Space archaeologists!


You know SETI, the nice folks out in California who scan the stars for radio transmissions, hoping to find evidence of E.T. You are probably also aware that this strategy hasn't exactly panned out. (Quick clarification: The preceding does not mean I think SETI isn't productive—they're involved in a lot more work than simply scanning for alien life, and that work contributes to science and space exploration in important ways. They haven't found E.T. yet, but they still rock.) Now, some physicists are starting to pipe up, suggesting that SETI's problem maybe isn't so much a lack of aliens, but an over-dedication to searching for one, narrowly defined artifact of intelligent life. SETI is space archaeology, they say. And current practice is the equivalent of studying ancient Earth-bound civilizations using nothing but flint spear points—there's a lot of cultures you'd completely miss, because their technology was more advanced.

Paul Davies, a physicist at Arizona State University, points out that widespread radio communications may prove a short-lived historical phenomenon on Earth. Humans are, after all, increasingly using fibre optics to talk to each other. Moreover, many modern radio devices (such as mobile phones) rely on a technique called "spread spectrum" encoding. It uses signals that look like background noise, except to a receiver equipped with the right unscrambling code. Radio signals that are clearly artificial in origin may, then, be only a transient sign of civilisation.

What to look for, instead? Scientists interviewed by The Economist suggested everything from pollution (the fact that there are Earth-based telescopes capable of studying the atmospheric composition of planets outside our solar system is mind-blowing enough on its own), to evidence of intelligent tampering with the energy output or aging process of distant suns. The Centauri Dreams blog gets into those later, sci-fi inspired possibilities a bit more in-depth.

It seems like the key to this new approach is looking ahead in our own development, rather than behind or alongside, for searchable signals of intelligent life. And that's fascinating, not just for its possibility in the field of alien hunting, but for the questions it forces us to ask about Earth-bound technologies. Things like: Is there a better way we could be doing some of our basic techie activities, and how soon would it be able to supplant current methods? What might we be capable of in 1000 years, and what impact could that technology leave on our planet and our solar system? At the very least, I fully expect this line of inquiry to lead to some great, new literature—and maybe some usable tech ideas, too.

(Via Lee Billings)

Image courtesy Flickr user pasukaru76, via CC


  1. So we’re going to stop looking for flint spear points, and start looking for axes instead?

  2. I’m not sure if I agree with this looking-forward-rather-than-backward reasoning. As an archaeologist, I know that the flint spear head analogy used above is a faulty one. In the case of projectile points, they actually tended toward becoming less technologically sophisticated as time went on. In other words, points that were manufactured 10,000 years ago were more sophisticated than the ones that were manufactured 1,000 years ago.

    And projectile points aren’t alone in this. A couple hundred years ago, those who could write tended toward a certain skill level with calligraphy that only experts possess today. 50 years ago, most anyone who could write could be expected to be able to put a sentence together. Today we have LOL OMG FTW ;)

    Also, some technologies never really go away. You could go into a hardware store right now and buy a shovel. If you could travel through time to ancient Rome, you could give that shovel to any legionnaire, who would immediately recognize it and know how to use it.

    I don’t think it’s a great idea to just substitute SETI’s narrow focus for a new narrow focus. Maybe we should try broadening the search instead.

  3. I’m kinda hoping that the atmospheric pollution is a short term effect too. Advances in technology and awareness of the short sightedness of polluting should mean that we stop doing it!

  4. “Now, some physicists are starting to pipe up, suggesting that SETI’s problem maybe isn’t so much a lack of aliens, but an over-dedication to searching for one, narrowly defined artifact of intelligent life.”

    Someone should have listened to this whacky stoner some 27 years ago. Stupid physicists (/Homer):

    “To search expectantly for a radio signal from an extraterrestrial source is probably as culture bound a presumption as to search the galaxy for a good Italian restaurant.” – Terence McKenna (

  5. Gee Terry, in the far advanced civilizations, their master calligraphers and omnipotent secret government militaries would have all the bio-cloned geniuses creating all the super duper new technology to ride about the galaxies, so it wouldn’t matter if internet neckjack joe and jane could only snark ROFL then click the next dweeb game icon, or gurgle out “Alpha Centauri” into the Millenium Falcon’s voicebox recognition lightspeed TomTom.
    I mean come on.
    You’re talking about the new tarded underclass of advanced societies, and why take it back to Rome, hit places all over this planet right now and a shovel is the best tech there.
    Point is, the government / MIC is using laser powered CRAY plus controlled sound radar bouncing light cutters to scoop out that perfect hole in the new mettalurgic alloy, or HAARP, and you and I aren’t using, building, or knowing much about that supercomputer, laser, microwave signaller…
    Technology leaves a large portion of those using it dumb as rocks in comparison.
    All of us here on our internet PC’s qualify to varying degrees – we’re exactly that ignorant on how they actually work – but our PC’s still exist as new technology the paper and pencil math method of barely a few decades ago is squashed by.
    A lot of us can’t do the math now, huh, but the alien computer technology does.
    We should still be looking for silicon computers, not paper pads and pencils, or an abacus.

    1. So what you’re saying is that we should be scanning the depths of space for silicon computers. Makes perfect sense.

  6. No, cartianly wasn’t saying that of course, but I think you were saying shovels (radio signals) could still be in use in advanced societies, and after thinking about that, I suppose it’s plausible, not like that portion of the spectrum could be expected to disappear nor be banned.
    So, if we go with that, they should be finding something… LOL

  7. This reminds me of a series of Greg Bear novels where Earth is destroyed by a self replicating machine civilization that hunts down “noisy” civilizations that are putting out lots of radio waves and other “new to science” signals.

    Presuming that there are other forms of intelligent life in our galaxy it might be the case that they’re being deliberately quiet.

    1. The thing is, only one civilization doesn’t have to be quiet. It’s the same analysis about how fast it would take to colonize the entire galaxy. The entire galaxy should be colonized, because it would only take one civilization to pull a Captain Kirk and say, “Screw your Prime Directive! I’m banging hot green girls!”

      Personally, I waffle between there not existing any advanced intelligent tool making life other than our own, and the fact that it’s nigh-impossible for interstellar travel.

  8. Linus Vesptas has thought out the details of what’s needed for finding spread spectrum signals (or pseudo-random noise, or PRN-encoded), particularly for the DIY searcher in “A Better Way to Search for ETI Signals”:

    “A better way to search for radio signals from extra-terrestrial intelligences is to look for PRN-encoded signals. Such encoding techniques offer powerful signal-to-noise improvements, making communication far, far more practical than using unencoded radio signals. This search technique will prove practical in the coming decades as Moore’s Law provides the CPU cycles needed for such a search. ETI know Moore’s Law, and depend on it to become intelligible.”

  9. I always wondered why we were searching for intentional signals when we have not, as far as I’ve know, blasted the heavens with our own intentional waving flag of signals. (I know, we send out a lot of junk noise, but people seem to say we will get some sort of one-two-thee-five sort of thing from outer space)
    And as radio gets quieter and less used, we’re basically looking for a 150 year span, MAYBE, of another civilization.

  10. I’ve pointed out to people who ask me about this (there have been a few!) that beaming signal in all directions is ridiculously wasteful for all but the most universally-useful signals. Maybe, maybe 0.1% of the signal energy you’re beaming out is getting absorbed by an antenna. Fiber or targeted beams are cleaner and more efficient. For the short distance stuff (cell phones, for example), we’re talking WiFi equivalent outside of special occasions where you’re far from civilization.

    Anyway. There’s a reason satellite phones suck, and it’s the r-squared law of decreasing signal intensity. Avoiding that is just good engineering, so I expect we won’t be “broad”casting much in the future.

  11. Presuming a similar technological path as our own, I would think there would be artifact transmissions from planetary and space exploration projects that would continue, even as radio broadcasts become obsolete and less frequent. Also, do we not still rely heavily on satellite transmissions?

  12. Someone has to be top dog. Someone has to be first. Why not us? Is that just too depressing? Yeah. It is. But life isn’t always fair. Space is big, empty and cold. The solar system beyond Earth is cold lifeless rocks. Either completely airless rocks, or rocks shrouded in a perpetual fog. Travel between the stars is slow, even at maximum speed. (Yeah potentially you could come up with something that kind of bends the laws of physics, but show me a natural phenomena that does this, then we’ll talk.) With the notable exception of Saturn, not even that interesting to look at.

    While the universe is great place to live and study. It ain’t a cocktail party.

    Wishing we lived in Star Wars

    1. I’ve always wondered why it was assumed there are more advanced civilizations than ours. Maybe we are the top dog, as you said, or perhaps we’re one of a handful of the most advanced civilizations that are at about the same level. Either way, we’re not making contact for (possibly) thousands of years. Sigh.

  13. I think I heard this guy interviewed on the radio the other day. One of the things he was suggesting as possible places to look for messages from intelligent lifeforms was in DNA. He suggests it would be possible to encode a message of some sorts into the DNA of a virus that could then be spread throughout the universe using different methods. It wouldn’t need to be something that killed or even made the carrier sick…just got into it’s DNA somehow and got passed on from generation to generation till a species got intelligent enough to start picking studying DNA and would stumble upon it. He wasn’t suggesting at all that aliens influenced life on Earth, just suggesting one possible way of spreading a message to a society that might not have developed yet.

    He was doing a talk here in Seattle somewhere. Sounded like it might be interesting.

  14. Did it ever occur to you munchkins, that what you feel or determine is relevant to society at large, is not valued? Are you so bereft of simple common sense that you have the gall to even speculate on the most significant issues that affect our common weal.You are living in an intellectual vacuum .Wake-up and smell the ???

  15. Amen, wizardofplum.

    I understand the desire of scientists to conjure a possibility of our connection with intelligences Out There, but it’s ultimately fear-based and emotional, something they will never admit to, due to the severe limits imposed by the Scientific Method.

    MachineElf’s McKenna quotation sums up the dilemma efficiently and humorously.

    But it’s a fascinating dilemma, one that we can argue about for eternity until some meaningful answer is found. I personally think the answer is already in front of us, without telescopes, but most of us (***coughscientistscough***) just don’t know how to see it yet. But we’re getting there. Slowly.

  16. If you were looking at earth from distant space, how would you detect intelligence? I am not sure you would hear normal radio signals, but you might be able to pick up sodium, mercury, and phosphor lines from the world’s lighting. As the Earth went around the sun, you could deduce that this light might be coming from the dark side even if you couldn’t resolve the Earth’s disc.

    I would not expect this signal to last. If we get our population down to something the rest of the Earth might be comfortable with, then the number of lights might go down too. High pressure lamps will give broad spectra rather than lines. But, right now, we probably look like mercury and sodium from space.

  17. Surely the focus now is looking for Earth-like planets, since we have developed techniques to spot them, and then just study them intently?

    Find a few needles, rather than just keep smashing away at the haystack hoping to get pricked.

  18. Professor Paul Davies (whose book The Eerie Silence was referred to by igpajo above) talked about neutrino streams as well as the genome for possible (albeit tremendously unlikely…) message encoding and transmission. He also makes the point that you don’t just need life; you also need to evolve intelligence and a particular mindset that would seek to make contact with others in the first place, let alone be capable of developing the technology to do so.

    There’s a recent Little Atoms podcast in which he’s interviewed on the subject – worth a listen. As chair of the SETI Post-Detection Taskgroup, he’s well placed to talk about it!

  19. If you’re looking in atmospheres for their chemical composition, start by looking for stuff that ought not to be there. Oxygen’s a good one – it should be in rocks and CO2, not wiffling around for us to breathe.

    James Lovelock’s early work with NASA was on this: he looked at the composition of Mars, found it to be pretty much what you’d expect of a dead rock, and it’s fair to conclude from that that life’s not big there, not anymore.

    Adiabatic steady state = dead rock. Something wacky = possible biosphere. Biosphere = a good candidate for hot green chicks.

  20. You know SETI, the nice folks out in California who scan the stars for radio transmissions, hoping to find evidence of E.T. You are probably also aware that this strategy hasn’t exactly panned out.

    This is very wrong. The strategy hasn’t yet yielded any detections, but concluding from this that the strategy hasn’t panned out is a false conclusion.

    Get on a boat, and go out on to the ocean. Drop a bucket down into the water, and pull it back up. Are there any fish in the bucket? If there aren’t any fish, do you then conclude that there are no fish in the sea? Drawing that conclusion would be the same as concluding that there are no radio signals out there for SETI to find. The effective phase space that has been searched is equivalent to a bucket in the ocean.

    We don’t know a lot about the distribution of intelligent civilizations, because we have only anecdotal evidence (i.e. the one we know about). So we’re left with the basic parameters of the Universe. Radio is a great way to communicate over long distances. What’s more, while there are lots of frequencies, there is an obvious one to communicate at (the frequency of Hydrogen) if you want to talk to technological civilizations that have learned the most basic things about our Universe.

    SETI is best tuned for looking for civilizations that are broadcasting a hello, and that are doing that by thinking about what’s common and basic as a communication method. But… would any civilization actually broadcast a hello? Well, anecdotal evidence suggests they would, because *we* did. Although, I should note that our current technology level, SETI is only able to detect broadcasts from civilizations that are more advanced than ours… but to conclude that they’re not there based on the data from SETI so far is like concluding the ocean has no fish because your bucket has only water.

  21. We should figure out what kinds of signal that we could construct here in our solar system have the best chance of being observed within 1000 light years of us. Then look for those signals. My guess is radio would still be a top contender.

  22. To paraphrase Clarke’s Law: “any sufficiently advanced technology is indistinguishable from random noise.”

  23. Actually, the alien FCC gave the bandwidths SETI is looking at to the alien cable companies who thought they might really need it, but they’re not doing anything particularly useful with it.

  24. Define “pollution” for a species we know nothing about? Oxygen could be their pollution, for all we know.

  25. Wouldn’t it make more sense to look for ways to communicate with other parallel Earths? We can safely assume that the most similar parallels will use the same technology as ourselves. Not saying that there is not merit to search interstellar space, but we’ve got neighbors right next door.

  26. Deckard68, how do you know that all Boing Boing posts originate from the same Earth? :-)

    I contribute to SETI at Home using the BOINC client.

    As Terrence McKenna said, it is indeed a bit of a conceited way to search. What if the alien culture considered any form of ‘broadcasting’ to be an awful social affront, so outrageous as to merit imprisonment?

    Despite the program’s limitations, and the poor chance of getting a candidate signal in our lifetimes, it is cheap, fun to participate in, and far better than not ‘listening’ at all – that would be very foolish.

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