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The Why of METI and SETI

by Larry Klaes

About a decade ago while attending a SETI conference, I was listening to a researcher give a talk about detecting messages from other galaxies such as the giant elliptical galaxy Messier 87 and the immense Virgo galactic cluster it resides in. Since M87 is about 60 million light years from the Milky Way, I later asked him why would someone send a message that they could not hope to get a reply to for 120 million years at the least.

m13

His reply was rather vague and dissatisfying to me. It was along the lines of they would do it for the sake of being able to sending such a message across such a vast distance and time. I was left with the impression he did not fully think out why any intelligence would send messages across millions of light years of intergalactic space with even less hope of a reply than our token METI (Messaging ExtraTerrestrial Intelligence) effort with Messier 13 in 1974 via Arecibo, for which we will need to wait 50,000 years for the quickest reply from there if ever.

Image: Messier 13, a globular cluster containing roughly one million stars in the halo of the Milky Way. It lies in the constellation Hercules, 25,000 light years from the Sun. Credit: Robert Lupton, Sloan Digital Sky Survey).

The SETI researcher seemed focused on the mechanics of how such a message would be done, which is good in itself of course, but not the why of it, which for me is the entire key of whether such transmissions will ever take place or not. Setting aside funding and resources for a moment, no serious science project is going to happen unless you give those in control of such things a reason for doing so that is agreeable to them.

Look at the Apollo manned lunar project conducted by the United States in the 1960s. If it were not for the underlying major goal of the two main Cold War nations trying to best each other via space, it is more than likely we would still be talking about sending humans to the Moon some day in the future. Just look at how we haven’t left LEO in person since late 1972 because of changes in the geopolitical climate.

Later on at the same conference I talked with some other SETI scientists about a METI type of idea that had intrigued me since I read author James Gunn’s 1972 SF novel The Listeners, where a civilization circling the star Capella sends humanity all its knowledge because its sun is going to explode and they know they cannot escape it otherwise (at the very end of the novel, it is revealed that a similar broadcast is also on its way to Earth from the region of the Crab Nebula, the remnants of the famous supernova of 1054 CE).

This made sense to me, as a sophisticated culture would not want to die off in vain and disappear completely from existence. They also would have nothing to fear or lose from signaling the rest of the galaxy about themselves. Not only would they remain alive in their records and the memories of others, but perhaps their knowledge might even enlighten and enrich their neighbors. And they wouldn’t be around if the recipients weren’t friendly in any event.

DNA radiotelescope

Image: Even a description of DNA could be sent to the stars. Art by Jon Lomberg (from the collection of Frank Drake).

I brought up this idea to these SETI folks, who surprisingly dismissed it out of hand. Maybe some things have changed in the last ten years, but I got the distinct impression that at least some of those who work in SETI thought that aliens would contact us purely for the good of increasing scientific knowledge. Or as I said above, the focus from these researchers seemed to be on the methods of interstellar (and intergalactic) signaling, not the potential range of reasons behind it, which is no small factor here.

Maybe there are such enlightened and altruistic societies out there with only those pure motives in mind. Certainly I am taking educated guesses here as much as anyone else from this planet. But just as Apollo happened mainly to showcase international and ideological might with science taking a backseat despite how NASA presented things, I am willing to bet that any alien species, even an insane one, will be conducting such a major undertaking as a sustained METI effort with more than one motive in mind. Certainly these motivations will include improving the various situations for the signalers.

evpatoria

Thus my desire to focus on delving into *why* any race of beings might want to conduct METI, especially one designed to last for many years and cover much of the galaxy, which would make sense if you don’t know who your neighbors are and you want to make sure to hit as many potential targets as possible. As a bonus for humanity, figuring out why an intelligence might want to signal us will help narrow our search in that very big celestial haystack out there, saving our SETI projects money, time, and resources in the process.

Image: The Evpatoria radio telescope in the Crimea, from which several METI signals have been sent to the stars.

The following is a short list of ideas I have created to consolidate my thoughts on why an alien intelligence would conduct their own METI program. It is certainly not meant to be complete and other ideas are welcome.

1. An ETI signal is intercepted by humanity by mistake. This would be an ETI message aimed our way by accident that was intended for someone else. Obviously, this one could come from anywhere at any time.

2. A “stunt” message, just like certain groups of humans have been doing lately by broadcasting Beatles songs, Doritos advertisements, and personal messages towards nearby star systems. I would even put the possibility of a practical joke in here, as some aliens may be as big a bunch of wiseasses as we are. Note how often humor is left out of the equation when considering the motives and behaviors of other intelligences. Why can’t they laugh about the absurd as much as we do? It may be not only a sign of intelligence but also a survival mechanism in this often bizarre and frequently dangerous Universe.

These messages could come from just about anywhere, but they have the serious drawback of being of very short duration. Only recently have we started more than a handful of consistent SETI programs, and even they are limited to a few electromagnetic realms and often with numerous gaps in data gathering time.

3. A deliberate “ping” to get our attention to open up a dialogue and information exchange. This can range from sheer scientific curiosity to the need for something they don’t have but we do (Nachos?). They may also be doing this for darker motives, from seeing who is out there to convert, conquer, colonize, or outright destroy. After all, if one species can colonize the whole Milky Way galaxy in just a few million years as has been asserted, others may find that to be a very legitimate threat to their existence and want to stop such a problem in advance.

I would like to think that 400 billion star systems across 100,000 light years of space should be room and resources for lots of beings – but when did logic ever play into certain motives when it comes to survival?

I have always always been a bit skeptical of the idea pushed by Carl Sagan about advanced intelligences broadcasting the equivalent of the Encyclopedia Galactica around the Cosmos to anyone who might want it. No one in their right mind goes around sharing every detail and secret of their lives with unknown and unpredictable strangers, so why would even an advanced species want to share their knowledge and power with potential rivals? Plus as SF author David Brin has pointed out, information unique to us may be our one bargaining chip with alien societies and we would not want to give it away for free.

4. A flood of information from a society that knows it is going to be destroyed not only as a species but their knowledge and works, too (see above). Having little to lose or fear from their information being used against them, these ETI send us and others all that they know to preserve themselves at least in data form.

This is one legit reason for SETI to aim its instruments at novae, supernovae, hypernovae, and GRBs, along with red giants, white dwarfs, pulsars, and even black holes. Supernovae are also important to check out for signals from non-threatened ETI who might use them as natural cosmic beacons.

5. Really advanced beings might signal us to say things like “Hey, we’re the big guys on the block – don’t even think about messing with us” to “We need your solar system for our latest Dyson Shell Galactic Mind Expansion Project, thanks ever so much” to “Hey, Charlie, we found some more vermin over here – get the Raid!” These guys might be found around the galactic core, in globular clusters, around black holes, or way out in the very cold fringes of the galactic edge.

To be honest I think we will have a better chance of finding them by their infrared signatures or astroengineering structures, as I don’t know if such beings would ever bother talking to us, but obviously I could be wrong. They might message us just because they know they can and cannot be harmed by us. People have been known to poke a stick in an ant colony just to see how the little insects will react.

arecibo

Of course, G class stars with exoplanets where the Jovian-type worlds are not orbiting their suns in a matter of mere days and could therefore have Earthlike worlds (or habitable exomoons orbiting any Jupiter-type exoplanets) are potentially good bets too. And we might have beings exploring or colonizing all kinds of other star systems such as red dwarfs, but whether they would be doing METI as well is another matter.

Image: The Arecibo radio observatory in Puerto Rico. It was during the dedication of this facility that a message toward the globular cluster M13 was sent. Credit: SETI Institute.

Now there have been a number of legitimate METI projects over the years emanating from Earth that were not just stunts. A list of these efforts may be found at the Wikipedia entry on Active SETI. While these information messages were put together with some thought and planning and were sent out using powerful radio telescopes, they still suffer from being relatively brief in duration and therefore have limited chances of being picked up by unsuspecting (and hypothetical) alien species.

As one example, the Arecibo Message of 1974 to Messier 13 was just three minutes long. What are the odds that even if there are a fair number of suitable ETI living in that globular star cluster 25,000 years from now that even one of them will just happen to detect that transmission as it zips along? Not even the “covert” 20-minute METI effort by Joe Davis of MIT in the early 1980s has much better odds of being detected in the Milky Way. More recent METI broadcasts have all been narrowly focused and capable of being received by relatively few stars.

The shortness of these METI efforts is why I left them off the list but wanted to mention them just the same. ETI could be doing similar such broadcasts, but the odds of our detecting them with our current SETI programs are slim. Thus our chances lie with the sustained METI programs, which as has been pointed out already, may have some very interesting reasons behind their existence.
 
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Comments on this entry are closed.

  • Thomas September 18, 2009, 10:32

    Regarding #2, what if indeed it’s the opposite? What if they ping us to tell us to shut up and quit spamming them?

    (just an idea)

  • yeti September 18, 2009, 11:16

    always thought an S.O.S signal might be a good reason for a ET civ to send a signal. Maybe they can forsee a disaster that is thousands or millions of years in the future and they dont know how to stop it. They may send out a signal asking for help at the same time as working on the problem themselves.

    Perhaps our best bet is detecting leaked signals rather than deliberately beamed ones. If an ET civ was conducting a NEO (near earth object) program searching for rogue asteroids we may pick up these radar signals if they are strong enough.

  • Michael T. September 18, 2009, 12:51

    Thanks for the thought provoking post. It got me to thinking about our current efforts to detect extra solar planets and even the possibility of spectroscopic determination of atmospheric composition – truly amazing. If we fast forward say 20 years or more then no doubt we will have discovered lots of interesting maybe even habitable worlds. If there are any advanced ETs out there then it is likely they may or have employed similar approaches. Could it then be possible that the proverbial needle in the haystack (Earth) has already been identified as a planet of interest. And given this, any SETI/METI efforts should be directed at those worlds we are likely to find in the coming decades.

  • Paul Titze September 18, 2009, 13:16

    Hi Paul,

    Interesting thoughts on SETI/METI. Assuming there are other teachnologically enabled civilisations in our galaxy, the chances of detecting messages from them are slim for the reasons you mentioned. Given the vast distances these messages would have to travel just to reach us at the “slow speed” of light forbids any practical conversations with these ETIs as well. They may prefer to keep queit or send an occasional broadcast or a continuous beacon for whatever reasons. We may be bathed in their signal right now and not know about it because we are listening/looking at the wrong frequencies/direction. Even if we do detect their signal, that civilisation may no longer exist by the time we receive it due to the reasons you mentioned (star going into supernova etc) and the signal transit times.

    I think looking for side-effect signs of advanced civilisations is more promising as you mentioned astroengineering structures, interstellar internet networks, ET navigation beacons?

    Either way we’ll only be spectators in our galactic neighbourhood unable to participate in a friendly conversation with our neighbours unless we come up with a practical solution to interstellar flight.

    Cheers, Paul.

  • Jeff Noyle September 18, 2009, 13:38

    A thought on point 3 (the “ping” scenario):

    It seems clear to me that any industrially-capable intelligence like ours must evolve towards machine instantiation. Either our machines overtake us and raw humans become the irrelevant intellectual have-nots, or we learn to integrate ourselves with machines, either by mind-upload or slow integration and replacement of our biological minds with the mechanical.

    If digital intelligence is thus the common case in the Universe, then interstellar messages should be thought of as _travel_, rather than communication.

    The nice thing about commuting by transmission is that you don’t experience the jet lag, so to speak. The mere extra few centuries of delay induced by not having straight-line communication is not relevant (since the traveler is merely “paused”), but the error rate induced by long-distance comm is a concern. One is therefore tempted to imagine a galaxy-spanning network of routers used by ETIs to travel over many shorter hops. These routers would be close to power supplies that are stable over tens or hundreds of millennia, i.e. stars.

    So if a ping is going to come, it’s going to come from one of the nodes in this network. So perhaps we should look at the kind of stars that represent the best ratio of available energy versus noise. Now, the noise that’s relevant is that part that is emitted along the connection paths of the network and would therefore be interfering with the signal. So, we can find candidate node stars by figuring out which pairs of stars are a) close and b) have very few noise sources behind them from the point of view of the other star in the pair.

    -Jeff

    p.s. I’d just like to gush a bit about your blog. It is filled with exuberance and humor and excitement and is _much_ more interesting than the compiler that’s waiting for me on my other monitor. Thanks for all your posts.

  • Administrator September 18, 2009, 13:57

    Jeff, you’re more than welcome, and I much appreciate your thoughts.

  • tacitus September 18, 2009, 14:03

    Larry, intergalactic METI may be driven by sheer loneliness. What if it turns out that we’re the only intelligent species to evolve in this galaxy? And what if intelligent life is so rare that it evolves only once or twice in any galaxy?

    Assuming we succeed in becoming a galactic civilization and find out that we are alone, we will have two choices if we want to find companionship outside of own species — create our own (uplift, guided evolution, etc.) or seek it out further afield — Andromeda and beyond.

    The time involved will not be a issue for a mature civilization, assuming that death has become optional by that time, and the distances involve means that even if you stumble across a hostile civilization, they would almost certainly never become a threat — heck, they could even evolve out of being a hostile species in the time it takes to cross between galaxies!

    Closer to home, one could see it happening on a smaller scale. If interstellar travel simply proves too difficult to accomplish, then we are stuck in our island solar systems, and at some point I suspect we would feel the need to reach out and touch someone — even if by long distance radio communications. The equation is a little different, since we should eventually have a pretty good idea of what’s out there — at least within a few hundred light years of Earth (via fleets of Terrestrial Planet Finders, etc.) — and would be able to target any METI program specifically to worlds that show signs of harboring a technological civilization.

    I like the idea of a dying civilization broadcasting its science, culture, and history out into space — though I suspect such a message may, at least in part, announce the existence of, say, a fleet of spacecraft launched into interstellar space, that contained the full set of information (just in case you missed some of it!).

    The message could also be a lifeboat. If the aliens broadcast their genome (or equivalent) into space, then theoretically there is nothing to stop an advanced civilization from reconstructing it and thus resurrecting the lost alien species. Of course, there is always the risk that your resurrected descendants could become nothing more than a zoo exhibit, but I suspect that most doomed civilizations would take that chance.

    Finally, a word on the risks of METI. Frankly, the odds of any METI increasing the threat from an alien species is very low indeed. As I have said before, Earth is not hidden away out of sight. Our bright blue ball is broadcasting its presence hundreds of light years in all directions. All you need to do is build a telescope sensitive enough to see it, and the impact life, and our civilization has had on it. And said telescope is likely orders of magnitude easier to build than any interstellar craft. I don’t know the practical limits of the detectability of Earth (it would be great if a professional astronomer could chime in) but I suspect that our presence on Earth would be no secret to any civilization that was merely a few centuries more advanced than us within at least 1,000 light years or more.

    Remember, the Kepler mission may detect another Earth-like planet as far as 15,000 light years away within the next three years! (Yes, I know, it’s a special case and we will not be able to image planets at those distances — yet — but give us another couple of hundred years…)

    So *if* there are hostile aliens out there nearby, then we’re likely doomed anyway, METI or no METI, since they already know we’re here (or will be once the spectrographic signature of our technological civilization reaches them (that possibly only out to 100-150 light years so far, so there could be time!). The only sensible thing to do is to continue developing our own planet-finding capabilities so that we can at least check to see if there is anyone out there, within striking distance.

  • Edg Duveyoung September 18, 2009, 14:26

    I think this discussion is somewhat “valid” now, but it is such a “blink” in our technological history — like rocks at the edge of a waterfall that are about to fall “very soon” in the next 100,000 years — that this discussion is doubtlessly going to be laughably off the mark in less than a decade. And, in far less than a few decades, we’ll certainly going to have had one or more singularities occur that obviate most of the issues about METI and SETI. If true A.I. is achieved, then we will know that that “solution” is available to all other ETIs, and thus, time and speed limitations for propagating knowledge are largely attenuated if a “robot” can travel “forever.”

    But it doesn’t have to be A.I. or other singularities, it can merely be “technological advancement that is only a matter of time” that routinely comes about that will reframe this discussion, e.g., our ability to see other planets is improving by significant notches and will “shortly” be able to observe other planets so well that if we do happen upon one that has life or intelligent life, we’ll be able to deduce that EASILY. Already we’re examining the spectra of the atmospheres of many space bodies, and much can be derived from but scant few photons received. Is it reasonable to expect that we might have the ability to “read license plate numbers” on other planets as do our spy satellites do today? I think so — think gravitational lens and large lens arrays on the moon’s backside etc.

    Nor, does the present discussion consider that psychology is impacted by technological advance, and that what the motivation of an ETI would be is probably UNimaginable by us until we too can, what?, teletransport, move faster than light, change any matter into any other type of matter, etc. And these things are, if possible at all, just “around the corner for us.” Think about how scientists thought of alien civilizations 100 years ago as opposed to today’s considerations. Technological advancement increases the imaginative potentials.

    Given what we can reasonable expect to achieve on Earth in the next 100 years, we’ll be very close to being gods with our minds wirelessly connected to all sorts of instrumentalities — we’re not going to be thinking the same way if we get our human powers amplified, borgified, and fitted with afterburners.

    Nor will the ETIs out there be anything but gods with godlike plans. And it will be a matter of kind — not degree — that such gods will present to us. We simply cannot anticipate their minds without experiencing and getting jiggy with super-empowerments we can reasonably expect to have in the next 100 years.

    Edg

  • kurt9 September 18, 2009, 14:31

    Looking for artifacts seems a more fruitful approach than trying to eavesdrop on essentially cell phone conversations. Perhaps looking for anomalous deposits or absences of minerals may indicate alien visits to our solar system in the distant past (say 540 million year ago). Maybe those natural nuclear reactors in Africa are actually alien artifacts from 1.6 billion years ago.

    http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml

  • Tuguldur September 18, 2009, 16:56

    we dont necessarily send messages to get replies. Of course it would be great if there we’re replies, but that is not the ultimate reason for sending stuff. I think ur question u asked from the SETI guy is itself pretty ‘silly’.

    just knowing that somebody is really out there has big enough implications.

  • Adam September 18, 2009, 18:07

    Hi All

    Larry, what an excellent piece. Does make the prospects seem rather different to the old SETI tropes. I think the Benford-Trio covered similar lines of reasoning in their twin papers from not so long ago. Another option, more difficult to initiate, is trade in information. The ETIs send software Agents our way to handle their real-time affairs and beam back the direct proceeds, while handling local ‘cash’ matters. Made for a good series of stories in “Analog” recently, but it’s far from an absurd idea. Certainly cheaper than flinging cargo between systems at relativistic speeds – at least until electromagnetic deccelerators are available for regenerative braking.

  • James M. Essig September 18, 2009, 20:58

    Hi Folks;

    I just got off the phone with a good buddy of mine where we discussed a mechanism for storing the entire set of available information ever generated by we humans in symbolic and/or digital form and then sending these information pods out in droves throughout the galaxy.

    Assuming a one cubic centimeter device can store information on the scale of cubic nanometer cells, the cube might store roughly 10 EXP 20 Bytes assumming 8 bits to a bit. This data might be encoded in some form of layered arrangement using some form of graphene stencils with cut outs to represent all of the summarized scientific, cultural, technological, religious, philosophical, political, historic, demographic and so on data compiled by our civilization. Even classified research such as in black aerospace projects, high energy density materials, lasers, particle beams, C3I technology and the like could be encrypted on these graphene cubes.

    We could launch millions of such cubes per year, and when manufacturing technology was ramped up, we could eventually send out billions per year.

    This would be an excellent way of doing SETI at our end. Note that graphene sheets one atom thick are theoretically even stronger that the theoretical maximum strength of carbon nano tubes.

  • Gregory Benford September 18, 2009, 21:28

    Adam:
    What were those stories? I’m behind in my reading, alas.

  • Tulse September 19, 2009, 0:27

    Regarding 4, presumably there would be little point in targetting the remains of stars, since no broadcast device is likely able to survive a star’s violent death (any culture that could build such a device could likely come up with a way to ensure its own survival). What we’d need to do is target suns that are about to die, but I’m not sure how easily we can determine that to any useful temporal resolution.

  • Ron C. de Weijze September 19, 2009, 5:53

    Why METI? How about msg time traveling NOT as ‘slow’ as it is thought, e.g. through (QM) wormholes.

  • James M. Essig September 19, 2009, 9:07

    Hi Folks;

    Regarding the graphene modules concept in my previous post.

    If rotating black holes have wormholes affixed or proximate with respect to their center structure which theoretically exist in the form of a rotating ring like structure, perhaps these grapheme pods can be send toward the super massive black holes that have been found to exist within the center of our galaxy, or even into mid-range black holes that might populate our galaxy, whereupon some of these grapheme pods would enter a space-time wormhole and enter another universe, a parallel universe, or perhaps a remotely located space time region within our universe, past, present, nearly present, or future.

    Just think, in time we could send out trillions if not quadrillions of these pods using nothing other than ordinary chemical rocket technology as we used for getting Voyager I and Voyager II beyond our current planetary solar system.

    Another option is to selectively dope the graphene modules with quantum dots made of one or more refractive elements or alloys such as tantalum, tungsten, titanium, iron, and the like. Since the inclusion of such refractive and dense elements having a high bulk modulus for the purposes of representing bytes can add additional information, even more information could be encoded in the modules than simply using the above stenciled approach.
    However the modules would be fabricated, one or more keys could be included so that the data could be decoded.

    If we could eventually send out quadrillions of these modules, I can not help but think that at some future time, an ETI civilization would find them. If we specifically directed some of these modules on a collision course with the super massive black holes that reside near the center of our galaxy, I would think that some of them would enter one or more of these black holes and pop out God knows where.

    Alternatively, the modules might be launched with space based mass drivers that could accelerate the modules to 0.01 C to 0.1 C whereupon the modules would be free to roam intergalactic space essentially for eternity. The modules might be fitted with a set of high strength magnets so that they effectively have a mini-magneto-sphere which would help shield them from cosmic rays and the resulting degradation that could result over eons.

    Another option is simply to send out spheres with a diameter of about 1 meter composed of grapheme wherein the volume occupied by the individual bits and therefore the bytes is considerably larger so as to avoid environmental degradation within the radiation filled vacuum of space. We could launch a few of these probes per rocket on a trajectory that would take them into interstellar space.
    Eventually, when nuclear propulsion systems are developed, we could send these pods out in droves at speeds as high as 0.01 C to 0.1 C.

    What a perfect gift to the future citizens of the Milky Way and even the visible universe, whatever forms of life these future persons might take.

    Sending out simmilar information pods is something we can do with current technology and ordinary chemical, radiothermal generator powered, or solar PV powered electrical propulsion systems.

  • Adam September 19, 2009, 16:09

    Hi Greg

    Edward M. Lerner’s Interstellar Net stories…

    http://www.analogsf.com/0607/interstellar.aspx

    …he discusses the science behind them and gives a list of stories so far. The last one was a multi-part short novel which asks what happens when the aliens can finally come visiting. They picked up some rather nasty passengers on the way in this case.

  • Athena Andreadis September 19, 2009, 17:11

    I enjoyed Larry’s article and Jon’s lovely image, but I think we should hold off on covering trodden ground at least until the CoRoT mission finishes gathering evidence. Already, rocky planets are popping into view.

    As for ETI, a picture (or cartoon) is worth a thousand words: The Search

  • Duncan Ivry September 19, 2009, 19:37

    The article by Larry Klaes is interesting and valuable, because it brings more rationality into the discussion about why alien civilizations should and will talk to each other. I hope somebody will find the following contributions useful.

    1. Motivations of scientists

    The behaviour Larry experienced when asking those scientists some questions may partly be caused by the phenomenon of the “two cultures”, i.e. the insufficient communication between the participants of the natural sciences and those of the humanities. Many, if not all, reasons for communicating with alien civilizations originate in areas, where the humanities are in charge — Larry described some of these reasons. Unfortunately too many natural scientists are not interested in these things and don’t know enough about them (it’s the same with the participants of the humanities in the reverse direction).

    2. More reasoning about the why of communication

    In history here on earth in the past and today we see a lot of different cultures. As examples the cultures in China or in various parts of Africa have been and still are rather different from the culture of the West. As a further example the modern European culture is very different from the medieval European culture — yes, indeed, some European historians say, a modern European human, being moved into medieval time, would feel like being on a different planet.

    We should expect civilization on earth in several hundred years from now to be again very different from today’s civilization. This change will include some of the motivations for talking to alien civilizations. It’s plausible, that there will be motivations completely — yes — alien to us today.

    Taking this one step further, we should assume, that civilizations on distant planets, which are completely alien from the beginning, may have completely alien reasons for communicating — or not communicating (I don’t exclude the existence of civilizations not so different from our own). I think, finding out completely alien reasons, will be very difficult.

    The above implies, I think, that the question about the why of interstellar communication between different civilizations, especially about the why of METI and SETI, has found some good answers already by Larry Klaes, but still remains wide open. As Athena Andreadis said “we should hold off on covering trodden ground”.

    3. Difficulty or impossibility of communication?

    The sociologist Niklas Luhmann created a sociological theory, the most important element of which is communication (his opus magnum: “The Society of Society”). Luhmann says, that, beginning in the 20th century, there is one and only on society on earth, which is a closed system having no understanding for the way other systems perceive their environment. Well — Luhmann’s publications are very difficult to read, and I’m no sociologist — I don’t know if this implies, that communication between our society on earth (our civilization) and alien societies on distant planets (alien civilizations) is fundamentally impossible, or at least much more difficult as we usually think.

  • ljk September 19, 2009, 20:12

    I really appreciate the great replies I have read in this thread.
    I want to reply to as many of them as possible when I get the
    chance to focus on them properly.

    For the moment I want to remind everyone that today is the
    fiftieth anniversary of the science paper that started the
    modern SETI era.

    On September 19, 1959, the science periodical Nature published
    a paper written by two Cornell astronomers about the possibility
    for using certain radio frequncies as a means to detect and
    communicate with beings around other suns in the Milky Way
    galaxy.

    Their idea caught on with people like Frank Drake, who began the
    first modern SETI effort called Project Ozma in 1960. While most
    SETI programs have been sporadic and focused on radio waves, a
    half century after the famous Morrison-Cocconi we are finally
    started to see both truly dedicated SETI projects and efforts
    focused on other areas of the electromagnetic spectrum. Even the
    idea of alien probes in our Sol system monitoring us is finally
    starting to be taken seriously.

    Last December I wrote an article on the passing of Cocconi that was
    posted on Centauri Dreams here:

    https://www.centauri-dreams.org/?p=4914

    This piece describes Cocconi and Morrison’s early ideas on the
    subject and contains a link to the original Nature paper. I also
    reproduce their famous quote at the end of this landmark paper,
    which still holds true today.

  • Elon September 19, 2009, 21:49

    Re: “1.An ETI signal is intercepted by humanity by mistake.” and it’s “router” style pair-search comment: “we can find candidate node stars by figuring out which pairs of stars are a) close and b) have very few noise sources behind them from the point of view of the other star in the pair. -Jeff [Noyle]”

    I’d add, for likelihood of interception: c) are roughly co-linear with Sol.

    In order to increase the odds at eavesdropping in the edges of a relatively tight beam. I’d think c should be judged by a metric balancing: the deviation of Sol from the line between the pair; and the length of the line. (using a prediction of likely beam diffusion — for instance, equal power at a given deviation distance is generally proportional to the square of the total distance, isn’t it?)

    Since it’s hard to figure noise for b not knowing the transmission method, for b a simple first assumption could be that all stars are equally noisy. Then a, b, c together should be pretty easy to compute given a list of stellar coordinates. Is there one handy?

    Due to how empty nearby interstellar space is, I’d guess the top targets found this would be way above the rest.

  • tacitus September 20, 2009, 0:17

    Duncan, I doubt very much that communicating with alien civilizations (assuming they exist) could be fundamentally impossible–assuming the technological lines of communication have been opened–simply because we will have so much in common.

    Of course, I don’t mean sociologically or culturally–we could be light years apart in those terms–but simply put, we share the same universe. In other words we all live according to the same physical laws of science and thus we have a very broad basis for a common understanding.

    That’s not to say it won’t be difficult, especially if one is, say, a million years more advanced than the other, or the structure of the societies are very alien to each other, but given a mutual good faith effort, I suspect it would (will?) be easier than most people would think.

  • tacitus September 20, 2009, 0:33

    James, that’s an interesting blue sky vision you have there in terms of discussing the technology behind an effort to ensure our legacy would live on, but I just can’t see any circumstances (beyond some unforeseen, but predictable disaster in the next couple of centuries or so) where we would ever come together and commit to undertake such a task.

    Assuming we had enough time to develop the wherewithal to do it, I suspect all efforts would be focused instead on our own survival, not just the information we have accumulated. Even if that meant the survival of only a small proportion of the human race, it would suck up all the available resources to improve the chances of success.

    Now, if saving the human race meant sending some of it out amongst the stars then it would obviously be a good idea to send as much of our accumulated knowledge as possible along with them in the hope that civilization can be started elsewhere, so some of the ground work for your proposed effort (the gathering of the information) would be necessary anyway. And perhaps, as the ultimate last resort, the data set would include the genomic information of enough people to allow some future advanced civilization to recreate a breeding population which would reclaim the informational heritage discovered alongside.

  • Marc Millis September 20, 2009, 11:34

    Thanks for this article and to those who posting their reactions. I like it. What I really enjoyed was the observation that the SETI and METI enthusiasts seem more focused on the ‘how’ than the ‘why’. I’ve run into this peculiar situation too when trying to coax a substantive rational for METI from Dr.A.Z.(unsuccessfully)

    And that made me think of another motivation transmitting … that the individual sender is just trying to feel important. This worries me because such private actions have consequences that affect all of humanity.

  • Adam September 20, 2009, 16:23

    Hi All

    Rose & Wright pointed out a few years back that sending “messages in a bottle” was more effective than sending electromagnetic signals as a means of passing on large amounts of data. If such were propelled by solar-sails the energy cost would be minimal and speeds of ~0.001-0.01 c feasible, allowing dispersal across the Galaxy. We’re not that far off from being able to do so ourselves, even privately. But would we know a message bottle if we found one?

  • Joe Davis September 20, 2009, 17:02

    Larry,

    I have two comments for you. The first is excerpted from a paper I wrote for College Art Association’s Art Journal (Spring, 1996) and I think it may help to answer the principal question put forth in your article:

    “Any message to extraterrestrial intelligence is about Homo sapiens. Whoever discovers and interprets such a message correctly will have to be like Homo sapiens in many respects. Similar abilities to read and write language are called for; to relate to nature with a scientific attitude; and, if the message is visual, to see. Whoever receives the message will therefore require both physiological and psychological parity with the human beings who transmitted it.

    Ultimately, by sending messages to extraterrestrial intelligence, human beings are even more importantly engaged in a search for themselves. If message-senders are to reveal themselves to anyone else, they must first reveal themselves to themselves. This has not only been a central dilemma in the search for extraterrestrial intelligence, It has also been an essential ingredient in the body of art, poetry, history, psychology, …etc., and an important problem in classical philosophy.

    Aristotle called it the principal of recognition and reversal [Aristotle: Theory of Poetics]. Recognition (or anagnorisis, in Aristotle’s theory of tragedy) of a message for extraterrestrials implies a reversal to re-transmit the signal to human beings. The tragedy, recognition and reversal, is that the loneliness implied by the search is perpetuated by the futility of attempting to communicate with anything ultimately other (including, unfortunately, other human beings). Yet far from being a reason to refrain from creating and sending such messages, serious efforts to contact extraterrestrials will necessarily raise the vital questions: Is this what we know? Is this who we are? – and thus revealing the need to continue the search.” [Excerpted from “Microvenus” – Art Journal, Spring 1996, College Art Association]

    My second comment addresses more practical issues that your article also brings to mind. As I see it, the three biggest technical problems associated with METI are

    1) as you rightly point out, METI delivery system operations, even relativistic ones, will require very long periods of time.

    2) [actually a subset of the first problem] messages and message carriers must not only remain intact or “viable” for periods of what we would call “geologic time”, they must also be able to withstand the harsh environments of interstellar space including temperature, vacuum, radiation, etc..

    3) in order to allow for even remote chances of successful METI, many billions of messages must be created for many billions of targetable star systems .

    With these problems in mind, it seems to me that prospects for biological METI carriers continue to be grossly underestimated.

    Note that our most successful biological messages for ETI may be entirely inadvertent ones:

    http://www.telegraph.co.uk/science/space/6206742/Astronaut-urine-spotted-in-skies-above-North-America.html

  • tacitus September 20, 2009, 19:57

    And that made me think of another motivation transmitting … that the individual sender is just trying to feel important. This worries me because such private actions have consequences that affect all of humanity.

    This will certainly happen if and when we discover evidence of life on another planet (outside the Solar System). It won’t even matter that we haven’t confirmed that there is anyone or anything capable of receiving what we’re sending. Indeed, even if there is only a hint of the presence of macroscopic life forms somewhere, I would expect a multitude of cultist groups to form, at least one of which would likely be well funded enough to attempt communication.

    But you would have a very hard time convincing me that there any dire (or even very detrimental) consequences of such actions. If we are capable of detecting them, then they almost certainly already know about us, especially if they are in a position to be any kind of threat to us. If our rogue message is the first they’ve heard of us, they won’t have the interstellar capabilities to act on any intelligence they might gain.

    I guess if they think that we’re completely bonkers having heard a few cult-originated messages, that might be a tad inconvenient, but nothing that a few explanatory follow-up messages can’t smooth out!

  • Mark September 20, 2009, 21:53

    Whenever I think about communicating with alien intelligence, I think about the intractable difficulties in communicating between human races displaced in time and across culture.

    Take the ancient Egyptians for instance. If there had been no Rosetta Stone, would we have ever been able to decipher the hieroglyphics? What about the Mayans?

    Thought experiment. Earth and a nearby planet (say a Mars capable of supporting life) evolve identical human races except with one difference: say on Earth, only English-speaking culture evolved. On Mars, only Chinese speaking culture evolved. If communication were to be established between the worlds, would Earth ever decipher the Chinese language? Would Mars ever decipher English?

    We also have intelligent species on earth that are perhaps millions of years behind us on the evolutionary timescale. We can’t speak Dolphin. Maybe they’re a million years ahead of us. They can’t speak English. We’re certainly millions of years advanced from dogs. We can’t speak dog. Best we can do is train them, but we really can’t bark at them, or synthesize barks that communicate to them half as well as they do among themselves.

    With regard to the idea of shooting tiny informational cubes out into the universe… My first thought is we’ll get a ticket from the galactic police for littering. Who knows what these millions of tiny cubes would do to the hull of faster than light ships? We might really get off on the wrong foot by doing that. Hell we might even get in trouble for the Pioneers and Voyagers. Can you imagine the havoc that would be caused if a primitive and isolated society independently invented jet airplanes and began flying them without benefit of hooking in to the global air traffic control system?

  • Bruceleeeowe September 21, 2009, 0:29

    About METI, I’m not sure, even if any intelligent civilization or ETI whatever you say, with an different biochemistry and environment exists, it don’t seem likely, they would recognize our signal or decode it because it is more likely that they may be using a different type of radiation for such communication.

  • Ronald September 21, 2009, 4:25

    I agree with tacitus that the main reason for any civilization to try to communicate with another one may be the realization of ‘cosmic loneliness’ and the fundamental desire of (any?) intelligence to communicate, something that we also see, for instance, among (other) primates and dolphins.
    Potentially suitable terrestrial planets and biological life may be quite common, but advanced intelligence exceedingly rare.
    Furthermore, any intelligence, in order to make it as a techno civilization, will need to be social, cooperative and reasonably non-violent (or at least self-restrained with regard to violence), a strong self-selection mechanism. The loners, brutes and anti-socials just don’t make it.

    At the same time, the window of opportunity for any civilization may be very short, we just don’t know yet, something which would make advanced civilizations occurring at the same time even rarer. This would in turn greatly enhance the (awareness of) cosmic loneliness.
    I think that any existing advanced civilization would be fully aware of this, and this very awareness, plus the innate desire to communicate and exchange information, plus the inherent cosmic abundance of resources, would easily overcome the more primitive instincts with regard to resource competition, fear of hostility and the galactic pecking order.

  • Darrell E September 21, 2009, 12:40

    Mark September 20, 2009 at 21:53
    Whenever I think about communicating with alien intelligence, I think about the intractable difficulties in communicating between human races displaced in time and across culture.

    Take the ancient Egyptians for instance. If there had been no Rosetta Stone, would we have ever been able to decipher the hieroglyphics? What about the Mayans?

    A very significant difference between the two types of scenarios that you postulate is that in the one case you have two extant intelligent species that are actively trying to learn to communicate with each other. In the second scenario you have one extant culture attempting to decipher the written communications of a long dead culture with no living representatives around to help.

    Ronald September 21, 2009 at 4:25
    Furthermore, any intelligence, in order to make it as a techno civilization, will need to be social, cooperative and reasonably non-violent (or at least self-restrained with regard to violence), a strong self-selection mechanism. The loners, brutes and anti-socials just don’t make it.

    I don’t know about this. Currently we have exactly one example to study, ourselves. While we have gotten better about killing each other, we still do kill each other in large numbers, and there are plenty of loners, brutes and anit-socials among the world’s population. I HOPE this changes for the better as we advance into a future where we realize our scientific and technological dreams. But, I don’t see WHY we, or any species, would HAVE to become uniformly near perfect model beings in order to advance to a very high level of technology.

    In general I think it is premature to hold any position strongly, make strong assertions or statements, about alien life, ET civilizations or cultures, and escpecially about ET behavior. There just ain’t any data to go on. Speculation is fine, but don’t get too attached to any one idea. It is one thing to try and determine constraints based on our understanding of how reality works as discovered through our use of science. It is quite another thing to try and desribe how an alien culture would behave based on our imaginations informed only by our experience with our own species cultures, when we have no evidence that our culture, behavior or psychology, is in any way similar to any alien species.

  • ljk September 21, 2009, 13:22

    I want to thank everyone for the wonderful and informative responses sent to this topic so far and I hope to see more.

    Here I hope to answer some of the numerous questions and comments posted regarding my article. My replies will come in a series of posts in this thread to make things easier to digest for both sides.

    I was deliberately a bit vague on the communications methods that the hypothetical alien METI participants might use so as not to restrict their means of transmitting to the radio realm. I also did not want to get caught up in delving too deep into the methods of interstellar communications, as that would detract from the WHY factor of METI and therefore the whole point of my article.

    However, I would refer to radio as a “default” method because if an ETI was trying to get the attention of others in the galaxy for initial communication purposes it may be assumed that the potential recipients are not highly advanced and radio might be one of the first methods of interstellar communication understood and deployed by beings such as… humanity. If the whole point of a sustained METI project is to get the attention of an alien species that is not a Kardashev Type 2 or 3 civilization, then starting with something easy and (hopefully) universal is the smart way to start.

    As a real life example, look at the image contents of the Voyager Interstellar Record: While the beings who would be able to detect, capture, and study the probes and their records in deep space will require sophisticated interstellar travel capabilities, the human record makers opted to start off with simple imagery and mathematics because they rightly assumed that an alien species might not think or act exactly the way we do no matter how fancy their technology. Hopefully anyone else conducting METI will also be that considerate to their celestial neighbors.

    Certainly lasers or neutrino beams are much better at sending lots more information than radio, but they need to be aimed at precise locations in space or the recipients will miss them entirely. Radio can cover a wide area and thus improve on the chances of being detected. Laser communications may come into play once the message senders have received a reply from a willing participant in an interstellar dialogue and they want to get past the prime numbers or their equivalent.

    Regarding physical messages sent across the stars, such as the aforementioned Voyager Records or a big black Monolith buried on the Moon, while they certainly have a better chance of keeping their messages and information intact unlike radio, which can be messed up by such galactic hazards as dust clouds and radiation, they suffer from several drawbacks: They might arrive much much later than a radio or light transmission; unless the senders send out a lot of similar information packages all over the galaxy, the “hard” communications methods suffer from being too narrowly focused just as the laser beams do; in the unlikely but not impossible situation that the recipients decide to reply by a similar method, it is going to be one long conversation and one of the parties might no longer exist by the time one gets back to the other.

    Uh oh, I am getting too SETI nuts and bolts here, better stop. :^) Next time, more philosophical musings yet again.

  • ljk September 21, 2009, 14:17

    Some folks have noted that an alien intelligence might want to signal the potential inhabitants of the Milky Way galaxy or other galaxies simply because they can or because they are cosmically lonely and want to converse with other minds out there.

    I got the feeling that some of these commenters thought I left out those ideas either because I didn’t think about those possibilities or I just plain rejected them.

    Neither was the case here, especially in light of the fact that certain groups of humans from this planet have already conducted such activities several times over and will very likely do so multiple times again in the future. It is certainly possible that other intelligent species, especially relatively young ones like ours who have just become aware and capable of transmitting into the galaxy, might want to shout out their presence to others for very similar reasons.

    As I stated in my article, the “problem” with even the serious METI efforts such as and similar to the ones from Earth, is that any METI project which is not constantly beaming messages into space on a regular basis across a wide spectrum and field for a long period of time is probably not going to be detected in such a big place as the Milky Way; certainly we won’t get these short-duration METI signals unless we very lucky.

    So I am not trying to reject or halt anyone’s exuberance or right to free speech; I am pointing out that if the senders no matter who or what they are want to be serious about getting a reply to their cosmic shout out, then they better have more than a little bit of technical know-how, resources, currency, time, and patience stored up to make their METI effort a reality.

    As I said before, maybe there are some enlightened societies who devote their time and money to purely enriching their minds and want to share and understand this knowledge with others.

    But here is the key item to note: The ETI who we expect to pick up with our various SETI projects will need to have at least a few things in common with our society. To find REALLY alien aliens may have to wait for actual interstellar expeditions (or a galactic neighbor who is kind enough to share such information with us). So our hypothetical METI senders may have the same issues we do with such non-trivial matters as where does the funding go to which projects?

    How many societies with limited resources will be willing to spend money and time on signaling unknown (and potentially dangerous) beings for many years? As I said, at our current level of SETI, we will need an alien species with a big sustained METI program or we will be waiting a very long time to find any galactic neighbors.

    At the risk of projecting too much humanity out there, one potential group type that might have little issue with using limited resources and time on METI would be the equivalent of religious fundamentalists. Look at how certain religions have spent money, resources, and time on such things as huge cathedrals and temples which they felt were for a higher purpose while pragmatically they could have been better used for more basic needs. Or missionaries who travel to remote places and risk (and sometimes lose) their lives to spread the word of their beliefs, forsaking comfort and even self-preservation in the process.

    This is the type of mentality and social organization that would have the will, coordination, and ability to conduct a big METI program. It may be presumptuous of me to assume that an alien species might have a religious or spiritual mindset as we do, but that may be the very first type of messages we get some day.

    And don’t kid yourself that religious groups from this planet won’t be conducting this very type of activity some day, so long as there are potential souls to “save” out there. Things will get very interesting if two such similar groups ever meet up one day.

  • tacitus September 21, 2009, 15:22

    And don’t kid yourself that religious groups from this planet won’t be conducting this very type of activity some day, so long as there are potential souls to “save” out there. Things will get very interesting if two such similar groups ever meet up one day.

    Absolutely, though it doubt it will be any of the current crop of organized religious fundamentalists who will do that, at least not until it has been proved conclusively that there is other intelligence life out there. They prefer to believe that Earth is special and the only place where God’s plan is being played out.

    But, as I mentioned in a previous comment, I suspect there will be plenty of cults/religious groups springing up if we find evidence of life on other planets (even in the absence of intelligence). People are already holding conferences where the headline speakers claim (in all seriousness) that they are in contact with aliens from Arcturus, Alpha Centauri, or some other star system that’s flavor of the month. Imagine the big tweak in the volume control of such claims if and when an Earth-like planet is discovered in the cosmic neighborhood.

  • ljk September 21, 2009, 15:27

    Tulse said on September 19, 2009 at 0:27:

    “Regarding 4, presumably there would be little point in targetting the remains of stars, since no broadcast device is likely able to survive a star’s violent death (any culture that could build such a device could likely come up with a way to ensure its own survival). What we’d need to do is target suns that are about to die, but I’m not sure how easily we can determine that to any useful temporal resolution.”

    If the ETI know their species is about to go extinct due to some big catastrophe
    such as their sun going supernova or a giant comet is about to strike their planet
    and they do not have the means to escape as a society, then they may have
    enough time to put together a means to send out information about themselves
    and their world before the disaster strikes.

    If they send all this data by radio or laser, the transmission will be moving at
    the speed of light and will therefore outpace even something as powerful as
    a supernova so long as it leaves their solar system before the star explodes.

    Assuming they do not have the time and/or ability to escape their world and
    system in person, they might also opt to place all their knowledge in vessels
    that can survive just about any cosmic hardship and launch them out of their
    system into the galaxy. The drawback is that unless they have the capability
    and time to launch a lot of data packages, it will be hard to find them unless
    they have locator beacons that are both powerful and long-lasting.

    On the other hand, a well-protected artifact in deep space can survive for a
    very long time. The side of the two Voyager Records exposed to space
    (behind a gold cover) is conservatively estimated to last 1 billion years in
    interstellar space, while the record side facing the probe itself should
    remain readable for much longer. And note that the Voyager Record team
    had only a matter of months to get the whole project together before the
    robot probes were sent off into the void.

    As for supernovae and SETI in general, it has been suggested that since
    exploding stars are some of the most obvious and powerful natural forces
    in the Universe, that they would make great ready-made beacons for
    getting celestial attention. A species could aim signals in the opposite
    direction from a supernova and hope that any other intelligences who
    have at least our level of astronomical knowledge and technology might
    detect their signals while observing the supernova. It is no less possible
    than many other SETI/METI strategies and has the merit of being one
    of the best ways to utilize a real galactic attention-getter.

  • ljk September 21, 2009, 17:20

    My replies to Joe Davis from his comments linked from here:

    https://www.centauri-dreams.org/?p=9489#comment-74722

    Carl Sagan said that the information engraved on the Pioneer Plaques and in
    the Voyager Records were for humanity as much as any alien intelligences.

    These early METI efforts certainly did stir up a lot of thought and commentary
    back when they were first revealed and to this very day. Indeed the plaques
    and records are often focused upon as much and even moreso than the main
    space missions these robot probes were sent on, which I think speaks volumes
    about this aspect of the contemporary human mindset.

    If I may, I would like to point out to folks your effort to “correct” several
    important missing items on the Pioneer Plaque here:

    http://www.viewingspace.com/genetics_culture/pages_genetics_culture/gc_w03/davis_j_webarchive/davis_profile_sciam/jd.htm

    As for METI efforts being purely biological in nature, I think we are finally
    starting to see “mainstream” SETI get beyond its radio roots and into other
    fields and realms such as what you have been recommending for a while now.

    It seems to take a while for a variety of reasons, one of which of course is
    getting past the UFO stigma. And just ask Stuart Kingsley what he had to do
    and go through to get Optical SETI recognized by the mainstream, even though
    it was proposed by the inventor of the laser, Charles Townes, back in 1961:

    http://www.coseti.org/mileston.htm

    So there needs to be more of a paradigm shift in SETI, of which there is a start.
    There also needs to be more interdisciplinary efforts for SETI projects. This
    too is happening in SETI and especially astrobiology, but I would like to see
    every such effort contain at least a few more professional biologists, sociologists,
    and historians, along with people who can convey all this to the general public.

  • tacitus September 21, 2009, 17:58

    As for supernovae and SETI in general, it has been suggested that since exploding stars are some of the most obvious and powerful natural forces in the Universe, that they would make great ready-made beacons for getting celestial attention.

    Agreed, though a cluster or perhaps a line of supernovae would be necessary to make the beacon stand out from natural event — after all, we’re already detecting more than one supernova a day as it is.

    That would make a detecting supernova beacon a long term effort, since we would be extremely fortunate if the beacon was lined up precisely enough with Earth to have more than one supernova component of the beacon going off at a time. So perhaps one day someone will go down in history after searching the old galactic supernova records and finding a tell-tale periodic line of supernova that was just waiting there to be discovered.

  • ljk September 21, 2009, 22:25

    Tacitus said:

    “Agreed, though a cluster or perhaps a line of supernovae would be necessary to make the beacon stand out from natural event — after all, we’re already detecting more than one supernova a day as it is.”

    I don’t think that is necessary. Any supernova will do, though of course
    one in our galaxy would be ideal (just so long as it isn’t too close). A
    continuous SETI program would be able to monitor one supernova
    a day.

    And to make clear: The aliens conducting a METI campaign using
    supernovae as a beacon would not have to be in the galaxy where
    a supernova is spotted. They could be in our Milky Way and just
    aim their transmission in the opposite direction between the SN,
    themselves, and whoever might be observing the stellar explosion
    along the line of sight on the opposite side.

    And yes, let’s observe other types of dying and dead stars in case
    whoever was there at one time left a calling card for the reasons
    stated previously.

  • Duncan Ivry September 25, 2009, 10:33

    More about the difficulty or the impossibility of communication.
    Especially: Is it enough sharing the same universe or having the same nature as a common foundation.

    tacitus: “I doubt very much that communicating with alien civilizations (assuming they exist) could be fundamentally impossible … simply because we will have so much in common. … we share the same universe. … we all live according to the same physical laws of science and thus we have a very broad basis for a common understanding.”

    Looking at human beings and human cultures on earth may be helpful.

    We do not have any kind of direct access to the world around us, but everything has to go through several filters:
    – our senses;
    – our brain; the human brain changes permanently throughout live; there are no two identical brains on earth; the “brains” of one human being at different times are more or less different from each other;
    – our mind; a still unsolved problem: how are our thoughts, emotions, etc. built (hmmm) “upon” sensorical input and physical/chemical/… brain processes; e.g. our impressions are permanently “coloured” by emotions;
    – the culture we live in; (see a comment of mine above) cultures of the same time and cultures of different times, even when one has grown out of the other, are partly incompatible.

    There is no absolutely objective foundation of knowledge. Even “nature” (and “universe”) is a concept developed in a cultural process (I know, some talk about “natural laws *as such*” or “absolute facts”, some seek a foundation in religion, but I don’t buy all this). Strictly speaking, there are even different valid concepts of nature e.g. in physics and in the arts, and e.g. in physics today and in physics of the past. Indeed some historians of science (e.g. Thomas Samuel Kuhn, but there are others) state, that, when a scientific revolution takes place the paradigms “before” and “after” are incompatible (Kuhn: “incommensurable”), and even some old school scientists never get it.

    Cautiously we should expect this all being true for alien beings and alien cultures too.

    Well, then, if this is so difficult, how is it possible to achieve some understanding between human beings and some objective, especially scientific, knowledge about nature?

    There are two factors at work — unfortunately bringing into play a certain limitation regarding communication with aliens on distant planets.

    1. Achieving understanding

    Human childs and young persons go through a process of socialisation. Based on their biological equipment and accompanied by society they turn into more sophisticated human beings, adult persons, social entities etc. They even “learn” to make conclusions about the state of another human’s mind. This latter, admirable practice can be observed e.g. in the partnership (does somebody love somebody?) and in the courtroom (does somebody tell the truth?).

    And here is the limitation: “accompanied by society”, i.e. performing everyday live *together* and taking responsibility. This cannot be managed regarding aliens on *distant* planets. It can be replaced to a certain degree by transmitting fiction stories. But many aspects — and I think, among them very important ones — cannot be understood without *living* together with the “others”.

    Even if it looks like there is (as Niklas Luhmann said) or will be one and only one society on earth, it is questionable, whether this convergence is inescapable (Karl Marx did fail with his iron laws of history). I think, evolution and history could have had very different results, even ones incompatible to what we have today. It may well be, that some aliens do not have much in common with us.

    The lesson: Aliens may be like us, or as well rather different, and some of them may even be incompatible to an amount, that communication will be impossible.

    2. Achieving objective, scientific knowledge

    Modern physics (let me take this example only) has been developed in the course of a long lasting and sophisticated cultural process. Nowadays physicists learn during their education what the foundational concepts and conventions are, how to conduct experiments, how to write a scientific publication; there are peer reviews, other physicists discuss and repeat experiments, there are textbooks containing generally accepted knowledge, we are able to check whether somebody is a physicist or a charlatan, etc. etc.

    One important aspect is, that physics provides means for producing statements being much more reliable and useful than everyday statements. Having successfully gone through the whole, costly process established by the community of physicists, statements cannot be thrown away lightly, and can be used by everybody in everyday business. Those statements can be used as preconditions in further conclusions (e.g. predictions of the movement of physical and technical systems), and those people making the conclusions can take the responsibility for the consequences. We have — in a certain sense, *not* absolutely — “objective” knowledge (this, of course, is stated very briefly).

    Now, if alien cultures have science too, can we assume, that it is like our science?

    Again, because of the different ways, evolution and history may and will go, “sciences” on distant planets will not necessarily converge completely. Stating it very cautious, I hope, there is enough in physics being “culturally invariant”, such that at least physicists are able to communicate a lot. But, we should be aware of physics, and even science altogether, being not the most important thing for everybody — and every alien.

    Well, so much to think about, and not enough time ;-)

  • James M. Essig September 26, 2009, 17:09

    Hi Duncan;

    Having recieved my B.S. degree in physics and having taken several graduate level math and physics courses has well as having explored the issues of the philosophy of science albeit in only two philosophy of science courses, I must confess to being a realist who believes in objective order and reality and the ability of our species to attain an understanding of the relationships among objects, principles, and other agents operative within the cosmos.

    Though not intending to promote faith or religion here, from a purely sociological perspective as an inventer and co-applicant of about 1 dozen issued patents and many additional patents pending, I must confess I firmly believe that the order within the cosmos is neccessary for the inventions to work reliably and predictably on the scale on which they operate even for a complete stranger who knows nothing about the technology I have inpart developed but has read directions on how to use the invented equipment.

    For the record, from a purely sociological perspective, I believe that there exist in a reified manner an absolute moral truth which is of an altogether higher principle or type of truth than the metaphysical truth of whether a proposition is true or false.

    Although this website is not a normally a place for above personal proclamations about myself, it does go to show that there are capable realists who are also trained in the sciences and who are quite sucessfull as such.

  • tacitus September 26, 2009, 23:41

    Duncan, I understand it’s not possible to be certain about anything in the absence of a single data point other than our own civilization, but I still see no reason to be pessimistic about being able to communicate with the intelligent species we may encounter.

    My point about sharing the universe with our alien neighbors is that any space-faring race will have had to overcome the same science and engineering difficulties we have. There are only a small number of ways we can achieve orbit, and all of them require advanced knowledge of mathematics, science, and engineering and thus all of which we will have in common.

    It is also likely that space-faring civilization will have a sophisticated understanding of the universe around us, and even if they don’t have the same cosmological understanding that we have (it might be very different) when it comes down to things like orbital mechanics, solar fusion, the life cycles of stars, etc.

    It would seem to me that any society that has developed space-going technology must have some level of curiosity and drive to understand the unknown, otherwise development would have stalled out a the subsistence level. This would be particularly true if they were attempting to communicate across interstellar space. Thus that is another thing we would have in common.

    Obviously if the aliens are only interested in broadcasting excerpts of their holy scriptures then we could be in for decades of frustration, but if they have any interest in beginning a dialog, then starting from first principles — broadcasting prime numbers or the value of pi to confirm the artificiality of the signal, and then some basic template for reaching some level of common understanding upon which to build, should be quite possible.

    I don’t doubt it could be very difficult in some cases, but I don’t foresee mutual attempts at reaching an understanding ever proving to be impossible.

  • david lewis October 1, 2009, 8:52

    These words are one I would strongly agree with.
    ———————————-
    In general I think it is premature to hold any position strongly, make strong assertions or statements, about alien life, ET civilizations or cultures, and especially about ET behavior. There just ain’t any data to go on. Speculation is fine, but don’t get too attached to any one idea.
    ———————————-

    We don’t yet know enough to form sound opinions on alien intelligences.

    Are they even capable of understanding loneliness? We can not just assume they do because life on this world does. It might be something that never evolved on their world, or they might have more in common with a hive species than we humans.

    Would they know we are here? Maybe. If they were a human civilization that’s a few centuries a head of us the odds are they would. However, we are not talking of human civilizations but alien ones. If they don’t know loneliness would they bother searching? And even a human civilization might put things like war a head of things like seti. I’m sure there are many people who would take a few extra planes in their military over a seti program. Or they might have decided that ending poverty (assuming they even understand the concept of poverty or have it) takes precedence.

    Would their society be non-violent? Our’s is within a century of being able to peer at alien worlds as if they were next door, and we are definitely not non-violent. In fact a significant amount of our resources goes into war and fighting crime. They might for example practice eugenics to a degree that would terrify us. And a race willing to slaughter their own on such a scale might not be too hesitant about slaughtering a few billion homo sapiens.

    Would they even have curiosity? Or have it to the degree that we humans do? Just because it developed as a survival trait here doesn’t mean it would elsewhere. At least not every elsewhere. A strong survival drive might drive technological research even where curiosity doesn’t exist to the extent we humans are curious. Heck even amongst humans curiosity isn’t a given.

    We cannot be 100 percent sure they are non-hostile.
    We cannot be 100 percent sure they know we are here.
    We cannot be 100 percent sure we can ever communicate with them.

    The best we can do is search for them. Hope they are non-hostile. And try to communicate. It would be nice to know something about them, like if they are hostile and if they have the capacity to launch attacks over interstellar distances, before we try to communicate and let them know we are here. We are within decades of being able to do that. Probes to the sun’s gravitational lens for example to observe their world.

    It strikes me as sort of funny that a species with thousands of nuclear warheads, possessing chemical and biological weapons, with members of that species involved in the slaughter of millions of their own kind over the last few decades could even assume that non-hostile intelligences would be 100 percent peaceful.

  • tacitus October 1, 2009, 18:49

    David, I agree that all this talk about the nature of ETIs is pure speculation — that’s part of the fun!

    Regarding loneliness as a driving factor for SETI, again this is just conjecture, but imagine an ancient civilization that has already spread throughout their home galaxy only to find that they are the only sentient lifeforms out there. It’s not hard to imagine that they would be asking themselves as they look out on the millions of other galaxies, are we really alone? Are we all there is? And then being driven by that question to create some type of intergalactic SETI/METI program. It’s likely, probably not, but it’s certainly possible.

    We cannot be 100 percent sure they are non-hostile.
    We cannot be 100 percent sure they know we are here.
    We cannot be 100 percent sure we can ever communicate with them.

    I really don’t find these types of assertions useful. I don’t know how many times I’ve read things like “We cannot be 100 percent sure that the Face on Mars isn’t an alien artifact” or “We cannot be 100 percent sure that there aren’t transparent alien buildings on the Moon.” These types of assertions are trivially true but tend to be trotted out when people have run out of substantive arguments. I would advise you to avoid them.

    In any case, I haven’t seen anyone on this blog making the claim that they are 100% certain that the aliens will be non-hostile. When someone argues that it’s more likely that first ETIs we make contact with will be non-hostile, it doesn’t mean that they believe that they are 100% sure of the fact. It also doesn’t mean that they don’t believe there is still a reasonable chance that the aliens could be hostile in some way.

    Personally, for reasons that are too long to go into in this comment, I do believe that any space-going ETIs we make contact with are likely to be non-hostile. That doesn’t mean I am 100% sure that they will be, or 99% sure, or even 90% sure. In fact I have never put a number of it other than saying that it’s more likely than not.

    The same goes for the other two points about them knowing we’re here and being able to communicate with them once we meet. I would estimate those odds as higher than meeting non-hostile aliens, but never all the way to 100%.

    What I can do is make a substantive argument that given the distances involved, and the incredible difficulty of interstellar travel, especially when compared with the relative ease with which planets can be imaged from distances up to 1000 light years and perhaps more, that it is highly unlikely for a hostile ETI civilization on the prowl in our neck of the woods to be alerted to our presence only after we set up a METI beacon of some kind. I would not put the possibility of that scenario at 0%, but it would be pretty low, and definitely under 10%.

    Finally, for a species “with thousands of nuclear warheads, possessing chemical and biological weapons, with members of that species involved in the slaughter of millions of their own kind over the last few decade” it’s not at all difficult to imagine how and why we would not be hostile towards an ETI civilization that makes contact with us.

    Of course, it would depend on their motivations, but assuming they’re only here to say “hello” and perhaps exchange ambassadors and open up trade negotiations, then there is every reason to believe that the human race will remain non-hostile in such circumstances, in spite of our ugly track record. So evidence of our own violent past is really of little use in divining the motives of alien species.

  • david lewis October 2, 2009, 1:10

    ———-
    it’s not at all difficult to imagine how and why we would not be hostile towards an ETI civilization that makes contact with us.
    ———–
    Oh, we undoubted would not be hostile to such a civilization. (One that makes contact with us) Especially if they are capable of reaching us while are not capable of reaching them. On the other hand, if we able to reach a world where the natives are a thousand years behind us technologically I’m not so sure we wouldn’t be hostile in that case. We humans are pretty good at creating scapegoats out of each other – imagine how much easier to make a scapegoat out of an alien species. Especially if we observe them while they are engaged in the equivalent of WWI or WWII or have practices we consider barbaric.

    ———-
    So evidence of our own violent past is really of little use in divining the motives of alien species.
    ———
    I would suggest that just not our violent past, but anything of human nature, cannot be used in divining the motives of alien species. Including the assumption that they would feel emotions like loneliness and curiosity in the same way we do. That is why we should be so extremely careful when making first contact with any alien species.

    ———
    What I can do is make a substantive argument that given the distances involved, and the incredible difficulty of interstellar travel, especially when compared with the relative ease with which planets can be imaged from distances up to 1000 light years and perhaps more, that it is highly unlikely for a hostile ETI civilization on the prowl in our neck of the woods to be alerted to our presence only after we set up a METI beacon of some kind. I would not put the possibility of that scenario at 0%, but it would be pretty low, and definitely under 10%.
    ———
    If they were human, I would agree. However, since they are not I don’t see how any argument other than space is vast (to us at least) and how getting to their sun’s gravitational lens would be easy compared to interstellar travel. What if they don’t even consider the possibility of there being alien intelligences until they intercept our signals? There are plenty of humans who consider the possibility of aliens as impossible.

    To put it another way, when I come across a pond I don’t just dive head first into the water until I’ve checked the depth. The odds of it being too shallow might be less than 10 percent, or even less than 0.1 percent. But still the wise thing to do is to check it first. Until I do check it I can’t do anything but speculate on the depth and whether or not it’s safe.

    Personally I hope any super advanced aliens are extremely peaceful. But with zero evidence either way I am hesitant to want to gamble the survival of our entire species on it. That is a lot to place on any one gamble, even if the odds of them being hostile are low.

    We could always go crazy on the space exploration thing first. Find all the worlds with any bio-signatures close to the earth (1000 ly maybe). This could be done from earth or earth orbit. Then probes to the sun’s gravitational lens to study those worlds with a bio-signature. Should we find any worlds with indications of primitive intelligence we could try to study them. Get a sample of intelligence that involves more than one biopshere.

    How large would a telescope need to be at the sun’s gravitation lens to get details at a resolution of 1 inch from several hundred light years? Is such resolution even possible. Anyway, we could follow any such intelligences for a while – observe if they have war or if they even kill each other like we do. Even study how they treat the other animals, the non-intelligent species, on their own world.

  • tacitus October 2, 2009, 14:28

    Everything you mention could be true. Without any data points from ETIs we just don’t know. But there is one quibble I have with your worst case scenario, and it’s an important one. You don’t need to use a star as a gravitational lens to detect that there is intelligent life on Earth from hundreds of light years away. Air pollution is a dead giveaway (via spectral lines), as is the sodium glare from billions of street lights when the night-side hoves into view. We will be able to do this ourselves within a few decades, centuries, perhaps thousands of years before we finally manage to set foot in another solar system.

    It would be extremely unlikely that any expansionist/curious ETI civilization would not have already completed a comprehensive exoplanet survey long before they were able to set out and visit any of them. Human beings aren’t even the only form of life on this planet to employ scouting behavior before expending further efforts (ants for one do this), so it’s straining credulity to believe that ETIs who have managed to develop the technology to venture into space would not complete a survey of the surrounding systems before selecting a destination and expending vast resources and time in an attempt to travel to get there.

    In any case, I’m not really fussed either way regarding setting up a METI beacon ourselves. There is zero chance that it would be of any use (or danger) within my lifetime so I see no real benefit to doing so. If people don’t want to do it out of a preponderance of caution, then that’s fine by me.

    What I do think is ridiculous is those who fret over the publicity stunts involving sending a short, one time signal to some random star. I think you will have to agree if there are aliens listening that closely for radio signals then they will probably have expended the small amount of effort it takes make a visual survey of the surrounding systems. The chances of a random one-time signal dooming our civilization are vanishingly small.

  • ljk October 4, 2009, 14:56

    david lewis said on October 1, 2009 at 8:52

    “These words are one I would strongly agree with.
    ———————————-
    “In general I think it is premature to hold any position strongly, make strong assertions or statements, about alien life, ET civilizations or cultures, and especially about ET behavior. There just ain’t any data to go on. Speculation is fine, but don’t get too attached to any one idea.
    ———————————-

    “We don’t yet know enough to form sound opinions on alien intelligences.”

    Let me state again the purpose of my article. Obviously we do not know
    how other intelligences in the Milky Way galaxy and elsewhere might
    think and act precisely until we actually find some one day.

    But there have been SETI programs running since 1960 (I am not
    counting the 1924 attempts to listen to and contact Mars since they
    were too limited in scope and would have failed in any event as we
    discovered a matter of decades later). Both their goals and
    capabilities demanded that any ETI signals they might detect
    would be deliberately sent to Earth. Yes, there was and is always
    the chance we might pick up some stray transmissions from them,
    but since those signals would not be purposely aimed or meant for
    us, the SETI folks always knew our best bet was an intentional hello.

    So this philosophy and our technical limitations when it comes to
    SETI allows only certain types of transmissions being sent for
    particular reasons to our world and society. As a result, we can
    eliminate a number of factors in this equation, which naturally
    includes a lack of other intelligences or beings that don’t know
    how or want to signal their celestial neighbors. They won’t be
    signalling so for our present SETI purposes, it serves little
    point to speculate on them or emphasize over and over that we
    don’t really know how an alien society and mind might work.

    We have to go with what we have now, which is mainly listening
    and looking for radio and optical (laser, infrared) signals using
    equipment attached to Earth. As we expand our space presence
    and can start lofting huge space telescopes both free-floating
    and bolted to the lunar farside, and then get serious about sending
    out interstellar probes, THEN we can expand on looking for aliens
    in a wider variety of possibilities.

  • david lewis October 5, 2009, 5:32

    —————
    You don’t need to use a star as a gravitational lens to detect that there is intelligent life on Earth from hundreds of light years away. Air pollution is a dead giveaway (via spectral lines), as is the sodium glare from billions of street lights when the night-side hoves into view.
    ————–
    Assuming their activities generate any pollution. Maybe they take better care of their world than we do ours or are a few centuries advanced and have eliminated many sources of pollution. Street lights assumes they need light to see during the night. But my main purpose in telescopes at the sun’s gravitational lens wouldn’t be to ensure there was intelligent life on such a world, but to be able to study the world in enough detail that we could make observations about life on that world. And if there is intelligent life answer questions like how advanced and do they make war.

    ———-
    I think you will have to agree if there are aliens listening that closely for radio signals then they will probably have expended the small amount of effort it takes make a visual survey of the surrounding systems.
    ———-
    Yeah. Most likely. Anyone who detects a signal that faint is probably intensionally listening and searching. And if they are intensionally searching and listening they probably know of us.

    ———
    Let me state again the purpose of my article. Obviously we do not know
    how other intelligences in the Milky Way galaxy and elsewhere might
    think and act precisely until we actually find some one day.
    ———
    I’m not against SETI. METI on the other hand makes me nervous. An ant that gets the attention of a human doesn’t always fare well. And any intelligence we do contact is likely to be as different from us as we are from ants and as powerful compared to us as we are to ants.

    But even then I’m not against METI. I just think we should scout out the situation before we toss our whole race into it. Scouting behavior is so common on earth because it works.