educated guesses within the confines of methodological naturalism. But isn't that how science works? I think before anyone can accept the exceptionalism argument, we need to know if the Earth is genuinely unique. We won't know that until we have better astronomical instruments with a resolution sufficient for identifying atmospheres and moons. Without an empirical result, the probability of a Type II error is very high. In the meantime, I don't think there's any harm is searching for an answer.
  • Jun 6 2012: Before it became science, most science was wishful thinking.

    In this area, the numbers are all very rough estimates. We just do not know what the probabilities are for life.

    I think SETI should continue, and should be funded. My reasons are:

    1. The notion of an alien invasion seems crazy, but if you look at it from the viewpoint of the commander in chief, isn't it his responsibility to at least consider the possibility? If we are invaded, the lack of funding will seem extremely foolish. Consider the argument that still goes on about the attack on Pearl Harbor. Just what was the responsible thing to do then, and what is the responsible thing to do now? My answer is, be prepared.

    2. SETI is the poster child of pure science. Science is exploration of the unknown. If we fund ANY pure science, SETI must surely be high on the list.

    3. The discovery of extra terrestrial intelligence would be the biggest discovery of all time. It would change this world in ways no one can possibly predict. Imagine the first generation, growing up knowing that we are not alone, taking it for granted, and figuring this fact into their every decision.

    4. If SETI is successful, the return on investment could be billions of times the initial investment.

    I could probably find other reasons, but I think those are more than sufficient.

    Now, after having said all of that, I strongly suspect our search will fail. I could give lots of reasons, but no matter how convincing these reasons are, we still have to search. We have to search for a simple reason: we do not know, and we must try to know.
    • P C

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      Jun 7 2012: "Before it became science, most science was wishful thinking." This makes no sense.

      Perhaps science doesn't do a very good job with respect to communicating with the public on the differences between postulates, hypotheses, theories, and laws. Often the public thinks that because something exists in a formula, it must be a theory or a law.

      SETI has not been federally funded for a few decades. It's now mostly funded through grants and private donations.
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      Jun 7 2012: I agree that the search should continue. But I reject the propagation and popularization of the notion of inevitable existence of, and contact with, ET. I am a fan of the old Star Treks, don't get me wrong, but I also appreciate that Star Trek is science fiction, not science, pure or otherwise. As SETI enters its second half-century and the cosmos remains silent, this should increase the sober prospect that we are alone on one precious island oasis of habitable worlds. Perhaps such a sober perspective, if propagated with the same ardor and TED exposure as Shostak, will make us less cavalier about messing our oasis up as if we can be rescued by ET or find some new oasis to colonize. Maybe SETI's ongoing negative results are the most important discovery of our time.
      • Jun 8 2012: I agree that a negative result from SETI would be a very important discovery, but disagree about your immediacy. SETI has searched only a small portion of the high priority targets. Lets give Seth Shostak another thirty or even fifty years before we consider the result negative.

        As for the popularization of the inevitability of ET, all we can do is try to spread the more sober message, that we are likely alone. Unfortunately, Seth has the sexier message.
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          Jun 12 2012: Your point that Seth has a sexier message is well taken. Certainly the NASA Astrobiology Institute, SETI's closest kin, rather overtly capitalizes on Americans' fascination with Star Trek, Avatar, and the like. They found a way to take this love of the genre and turn it into popular support for esoteric research, like investigating extremophile bacteria and Archean rocks. Sadly, and I think irresponsibly, they also legitimize the fiction of limitless frontier as if there are truly new lands for us to conquer as we lay waste to our home planet.