Indistinguishable from magic?

SETA: Finding a 'Graveyard Civilization' (Centauri Dreams)

What we don't know is how representative we are. Nor do we know the limits of exponential growth, for they may lie not at the planetary but the solar system level, assuming they’re not fully surmountable in the first place (by some future civilization if no one has done it in the past). A success at finding some kind of artifact here in our own system would at least tell us that an interstellar crossing is not out of the question, but how much further do we want to take these conclusions? The authors raise the question themselves, and point out that " . . . we cannot rule out the possibility that ETI civilization may follow a development pattern sufficiently different that we wouldn't recognize it even if we detected its signal."

Italics mine.

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Today's word is "von Neumann."

Two fascinating perspectives:

Growing the Interstellar Probe (Centauri Dreams)

Freitas later turned to nanotech ideas in advocating a probe more or less the size of a sewing needle, with a millimeter-wide body and enough nanotechnology onboard to activate assemblers on the surface of whatever object it happened to find in the destination system.

Now we're looking at a biological variant of this concept that could, if extended, be turned to self-replication. Rothemund says that he wants to write molecular programs that can build technology. A probe built along these lines could use local materials to create the kind of macro-scale objects needed to form a research station around another star, the kind of equipment we once envisioned boosting all the light years to our target. How much simpler if we can build the needed tools when we arrive?

Are Von Neumann Probes Ethical? (Chris Wren)

Von Neumann probes would be small, self-replicating robots. Small, easy to manufacture in large numbers and because of their low mass, easy to accelerate t

We're still grappling with the ethics - and unforeseen consequences - involved with releasing genetically modified strains of crops into the environment. There are always unforeseen consequences with any technology. The more sophisticated the technology, the more extensive and impossible to foresee those consequences are certain to be.

Would a more advanced civilization, if they were also more ethically developed than we are (not hard to imagine) consider von Neumann probes a form of cancer and take steps to eradicate them? Worse, would they take punitive measures against any civilization irresponsible enough to set them loose?"

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Have we detected an extraterrestrial signal?

SETI Picks Up Regular Laser Pulse Emanating From Space

Several years ago Bhathal, a researcher at the University of Western Sydney, suggested that a likely form of extraterrestrial communication would be laser bursts. He set up a facility at his lab which sweeps a nearby volume of space, within about 100 light years, for laser bursts that come in a regular pattern. Any kind of communication would likely be distinguished from background noise by coming in repeated or non-random patterns.

And a few months ago, Bhathal found the kind of regular pattern he's been looking for. He's been analyzing it and seeking a repeat pattern in the same area of space ever since. Though he's cautious about claiming it as a genuine extraterrestrial signal, his discovery has been making local news.

The latest from Centauri Dreams

A New Tilt on SETI

The planets in our Solar System rotate around the Sun more or less in a plane (the ecliptic) that is tilted some sixty degrees with relation to the galactic disk. It's interesting to speculate that this could have ramifications in terms of the SETI hunt. Shmuel Nussinov (Tel Aviv University) considers the possibility that any extraterrestrial civilizations might try to contact us only after they had a fair idea we were here. And just as we are now trying, via Kepler and CoRoT, to track down small planets using the transit method, so too might extraterrestrials try to observe our transits, and having done so, to transmit a message.

Bracewell probes: part three

As we enter an era of molecular manufacturing and ubiquitous computing, it becomes increasingly difficult to imagine what form an extraterrestrial presence might take. I'm personally convinced that the UFO phenomenon, bizarre as it initially seems, conforms to at least some of the "acceptable" criteria for a Bracewell-type probe. If I'm right, then the electromagnetic bias evidenced by our radio searches takes an abrupt and unwelcome backseat to something far stranger.

If our solar system is host to an ET intelligence, argue transhumanist pundits, it's unlikely we'll meet flesh-and-blood aliens. Metallic interstellar spaceships with biological passengers made sense to pre-computer audiences, but the reality-bending potential of the Silicon Age has cautioned theorists from expecting anything so blatant as the arrival of a "mothership." It's more likely that our first meeting with ETI will involve a novel form of artificial intelligence -- perhaps even the encoded persona of the ETs themselves. (It's worth noting the possibility that the fabled signal awaited by SETI researchers may turn out to be a practical blueprint instead of a mere greeting. In Carl Sagan's "Contact," the blueprint provides humanity with a transportation device, but perhaps it's just as reasonable to expect instructions for building an "alien-making machine": certainly an elegant solution to crossing the void in a messy, energy-intensive spacecraft.)





If we're dealing with an interstellar AI, its capabilities could be quite "indistinguishable from magic" -- and its motives substantially weirder than expected by mainstream scientists intent on marketing ETI as a readily comprehensible "product."

A sufficiently ancient ET presence could easily predate humanity and could even have played a role in guiding our evolution (a la Arthur C. Clarke's enigmatic black Monolith in "2001"). If so, there's no reason it should simply vanish upon our achieving what Sagan aptly called "technological adolescence." Indeed, an abiding alien intelligence might consider our continued existence imperative, offering the prospect that we've been subjected to some elusive form of psychosocial engineering lest we exterminate ourselves through warfare or environmental abuse.

Granted that a "neo-Bracewellian" presence could appear much how it wanted to, bound only by the laws of physics, might the UFO phenomenon shed light on our seeming cosmic isolation?

This piece originally appeared at aboutSETI.com.

Bracewell probes: part two

Assuming that aliens have dispatched Bracewell probes to distant planetary systems, it's reasonable to expect marvelously sophisticated devises. I'd be genuinely surprised, for instance, to discover a relatively nearby alien artifact "merely" eavesdropping on terrestrial transmissions and notifying its creators. Such a craft smacks of human engineering, not of the ancient galactic civilizations we may be forced to confront if SETI is to shed its cozy anthropomorphic chauvinism. Given speculative breakthroughs in fields as seemingly diverse as nanotechnology and artificial intelligence, I think it's more likely to expect Bracewell probes to exhibit behavior in keeping with the recently popularized "law of accelerating returns"; in other words, machines engineered by ETs should be truly intelligent, not simple telerobotic puppets limited to radio transmission.

Instead, Bracewell probes could very well outsmart their own makers and transform themselves into machines quite unlike the quaint transponders imagined in "The Galactic Club." Once the potential of nanotechnology and self-replication are accounted for, the potential for visiting ET craft appears nearly limitless. Not only could such emissaries engage an emerging technical civilization in an excruciatingly patient dialogue before alerting others, they could choose to remain chameleon-like, perhaps operating in the background like stealthy computer viruses. We might never even suspect they're here (neatly accounting for the so-called "Fermi Paradox"). Conversely, we could have been deliberately inoculated to their presence long ago, never seeing their machinations for what they are.

Supposing, for sake of argument, that a Bracewell device resides in our solar neighborhood, what might it be doing? More pertinently, why would it elect to remain hidden when we Earthlings have developed an unmistakably "intelligent" electromagnetic signature?

Both questions force us to reconsider Bracewell's legacy in ways I'll explore in my next post.

This piece originally appeared at aboutSETI.com.

Bracewell probes: part one

Lately much speculation has trended away from the "classic" SETI paradigm and into the domain of hypothetical ET devices such as self-replicating spacecraft and automated communications platforms (an idea proposed by astronomer Ronald Bracewell in his book "The Galactic Club").

Both concepts come as invigorating alternatives to the original SETI paradigm championed by Frank Drake and Carl Sagan. On the other hand, they leave us faced with the unnerving prospect of a galaxy bereft of intelligent life. If deep-space is impregnated by the robotic emissaries of far-flung galactic intelligences intent on achieving long-range contact, we have yet to receive an irrefutable signal. No sign of the telltale prime numbers celebrated in Sagan's "Contact." No invitations to subscribe to the "Encyclopedia Galactica," however hard we might wish to mingle with our elders in the local stellar neighborhood.

Or so it might seem.

SETI pundits tend to assume that contact with an alien device would unfold basically along the lines as direct contact with an actual civilization. Even Bracewell, an adventurous thinker in many respects, assumed that his eponymous probes would be little more than advanced versions of our own far-flung exploratory spacecraft; he envisioned Earth-based radio astronomers striking up a rudimentary dialogue with a probe dispatched to monitor the potential emergence of intelligence in our sector of the galaxy. After learning of our technological capacity (specifically, our ability to communicate via radio transmissions), the probe would then alert its makers, who might then choose to communicate in "person."

If this scenario sounds cumbersome, that's because it's inherently limited by the speed of light. Any ET civilization capable of wafting its cybernetic spore into the galaxy might very well have achieved effective immortality, but prospects for our own world are less certain; we could self-destruct or succumb to environmental catastrophe many thousands of years before achieving a meaningful long-distance relationship. Knowing we're not alone may come with a certain existential comfort, but, by itself, would be of no specific practical value.

And although SETI advocates almost invariably expect that ET societies will want to communicate with us, we shouldn't dismiss the unflattering possibility that we're subject to some form of quarantine. Perhaps we're being watched by "intellects vast, cool and unsympathetic," if not as war-like as H.G. Wells' imperious Martians.

Does the apparent absence of Bracewell probes prove that we have yet to be visited? Hardly. Maybe we're just not looking hard enough. Maybe we need to think like an alien.

This piece originally appeared at aboutSETI.com.

Rethinking ET "civilizations"

When scientists address the possibility of contacting extraterrestrial intelligence, they generally use terms in keeping with our own (necessarily limited) experience. Consequently, we're treated to expansive speculation about the agendas of ET civilizations. But why the typical assumption than ETI will necessarily take a readily comprehensible form? After all, the galaxy might be governed by novel forms of intelligence that challenge conventional definitions of government, economics, and even personhood.

To be sure, terms denoting some form of alien "civilization" make speculating about the nature of ETs easier -- usually by implying that even the most technically savvy aliens, despite cultural differences, will be fundamentally comprehensible to present-day humans. But it's a big universe. If we achieve contact -- whether through the discovery of artifacts in our solar system or by happening across a telltale signal -- there's no promise the senders will hail from any sort of familiar social structure. Indeed, it's not unlikely that an alien intelligence "merely" a few thousand years ahead of us would completely defy comparison to terrestrial institutions.

I've always been frustrated by the prevailing assumption that aliens will eschew interstellar travel in favor of radio transmission due to the presumed cost of space travel. While aliens might suffer from constraints posed by limited access to resources, the notion of "cost" is rooted in our own brief, limited experience as social primates. We humans might bemoan the seemingly prohibitive price of manned spaceflight, but a more far-sighted intelligence might possess vastly different priorities. Spared the hurdle of terrestrial economic imperatives, I would expect aliens to prove surprisingly resourceful.





Contemporary discussion about a "post-scarcity" economy predicated on molecular manufacturing begs theorists to re-evaluate the likelihood that ET intelligences will conform to the models conceived by Frank Drake and Carl Sagan. For instance, instead of communicating with groups of like-minded beings, we may find ourselves in the midst of solitary god-like beings with only tenuous ties to their biological forebears. Allegiance to a community might turn out to be a uniquely human trait.

If galactic civilizations are indeed exceptional rather than the norm, much of SETI's operative wisdom will demand reinvention. For example, we may have to dispense with realistic hopes of happening across Sagan's "Encyclopedia Galactica." Likewise, we may never be invited to "join the club" -- not because we're not deserving, but simply because there's no club to join in the first place.

Ultimately, I'm haunted by a vision of a Cosmos inhabited by forever-roaming AIs who have long since jettisoned the quirks and baggage forged during their ancestors' brief tenure as biological beings. Some of these wandering minds might be quite indifferent to the antics of emerging technological civilizations such as our own. Others, possessed of infinite patience, might choose to observe.

But the ones who want to play are the ones that interest me most of all.

This piece originally appeared at aboutSETI.com.

SETI is for chumps (and other reasons why we have yet to hear from aliens)

As I've illustrated in previous postings, I'm not convinced the "Fermi Paradox" is quite the insoluble puzzle it's generally made out to be. On the contrary, I think there's ample reason to think the human species could be interacting with a fantastically novel (and secretive) form of ETI, although I realize that proving my hunch is another matter altogether.

Nevertheless, it's worth examining some of the reasons we have yet to receive the popularly conceived extraterrestrial signal currently sought by mainstream SETI researchers. If nothing else, a breakdown of the options casts our own brief legacy as a technological species in a sobering glow.

1.) Maybe some intelligent ETs forego radio transmission in favor of crewed exploration. Although unwieldy by human standards, there are innumerable reasons why spacecraft might be deemed preferable to manning radio telescopes. Put less gently, perhaps SETI is for chumps.

2.) Forget exploration; maybe aliens lose interest in such arduous ventures as soon as they develop technologies that enable them to inhabit custom-engineered realities. Imagine a future incarnation of Second Life; would users voluntarily leave worlds (and bodies) of their own creation if their needs were provided for?

3.) Maybe the situation's grimmer than we like to admit and ET civilizations almost inevitably self-destruct. We've only narrowly avoided nuclear Armageddon here on Earth, and we're still far from reaching a sustainable geopolitical milieu. Why should ETs necessarily be any different?

4.) Of course, there's the "quarantine" hypothesis, which maintains that while at least one ET presence in aware of us, it elects to remain unseen -- at least until we reach some arbitrary level of sophistication or enlightenment. In one version of this scenario we're being actively (if clandestinely) groomed for eventual contact, which might explain aspects of the UFO phenomenon.

5.) Perhaps aliens do rely on radio, but only briefly, inevitably graduating to vastly improved modes of communication (some possibly beyond the scope of modern physics). In this case there's a chance we could eavesdrop on a stray transmission, but it would be so old that it would tell us very little about what the originating civilization was up to now . . . or if it even still existed in recognizable form.

6.) We could be the first. After all, someone has to be. But the sheer number of stars in our galaxy -- to say nothing of the discovery of ubiquitous exoplanets -- argues that we aren't. (Perhaps it's equally likely that we're the last, and that other intelligences have long since abandoned long-distance radio communication in favor of hedonistic virtual worlds or a "postbiological" existence antithetical to scientific curiosity. Having ensured their survival, advanced aliens might be a curiously unimaginative lot.)

7.) On a more ominous note, maybe detectable civilizations arise regularly but are quickly snuffed out by a galaxy-spanning intelligence that's adopted the role of cosmic exterminator. Interstellar warfare would seem to be the stuff of pulp science fiction, but the survival imperative is rooted in basic Darwinism. We can't rationally exclude the possibility, however slim, that candidate civilizations invariably fall victim to vengeful self-made gods.

8.) Encrypted transmissions could be so complex -- or so excruciatingly simple -- that we simply don't recognize them as the work of intelligence. Although we take great pains to envision "the alien," our objectivity could be hobbled by our innate tendency to assume ETs will resemble ourselves in at least basic respects.

9.) Some scientists insist that while primitive ET life is relatively common, ET intelligence is effectively impossible in light of the myriad variables that spawned complex life on Earth. Proponents of the "Rare Earth" hypothesis aren't afraid to argue that we could be the only intelligent species in the galaxy, if not the entire universe.

10.) Finally, returning to the scenario outlined in my previous post: Maybe we have intercepted a signal, recognized it as such, and kept it a secret for fear of its potential to destabilize entrenched social structures.

This piece originally appeared at aboutSETI.com.

A SETI taxonomy?

If our galaxy is home to advanced ET civilizations, it would be helpful if we knew what we were looking for. For instance, how do we define "advanced" -- and might a civilization's level of development make it easier (or harder) to detect?

In 1964, astronomer Nikolai Kardashev proposed that ET societies fall into three fundamental categories, each based on environmental resourcefulness. A hypothetical "Type I" civilization, for example, effectively conquers all available resources on its home planet (and, just as importantly, fails to destroy itself in the process). A "Type II" civilization is more robust, utilizing the resources of its solar system. Even more daunting, a "Type III" civilization is characterized by its ability to harvest energy on a galactic scale.





If a Type I or Type II civilization seems godlike to our own relatively primitive "Type O" civilization, it's worth remembering that even a solar system-spanning intelligence is far from immortal. But destroying a Type III civilization would prove considerably more difficult. Having inundated space and assumed control of millions of stars, a Type III civilization would be able to anticipate celestial mishaps and perhaps even prevent them.

The "Kardashev Scale" has become a mainstay among futurists seeking to plot humanity's own future. But while not without its usefulness, Kardashev's model remains speculative. There's no guarantee that a high-technology ET civilization will abide by his template, however sensible it might seem. The Kardashev Scale assumes, for instance, that aliens will share our own imperialistic sensibility. In truth, they might be far less aggressive, requiring less energy than we might expect; there's no readily apparent reason why even the most resplendent of civilizations would require the resources of an entire galaxy.

One can think of any number of activities that might engage ET societies; our evident failure to observe Type III civilizations is hardly proof that ETs don't exist. Ultimately, the Kardashev Scale serves as an engaging speculative exercise. Unfortunately, like the Fermi Paradox, it's evolved into a sort of cosmic doctrine, eagerly defended by pundits who seem genuinely incapable of realizing its anthropocentric limitations.

This piece originally appeared at aboutSETI.com.

The "Great Filter"

Oxford philosopher Nick Bostrom recently wrote an article for "Technology Review" championing the concept of a "Great Filter" -- a sort of existential black hole assumed to either preclude the emergence of complex life or else destroy advanced civilizations (thus SETI's failure to detect intelligent signals). Bostrom posits that we should hope to find our own solar system devoid of primitive life, since such a discovery would indicate that the Great Filter lies in our future instead of our past, thereby effectively condemning humanity to extinction before we're able to announce our presence to the galaxy (assuming we'd want to).





If Bostrom's right, then he's managed to neatly encapsulate the Fermi Paradox within a cautionary philosophical framework -- no mean feat. But his argument is boundlessly porous, imposing anthropocentric logic on extraterrestrials about which we know nothing. As I've argued in a previous post, there's little reason to suggest that Enrico Fermi's famous "paradox" is anything of the sort. Unfortunately, Bostrom's acceptance of the Fermi Paradox as a cosmic directive, rather than an engaging scientific challenge, constitutes a glaring failure of imagination.

It probably goes without saying that Bostrom ignores the UFO controversy and its implications for ETI. But one doesn't need to accept UFOs as evidence of visitation to discern grave problems in Bostrom's notional "Great Filter." The most daunting problem lies in his presumption that technologically inclined ETs will necessarily make themselves known, whether through electromagnetic pollution or works of astro-engineering. Of course, Bostrom's conjecture only makes sense if the aliens are essentially like us, driven by a form of galactic colonialism. He all-but ignores the possibility that advanced ET societies might possess vastly different imperatives, perhaps eschewing the harsh realities of deep space for other, no less-aspiring ventures.





Galaxy-conquering civilizations might set the stage for science fiction novels (Isaac Asimov's enduring, if dated, "Foundation" series springs to mind), but in light of our failure to readily detect their broadcasts they seem more than a little like quaint extrapolations of our own technology-fixated era. Absence of evidence isn't evidence of absence; in his haste to praise the merits of the Great Filter, Bostrom presents a scenario that seems almost deliberately contrived to engage academics at the expense of genuine inquiry.

Which isn't to say we needn't fear the very real threats facing our species. If ET civilizations are common, it beggars belief to assume that all of them survive indefinitely. On the other hand, perhaps some of them manage to reach a technological "island of stablity" in which their social structures exist in relative harmony with their technological potency. For example, astronomer Milan Ćirković has argued in favor of ET "city-states" that, aside from harboring sustainable civilizations, would fail to be easily detected -- an idea that makes at least as much sense of the Fermi Paradox as Bostrom's fatalism.

This piece originally appeared at aboutSETI.com.

Are we a simulation?

In my last post I listed five off-the-cuff reasons that might help explain why aliens haven't made formal contact (in the event they're visiting us in the flesh -- or its alien equivalent). But there's another possibility that begs consideration: That our universe is a simulation with finite boundaries. Maybe we have yet to achieve contact with aliens because the universe we observe is a computational artifact and there are no aliens . . . except, possibly, for the ones responsible for the simulation in the first place.

It's a lavishly paranoid idea, but not without a perverse philosophical appeal. Achieving mainstream popularity in 1998 when "The Matrix" hit theaters, the concept isn't as new as it might seem. Science fiction author Philip K. Dick pioneered the sort of solipsistic dream-or-reality fiction that would later find renewed urgency in the cyberpunk novels of the 1980s. The idea's staying power is arguably due to the fact that there doesn't seem to be a convincing technical reason why our world (if not the Cosmos itself) couldn't be an incredibly rich software program operating according to set parameters (which we might interpret as physical laws and constants such as Einsteinian relativity and the counterintuitive domain of quantum uncertainty).





Novelists and philosophers alike have devised myriad reasons why an advanced intelligence might create a simulated world. Arbitrarily capable scientists might want to tinker with physics, recreating the "real" world while incorporating experimental content: an endeavor to which our own scientific community aspires, often aided by advanced computational models. Or maybe we're an anthropological experiment set loose in an agar of code; somewhere, overseers could be watching our plight with keen interest.

Metaphysicians typically refute the idea that consciousness can be reproduced through purely mechanical means, in which case the argument for our existing within a simulation (with or without simulated aliens) can be summarily forgotten. But if self-awareness is indeed epiphenomenal -- the inevitable outcome of physical processes within the brain -- then the possibilities become effectively endless. For example, we may not only be a simulation, but a simulation within a simulation. Or, more demeaning yet, a simulation within a simulation within a simulation.

If so, the question of whether or not we're alone in the Cosmos is faced with some unexpected variables, none so vexing as our potential inability to determine whether there really is an "out there" or if we're merely staring at the bars of a cosmic jail cell.

This piece originally appeared at aboutSETI.com.

Fermi's legacy

"Where is everybody?"

--Enrico Fermi, 1950

If we subscribe to the conventional interpretation of the Fermi Paradox (a thought experiment that forces us to struggle with the prospect of a Cosmos largely devoid of intelligent life), it would seem we're indeed alone, at least insofar as we have any hope of making contact with interstellar neighbors. But what exactly is the Fermi Paradox? And does it necessarily imply that we're a freak of stellar and biological evolution, potentially the only intelligent species in the universe?

Physicist Enrico Fermi's vaunted "paradox" began as an off-the-cuff thought experiment. If the galaxy is suited for the emergence of life and intelligence, Fermi asked, then why do we fail to readily detect the handiwork of extraterrestrial species? After all, according to the wisdom of his era, expansion into space seemed near-inevitable. And if humans were poised to become a multi-planet species, then certainly aliens had accomplished the same feat long before we arrived on the stage, perhaps transcending their home solar systems in favor of interstellar colonization and mind-boggling feats of "astro-engineering." (Fermi would probably have been hard-pressed to imagine an early 21st century bereft of Mars colonization, let alone the demise of the Apollo program.)





Today, Fermi's query has attained the status of a cosmic statute, especially among theorists convinced that intelligent life is witheringly rare. Proponents of the Anthropic Cosmological Principle, for instance, believe the universe shows unmistakable evidence of existential "fine tuning," presumably to allow the existence of human life. (An engaging alternative is that the universe is as we perceive it because, if it were otherwise, its history would have precluded our evolution and we simply wouldn't be here. More recently, cosmologists have speculated that we might inhabit a "multiverse" comprised of an infinite number of universes, all governed by variations of the laws of physics as we know them. If such is the case, we shouldn't be especially surprised to find that physical laws seem "fine-tuned" for our existence, as our universe would be one of many: a cosmic jackpot well within the realm of probability.)

Despite the emphasis routinely placed on Fermi's famed quip, there's no evidence that Fermi himself ever intended it to be anything more than a useful thought experiment. He wasn't condemning the existence of extraterrestrial intelligence so much as speculating on the form alien intelligence might take -- and challenging his colleagues to devise ways in which potential civilizations might be detected.

In many important respects, Fermi's challenge has been neglected by science; we have yet to rise to the task of envisioning truly alien aliens. Too often, the extraterrestrials envisioned by SETI researchers are little more than simple extrapolations of ourselves, encumbered by human priorities, human psychology and even human economics.

But even Fermi's hunch that intelligent species will in some way make themselves visible to us is necessarily anthropomorphic; in reality, extraterrestrials might have better things to do, even if they're very much aware of our presence. (As argued in prior posts, revealing themselves -- whether to us or to the galaxy at large--might prove incredibly silly or even fatal.)

In part, we long for hard evidence that we're not alone not because we want to know that our own civilization can endure the long, hard centuries to come. The evident silence that greets our radio telescopes, far from proof that our universe is unreasonably hostile to life or that aliens succumb to disasters of their own making, is a mute challenge. Fermi's question remains relevant -- just not in the way some experts would have us believe.

This piece originally appeared at aboutSETI.com.

Contact: Would we know if it happened?

Forgive my cynicism, but I have to ask: If we received an irrefutable ET signal, would the public ever know?

Suppose it happened tomorrow: Radio astronomers detect an intelligently crafted burst of data lurking in the interstellar noise. According to international SETI protocol, the receipt of such a signal, once verified, would be disseminated among the astronomical community and made public. Indeed, international cooperation might be necessary in order to distinguish a legitimate alien signal from any number of phenomena capable of generating false alarms.

SETI's disclosure scenario only makes sense if the signal in question is of no strategic importance. But, in reality, we have no way of anticipating what an alien intelligence might choose to send us. While many scientists find the prospects of interstellar hate mail slim, we can't immediately rule out the existence of malevolent ETs or cosmic "spam."

A transmitting civilization wouldn't even have to be hostile to pose grave threats to SETI's promise of prompt dissemination. For example, a radio-frequency communiqué might contain data pertaining to a relatively near-term celestial threat such as an impending supernova. In effect, our first signal might prove to be a warning from a galactic emergency broadcast system. While the motive behind the message might be perfectly benign, the effect on our society could prove debilitating.

Which begs the question: How do we distinguish between the sort of lofty, abstract dialogue immortalized by Carl Sagan and less palatable alternatives? More pressingly, how do we make such a determination within a reasonable time-frame?

The arrival of an extraterrestrial signal would almost certainly be fraught with some degree of bureaucratic interference, and it would be the height of naïveté to expect the national security establishment to content itself with idle observation of the proceedings. At some point during the decryption of a candidate signal someone is bound to intervene. If the message seems at all intriguing, I can't help but envision the discovery going underground . . . at least until sufficiently analyzed. (One naturally wonders if the public announcement of an ET transmission would represent the whole signal or a "sanitized" remix.)

Lest my concerns seem like so much "X-Files" paranoia, it's worth considering some of the reasons an ET intelligence might send us a message in the first place. Perhaps, as noted, we're due to experience an unforeseen "existential threat" via gamma radiation or the close approach of an uncharted black hole. Or we may be in the line of fire of someone else's war. More extravagantly, we might discover that our section of the galaxy is scheduled for demolition in order to make room for an astro-engineering project -- in which case our stellar landlords could be sending out a most unwelcome eviction notice (albeit one we can postpone heeding for a few thousand years).

The threats above may seem reassuringly distant to citizens of the West, but the governments of less-developed regions might see things quite differently. While our ET neighbors might be able to take a long-range view, we can scarcely say the same for our own species.

Ultimately, would nation states elect to gamble with their respective economies and socio-political agendas for the sake of imparting knowledge of no apparent practical consequence?

I think the answer is no.

This piece originally appeared at aboutSETI.com.

Terence McKenna: Communication via fungi?

The late psychedelic philosopher Terence McKenna isn't typically associated with the search for extraterrestrial intelligence; he mostly concerned himself with the actualization of intelligence here on Earth, taking a welcome cosmic perspective that revealed our species' failings and latent potential. But he introduced at least one new idea to the SETI controversy that deserves consideration, especially in light of recent discoveries.

McKenna suggested that the surreal hallucinatory states experienced by "trippers" might constitute a form of extraterrestrial contact, vastly more intimate than the radio signals anticipated by his mainstream counterparts.

Ludicrous? Perhaps not. Hallucinogenic mushrooms are dispersed as hardy spores capable of traveling incredible distances. McKenna wondered if such spores could have been deliberately wafted to Earth in the remote past, inviting the proposition that many planets conducive to life might have been likewise seeded.





Boldly venturing away from conventional evolutionary narratives, McKenna speculated that homo sapiens might owe its unique cognitive abilities to exposure to psilocybin, a mushroom-derived substance with pronounced neurochemical effects. In McKenna's scenario, the medium is the message: the bizarre worlds encountered by people under the influence of psilocybin are components of an "invisible landscape" with which we share a profound and unacknowledged symbiosis. (McKenna credited the advent of language, among other phenomena, to chemically altered states.)

That our brains harbor receptor sites to specific botanical chemicals indicates a relationship of some complexity, regardless whether the originating organisms are indigenous to Earth or hail from space. If our planet was indeed seeded with fungi, psychedelic experiences might comprise an authentic message, albeit one we have yet to decipher. (Alternatively, McKenna offered the fascinating possibility that hallucinogenic mushrooms themselves could be intelligent in an unrecognized sense, challenging our very definition of the word.)

Recent experiments demonstrate that spores are surprisingly well-suited to the rigors of the interstellar vacuum, vindicating at least a portion of McKenna's proposition. If he was right, then the "aliens" could have already arrived -- a revolutionary notion that pales only when one considers the role they may have played in the development of human consciousness.

This piece originally appeared at aboutSETI.com.

Searching for nonfractal signatures

The search for artifacts on other planets is by no means limited to "seeing faces." Aside from calling on archaeologists when confronted with anomalous surface formations, mission planners can test spacecraft images for telltale "nonfractal" terrain signatures.

Geological processes are inherently fractal. Unlike artificial sites such as cities and farms, defined by uniformity and harsh angles, natural landscapes repeat themselves on multiple levels. A mountain, for instance, is "repeated" in any of the countless rocks that litter its slopes. (Weirdly enough, we seem to inhabit a massive fractal: orbiting planets recall the structure of atoms; galaxies themselves bear a passing structural similarity to their constituent star systems.)





As part of a long-running "debunking" campaign, Malin Space Science Systems (the camera subcontractor for NASA's Mars exploration program) has popularized the so-called "Happy Face Crater," a feature often cited to defuse discussion of the more robustly detailed Cydonia Face. Consisting of a crater basin with attendant debris in the shape of a crude smile, there doesn't appear to be anything truly anomalous about the Happy Face. But subjecting the crater to an impartial scan in order to ascertain its fractal signature would go a long way toward arriving at an objective conclusion.

Is the Happy Face more or less fractal than its neighboring craters? Better yet, how would it stack up to the better-known Face in Cydonia?

Intrigued by the potential of fractal algorithms to deduce artificial constructions, image processor Mark Carlotto tested images of the Cydonia region. The Face registered suspiciously high, as did another contested feature. Since Carlotto's computer algorithm wasn't designed to seek out faces, the Face's conspicuous nonfractal signature offered a quantitative argument favoring an artificial origin.

Carlotto's enticing proof-of-concept has yet to be embraced by the space science community. Indeed, Carlotto himself has yet to put newer images of Cydonia to the test. But given the computing might of today's desktop systems, it's not unrealistic to imagine a committed search for anomalous fractal signatures on distant planetary surfaces. What do we have to lose?

This piece originally appeared at aboutSETI.com.

The "Face on Mars" and pareidolia

Mainstream skeptics commonly dismiss the Face on Mars as an example of "pareidolia," the brain's attempt to attribute meaning to random stimuli. After all, there are several natural formations here on Earth that bear a passing resemblance to human faces. The now-toppled "Old Man in the Mountain" is probably the most-cited example.

Most of the likenesses described by Face on Mars debunkers are profile images: Viewed from only a slightly different angle, the celebrated face-like resemblance vanishes, replaced by an obviously natural phenomenon. While profiles rely on a minimum of information to convey a sense of the mysterious (contours to suggest features such as a "nose," "mouth," etc.), the Face on Mars is different in several notable respects. For instance, the Face appears to be a frontal portrait. While computer modeling reveals a striking facial profile when seen from the perspective of an observer on the Martian surface, the Face retains a humanoid likeness when viewed from above. This doesn't prove that the Face is the work of intelligence, but it tends to elevate it from the oft-mentioned examples wielded by geologists convinced the Face on Mars must invariably yield to prosaic explanations.





Moreover, and perhaps more interestingly, high-resolution images of the Face reveal detail not visible in the early Viking photographs. Astronomer Tom Van Flandern, for instance, quickly noted the presence of accurately situated features such as an apparent "pupil" in one of the "eyes" as well as "nostrils" and "lips" -- all of which were beyond the resolving power of the Viking mission.

The low odds of such secondary facial characteristics occurring by chance helped belie the notion that the Face on Mars was the product of garden-variety pareidolia. If the Face on Mars is indeed a windblown butte, it's a great deal stranger than imagined prior to high-resolution scans. Indeed, if the same level of detail had been detected on a terrestrial surface feature, it's probable that archaeologists would have been consulted in order to assess its merit as a potential artifact.

It would seem the Face's unlikely presence on a "dead" world has effectively doomed it to pop-science oblivion. But the Face is far from a solitary anomaly; it shares the Cydonia region with other, equally intriguing features that call for careful analysis. Taken together, an objective viewer is presented with a gnawing puzzle that may ultimately demolish the easy certainties that coincide with the traditional view of our solar system.

I'll continue to explore the anomalies on Mars in my next post.

This piece originally appeared at aboutSETI.com.

Redefining SETI: The case for Martian archaeology

Few subjects within the astronomical community have aroused as much scorn as the 1976 discovery of a face-like formation in the Cydonia Mensae region of Mars. The now-iconic "Face on Mars" has become the source of endless derision among mainstream scientists. Uninitiated readers are typically assured that the unusual feature is a naturally occurring hill (or mountain, or butte, or "pile of rocks," depending on the debunker's bias). To be sure, the face may well prove to be natural. But I've always been disturbed by the divisive climate that's surrounded the subject -- and not a little frustrated by the factual mistakes made by self-proclaimed "skeptics" who should know better. Far from being a dead issue, the face and its seldom-remarked associated anomalies constitute a novel challenge that has yet to be taken seriously except by a relative handful of curious agnostics.





My previous post emphasized the need for archaeologists if "planetary SETI" is to contend with its radio-based predecessor. After all, if we find candidate artifacts on other worlds, it's likely they'll be extremely old. Mars, blanketed by dust and pocked with craters, is hardly an ideal location for preserving artificial structures. Although not as corrosive as Earth, the Red Planet boasts scars that hint at a geologically active past; anything constructed during Mars' tenure as a "living" planet is likely to have endured many of the same processes that have sculpted the planet into the wasteland we see today. If so, how tenable are NASA's casual dismissals of potential Martian artifacts?

When the face was reimaged in 1998, debunkers condescendingly noted the lack of "roads" and parked "flying saucers" that would conclusively demonstrate artificiality. But given Mars' age and geological history, superficial features like "roads" would be the last things one might reasonably expect to find -- unless, of course, Mars was home to an active alien civilization with a penchant for terrestrial architecture.

The fact that virtually no one seriously considered Mars to be home to an extant civilization was brushed aside to accommodate the skeptical community's need to shoot down the looming myth that the face has become in the decades since it was first photographed. Sadly, the opportunity to address the issue of extraterrestrial archaeology in scientific terms was squandered, leaving a residue of misconceptions that only fueled the "fringe's" obsession with conspiracy theories.

Fortunately, there's no reason we can't take up the case for unbiased, disciplined appraisal of candidate Martian artifacts. In future posts I'll explore options and possibilities that may lead the search for extraterrestrial intelligence in some unexpected directions.

This piece originally appeared at aboutSETI.com.

Redefining SETI: Where to begin?

[As my most recent submission to aboutSETI.com has yet to be posted, I must assume that I've been forgotten. As a backup measure, I've decided to recycle my earliest aboutSETI entries, beginning with the following essay from February of 2008. --Mac]

A few readers have expressed some deserved confusion about what disciplines I was referring to in the previous post. After all, SETI's long affiliation with radio astronomy makes the idea of invoking non-technical disciplines seem both heretical and ill-advised. Wouldn't we be best served, mainstream SETI pundits might ask, by "staying the course" with increasingly robust sky scans? After all, if "they're" out there, it strains orthodox acceptance to consider the possibility that "they" might have made it here.

I'm frankly disillusioned by the casual assumption that SETI is an endeavor best left to radio astronomers. While I support radio SETI, I think an equally valid case can be made for searching planetary surfaces for traces of extraterrestrial habitation.

The lunar surface -- airless and spared the erosion constantly at work on dynamic worlds like Earth -- would seem to be a prime candidate for methodical study. It's not out of the realm of possibility that the Moon (and perhaps Mars) has been visited at least once by a visiting civilization. Ironically, none other than SETI pioneer Carl Sagan championed the possibility that the Moon might serve as a platform for ET monitoring devices. (Sagan's scenario is memorably encapsulated in Arthur C. Clarke's "2001: A Space Odyssey," a book widely regarded as a formative work of "serious" science fiction.)

But if we're to take up the hunt for ET artifacts, radio-based SETI suddenly becomes of limited use. A meaningful search for lunar artifacts might reasonably call on the expertise of archaeologists (many of whom rely increasingly on remote sensing technology), anthropologists and even artists. Hardly the "hard" sciences typically associated with searching for ET life, they're nonetheless decidedly relevant if we're to advance planetary SETI as a viable alternative.

Is such an unorthodox study feasible in the face of radio SETI's staunch "electromagnetic chauvinism"? I argue that it is, and that its chances for payoff are high enough to justify committed research. In fact, it's just possible that we've already stumbled upon candidate ET structures, only to reject them for fear of violently offending the status quo.

I'll return to just such a case in a forthcoming post.

ET civilizations: how many?

Number of alien worlds quantified

The discovery of more than 330 planets outside our solar system in recent years has helped refine the number of life forms that are likely to exist.

The current research estimates that there are at least 361 intelligent civilisations in our Galaxy and possibly as many as 38,000.

The work is reported in the International Journal of Astrobiology.

Chris Wren writes:

Sure, it's based on a simulation - a very complex simulation, but it beats saying "I didn't see any alien Von Neumann probes when I looked out my window this morning. We're obviously alone in the universe." Which is basically all the Fermi "Paradox" amounts to, no matter how people try to dress it up.