Is geoengineering an existential risk?

Well, Milan M. Ćirković and Richard B. Cathcart think it's a distinct possibility. In fact, it may even (partly) explain the Great Silence. Check out the abstract to their article, "Geo-engineering Gone Awry: A New Partial Solution of Fermi's Paradox":

Technological civilizations arising on such planets will be, at some point of their histories or another, tempted to embark upon massive geo-engineering projects. If, for some reasons only very recently understood, large-scale geo-engineering is in fact much more dangerous than previously thought, the scenario in which at least some of the extraterrestrial civilizations in the Milky Way self destruct in this manner gains plausibility. In addition, we speculate on possible reasons, both physical and culturological, which could make such a threat even more pertinent on an average Galactic terrestrial planet than on Earth.

Be sure to read the entire article (PDF). Learn more about geoengineering. And be sure to read Jamais Cascio's article, "It's Time to Cool the Planet."

New theory suggests that we may not be alone after all

Astrophysicist Brandon Carter's long-standing argument against finding intelligent extraterrestrial life has been roundly challenged by a team of Serbian researchers led by Milan Ćirković.

Carter's theory assumed set timescales for two processes: the life cycle of a star and the emergence of complex life. By statistically combining the two Carter concluded that complex life takes longer to emerge than the life-friendly duration of most stars -- with the implication being that intelligence is excruciatingly rare in the Galaxy and we may be alone.

Not satisfied with this conclusion, Ćirković and colleagues Branislav Vukotić and Ivana Dragićević are now disputing these assumptions. In their Astrobiology paper, "Galactic Punctuated Equilibrium: How to Undermine Carter's Anthropic Argument in Astrobiology," they contend that there is no reason to assume life evolves only gradually. They argue life could evolve in fits and starts - mirroring an evolutionary theory called punctuated equilibrium.

The abstract of their paper reads,

Our approach is based on relaxing hidden uniformitarian assumptions and considering instead a dynamical succession of evolutionary regimes governed by both global (Galaxy-wide) and local (planet- or planetary system–limited) regulation mechanisms. Notably, our increased understanding of the nature of supernovae, gamma-ray bursts, and strong coupling between the Solar System and the Galaxy, and the theories of “punctuated equilibria” and “macroevolutionary regimes” are in full accordance with the regulation-mechanism picture. The application of this particular strategy highlights the limits of application of Carter's argument and indicates that, in the real universe, its applicability conditions are not satisfied. We conclude that drawing far-reaching conclusions about the scarcity of extraterrestrial intelligence and the prospects of our efforts to detect it on the basis of this argument is unwarranted.

In plain English, the conditions in the Universe required for the emergence of intelligent life have only recently been established (in cosmological scales). Prior to 'recent times', universal mechanisms were in place to continually thwart the evolutionary development of intelligence, namely through gamma-ray bursts, super novae and other forms of nastiness. Occasional catastrophic events have been resetting the "astrobiological clock" of regions of the Galaxy causing biospheres to start over. "Earth may be rare in time, not in space," they say. They also note that the rate of evolution is intimately connected with a planet's environment, such as the kind of radiation its star emits.

This is why the authors reject a strict uniformitarian approach; the Universe is not the same now as it was in the past.

And importantly, given the possibility that the conditions for intelligence to emerge are now in place, we shouldn't give up hope about our chances of discovering extraterrestrial life.

Freeman Dyson at TED: We can look for life in the outer solar system

Renowned theoretical physicist Freeman Dyson suggests that we can look for life on the moons of Jupiter and out past Neptune, in the Kuiper belt and the Oort cloud. He talks about what such life would be like (e.g. creatures that look like lenses and mirrors with roots that go deep into the ocean) and how we might find them.


Dyson is one of my favorite people in the whole world -- one of the great minds of our time. I'm overjoyed that he's still going strong well into his 80's.

Guest Blogger: Russell Blackford: Where's my alien civilisation? Part 2.

Where were we?

This year we have Darwin's 200th birthday and the 150th anniversary of the publication of On the Origin of Species. It's a natural time for thoughts to turn to issues about the origins of life and the trajectory of biological evolution. It was in that context that I found myself, this week, thinking again about the Fermi paradox and the mysteries of the Drake equation, after some discussion of these over on Richard Dawkins' site. The discussion on Dawkins' site got a bit acrimonious, for some reason, but I'm sure we can avoid that here.

At the end of Part 1., I left the Fermi paradox with questions about the fate of technological civilisations. Do they self-destruct? Do they become unrecognisable to us? Or does the rate of technological progress flatten out, in which case we are not approaching a technological singularity – rather, we are somewhere on the steep part of a sigmoid curve.

Deeper into Drake's equation

I suspect that the evidence that we're on a sigmoid curve is pretty much illusory. E.g., the evidence from science fiction is probably just evidence of limits to our imaginative capacities. Still, it's not a scenario that can be ruled out (and it seems just as possible to me as the technological singularity scenario). It's certainly conceivable that at least some kinds of technological progress flatten out. At 1 per cent of the speed of light it would take us over 400 years to reach the nearest stars. We don't know how much longer to reach the nearest worlds that could easily be colonised. We tend to think that the problems will be solved in millions of years of future progress, but we may not be good at working out what problems can and cannot be solved, at least easily enough to be worth the effort, even over very long tracts of time.

That said, I'd prefer to look for an explanation deeper in the Drake equation, which uses several variables to calculate the number of technologically advanced species in our galaxy. The variables include the average rate of star formation, the fraction of stars that have planets, the fraction of planets that can potentially support life, the fraction of these that actually develop life, the fraction of these where intelligent life evolves, the fraction of these that develop civilisations that send detectable signs of themselves into space, and the length of time that such civilisations exist.

Some of the fractions that feed into the Drake equation may be very small indeed, so small as to make technologically advanced species, and the civilisations they create, incredibly rare. It's consistent with what we now know that the conditions required for life to form are extremely fortuitous and unusual. It may need very rare combinations of environmental factors. And even then, you can have life staying at levels of neurological complexity that don't lead to technology.

We know that life can stay at levels of intelligence well below our own pretty much indefinitely. If not for one or more catastrophic events at the end of the Cretaceous Period, including the bolide impact that caused the Chicxulub Crater, Earth might still be dominated by dinosaurs, which might not have developed any impressive levels of intelligence. They hadn't done so in the previous 150-odd million years, so there's no reason to think they would have in the past 65 million years.

We really need to know a lot more, and we soon reach a point where people are relying on nothing more than hunches. With that disclaimer, my hunch is that the evolution of a technological civilisation to our sort of level or beyond is a statistically improbable event. I.e., it is an event that takes place quite infrequently in an average galaxy. I can't be much more precise about what "quite infrequently" means, except to say that I wouldn't be at all surprised if human beings were the only species in our galaxy to have created technological civilisations.

There's a lot of things we'd need to know before we could say anything more confidently, or more precise, than that. E.g., we'd need a well-corroborated theory of the origin of life to give us an idea of how rare the conditions for it really are. We just don't have one. We have a well-corroborated theory of how life diversifies - neo-Darwinian evolutionary biology - but not of how it gets started. The best we have is an idea of what sort of theory would be a workable account of abiogenesis – some kind of theory of early kinds of self-replicating molecules that were able to develop into the building blocks for the kinds of life forms from which we, and the rest of contemporary life on Earth, all eventually diversified.

There are so many unknowns about all this that I think we're a long way from being able to deduce any pessimistic conclusions about humanity's future. Even if life itself is more common in the universe than appears so far, the evolution of human-level intelligence might be very rare indeed. Even if technological change ends up following a sigmoid curve, we don't know how to unpack the detail of that – it might mean that space travel at appreciable fractions of the speed of light is going to turn out more difficult than we commonly assume … but, for all that, our ability to transform our capacities may reach levels far beyond what is current. We can't predict the future, though we can forecast and consider various possibilities and scenarios.

Still waiting

Meanwhile, I'm still waiting for my alien civilisation. I'm also waiting for my jet car. If it doesn't turn up before I shuffle off this mortal coil, I don't know if that's a reason for pessimism or optimism.

Where has the damn thing gone?


Russell Blackford is an Australian philosopher. He has published extensively (novels, short stories, academic monographs and articles, and book reviews) and is editor-in-chief of The Journal of Evolution and Technology. His home blog is Metamagician and the Hellfire Club.

Nick Bostrom: "Why I hope the search for extraterrestrial life finds nothing."

Transhumanist philosopher Nick Bostrom desperately hopes that we never find signs of extraterrestrial life -- advanced or otherwise.

Why?

Because he understands the Fermi Paradox.

Or more accurately, he understands the implications of the Fermi Paradox and The Great Silence.

Because the Galaxy appears uncolonized and unperturbed by intelligent life, and because there has been ample time and motive for this to happen, we have to conclude that some kind of filter is in place that prevents life from arriving at this advanced phase.

In his recent article for Technology Review, Bostrom writes:

...the evolutionary path to life-forms capable of space colonization leads through a "Great Filter," which can be thought of as a probability barrier...The filter consists of one or more evolutionary transitions or steps that must be traversed at great odds in order for an Earth-like planet to produce a civilization capable of exploring distant solar systems. You start with billions and billions of potential germination points for life, and you end up with a sum total of zero extraterrestrial civilizations that we can observe. The Great Filter must therefore be sufficiently powerful--which is to say, passing the critical points must be sufficiently improbable--that even with many billions of rolls of the dice, one ends up with nothing: no aliens, no spacecraft, no signals. At least, none that we can detect in our neck of the woods.

Now, just where might this Great Filter be located? There are two possibilities: It might be behind us, somewhere in our distant past. Or it might be ahead of us, somewhere in the decades, centuries, or millennia to come.

We are hoping that the filter resides in our past, that we have already overcome highly improbable odds.

More disturbingly, however, it's likely that the Great Filter still awaits us in the future. There's some kind technologically instigated event that exists out there -- and no species can avoid it.

Again, Bostrom writes:

Throughout history, great civilizations on Earth have imploded--the Roman Empire, the Mayan civilization that once flourished in Central America, and many others. However, the kind of societal collapse that merely delays the eventual emergence of a space-colonizing civilization by a few hundred or a few thousand years would not explain why no such civilization has visited us from another planet. A thousand years may seem a long time to an individual, but in this context it's a sneeze. There are probably planets that are billions of years older than Earth. Any intelligent species on those planets would have had ample time to recover from repeated social or ecological collapses. Even if they failed a thousand times before they succeeded, they still could have arrived here hundreds of millions of years ago.

The Great Filter, then, would have to be something more dramatic than run-of-the mill societal collapse: it would have to be a terminal global cataclysm, an existential catastrophe. An existential risk is one that threatens to annihilate intelligent life or permanently and drastically curtail its potential for future development. In our own case, we can identify a number of potential existential risks: a nuclear war fought with arms stockpiles much larger than today's (perhaps resulting from future arms races); a genetically engineered superbug; environmental disaster; an asteroid impact; wars or terrorist acts committed with powerful future weapons; super­intelligent general artificial intelligence with destructive goals; or high-energy physics experiments. These are just some of the existential risks that have been discussed in the literature, and considering that many of these have been proposed only in recent decades, it is plausible to assume that there are further existential risks we have not yet thought of.

Bostrom, who is the director of the Future of Humanity Institute at the University of Oxford, concludes his article by making a case for increased foresight and vigorous inquiry into potential risks.

But even so, Bostrom asks, what makes us think we'd be immune to such a powerful filter?

Which is why, when he looks up at the stars, he is thankful that we have yet to see any signs of extraterrestrial life.

Read the entire article, "Where are They?"

Astrosociobiology article on Wikipedia deleted

The astrosociobiology page on Wikipedia has been deleted. For the sake of posterity, I present its final incarnation here:

Astrosociobiology

Astrosociobiology (also referred to as exosociobiology, extraterrestrial intelligence (ETI), and xenosociology) is the speculative scientific study of extraterrestrial civilizations and their possible social characteristics and developmental tendencies. The field involves the convergence of astrobiology, sociobiology and evolutionary biology. Hypothesized comparisons between human civilizations and those of extraterrestrials are frequently posited, placing the human situation in the same context as other extraterrestrial intelligences. Whenever possible, astrosociobiologists describe only those social characteristics that are thought to be common (or highly probable) to all civilizations. Since no extraterrestrial civilizations have ever been studied, the subject is entirely hypothetical and necessarily self-referential.

Contents

1 Methodologies
2 Assumptions
2.1 Possible unique aspects of Earth life
2.2 Counter-argument: abundance of alternative sources
3 Possible extraterrestrial characteristics
4 Civilization types
5 Notable astrosociobiologists
6 See also
7 References
8 External links

Methodologies

Sociobiology attempts to explain animal behavior, group behavior and social structure in terms of evolutionary advantage or strategy and using techniques from ethology, evolution and population genetics. Sociobiologists are especially interested in comparative analyses, particularly in studying human social institutions and culture.

Astrobiology is the speculative field within biology that considers the possible varieties and characteristics of extraterrestrial life. Astrobiologists speculate about the possible ways that organic life could come into being in the universe and the potential for artificial and postbiological life.

Astrosociobiologists, like evolutionary biologists and sociobiologists, are concerned with the phenomenon of convergent evolution, the evolutionary process in which organisms not closely related independently acquire some characteristic or characteristics in common, usually (but not necessarily) a reflection of similar responses to similar environmental conditions. Examples include physical traits that have evolved independently (e.g. the eye), ecological niches (e.g. pack predators), and even technological innovations (e.g. language, writing, the domestication of plants and animals, and basic tools and weapons). Astrosociobiologists take the potential for convergent evolution off-planet and speculate that certain ecological and sociological niches may not be Earth-specific or human-specific and are archetypal throughout the universe.

However, there may be limits to this kind of speculation, particularly if there is a dearth of comparable habitats to our own across the galaxy. Some thinkers, while acknowledging that biological and social evolution may follow similar patterns across the universe, also note the problem of evidence and the absence of extraterrestrial contact. Simon Conway Morris, in his book, Inevitable Humans in a Lonely Universe, notes life's "eerie" ability to repeatedly navigate to a single solution. "Eyes, brains, tools, even culture: all are very much on the cards," he writes. "So if these are all evolutionary inevitabilities, where are our counterparts across the galaxy? The tape of life can only run on a suitable planet, and it seems that such Earth-like planets may be much rarer than hoped. Inevitable humans, yes, but in a lonely Universe."[1]

Assumptions

In order for astrosociobiologists to embark on speculations about the condition and characteristics of extraterrestrial civilizations, a number of assumptions are necessarily invoked:

1. Extraterrestrial civilizations exist
2. Extraterrestrial civilizations operate in agreement with the known laws of physics
3. Extraterrestrial civilizations must in some part resemble our own, both in terms of: a) morphological and psychological characteristics, and b) civilizational traits and tendenciesIn other words, astrosociobiologists assume that intelligent life arises from similar environmental conditions and similar evolutionary processes as humanity.

It is currently difficult to tell if these are valid assumptions. For example, the Rare Earth hypothesis and the Fermi Paradox suggests that we might be alone in the galaxy. It's also conceivable that aliens and their civilizations may scarcely resemble our own. Astrosociobiology also involves a fair degree of environmental determinism. Astrosociobiologists counterargue that all of these points can be countered by the Copernican principle and the self-sampling assumption (a variant of the anthropic principle). We shouldn't assume, they argue, that we're unique and we should start from the premise that we are very typical.

Possible unique aspects of Earth life

It is possible that the unique conditions on Earth allow for specific technologies to develop which would take many times longer for a civilization not having these conditions to achieve. The list of possibly unique conditions on Earth, and of related discoveries, is quite long. Some examples:

* The Hall-Héroult process and the Bayer process, if not discovered in the late 19th Century, might have led to a delay in the creation of aluminium-dependent technologies, such as aircraft and rocketry.
* The Moon produces tides, and offers some protection from asteroids, comets, and radiation. [2]
* Many discoveries were essentially accidental, such as the discovery of penicillin. Others were based on a theoretical insight, such as the transistor.

It is possible that the conditions for the creation of hydrocarbons, coal, or natural gas would not exist on other planets. These fuels were essential for us to move past dependence upon wood and animal based energy systems. Although waterwheel, wind, and solar energy technologies existed, they were not developed further until suitable industrial techniques were found to produce better materials. These techniques consume massive amounts of energy, and therefore could not be powered by the unimproved technologies. A similar argument could be made that without fossil fuel technologies, more powerful technologies, such as nuclear reactors, could not develop.

Counter-argument: abundance of alternative sources

Human perception has a natural bias towards the known energy development paths of Human civilization. It must also be noted that during both the 1973 energy crisis and the 1979 energy crisis highly industrialized societies continued to function; many moved towards developing alternative energy technologies on a massive scale under the assumption that these could provide the energy needed to continue industrial and commercial processes should fossil fuel supplies be compromised in some critical way.

Given this development, it is possible that a society could develop without a stage where fossil fuel based energy production occurs. This version of Buckminster Fuller's argument on current solar income conforms with Paul Hawken's idea of restorative economy, stating that fossil fuel based energy production is not essential nor desirable given the effects and alternatives.

Possible extraterrestrial characteristics

Given these assumptions, astrosociobiologists attempt to make predictions about those characteristics that may be common to all extraterrestrial societies. For example, based on human experience, astrosociobiologists conclude very broadly that all civilizations go through similar developmental stages, including stone age and agrarian culture, industrialization, globalization, and an information age. Similar assumptions are made about the development of technological innovations (universal technological archetypes) and scientific breakthroughs (including the rough chronological order in which these advancements are developed). The possibility also exists for the existence of common cultural and meta-ethical characteristics of advanced societies (i.e. the notion that advanced societies will independently reach the same conclusions about ethics, morality and social imperatives).

Astrosociobiologists also theorize about the existence of developmental mechanisms that constrain and give directionality to the evolution of organisms and society itself. One such guiding evolutionary force is the notion of the megatrajectory. Posited by A. H. Knoll and R. K. Bambach in their 2000 collaboration, "Directionality in the History of Life," Knoll and Bamback argue that, in consideration of the problem of progress in evolutionary history, a middle road that encompasses both contingent and convergent features of biological evolution may be attainable through the idea of the megatrajectory:

We believe that six broad megatrajectories capture the essence of vectoral change in the history of life. The megatrajectories for a logical sequence dictated by the necessity for complexity level N to exist before N+1 can evolve...In the view offered here, each megatrajectory adds new and qualitatively distinct dimensions to the way life utilizes ecospace. – [3]

According to Knoll and Bambach, the six megatrajectories outlined by biological evolution thus far are:

1. the origin of life to the "Last Common Ancestor"
2. prokaryote diversification
3. unicellular eukaryote diversification
4. multicellular organisms
5. land organisms
6. appearance of intelligence and technology

Some astrosociobiologists, such as Milan Ćirković and Robert J. Bradbury, have taken the megatrajectory concept one step further by theorizing that a seventh megatrajectory exists: postbiological evolution triggered by the emergence of artificial intelligence at least equivalent to the biologically-evolved one, as well as the invention of several key technologies of the similar level of complexity and environmental impact, such as molecular nanoassembling or stellar uplifting.

Along similar lines, historian of science Steven J. Dick, in his 2003 paper "Cultural Evolution, the Postbiological Universe and SETI," posited a central concept of cultural evolution he called the Intelligence Principle:

The maintenance, improvement and perpetuation of knowledge and intelligence is the central driving force of cultural evolution, and that to the extent intelligence can be improved, it will be improved. [– [4]]

It is through the application of this principle, argues Dick, that speculations about the developmental tendencies of advanced civilizations can be made.

The difficultly of engaging in such speculation, however, is that it is highly theoretical; there is very little empirical evidence. Moreover, humanity hasn't progressed through these later developmental stages. Astrosociobiologists currently have no data to support the idea that human civilization will continue on into the foreseeable future. Indeed, in considering the Fermi Paradox, scientists may actually have a data point suggesting a limitation to how far advanced civilizations can develop.

However, with each advancing step that the human species takes, astrosociobiologists will assume that extraterrestrials--both past and present –will have gone through similar stages.

Civilization types

A method for classifying civilization types was introduced by Russian astronomer Nikolai Kardashev in 1964. Known as the Kardashev scale, classifications are assigned based on the amount of usable energy a civilization has at its disposal and increasing logarithmically:

* Type I - A civilization that is able to harness all of the power available on a single planet, approximately 1016W.
* Type II - A civilization that is able to harness all of the power available from a single star, approximately 1026W.
* Type III - A civilization that is able to harness all of the power available from a single galaxy, approximately 1036W.

Human civilization has yet to achieve full Type I status, as it is able to harness only a portion of the energy that is available on Earth. Carl Sagan speculated that humanity's current civilization type is around 0.7.

Notable astrosociobiologists

• Frank Drake
• Freeman Dyson
• Nikolai Kardashev
• Carl Sagan
• Frank Tipler

See also

• Allen Telescope Array
• Astrolinguistics
• Drake equation
• Exobiology
• Fermi Paradox
• Interstellar Responsibility Quarantine
• SETI
• S.W.A.G.
• Sociobiology
• Technological Singularity
• Transhumanism

References

1. ^ Morris, Simon Conway (2004). Life's Solution: Inevitable Humans in a Lonely Universe. Cambridge University Press. ISBN 0-521-60325-0.
2. ^ Comins, Neil F. (1995). What if the Moon Didn't Exist?: Voyages to Earths That Might Have Been. Harper Perennial. ISBN 0-06-092556-6.
3. ^ Knoll, A. H.; R. K. Bambach (2000). "Directionality in the history of life: diffusion from the left wall or repeated scaling of the right". Paleobiology 26 (4): 1-14.
4. ^ Dick, Steven J. (2003). "Cultural Evolution, the Postbiological Universe and SETI". International Journal of Astrobiology 2: 65-74.

External links

• Astrobiology Magazine
• Astrobiology Web
• SETI Institute

The Fermi Paradox: Possible solutions and next steps

This article is partly adapted from my TransVision 2007 presentation, “Whither ET? What the failing search for extraterrestrial intelligence tells us about humanity's future.”

In my previous two articles I attempted to re-affirm the Fermi Paradox (FP) and circumscribe some of the possible interstellar activities and developmental aspects of advanced extraterrestrial intelligences (ETI’s).

In this article I will offer two broad solutions to the FP: 1) unavoidable self-destruction and 2) localized non-migratory existence.

It is not my intention at this time to provide a complete list of possible reconciliations, nor am I claiming to have found any kind of special answer; I just wish to explore these two particular possibilities.

At the conclusion of this article I offer some suggestions to help us move forward as we work to solve the observational problem that is the Great Silence.

Self-Destruction and the Great Filter

This is the most likely and philosophically satisfying answer to the Fermi Paradox – although hardly the most desirable.

Looking at ourselves as a typical example of a pre-Singularity civilization, what do we find? We find a species already in possession of apocalyptic technologies and on the verge of developing an entirely new generation of lethal weapons. In short order we will be required to manage an assortment of apocalyptic technologies; it will be akin to spinning plates. There are only so many that can be managed before one of them falls – and one is all that is needed to end the story.

Examples of pending existential risks include the ongoing threat of nuclear holocaust, a nanotechnological disaster, poorly programmed artificial superintelligence (ie Singularity as extinction event), catastrophic pandemic, and so on.

A counter-argument is often made that self-inflicted catastrophism could never be exclusive to all civilizations. How is it, ask critics, that all civilizations cannot escape such a fate? Robin Hanson attempted to answer this question by proposing the Great Filter hypothesis – the suggestion that a developmental stage exists for all life which is insurmountable. The question then: is the Great Filter behind us, or does it await us in our future?

I would argue, based on much of the data I presented earlier, that the Rare Earth hypothesis has to be rejected. Moreover, a healthy application of the self-sampling assumption strongly indicates that the filter is ahead of us should it exist. The Galaxy is likely brimming with life, including complex life.

As for as the search for extraterrestrial life is concerned, Hanson argues that the detection of ETI's would be bad. This would indicate, given our observation of an unperturbed, uncolonized galaxy, that the Great Filter is indeed still ahead of us.

Another disturbing data point as a self-sampling species is that we here on earth have come to possess apocalyptic technologies long before we have developed the capacity to live off-planet or live in self-contained biospheres. All our eggs are in one basket and they will continue to remain that way into the foreseeable future.

And then there's the disturbing Doomsday Argument which suggests that we're closer to the end than the beginning of human civilization.

Perhaps the most common and smug solution to the Fermi Paradox is the suggestion that we are the first. It is frequently used because it is said to best satisfy Occam’s Razor. But while it may be the simplest solution, it defies our sense of probability and disregards the central lesson of the Copernican Principle – the idea that we are not unique, and very likely a typical example.

Earlier I presented a picture of a biophilic Universe. If this issue is to be settled by a battle between Occam’s Razor and the Copernican principle, on this matter I’ll take Copernicus any day.

Interestingly, the longer we survive as a species without extraterrestrial contact, the more we can assume that we have passed the Great Filter.

Localized non-migratory digital existence

Now, the prospect of human extinction is quite obviously mere speculation. As Morpheus proclaimed in the Matrix: “We are still here!” Consequently, there are some non-extinction scenarios that I would like to explore.

The past 40 years of scientific progress has forced a re-evaluation of humanity’s potential. We appear to be headed for a transformation that takes us away from biological existence and towards a postbiological, or digital existence. Our future visions must take this into account. As Milan Cirkovic and Robert Bradbury have noted, we need to adopt a digital perspective (pdf).

Why leave the local system when everything can be accomplished at home? Localized existence may hold promise for all the aspirations that an advanced intelligence could conceivably conjure.

Specifically, advanced intelligences may engage in computational megaprojects and live virtual reality existences. It would be an existential phase transitioning into virtual space such that interstellar colonization would never emerge as a feasible option or experiment.

For example, advanced ETI’s may construct Jupiter (pdf) and Matrioshka Brains. A Jupiter Brain would utilize all the matter of entire planet for the purpose of computation, while a Matrioshka Brain (a kind of Dyson sphere) would utilizes the energy output of its parent star.

Determining an upper bound for computational power is difficult, but a number of thinkers have given it a shot. Eric Drexler has outlined a design for a system the size of a sugar cube that would perform 10^21 instructions per second. Robert Bradbury gives a rough estimate of 10^42 operations per second for a computer with a mass on order of a large planet. Seth Lloyd calculates an upper bound for a 1 kg computer of 5*10^50 logical operations per second carried out on ~10^31 bits – this would likely be done on a quantum computer or computers built of out of nuclear matter or plasma [see this article and this article for more information].

More radically, John Barrow has demonstrated that, under a very strict set of cosmological conditions, indefinite information processing (pdf) can exist in an ever-expanding universe.

This type of computational power is astounding and defies human comprehension. It’s like imagining a universe within a universe -- and that may be precisely be how it's used.

What would a future civilization do with all this power?

A civilization’s transition into high-speed digital mode may come about as natural consequence of its development. The switch from an analog civilization to a digital one – one in which the clock-speed would be accelerated to billions if not trillions of times faster than before – would preclude the desire to interact with the outside world.

Megascale computers may be used to support uploaded civilizations. It may prove to be the existential substrate of choice – one in which the potential for self-destruction is greatly mitigated.

Advanced civilizations may also use this computer power to run simulations for reasons of scientific research, running ancestor simulations or for entertainment (pdf) purposes. Simulations may also be run as a part of some sort of ethical or sociological necessity.

Another possibility is the Hedonistic Imperative, a term attributed to David Pearce. Given that virtually every religion has fantasized about an afterlife of bliss and an end to suffering, paradise engineering may come to represent the optimal end-state for intelligent life. Ultimately, societies will always be comprised of conscious individuals. The optimization of subjective experience may take precedence over colonial ambitions.

This tendency may be part of a broader, more 'existential' focus on life. Civilizational achievement may not be measured by the rate of imperialistic expanse or by how much energy it can consume, but in how individuals relate to themselves and their place in the Universe. This quest for introspective enlightenment may be characterized by efforts to optimize the mode of conscious experience.

What about long term survival?

In regards to long-term survival, Vernor Vinge has predicted that post-Singularity intelligences will build local secondary systems to ensure the near-immortality of the infocomplex. These could exist in off-planet repositories. Shields composed of nanotechnology and femtotechnology could deal with the issue of gamma ray bursters and other cosmological threats.

As for the local star, it could be given added life through stellar-engineering projects in which the crucially low elements are re-introduced. Eventually, however, migration to a younger star would be necessary.

There may also be unknown reasons for this type of existence. But what is certain is that wide-scale colonization is not in the cards.

Moving Forward

Admittedly, these two broad solutions -- self-destruction and non-migration scenarios -- are unsatisfactory. The notion that not even one civilization can escape self-destruction is difficult to believe. Moreover, localized digital existence and the proliferation of colonization waves are not either/or scenarios; one can imagine a civilization embarking on both paths.

As we move forward in attempting to solve the FP we need to apply much stricter methodologies to the problem.

Solutions to the FP must avoid the trappings of sociological analyses, which often present non-exclusive scenarios. Answers like the ‘zoo hypothesis,’ ‘non-interference,’ or ‘they wouldn’t find us interesting,' tend to be projections of the human psyche and our own modern-day realities. Moreover, these sorts of solutions, while they may account for some of the actions of advanced civilizations, cannot account for all.

Instead, a more rigid and sweeping methodological frame needs to be applied– one which takes cosmological determinism and sociological uniformitarianism into account. In other words, we need to be concerned with cosmological limits and the pressure of physical and resource constraints.

This is what is Nick Bostrom refers to as the strong convergence hypothesis -- the idea that all sufficiently advanced civilizations converge towards the same optimal state. This is a hypothesized developmental tendency akin to a Dawkinsian fitness peak -- the suggestion that identical environmental stressors, limitations and attractors will compel intelligences to settle around optimal existential modes. This theory does not favour the diversification of intelligence – at least not outside of a very strict set of living parameters.

The trick will be to predict what these deterministic constraints are. One can imagine factors such as limited resources, access to energy, computational requirements (including heat dissipation, error correction, and latency problems) and self-preservational modes (i.e. political and social orientations that eliminate the possibility of self-destruction).

A side benefit of this exercise is that it doubles as a foresight activity. The better we become at predicting the make-up of advanced ETI's, the better we will be at predicting our own future.

Consequently, our very own survival may depend on it.

Part I: The Fermi Paradox: Back With a Vengeance

Part II: The Fermi Paradox: Advanced Civilizations Do Not...

The Fermi Paradox: Advanced civilizations do not…

This article is partly adapted from my TransVision 2007 presentation, “Whither ET? What the failing search for extraterrestrial intelligence tells us about humanity's future.”

As I stated in my previous article, “The Fermi Paradox: Back with a vengeance”:

The fact that our Galaxy appears unperturbed is hard to explain. We should be living in a Galaxy that is saturated with intelligence and highly organized. Thus, it may be assumed that intelligent life is rare, or, given our seemingly biophilic Universe, our assumptions about the general behaviour of intelligent civilizations are flawed.

A paradox is a paradox for a reason: it means there’s something wrong in our thinking.

So, let’s try to figure out what’s going on. Given the Great Silence, and knowing what we may be capable of in the future, we can start to make some fairly confident assumptions about the developmental characteristics of advanced civilizations.

But rather than describe the possible developmental trajectories of extraterrestrial intelligences (ETI's) (a topic I’ll cover in my next article), I’m going to dismiss some commonly held assumptions about the nature of advanced ETI’s – and by consequence some assumptions about our very own future.

Advanced civilizations do not…

…advertise their presence to the local community or engage in active efforts to contact

As SETI is discovering (but is in denial about), space is not brimming with easily detectable radio signals. SETI’s work during the past 40 years indicates that the quest to detect signals will not be easy.

This problem is not as simple as it sounds. A common apology is that we’ve only recently started our search and we have only scratched the surface. The trouble, however, is that it would be no problem for an ETI to communicate with us if they wanted to.

To do this all they would need to do is seed the Galaxy with Bracewell probes (a self-replicating communications beacon). This scenario was explored in Carl Sagan’s Contact in which a Bracewell probe was lying in wait about 26 light years from Earth in the Vega system. The probe was activated by our radio signals, causing it to direct powerful radio signals at Earth – signals that would not be overlooked.

We know that no such object exists in our solar system or within a radius of about 25 to 50 light years. Our radio activity should have most certainly activated any probe lying dormant in our local vicinity by know. It is also reasonable to assume that if ETI’s embarked on such a communications mission that every solar system would likely have its own Bracewell probe.

Which in turn raises a more troubling question: if ETI’s could construct and distribute probes in this way, why haven’t they gone the extra mile and spread other types of self-replicating devices such as uplift or colonization probes?

…engage in any kind of megascale engineering or stellar re-engineering that is immediately obvious to us within our light cone

All stellar phenomenon that we have observed to this point in time appears ‘natural’ and unmodified. We see no clusters of perfectly aligned stars, nor do we signs of Kardashev III civilizations utilizing the energy output of the entire Milky Way.

As for our light cone, the Milky Way is 100,000 light years in diameter; given the possibility that our Galaxy has been able to support intelligent life for about 4.5 billion years, a 100 million year time lag (at its worst) is not severe enough to cause observational problems (except for distant Galaxies).

…colonize the Galaxy

Our Galaxy remains uncolonized despite the theoretical potential for advanced ETI’s to do so – namely the time and the technology. All that would be required is a self-replicating Von Neumann probe that proliferates outward at an exponential rate. Technologies required to build such a spacecraft would include artificial intelligence, molecular assembling nanotechnology, and an advanced propulsion scheme like anti-matter rockets, beamed energy, or interstellar ram-jets.

The reason for non-colonization is not obvious (hence the Fermi Paradox). In addition to technological feasibility there is the issue of economic and sociological imperatives for colonization.

…sterilize the Galaxy

Finally, some good news. We know the Galaxy is not sterile because we exist here on Earth.

Like the colonization potential, the prospect for an advanced ETI to sterilize the Galaxy exists through the use of berserker probes (a term attributed to Fred Saberhagen). These probes could steer NEO’s at planets, unleash nanotechnological phages, or toast planets with directed beams of highly concentrated light.

And like the Bracewell scenario, if a beserker was lying dormant in our solar system it should have destroyed us by now. If sterilization is the goal, there is no good reason for it to wait – particularly as our own civilization hurtles towards a Singularity transition.

Reasons for unleashing fleets of berserkers can be conceived, including xenophobic sociological imperatives or a malign artificial superintelligence (pdf). And all it would take is one civilization to do it. But as Robert Freitas has stated, "The present observational record can only support the much more restricted conclusion that no rapacious galactic civilisations are currently loose in the Galaxy."

…uplift or interact with pre-Singularity intelligences and biospheres

As a civilization that has been left to fend for itself, we have to assume that we, like any other civilization out there, goes it alone. No one is coming to help us. The Great Silence will continue.

Moreover, our presence on Earth and our civilizational development can be explained by naturalistic phenomena. Our existence and ongoing progress has been devoid of extraterrestrial interventions. If we’re going to survive the Singularity, or any other existential risks for that matter, it will have to be of our own devices.

…re-engineer the cosmos

A number of prominent futurists, a list that includes Ray Kurzweil and Hans Moravec, have speculated that the destiny of advanced intelligence is to re-work the cosmos itself. This has been imagined as an ‘intelligence explosion’ as advanced life expands outward into the cosmos like a bubble. The entire Galaxy would be re-organized with much of its matter converted into computronium. Eventually, it is thought that the laws of the Universe will be re-tuned to meet the needs of advanced civilizations.

Unfortunately, we do not appear to inhabit a Universe that even remotely resembles this model. The cosmos appears natural and unperturbed.

This is reminiscent of the God problem and the presence of evil. We live in a Universe that is hostile, indifferent and pointless. If advanced ETI’s had the capacity to re-engineer the Universe such that it was safer, more meaningful and paradisical they would have done so by now. By virtue of the fact that we observe such a dangerous Universe we should probably conclude that such a project is not an option.

In the final part of this series I will make an effort to explain why advanced civilizations don’t do these things and what they might be doing instead.

Part I: Fermi Paradox: Back With a Vengeance

Part III: Fermi Paradox: Possible Solutions and Next Steps

The Fermi Paradox: Back with a vengeance

This article is partly adapted from my TransVision 2007 presentation, “Whither ET? What the failing search for extraterrestrial intelligence tells us about humanity's future.”

The Fermi Paradox is alive and well.

As our sciences mature, and as the search for extraterrestrial intelligence continues to fail, the Great Silence becomes louder than ever. The seemingly empty cosmos is screaming out to us that something is askew.

Our isolation in the Universe has in no small way shaped and defined the human condition. It is such an indelible part of our reality that it is often taken for granted or rationalized to extremes.

To deal with the cognitive dissonance created by the Great Silence, we have resorted to good old fashioned human arrogance, anthropocentrism, and worse, an inter-galactic inferiority complex. We make excuses and rationalizations like, ‘we are the first,’ ‘we are all alone,’ or, ‘why would any advanced civilization want to bother with us backward humans?’

Under closer scrutiny, however, these excuses don’t hold. Our sciences are steadily maturing and we are discovering more and more that our isolation in the cosmos and the dearth of observable artificial phenomenon is in direct violation of our expectations, and by consequence, our own anticipated future as a space-faring species.

Indeed, one of the greatest philosophical and scientific challenges that currently confronts humanity is the unsolved question of the existence of extraterrestrial intelligences (ETI's).

We have yet to see any evidence for their existence. It does not appear that ETI’s have come through our solar system; we see no signs of their activities in space; we have yet to receive any kind of communication from them.

Adding to the Great Silence is the realization that they should have been here by now -- the problem known as the Fermi Paradox.

The Fermi Paradox
The Fermi Paradox is the contradictory and counter-intuitive observation that we have yet to see any evidence for the existence of ETI’s. The size and age of the Universe suggests that many technologically advanced ETI’s ought to exist. However, this hypothesis seems inconsistent with the lack of observational evidence to support it.

Largely ignored in 1950 when physicist Enrico Fermi famously asked, “Where is everybody,” and virtually dismissed at the seminal SETI conference in 1971, the conundrum was given new momentum by Michael Hart in 1975[1] (which is why it is sometimes referred to as the Fermi-Hart Paradox).

Today, 35 years after it was reinvigorated by Hart, it is a hotly contested and relevant topic -- a trend that will undoubtedly continue as our sciences, technologies and future visions develop.

Back with a vengeance
A number of inter-disciplinal breakthroughs and insights have contributed to the Fermi Paradox gaining credence as an unsolved scientific problem. Here are some reasons why[2]:

Improved quantification and conceptualization of our cosmological environment
The scale of our cosmological environment is coming into focus. Our Universe contains about 10^11 to 10^12 galaxies, giving rise to a total of 10^22 to 10^24 stars[3]. And this is what exists right now; there have been a billion trillion stars in our past Universe. [4]

The Milky Way itself, which is considered a giant as far as galaxies go, contains as many as 400 billion stars and has a diameter of 100,000 light years.[5]

Improved understanding of planet formation, composition and the presence of habitable zones
The Universe formed 13.7 billion years ago. The Milky Way Galaxy formed a mere 200 million years later, making our Galaxy nearly as old as the Universe itself. Work by Charles Lineweaver has shown that planets also began forming a very long time ago; he places estimates of Earth-like planets forming 9 billion years ago (Gyr).

According to Lineweaver, the median age of planets in the Galaxy is 6.4+/0.7 Gyr which is significantly more than the Earth’s age. An average terrestrial planet in the Galaxy is 1.6 Gyr older than the Earth. It is estimated that three quarters of earth-like planets in the Galactic habitable zone are older than the Earth.

We have a growing conception of where habitation could be sustained in the Galaxy. The requirements are a host star that formed between 4 to 8 Gyr ago, enough heavy elements to form terrestrial planets, sufficient time for biological evolution, an environment free of sterilization events (namely super novae), and an annular region between 7 and 9 kiloparsecs from the galactic center that widens with time. [6]

The discovery of extrasolar planets
Over 240 extrasolar planets have been discovered as of May 1, 2007[7]. Most of these are so-called “hot Jupiters,” but the possibility that their satellites could be habitable cannot be ruled out. Many of these systems have stable circumstellar habitable zones.

Somewhat shockingly, the first Earth-like planet was discovered earlier this year orbiting the red star Gilese 581; it is 20 light years away, 1.5 times the diameter of Earth, is suspected to have water and an atmosphere, and its temperature fluctuates between 0 and 40 degrees Celsius.[8]

Confirmation of the rapid origination of life on Earth
The Earth formed 4.6 Gyr ago and rocks began to appear 3.9 Gyr ago. Life emerged quickly thereafter 3 Gyr ago. Some estimates show that life emerged in as little as 600 million years after the formation of rocks.[9]

Growing legitimacy of panspermia theories
There is a very good chance that we inhabit a highly compromised and fertile Galaxy in which ‘life seeds’ are strewn about. The Earth itself has been a potentially infectious agent for nearly 3 billion years.

Evidence has emerged that some grains of material in our solar system came from beyond our solar system. Recent experiments show that microorganisms can survive dormancy for long periods of time and under space conditions. We also now know that rocks can travel from Mars to Earth.[10]

Discovery of extremophiles
Simple life is much more resilient to environmental stress than previously imagined. Biological diversity is probably much larger than conventionally assumed.

Developing conception of a biophilic Universe in which the cosmological parameters for the existence of life appear finely tuned
As scientists delve deeper and deeper into the unsolved mysteries of the Universe, they are discovering that a number of cosmological parameters are excruciatingly specific. So specific, in fact, that any minor alteration to key parameters would throw the entire Universe off kilter and result in a system completely unfriendly to life. The parameters of the Universe that are in place are so specific as to almost suggest that spawning life is in fact what the Universe is supposed to do. [11]

Cosmological uniformitarianism implies that that anthropic observation need not be and cannot be specific to human observers, but rather to any observer in general; in other words, the Universe can support the presence of any kind of observer, whether they be here on Earth or on the other side of the cosmos.

Confirmation of the early potential for intelligent life
My own calculations have shown that intelligence could have first emerged in the Universe as long as 4.5 Gyr ago -- a finding that is consistent with other estimates, including those of Lineweaver and David Grinspoon.[12]

Refinement of evolutionary biology, computer science and systems theories
Evolution shows progressive trends towards increasing complexity and in the direction of increasing fitness. There has also been the growing acceptance of Neo-Darwinism.

Advances in computer science have reshaped our conception of what is possible from an informational and digital perspective. There is the growing acceptance of systems theories which take emergent properties and complexity into account. Game theory and the rise of rational intelligence add another level to this dynamic mix.

Development of sociobiological observations as they pertain to the rapid evolution of intelligent life and the apparent radical potential for advanced intelligence
Exponential change. Moore’s Law. Kurzweil’s Law of Accelerating Returns. Steady advances in information technologies. Artificial intelligence. Neuroscience. Cybernetics, and so on.

And then there is the theoretic potential for a technological Singularity, digital minds, artificial superintelligence, molecular nanotechnology, and other radical possibilities. There is also emerging speculation about the feasibility of interstellar travel, colonization and communication.

In other words….
There are more stars in the Universe than we can possibly fathom. Any conception of ‘rare,’ ‘not enough time’ or ‘far away’ has to be set against the inability of human psychology to grasp such vast cosmological scales and quantities. The Universe and the Milky Way are extremely old, our galaxy has been able to produce rocky planets for quite some time now, and our earth is a relative new-comer to the galaxy.

The composition of our solar system and the Earth itself may not be as rare as some astronomers and astrobiologists believe. These discoveries are a serious blow to the Rare Earth Hypothesis – the idea that the genesis, development and proliferation of life is an extremely special event[13]. It’s also a blow to Brandon Carter’s anthropic argument which takes a very human-centric approach to understanding cosmology, suggesting that our existence as observers imposes the sort of Universe that only we can observe.

Finally, the Universe appears capable of spawning radically advanced intelligence – the kind of advanced intelligence that transhumanists speculate about, namely post-Singularity, post-biological machine minds. Given intelligent life's ability to overcome scarcity, and its tendency to colonize new habitats, it seems likely that any advanced civilization would seek out new resources and colonize first their star system, and then surrounding star systems. Indeed, estimates place the time to colonize the Galaxy anywhere from one million to 100 million years.[14]

The fact that our Galaxy appears unperturbed is hard to explain. We should be living in a Galaxy that is saturated with intelligence and highly organized. Thus, it may be assumed that intelligent life is rare, or, given our seemingly biophilic Universe, our assumptions about the general behaviour of intelligent civilizations are flawed.

A paradox is a paradox for a reason: it means there’s something wrong in our thinking.

So, where is everybody?

Part II: The Fermi Paradox: Advanced Civilization Do Not...

Part III: The Fermi Paradox: Possible Solutions and Next Steps

---

[1] Hart, M. H. "An Explanation for the Absence of Extraterrestrial Life on Earth," Quarterly Journal of the Royal Astronomical Society, 16, 128-135 (1975).

[2] This list, which is not intended to be a complete re-affirmation of the Fermi Paradox, was inspired and partly adapted from: Ćirković , Milan M. and Bradbury, Robert J. "Galactic Gradients, Postbiological Evolution and the Apparent Failure of SETI", New Astronomy, vol. 11, pp. 628-639 (2006).

[3] "How many stars are there in the Universe?" European Space Agency, Space Scientist, February 23, 2004: http://www.esa.int/esaSC/SEM75BS1VED_index_0.html.

[4] Hanson, R. 1999, “Great Filter,” (preprint at http://hanson.berkeley.edu/greatfilter.html).

[5] See Harvey Mudd and S. E. Levine: “Mass of the Milky Way and Dwarf Spheroidal Stream Membership.”

[6] Gonzalez, G., Brownlee, D., and Ward, P. 2001, “The Galactic Habitable Zone: Galactic Chemical Evolution,” Icarus 152, 185-200; Lineweaver, Charles H., Fenner , Yeshe, and Gibson, Brad K. 2004, “The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way.”; M. Noble , Z. E. Musielak , and M. Cuntz: 2002, "Orbital Stability of Terrestrial Planets inside the Habitable Zones of Extrasolar Planetary Systems"

[7] "A Rush of New Planets," Astrobiology Magazine: Jun 02, 2007: http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=2351

[8] "All Wet? Astronomers Claim Discovery of Earth-like Planet," Scientific American, April 24, 2007: http://www.sciam.com/article.cfm?articleID=25A261F0-E7F2-99DF-313249A4883E6A86&chanID=sa007

[9] See Stephen J. Mojzsis: http://spot.colorado.edu/~mojzsis/

[10] Raulin-Cerceau, F., Maurel, M.-C., and Schneider, J. 1998, “From panspermia to bioastronomy, the evolution of the hypothesis of universal life,” Orig. Life Evol. Biosph. 28, 597; "Encore: Great Debates Part VI," Astrobiology Magazine, Aug 19, 2002: http://www.astrobio.net/news/article254.html

[11] The Wikipedia entry on the Fine Tuning argument has some good links and references: http://en.wikipedia.org/wiki/Fine-tuned_universe

[12] Dvorsky, George: 2006, “When Did Intelligent Life First Emerge in the Universe?” http://sentientdevelopments.blogspot.com/2006/06/when-did-intelligence-first-emerge-in.html;

[13] Ward, P. D. and Brownlee, D. 2000, Rare Earth: Why Complex Life Is Uncommon in the Universe (Springer, New York). Lineweaver, Charles H., Fenner , Yeshe, and Gibson, Brad K. 2004; Grinspoon, David, Lonely Planets, Ecco; 1st edition (November 4, 2003).

[14] Ćirković , Milan M., 2003: "On the Importance of SETI for Transhumanism." As it pertains to reframing the Fermi Paradox, Ćirković recommends Lytkin, Finney, and Alepko (1995; for Tsiolkovsky), Jones (1985; for Fermi), Viewing (1975), and Hart (1975), (Tipler 1980), Boyce (1979).

The Drake Equation is obsolete

Copyright Lynette Cook

I'm surprised how often the Drake Equation is still mentioned when people discuss such things as the search for extra terrestrial intelligence (SETI), astrobiology and problems like the Fermi Paradox.

Fairly recent insights in such fields as cosmology, astrobiology and various future studies have changed our perception of the cosmos and the ways in which advanced life might develop.

Frank Drake's equation, which he developed back in 1961, leaves much to be desired in terms of what it's supposed to tell us about both the nature and predominance of extraterrestrial life in our Galaxy.

The Drake Equation

The Drake equation states that:

where:

N is the number of civilizations in our galaxy with which we might hope to be able to communicate and:

R* is the average rate of star formation in our galaxy
fp is the fraction of those stars that have planets
ne is the average number of planets that can potentially support life per star that has planets
fl is the fraction of the above that actually go on to develop life at some point
fi is the fraction of the above that actually go on to develop intelligent life
fc is the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L is the length of time such civilizations release detectable signals into space.

Arbitrary at best

The integers that are plugged into this equation are often subject to wide interpretation and can differ significantly from scientist to scientist. Even the slightest change can result in vastly different answers. Part of the problem is that our understanding of cosmology and astrobiology is rapidly changing and there is often very little consensus among specialists as to what the variables might be.

Consequently, the Drake formula relies on 'stabs in the dark.' This makes it highly imprecise and unscientific. The margin of error is far beyond what should be considered acceptable or meaningful.

No accounting for cosmological development or time

Another major problem of the Drake Equation is that it does not account for two rather important variables: cosmological developmental phases and time (see Cirkovic, "The Temporal Aspect of the Drake Equation and SETI").

More specifically, it does not take into consideration such factors as the age of the Galaxy, the time at which intelligence first emerged, or the presence of physiochemical variables necessary for the presence of life (such as metallicity required to form planets). The equation assumes a sort of cosmological uniformity rather than a dynamic and ever changing universe.

For example, the equation asks us to guess the number of Earth-like planets, but it does not ask us when there were Earth-like planets. And intelligence itself may have been present as long as 2 to 4.5 billion years ago.

The Galaxy's extreme age and the potential for intelligence to have emerged at disparate points in time leaves an absurdly narrow window for detecting radio signals. The distances and time-scales in question are mind-boggingly vast. SETI, under its current model, is conducting an incredibly futile search.

Detecting ETI's

Which leads to the next problem, that of quantifying the number of radio emitting civilizations. I'm sure that back in the 1960's it made a lot of sense to think of radio capability as a fairly advanced and ubiquitous means of communication, and by consequence, an excellent way to detect the presence and frequency of extraterrestrial civilizations.

But time has proven this assumption wrong. Our radio window is quickly closing and it will only be a matter of time before Earth stops transmitting these types of signals -- at least unintentionally (active SETI is a proactive attempt to contact ETI's with radio signals).

Due to this revelation, the entire equation as a means to both classify and quantify certain types of civilizations becomes quite meaningless and arbitrary. At best, it's a way of searching for a very narrow class of civilizations under very specific and constrained conditions.

Rather, SETI should continue to redefine the ways in which ETI's could be detected. They should try to predict future means of communication (like quantum communication schemes) and ways to identify these signals. They should also look for artificial objects such as megascale engineering and artificial calling cards (see Arnold, "Transit Lightcurve Signatures of Artificial Objects").

The future of advanced intelligence

Although possibly outside the auspices of this discussion, the Drake Equation does not account for the presence of post-radio capable civilizations, particularly post-Singularity machine intelligences. This is a problem because of what these types of civilizations might be capable of.

The equation is used to determine the number of radio capable civilizations as they conduct their business on their home planet. Again, this is a vary narrow view of ETI's and the space of all possible advanced civilizational types. Moreover, it does not account for any migratory tendency that advanced civs may have.

The Drake Equation does not tell us about exponential civilizational growth on account of Von Neumann probe disbursement. It does not tell us where advanced ETI's may be dwelling or what they're up to (e.g. Are they outside the Galaxy? Do they live inside Jupiter Brains? Do they phase shift outside of what we regard as habitable space? etc.). This is a serious shortcoming because the answers to these questions should help us determine not just where we should be looking, but they can also provide us with insight as to the makeup of advanced intelligence life and our own potential trajectory.

In other words, post-Singularity ETI's may represent the most common mode of existence for late-stage civilizations. And that's who we should be looking for rather than radio transmitting civs.

Are we alone?

Michael Crichton once put out a very weak argument against the Drake Equation. He claimed that SETI was a religious endeavor because it was a search for imaginary entities. He is wrong, of course; we should most certainly search for data where we think we might find it. I believe, despite the low odds, that it is reasonable to assume that our search for life on other planets is warranted. Even a negative result can be meaningful.

Consequently, SETI should keep listening, but expect to hear nothing. If we should suddenly hear something from the depths of space, then we will have to seriously re-evaluate our assumptions.

At the same time we should find better ways to detect advanced life and tweak the Drake Equation in such a way as to account for the missing variables and factors I mentioned earlier.

Again, and more generally, we should probably adopt the contact pessimist's frame. Back in the 60's and 70's, when the contact optimists like Sagan, Shklovskii and Drake ruled the Earth, it was not uncommon to think that N in the equation fell somewhere between 10x6 to 10x9.

These days, in the post Tipler and Hart era of astrosociobiology, cosmologists and astrobiologists have to take such factors into consideration as Von Neumann probes, the Fermi Paradox, the Rare Earth Hypothesis, stronger variants of the anthropic principle and catastrophism.

Put another way, as we continue to search for advanced ETI's, and as we come to discover the absurdity of our isolation here on Earth, we may have no choice but to accept the hypothesis that advanced life does not venture out into space for whatever reason (the most likely being self-destruction).

Our other option is to cross our fingers and hope that something radical and completely unpredictable lies on the other side of the technological Singularity.