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Active SETI Redux

The thread on active SETI — broadcasting messages from Earth in a targeted way to other star systems — has been an active and fruitful one. Unfortunately, I’m getting a few reports that recent attempts to post new comments haven’t been successful. This may involve a size limit on comments to a single post; in any case, I haven’t yet figured it out. So to continue any comments on the active SETI thread, please use the comment area for this post. And let me know if you have any problems posting, or if any comments you make don’t appear.

In the meantime, if any of you have any knowledge of size limits on WordPress comments to individual posts, please let me know. Sometimes software seems more mysterious than the interstellar realm; at least, it does to me after spending a couple of hours this morning trying to figure out what was going on in the depths of WordPress. My spam filter’s behavior is also under active investigation.

Comments on this entry are closed.

  • Dennis September 30, 2006, 13:53

    There is one simple explanation to the apparent absense of ET. Let assume that complex civilizations are VERY RARE. Say only one per every barred spriral galaxy. Or one per THOUSAND spiral galaxies. That still allow for BILLIONS of civilizations in observable universe, but hardly we will ever find them. One the other side they certainly do exist, just like everyone knew before 1990s that there are extrasolar planets, for sure, although we were not able to spot them. Universe is not large, it is absolutely mind-crashingly large. What if civilizations are on average one billion ly apart? Is the any way to notice them?

  • philw September 30, 2006, 14:08

    Regarding nearest techical civs a billion LY or so away, we would need to stretch our imaginations a bit and extrapolate what we think some seriously advanced civ could do and its effect on the galactic environs and then look for that effect, if observable. The problem with this type of SETI is that far, far too many unsubstantiatable assumptions have to be made. Too many in my opinion to make any yet proposed search worthwhile. I will confess to a lack of imagination and might revise my opinion in the face of a brilliant hypothethis.

  • Adam September 30, 2006, 18:06

    Hi All

    Arch-SETI skeptic himself, Frank Tipler, as revised his stance and now believes They exist, but on the other side of the Hubble radius, and we’ll eventually meet up with Them as we expand into the far cosmos. If we build million kilometre wide telescopic arrays we might just image their home planets in the earliest post-Big Bang epoch.

    I think that’s effectively equivalent to saying ETIs are rare.

  • Fr. Gregory Hallam September 30, 2006, 18:27

    From my blog … (Ignore the faith-bits if they offend!)

    “It’s good to talk.” So went an advertising campaign in recent years for a telecoms company. It is indeed good to talk … “Jaw-jaw is better than War-war” as the great Sir Winston Churchill said pithily.

    Communication, language specifically, is one vital element in our distinctive humanity. Thinking is inconceivable (literally) without language, social interaction is enhanced by language, God is praised in words or heeded to in silence.

    Is it good to talk to everyone? I believe so, yes. Even when facing a hostile presence? Still I say yes. A story is told of St. Nicholas of Japan that one of his first converts was an enraged xenophobic Samurai warrior, a certain Sawabe intent on decapitation who was disarmed with the saints Godly words.

    So should we talk to aliens? These scientist believe so … Dr. Alexander Zaitsev, Charles M. Chafer, and Richard Braastad. Of course. attempts on a small scale have already been made as the linked article explains. However, the low powered beacons and artefacts so far sent into space will probably prove to be proverbial needles in vast haystacks. Something more grand is being talked about with M.E.T.I., (Messaging to Extra-Terrestrial Intelligence). So far we have been listening but not really talking. Intelligent life may be rare even if life itself is rather common. Why, therefore, should we not talk?

    Back to St. Nicholas of Japan. He didn’t flinch before Sawabe, he engaged. Some may think this counsel hopelessly naïve. After all, any alien intelligence we encounter in our galactic chatter will almost certainly be vastly more intelligent and advanced than ourselves … which is OK if our partners are benevolent but what if they harbour malice or even merely think that we are flies to be swatted for the sake of a greater harmony and tidiness, (after all we don’t have a very good track record on this planet). Of course, there are risks involved but are we really going to be silent, cowering in the corner in the cosmic vastness, mean spirited and hoping that no one will notice us? I hope not. It’s time to talk.

  • Eric James September 30, 2006, 18:50

    It seems likely to me that ETs couldn’t have developed many billions of years ago due to the relative lack of heavy elements in the early universe (thus making complex chemistry less likely). We might be the first.

    Also, life existed on earth for billions of years before the rise of multi-cellular species. Perhaps the transition to multi-cellular organization is particularly difficult. Perhaps so difficult that it generally doesn’t happen?

    In any case, the cosmic distances are so vast that no one is likely to visit us any time soon. Even if we gave ’em an invitation.

    I’m aware of the fact that this site advocates the possibility of propulsion that defies symmetry, conservation, relativity, and just about everything else currently understood about physics. Even so, we must be careful not to assume that these properties of physics are surmountable. We can only hope.

    Supposing they are surmountable and a species developed such a method, wouldn’t this indicate (at least in one aspect) they are smarter and/or more experienced than we are?

    If they were thusly proved to be so technically far ahead and they were aggresively trying to obtain and develop new systems, wouldn’t you think they’d be much farther ahead in their scouting and detection abilities than we are?

    It seems obvious to me that a heavily laced metallic system like ours, might be particularly attractive. Wouldn’t these systems be the first to be scouted?

    Considering our ability to detect metallicity at great distances, doesn’t it seeem logical that ETs might do the same?

    Therefore, hasn’t our sun been broadcasting the appaernet resource wealth of our system for billions of years?

    Lastly, I’m curious. Since so many on this site apparently believe that the laws of physcis can be broken and that malevolent ETs might already be close enough to attack us (should they “hear” us), how many believe we have already been visited? How many believe in the UFO phenomena and UFO cover-up/conspiracy? I’m particularly interested in the opinions of the heavy hitters here (scientists and authors).

  • Ron S September 30, 2006, 19:28

    “silent, cowering in the corner in the cosmic vastness, mean spirited and hoping that no one will notice us”

    Your arguments might have been more persuasive if you had not resorted to belittling and insulting those of us with opposing views.

    Regarding your samurai example, there is a strong intra-species and cultural connection between the two in conflict. There is no evidentiary justification to extend this so that it applies between humans and ETIs. You may guess it, believe it, rationalize it, or even reason it, but you do not know.

  • Ron S September 30, 2006, 19:35

    “How many believe in the UFO phenomena and UFO cover-up/conspiracy?”

    You talk of belief and you want the opinion of scientists? A scientist would talk of evidence and, perhaps, speculate on interpretation of that evidence.

    Authors ain’t “heavy hitters”. They’re articulate writers. If the author has expertise, that’s great, but expertise and articulation are not correlated with any certainty.

  • Eric James September 30, 2006, 20:36


    There is no evidence of FTL space-flight, alien technological civilizations, or even life beyond earth. Therefore it’s arguable that all of these things (currently being discussed) are merely speculative concepts in the minds of the posters. None of them have any real scientific merit.

    Therefore, either we have scientists that believe in the possibility of the apparently impossible, or we don’t have any real scientists (by your strict definition)… but rather merely a bunch of foolish folks that’ll believe in any wildly speculative concept (so long as it sounds scientific).

    Most of the authors that I recognize here are either scientists in their own right, or well connected with the scientific community. Their opinions should prove to be particularly lucid and eloquent.

    It seems to me that believing we might inadvertently contact a malevolent space-faring race that’s close enough to attack us is quite simply as ridiculous as believing alien spaceships have already visited and have a particular proclivity to kidnapping people who live in the Alabama swamps.

    Please explain in scientific terms why either concept is particularly more valid than the other.

  • Chris September 30, 2006, 20:53

    Okay, I’ve got a question that’s been bugging me for years. SETI requires that any signal detected that might be from an alien civilization be detected twice before being taken seriously (the Wow Signal was heard only once). Earth has sent a few messages to other star systems in the past, most notably the Arecibo signal. My question is: were those signals sent to each of those star systems at least TWICE, so that any ETs there with a similar criterion in their SETI program wouldn’t discount our signal as anomalous but unexplained?

  • Ron S September 30, 2006, 23:50


    I do not “believe” either that there exist or do not exist malevolent species out there. I have no data, so I don’t know. In my opinion, the probability of either is indeterminate until we have data. It is probably > 0, but is it 0.5 or 0.000000001? Your guess is as good as mine. What’s the probability earth will get hit by a killer asteroid within the next millenium? Still very low but something to be concerned about in humanity’s long-term planning.

    I am not a gambler. A very low probability (and again, we don’t know) is an unacceptable risk when the stakes of a bad bet are considered. This is a time for reasoned discussion, not decision making.

    As to the intentions of any ETI, many of the factors to determine this have been discussed in this thread. Try to put them together and you have an equation with many unknowns. It is even worse than the Drake equation which at least has a physical basis, because the additional unknowns are psychological. Assuming values for those unknown variables is interesting speculation, and probably even fruitful speculation, but it is not the stuff for the making of crucial decisions.

    You can get the opinions of all the scientists you want, but without data you’ll only get hypotheses. Not answers. I have no data, so asking me for a scientific justification for a position I do not even advocate is silly. What’s the scientific justification for yours? I merely advocate prudence and having a say before there is definitive action taken.

    Please stop characterizing someone’s position as “ridiculous”, especially when the person has not stated that position. Civility counts for something.

  • Eric James October 1, 2006, 1:03


    Then please don’t presume to determine whose opinions I should wish to solicit. It should be noted that I clearly asked for “opinions” and not “scientific evidence”. If they should wish to comment or not, let that decision be theirs, okay?

    I agree with your “gambler” paragraph. This is why I am against using the LHC on earth. Certainly the risks are very low, but as you say, “A very low probability is an unacceptable risk when the stakes of a bad bet are considered.”

    I apologize for characterizing anyone’s opinions on this subject as ridiculous. This was not my intent. I was meerely trying to emphasize that formulating an opinion on the safety of broadcasting or not with no evidence either way, is premature.

    Personally, I simply point again to the Fermi Paradox. If they exist, where are they? If they don’t exist, why not? Obviously these are questions we can’t currently answer. Therefore any speculative answer is arguably just as valid as the next.

    So it’s just as valid to state that attempting to contact them might be dangerous, as it is to saying that remaining quiet might be dangerous. Who knows what dangers abound that a technologically advanced species might save us from? Maybe they might even save us from ourselves?

  • Adam October 1, 2006, 10:16

    Good points Eric. ‘Hiding’ is probably a forlorn hope anyway, as interstellar capable civilisations could quite probably image the lights of our cities. We’re not too far off being able to do the same, at least out to a few parsecs. Mature civilisations probably can scan planets out to a few hundred light-years, monitoring them for interesting developments.

    And lastly we might have ETIs right on our doorstep, or their probes. There’s a lot of solar system to explore and we’ve barely touched it.

  • Alexander Zaitsev October 1, 2006, 11:05

    I never confused Active SETI with METI = Messaging to Extraterrestrial Intelligence: “…The science known as SETI deals with searching for messages from aliens. METI science deals with the creation of messages to aliens. Thus, SETI and METI proponents have quite different perspectives. SETI scientists are in a position to address only the local question “does Active SETI make sense?” In other words, would it be reasonable, for SETI success, to transmit with the object of attracting ETI’s attention? In contrast to Active SETI, METI pursues not a local, but a more global purpose – to overcome the Great Silence in the Universe, bringing to our extraterrestrial neighbors the long-expected annunciation “You are not alone!” Thus, it follows that in the context of METI, the answer to the general question of transmissions from Earth requires competence beyond the membership of the highly specialized SETI Permanent Study Group of the International Academy of Astronautics (IAA-SPSG). We therefore propose that, for solution to the various current METI problems, we establish both a METI Institute, and METI Permanent Study Group within the IAA (an IAA-MPSG)…” — quote from


  • Alexander Zaitsev October 1, 2006, 11:39

    In contex of “Imagining and Planning Interstellar Exploration” we should understand one single thing — there are two possible way for space development: (1) by sending material space probes to the stars, and (2) by sending probing EM-signals to the stars — that is developing of space ELECTROMAGNETICALLY. The synonym of the second way is METI…

  • Administrator October 1, 2006, 12:41

    Re Eric James’ comment above:

    “I’m aware of the fact that this site advocates the possibility of propulsion that defies symmetry, conservation, relativity, and just about everything else currently understood about physics…”

    Yes, I think you can say that this site advocates continuing research into such possibilities, but I also want to stress that the site (and I think I can speak for the Tau Zero Foundation on this as well) also advocates the idea that even if we make no such breakthroughs, interstellar flight can still occur through physics we understand today. Thus lightsails, antimatter, fusion and various other methods remain conceivable as interstellar options even if we never develop, say, an Alcubierre drive. Our payloads may be robotic in most of these scenarios, but perhaps later generations can make known-physics breakthroughs to change that.

  • Administrator October 1, 2006, 12:55

    This link via Slashdot seems apropos of our discussion re sending signals to possible ETIs:


    From the Slashdot posting: “The Irish Times notes that Europe goes intergalactic tonight with the broadcast of a program conceived for aliens and broadcast towards a point 45 light years away in the direction of the Big Dipper. The two naked hosts will present their own unclothed bodies as examples of our physical embodiments, and will tell about daily human existence. Music, art, and our own personal messages will be transmitted as well as discussions from sociologists, scientists, and space experts. This project is the brainchild of the French-based Centre National D’etudes Spatiales and is rooted in seriousness as a natural extension of the gold-plated ambassador disks of Pioneer 10. Those of us wishing to be included can still post messages to be sent into space via a CNES antenna. We will have to wait 90 years to learn whether or not some lifeform was listening.”

  • Hans Bausewein October 1, 2006, 15:00

    While SETI wants a discussion, others are actually broadcasting messages:


    A television broadcast (PAL+?) in french and german does not seem the most logical format to me.

    One reason not to send any messages could be, that future generations cannot withdraw them. The message is out and can never be stopped.
    (… but we also do a lot of other broadcasting, like the deep-space network contacting space probes)

    Have any calculations been done on how far a message can possibly get?
    Depends on the sensitivity of the receiver and the size of the antenna, of course, so say a reasonably upper boundary and a lower defined by our technology.

  • Adam October 1, 2006, 17:15

    Last night I was reading one of Carl Sagan’s last papers, the one which discusses how scintillation by interstellar plasma would cause random strengthening and weakening of radio signals, and thus could cause a lot of one-off signals getting through from the far reaches of the Galaxy, but never to be repeated consistently. The reverse applies to any of our own signals being distorted out of all recognition, becoming someone else’s “Wow!” signal. I suspect this is the fate of the European METI effort, and many more such signals to come. Only dedicated tight-beaming will get through the plasma environment and there’s no way of knowing if we’ll have a listening ear at the other end.
    I think, over all, what this implies is that messaging of serious information content will require interstellar message-probes. Self-replicating message probes would make this an incredibly cheap exercise compared to making a million Arecibos to beam to all the stars nearby.


  • Zen Blade October 1, 2006, 19:07

    I don’t know why everyone assumes alien races, even all powerful ones, would care about making contact with some ass-backward civilization that can barely visit its own moon…
    Imagine if we got signals from a lost tribe in S. America. sure, a few scientists may head out (if they can get the funding), but noone else would care, and it wouldn’t make it on the news. Imagine you are a large race, you may have contacted other large races, but who cares if you find YET ANOTHER anthill in a distant arm of the galaxy.

    I think there are tons of reasons why intelligent, powerful races can exist without contacting us. And I think we should focus less on these mid 20th-century ways of communicating, and more on “how would we communicate 50, 100, 500 years from now?”. And what implications would these new means of communication have on being able to detect alien life somewhere… Was it Sagan or someone who pointed out that the window of time that a civilization using communication technology that can be detected via SETI could be incredibly small?

    ON THE MULTICELLULAR issue, since that’s more of my field… I think this is perhaps less tricky than the actual beginning of life. Whether the RNA World Hypothesis is true, or whether there was a pre-RNA World… this process I feel would be more difficult; once you have life, it can thrive and do all sorts of interesting stuff, but getting the life in the first place…. For example, we know that single cell bacteria can act like a multicellular organism by sending various signals to neighboring cells, essentially asking for those cells to begin to either kill themselves or begin some other process.

    Also, the origin of Mitochondria, Chloroplasts, and a more recent discovery by a Japanese group [I forget the authors] that may elucidate how Mitochondria/Chloroplasts were originally taken in hint at how multiple cells/organsims essentially function as one organism—at least for a while–. And that isn’t too far from being multicellular.

    As for how the process of a single cell organism became a self-replicating multicellular organism, I’m not going to speculate… but there are plenty of examples that offer many avenues of speculation.

    If I can find the Japanese group reference, I will post it. It’s quite interesting. Essentially the one organism is “born” without the other organism inside it, but during it’s life it takes up a very specific bacteria as part of its life cycle.

    -Zen Blade

  • JD October 1, 2006, 20:50

    I would like to address the tendency (not very prevalent in this thread but common most every time the topic arises elswhere) of people denigrating the human species. Many people seem to consider their own species to be some murderous, backward, unworthy creature that should be kept in zoos or exterminated. These same people tend to veiw any possible ETI as some philosophical, benevolent race that would not stoop to interacting with such creatures as us. Why?

    Why is it assumed that any possible ETI would not have similare drives, motivation and history (speaking in the evolutionary sense) as our own? They may be far advanced yet inside (even if they’ve reached the much ballyhooed singularity) they are still creatures of evolution. Something resembling a survival instinct will still be inside them. Given that something resembling self interest will be present (discounting such possibilities as hive consciouse etc). If they’re advanced technologically then something akin to curiousity must be present (or else they were given the tech or took it from a race which did have curiosity).

    I can’t think of a single, reasonable evolution which would follow any other process leading to advanced technology. This doesn’t address the more extreme scenarios found in sci-fi but even if those are possible I doubt they would be wide spread (communal life forms, world minds etc. perhaps possible but really on the unlikely end of the scale).

    A society may have become mostly pacifistic over time but would still have those basic roots buried away somewhere. I can see where such could arise. I can also postulate scenarios where more extreme aggression could continue within a society by the vehicles of reproduction, territorial possesion, religeouse expression etc.. Xenophobia can arise due to any of these tendencies.

    Evolution progresses by the claw and the fang. We trim our claws and go to the dentist for crowns nowdays, well usually. I’m sure a far advanced race would have access to better nail clippers and orthodontists than we currently have, if they caired to use them. Even if they were pacifistic I would feel confident that they still have those attributes somewhere on them.

    Yes, if they’re out there, they will be extremely different from us but there will be some similarities in responses. The mechanisms channeling these responses will be exotic to us but when stripped away those few basic drives will be there. This could even be stretched to cover artificial life which may have benignly or aggressively supplanted the creators. The creators would have instilled certain priorities in their creations guided by their own basic imperatives.

    Whether or not we ever find a way to cheat I have hopes we’ll move outward. Either slow or fast as long as it happens. If nothing else it would insure our survival as a species (the only solution to some catastrophies is being far away when they happen and as long as humanity is tied to this solar system we are at risk). If we ever do meet those others I hope it’s a peacefull and prosperouse affair. If not I hope by then we can either win or be able to run away. I also hope whoever manages this hypothetical meeting doesn’t make unrealistic assumptions about those other’s motivations.

  • Eric James October 2, 2006, 0:52

    The administrator wrote:

    “…interstellar flight can still occur through physics we understand today.”


    With any of the varied technologies currently available to us, it would take centuries to get anywhere. Therefore any such mission should be sent more as a seed than a probe. Sort of a Noah’s ark (if you will). Hopefully, artificial intelligence and robotics will be sufficient to complete the mission on the other end. Perhaps such a mission was the precedent to our own Cambrian Explosion.

    On the other hand, it seems to be an almost instilled instinct to believe that the laws of physics can somehow be circumvented. “Propellantless Propulsion” just somehow feels right on a gut level that’s hard to describe. I often wonder why this is the case.

    Most physics absurdities are easily dismissed. I don’t believe I can snap my fingers and instantly teleport, so I don’t bother trying. I certainly don’t seriously seek a way to accomplish such a whimsical goal. Why then should the seemingly absurd notion of breaking symmetry engage me so? I don’t know. Even if it happened, I wouldn’t want to go anywhere anyway.

    Anyway, back to the subject at hand…

    Judging from history, isolationism is more dangerous than exploration. When the Europeans crossed the seas to see the other side, they risked death by supposed sea monsters, typhoons, unknown waters, rocky shoals, starvation, unknown enemies, and even falling off the edge of the earth… yet they went. The lessen: Don’t be afraid of what’s out there.

  • Joseph Baneth Allen October 2, 2006, 8:05

    There still is one curiously unanswered question about the overall goal of SETI/METI. What happens when the ETIs don’t live up to our expectations?

  • Adam October 2, 2006, 21:10

    Hi Joseph

    It’s guaranteed that ETIs won’t be what we expect. If they’re as venal and fractious as we are I doubt we’ll die of shock.


  • Adam October 2, 2006, 21:29

    Though it’s entertainment TV and frequently full of scientific misunderstandings I think “Stargate” has been a reasonably interesting look at ETIs and their potential interests in human beings. The concept that ETIs have deliberately seeded humans throughout the galaxy has been an occasional idea in written SF but fairly well explored in “Stargate”. If ETIs are relatively rare – there are only a few non-humans in “Stargate” for example – then we might be of considerable interest to more advanced species. FTL would give such species the pick of planets throughout the Galaxy and no real motivation to exploit ours.
    In which case the whole METI argument is moot because They already know we are here and are monitoring us for whatever reasons. An alien base in the Kuiper Belt could easily remain indetectable, and based on the new developments in optics, They could easily remain so for long after we leave the planet.
    I’m not saying that’s the source of UFOs and that They’re really abducting people. I think both aspects of the UFO phenomenon are intra-psychic and irrelevant to interstellar issues. But advanced technology should allow unobtrusive surveillance even up close to this planet. Passive space-drives using the solar-wind and Earth’s fields should allow probes to come and go without leaving obvious traces – a possibility made even more likely if Shawyer’s or Woodward’s propellantless drives are made reality.
    So, as a gedanken experiment, I suggest we explore the idea that we don’t have to message Them and They’re quite well aware that we are here.

  • Alexander Zaitsev October 3, 2006, 4:12

    False statement at:


    “Those of us wishing to be included can still post messages to be sent into space via a CNES antenna. We will have to wait 90 years to learn whether or not some lifeform was listening.”

    I have examined all CNES antennas and transmitters, and declare that all CNES antennas and transmitters are very, very low-powered to overcome 45 l.y. !

    See estimations for tree the most powerful Earth-based radar at:



  • Joseph Baneth Allen October 3, 2006, 9:35

    SETI activists often refer to ETIs as advanced, asscended beings – to use the popular Stargate SGI term. So if an ETI is slightly behind and/or on a level cultural and technical playing field with Humanity, is communication with this below average ETI going to take place? Or will SETI-ist bypass the below average ETI for a more “glorious” ETI contact?

  • Adam October 4, 2006, 6:40

    Hi Joseph

    I don’t know many that call ETIs ascended beings – UFO believers might use such language, but SETI implicitly discounts the ‘evidence’ of UFOs.

    If there’s anything to the whole concept of a technological Singularity then the odds are decidedly against ETIs being at the same level as us. Radio will be barely 200 years old by the time technological extrapolation tells us we hit the Singularity. I doubt we’ll be ‘ascended’ as a result, but things will be radically different. A timespan of centuries makes the odds of other intelligences being at our level very low.

    Conversations between civilisations will span centuries unless they have message-probe proxies intelligent enough to converse. Whether a civilisation that begins a conversation will be the same one that continues it is IMHO highly unlikely. Unless cultural stasis is a strong attractor past a certain level of development – a possibility – then it seems likely that communication will be a one time event for any civilisation. The species may stay the same – and that’s not guaranteed either – but cultures change too quickly for the lightspeed limit to allow two-way contact.

  • Alexander Zaitsev October 7, 2006, 3:21

    Dear Colleagues,

    Recently I put my paper “Proposing a METI Institute” into e-archive at

    By request of arxiv.org moderator, I re-named it into”Messaging to Extraterrestrial Intelligence” Please find it at:

    I ask you to make link on


  • Michael January 29, 2007, 7:58

    Hallo Mr. Zaitsev,
    can you tell us, how much cost a transmission to nearby stars like cosmic call?