A year ago on SentDev: The Drake Equation is obsolete

Just say no to N = N* fp ne fl fi fc fL.

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.

Cascio chimes in on Fermi

IEET colleague Jamais Cascio has responded to Nick Bostrom's suggestion that the detection of extraterrestrial life would be bad news.

Cascio is unconvinced that the parameters of Bostrom's argument are entirely correct, including the assumption that super-advanced civs take up interstellar colonization as a hobby.

Specifically, he argues that technologically advanced ETI's must be post-Singularity civs, and by definition, outside the bounds of current trajectorial models. As Cascio notes, "The demands and concerns and requirements of a post-Singularity civilization wouldn't be based on a pre-Singularity pattern."

Consequently, Cascio makes the claim that galactic empires are likely not on the post-Singularity to-do list. "To be clear, this isn't an argument that these interstellar-capable civs just sit at home. They could and would likely spread, and certainly explore," he writes, "But the notion that they'd hop from solar system to solar system planting their colonies, strikes me as terribly unimaginative, and definitely a pre-Singularity perspective."

I'm not entirely on board with Cascio here, but I will say that he is absolutely correct when he suggests that speculations about colonization-capable civs must presuppose their condition as being post-Singularity.

And I'll further this by noting that we should adopt a digital perspective. As NASA's Steven J. Dick has noted, we should be looking for post-biological brains.

Consequently, when we try to figure out what futuristic civilizations might look like, we should consider:

1. the demands imposed on a civ that's completely reliant on megascale computing
2. the potential mindspace of a post-Singularity superintelligence, its interpretation of utility, and the manner in which it achieves its goals

For the first point, we're talking about a postbiological modality that would likely require a hideous amount of computational power.

As for the second point, good luck with that one.

But where Cascio and I diverge is in how he deals with the non-exclusivity problem -- i.e. finding a solution to the FP that applies to ALL advanced civs.

Cascio argues that Galactic colonization is "unimaginative" and a "pre-Singularity" perspective.

Sure, this may be true. And perhaps 99.9% of all advanced civs would agree with him.

But it's the 0.01% that I'm concerned about.

It's not impossible or ridiculous to imagine at least one non-conformist civilization taking it upon itself to expand its presence across the Galaxy.

Moreover, the colonization process for a post-Singularity intelligence would be a rather pedestrian exercise -- one that doesn't really require much of a commitment. Interstellar colonization would be a largely automated process that exploits the happy consequence of exponential growth.

To be fair, Cascio does suggest that there may be an a universal upper bound to growth. Cascio notes, "Interstellar-capable civilizations that somehow remain wedded to colonization would inevitably fall into internal conflict because of speed-of-light communication/travel lag and divergent evolution (social or biological)."

I think the disconnect here is the notion that galactic colonization necessarily implies the expansion and interconnectedness of communication, economic and political networks. I'm not so convinced. Nodes spawned by Von Neumann probes could be stand-alone and completely segregated from its parent system. One could imagine a Von Neumann wave expanding outward, uplifting all life and matter in its path and leaving computronium in its wake; the probes would not be equipped with rear-view mirrors.

Cascio also presents another possible reconciliation to the Fermi Paradox -- the notion that we are not yet capable of detecting the activities of advanced civs. Specifically, he suggests that ETIs may use alternative communication schemes. Again, as Cascio argues, because we're talking about post-Singularity life, we simply don't know what we're supposed to be looking for.

Unfortunately, this doesn't really solve the Paradox. We are still still stuck with the colonization problem.

That's the crux of the the Fermi Paradox why it remains a non-trivial conundrum. It's also why the FP was given new life in the 1970s by Michael Hart, John D. Barrow and Frank J. Tipler, and why in recent times it has become more perplexing than ever.

The Fermi Paradox is alive and well.

Latest podcast posted: 2008.04.29

The latest episode of the Sentient Developments Podcast is now available. Alternative audio formats are also available.

This episode:

An overview of my recent talk at the Center for Inquiry

Discussing Twitter and Google Apps

Part 3 of my Fermi Paradox talk: Possible solutions and next steps

Why the male birth-control pill is so important for men; sorry, ladies—this pill isn't about you

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?"

Latest podcast posted: 2008.04.01

The latest episode of the Sentient Developments Podcast is now available. Alternative audio formats are also available.

This episode:

Considering the Hadron Particle Accelerator and asking the question: When is an existential risk TOO risky?

What the Fermi Paradox tells us about humanity's future: Making claims about what advanced civilizations DO NOT do.

Christopher Hitchens gets it wrong about Buddhism.

Latest podcast posted: 2008.03.18

The latest episode of the Sentient Developments Podcast is now available. Alternative audio formats are also available.

This episode: The Fermi Paradox is back with a vengeance, nanotechnology will reshape humanity, and why evolutionary psychology says we should cut Spitzer some slack.

Latest podcast posted: 2008.03.11

The latest episode of the Sentient Developments Podcast is now available. Alternative audio formats are also available.

In this episode I discuss seven ways to control the Galaxy with self-replicating probes, the problem with 99.9 % of so-called 'solutions' to the Fermi Paradox, and why we should work to overcome gender.

The problem with 99.9 % of so-called 'solutions' to the Fermi Paradox

Non-exclusivity.

Sure everyone has a convenient answer to the Fermi Paradox, but nearly all of them fail the non-exclusivity test. While some solutions to the FP may account for many if not most of the reasons why we haven't detected signs of ETI's, they cannot account for all.

For example, take the notion that interstellar travel is too costly or that civs have no interest in embarking on generational space-faring campaigns. Sure, this may account for a fair share of the situation, but in a Universe of a gajillion stars it cannot possibly account for all. There's got to be at least one, if not millions of civs, who for whatever reason decide it just might be worth it.

Moreover, answers like the ‘zoo hypothesis,’ ‘non-interference,’ or ‘they wouldn’t find us interesting,' tend to be projections of the human psyche and a biased interpretation of current events.

Cosmological determinism

Analyses of the FP need to adopt a more rigid and sweeping methodological frame.

We need to take determinism more seriously. The Universe we observe is based on a fixed set of principles -- principles that necessarily invoke cosmological determinism and in all likelihood sociological uniformitarianism. In other words, the laws of the Universe are moulding us on account of selectional pressures beyond our control.

Civilizations that don't conform to adaptive states will simply go extinct. The trouble is, we have no say in what these adaptive states might be like; we are in the business of conforming such that we continue to survive.

The question is, what are these adaptive states?

Strong convergence

Transhumanist philosopher Nick Bostrom refers to this 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 space of all possible minds...that survive

Consequently, our speculations about the characteristics of a post-Singularity machine mind must take deterministic constraints into account. Yes, we can speculate about the space of all possible minds, but this space is dramatically shrunk by adaptationist constraints.

The question thus becomes, what is the space of all possible post-Singularity machine minds that result in a civilization's (or a singleton's) ongoing existence?

And it is here that you will likely begin to find a real and meaningful explanation to the Fermi Paradox and the problem that is non-exclusivity.

Interactive Drake Equation

Space Radio: More Static, Less Talk.

Greer: Industrial civilization and the problem that is Fermi's Paradox

John Michael Greer explores energy limitations and resource constraints that may account for the Great Silence:

On another level, though, Fermi’s Paradox can be restated in another and far more threatening way. The logic of the paradox depends on the assumption that unlimited technological progress is possible, and it can be turned without too much difficulty into a logical refutation of the assumption. If unlimited technological progress is possible, then there should be clear evidence of technologically advanced species in the cosmos; there is no such evidence; therefore unlimited technological progress is impossible. Crashingly unpopular though this latter idea may be, I suggest that it is correct – and a close examination of the issues involved casts a useful light on the present crisis of industrial civilization.

Messages to ET and the precautionary principle

Science fiction author and futurist David Brin recently contacted me and brought me up to speed on his efforts to raise awareness about the active SETI approach, also known as METI (messages to extraterrestrial intelligences). Brin is vehemently opposed to this idea, as he believes it could put humanity in great peril. For all we know, he argues, some malevolent ETI is lurking in the neighborhood waiting for less advanced civilizations to draw attention to themselves.

Brin writes,

Let there be no mistake. METI is a very different thing than passively sifting for signals from the outer space. Carl Sagan, one of the greatest SETI supporters and a deep believer in the notion of altruistic alien civilizations, called such a move deeply unwise and immature....

Sagan — along with early SETI pioneer Philip Morrison — recommended that the newest children in a strange and uncertain cosmos should listen quietly for a long time, patiently learning about the universe and comparing notes, before shouting into an unknown jungle that we do not understand.

Brin invited me to join a closed discussion group where this issue is examined and debated. The purpose of the exercise is to not just think more deeply about this issue, but to also raise awareness and possibly prevent a catastrophe (i.e. alien invasion). Essentially, Brin argues that METI needs to be strongly considered before any group or individual takes it upon themselves to shout out to the heavens. He is particularly concerned how some groups, including SETI, are dismissive of his concerns. His fear is that someone will unilaterally decide to start transmitting messages into the depths of space.

I was unsure at first about whether or not I should join this group. As a contact pessimist I’m fairly certain that the fear about a METI approach is unwarranted -- not because ETI's are likely to be friendly, but because no one's listening. And even if they are listening, there's nothing we can do about it; any advanced ETI that's on a search-and-destroy mission would likely have the 'search' aspect figured out. I'm not sure how any civilization could hide in the Galaxy. Consequently, METI is somewhat of a non-issue in my opinion.

That being said, however, I did reach the conclusion that there is a non-zero chance that we could run into trouble should we change our approach from listening to messaging. For example, resident berserkers could be waiting, for what ever reason, for this sort of change in our radio signals. Perhaps they are waiting for a sign that we've passed a certain developmental threshold.

I think this argument is extremely weak and improbable, but it's not impossible; it should not be ruled out as a potential existential risk.

Which leads me to the precautionary principle. Since no one is listening, there is no harm in not sending messages out into the cosmos. Again, if a friendly ETI wanted to do a meet-and-greet, they should have no trouble finding us. But because there is the slim chance that we may alert a local berserker (or something unknown), we should probably refrain from the METI approach for the time being.

So, I took Brin up on his offer and I’ve joined the discussion group. We are currently considering the possibility of organizing a conference centered around the issue. I’ll continue to post about this topic as news develops. More information can be found here.

The dark side of the Simulation Argument

Kudos goes out to Nick Bostrom for having his Simulation Argument (SA) featured in the New York Times today. The SA essentially states that, given the potential for posthumans to create a vast number of ancestor simulations, we should probabilistically conclude that we are in a simulation rather than the deepest reality.

Most people give a little chuckle when they hear this argument for the first time. I've explained it to enough people now that I've come to expect it. The chuckle doesn't come about on account of the absurdity of the suggestion, it's more a chuckle of logical acknowledgment -- a reaction to the realization that it may actually be true.

But this is no laughing matter; there are disturbing implications to the SA. We appear to be damned if we're in a simulation, and damned if we're not.

Dammit, we're in a simulation!

If we were ever to prove that we exist inside a simulation, it would be proof that the transhumanist assumption is correct -- that the transition from a human to a posthuman condition is in fact possible. But that will be of little solace to us measly sims! The simulation -- er, our world -- could be shut down at any time. Or, the variables that make up our modal reality could be altered in undesirable ways (e.g. our world could be turned into a Hell realm).

Also, should we reside in a simulation, we have to pretty much assume that our digital benefactors are rather indifferent to our plight. Based on the amount of suffering going on around here we should probably assume a gnostic religious sensibility. These gods are not our allies; they may have created us, but they are not looking out for our best interests.

Dammit, we're not in a simulation!

Now, on the other side of the virtual coin, should we ever prove that we are not in a simulation, that would also be bad. It would be potential evidence that the transition to a posthuman condition may not be possible.

This problem is similar to the Fermi Paradox and the possible resolution that we are the first intelligent civilization to emerge in the Galaxy. This is a hard pill to swallow based on the extreme odds.

Similarly, we should be disturbed that we are not in a simulation because it may imply that we don't have a very bright future -- that civilizations destroy themselves before developing the capacity to create simulations. Otherwise, we have to take on a exceptionally optimistic frame and assume that we'll survive the Singularity and be that special first civilization that spawns simulations. Again, a probabilistically unsatisfactory proposition.

Of course, advanced civilizations may not create simulations on this scale. The Fermi Paradox offers yet another example as to why this is a problematic suggestion. Given the technological potential to colonize the Galaxy, why haven't advanced civilizations done so? Similarly, why wouldn't advanced civilizations create simulations given the technological capacity to do so?

The NYT article goes over a number of these issues and Bostrom provides some possible solutions. Ultimately, however, the answers are unsatisfactory.

The Simulation Argument solves the Fermi Paradox! Maybe...

Perhaps the answer to the Fermi Paradox is that we are in a simulation. It would certainly explain the Great Silence. Why bother simulating extraterrestrials? Maybe that's the point of the simulation -- to study how a civilization advances without any outside intervention.

Or maybe the Fermi Paradox exists because all civilizations are busy working on their simulations....

Or perhaps.....ah, forget it. My brain (which is probably sitting in a vat somewhere) hurts.

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.

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.

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 uni