August 6, 2007

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...


Brett D said...

A common objection raised for the there-is-no-ETI solution to the Fermi paradox is that there must be no ETI because any single factor limiting the spread of life/communication must be absolute and yet it seems that life and civilisation takes so many different courses and so surely some civilisation must overcome them. It occured to me that all of the objections to the spread of ETI may have an agregate effect so that whatever single obstacle one overcomes, there is another that presents one's influence from spreading beyond a certain distance.

On the other hand, or in addition to this, looking for a single limiting factor, I noticed that in almost every article discussing the Fermi Paradox, it was assumed that interstellar travel was, all things considered, in the long term etc., trivial.

In fact, interstellar travel it is not trivial, in any context. In order to traverse interstellar distances, one has to be able to survive in deep space. Fermi needs to be introduced to Darwin

Consider then the sort of being that has to build up a space-based civilisation before it ventures into real deep space. At first, no doubt, it inhabits an Oort cloud. Such beings would be likely to conserve energy and to think in the long term - that is, they'd be effectively stealthy as they'd leak as little energy as possible and ultimately, their culture would develop to such a degree that hot, fast, leaky creatures seem absurd to them and that sort of lifestyle would both abhorent and meaningless to them. Moreover, their communications would be compressed so much as to be indistinguisable from noise to people such as us (I remember reading somewhere and can't be bothered to check the exact attribution right now that, with apologies to Clarke, "Any sufficiently advanced technology is indistinguisable from noise").

I suggest that space and time itself are universal and very extremely effective selective factors favouring low mass/dark/cold/slow life and that any interstellar civilisation will not be interested in either mega-engineering or contact with beings that are from their perspective, mayflies.

I do not think that this is an absolute rule, but on a galactic scale there would be an overall favouring of beings that would not even be visible to us and which would perhaps be curious, but not especially interested in contact and engagement as it is normally described.

Anonymous said...

Good article! By the way, some of your links appear to be broken (they prepend the blogger URL to the true URL).

Anonymous said...

Re: The digital existence. Do you honestly think, with the quality of software generally available today, that we will have some form of commonly available AI in the near future?

The machines get faster, the graphics get better and the blood and guts of FPS gets more realistic, but Excel still calculates tables and Word still writes letter, noether of those alone.

I think it MAY happen, your beloved singularity, but I think it will take far longer than 50 years.

Anonymous said...

Interesting. I still think that evidence is lacking that the things in your second article (dyson "spheres", colonization, communication, etc.) could all be happening, just outside of our light "cone".; after all, from the perspective of looking at other civilizations, the information outside of the light cone is far more interesting that that inside of it. In other words, I still think we aren't close to narrowing down Drake's equation enough to suggest that it would be likely that we would have noticed a civilization, given the number of stars we've looked at. Heck, from a strictly communications perspective, it's quite possible that they're nearby, trying to communicate with us, and we simply haven't detected them yet. SETI really has just barely started.

Anonymous said...

@theo "Do you honestly think, with the quality of software generally available today, that we will have some form of commonly available AI in the near future?"

As someone who has formally studied AI and has done a small amount of work in the field, yes, I do. For that matter, it's pretty easy to obtain, and has been for well over a decade. Just load up any 1-player chess program (or, for that matter, nearly any game where the computer reacts non-directly to your input), and you've got yourself some AI, right there in your computer :-)

For a general, human-equivalent AI, if you make the assumption (which I do) that the human brain is a collection of physical processes, all of which can be modeled, then:
1) It should be possible to construct a model of the brain.
2) This would require finite (if large) computing resources, and
3) It is likely possible to construct something with equivalent intelligence that is simpler than an exact model of the brain.

Presumably, once you have a human-equivalent AI, it should be possible to improve it, which means that you'll get one that's "better" than human - presumably smarter. Whether it's faster or not (or even economical, in comparison to building one out of neural tissue) depends too much on information we don't know yet. From the bits I've read on high-speed transistor replacements, I strongly suspect that at some point it will also be faster (but, quite frankly, EE isn't my field).

As for actual dates, I'm not going to try to project that- that's the job of a futurist. I can tell you that I'd be shocked if it occurs within the next decade, though.

Anonymous said...

I think you guys are still too quick to dismiss the Rare Earth Hypothesis (REH).

It appears that part of the REH seems incorrect (required steller metallicity for terrestrial planet formation and, thus, the limited galactic habitable zone). However, the most significant aspect of the REH, which is the necessity for plate tectonics and its connection to having a large moon formed by an improbable impact in order for complex life to form, remains standing in my opinion. If this turns out to be correct, then the number of complex life harboring planets in the galaxy is likely to be 10,000 to 1,000,000 time less common than is generally thought. If true, this would certainly account for the Fermi paradox.

The reason why this is relevant is because I believe that REH is correct in that plate tectonics is essential for the formation of complex life. I also think that the giant impact that created our moon is also what broke up the crust so that plate tectonics can occur. This impact also created a thinner crust (both Venus and Mars have thicker crusts than the Earth), which also allows for plate tectonics. Also, the tidal effects of the moon are what maintain plate tectonics on Earth.

This is significant because I think without plate tectonics, an Earth-like world turns into a Venus hellhole. This is because, without the moderate vulcanism that plate tectonics allows for, the internal heat energy builds up for several hundred million years and then is all released at once in a global resurfacing event. It is these global resurfacing events, as well as runaway green house effect, that makes Venus be Venus.

In other words, if this is correct, all of those Earth-like worlds yoy guys think are out there are likely to be Venus-like worlds instead. This would certainly account for the fermi paradox.

All of this is testable, of course. First, Venus should be studied closely to determine why and how it ended up as it is. The connection between a lack of plate tectonics and global resurfacing events needs to be established.

The other thing is to develop the instrumentation, Earth or space based, to identify and characterize "Earth-like" worlds in the nearby steller neighborhood (say, 100 lyrs out) and determine if those "Earth-like" worlds are really "Venus-like" worlds.

Until this is done, this part of the REH remains valid.

Anonymous said...


No, I don't dismiss the Rare Earth Hypothesis; the last time I entered numbers into Drake's equation, I got something like 1/10,000 (i.e. there should be 1 civilization that has the capacity to communicate to another non-local solar system per 10,000 milky-way sized galaxies). Frankly, most of the inputs to Drake's equation are guesses (since we have insufficient data for conclusions on those portions), you can come up with almost any number you want; with marginally different assumptions, I could get thousands in this galaxy alone.

Personally, what I'd do with Fermi's paradox is the inverse; I'd use it as a tool to limit the solutions to Drake's equation. Given the number of stars we've surveyed, and the communications we could be receiving, perhaps the solution to Drake's equation is quite a bit less than 1. This helps bind a few of the terms slightly.

This is not to discount this series of articles; there is no intrinsic reason why you couldn't (alternatively) assume that the answer to Drakes equation is significantly above 2, in which case Fermi's paradox is useful, and his arguments apply. Conversely, it could be used to describe the consequences of a large solution to Drake's equation.

Anonymous said...

zimbel is right that we are just guessing here.

It may be called the Drake equation, but there's nothing scientific about the results since we have no data about ETI to start with. The only thing we actually know is life exists on one planet in entire universe. You can't calculate anything based on that. Its like doing an election poll by calling one person and then 'extrapolating' out your results...totally meaningless.

Anonymous said...

I think the central problem in this discussion, and Dvorsky's suppositions, is that we are all human, and as such, cannot think other than as humans do. Anthropocentrically.

A non-human, advanced intelligence or consciousness of some kind, originating elsewhere (whether it be extraterrestrial, interdimensional, quantum, or other) is just that, non-human.

As such, we cannot possibly know what "the others" may do, think, be, or know that may preclude "them" from making any kind of overt, formal contact with us.

Frankly, if I were an "other", I suspect it would be destructive to humanity for any such overt or formal contact to be made, for a variety of reasons:

1. The Prime Imperative--I use this term somewhat humorously, as it, I think, originated with Star Trek. The supposed rule is to preclude a more advanced culture to contact a less-developed or relatively primitive culture, as the consequences would be disruptive to the less advanced culture's independent development. Look at our own history: what usually happened in the past when a foreign, more technologically advanced culture made contact with those cultures or societies was the eventual destruction and elimination of those cultures, whether intentional or not. And that's just human to human contact on this planet. Can you imagine the impact of aliens on human culture worldwide, in terms of belief structures, co-dependence, and psychological reaction? I think human culture today, as interdependent, interactive, and technologically dependent as we have become has created a greater fragility than most of us may be truly aware of.

Throw an intelligence into that mix that is, relative to us, as great a difference in consciousness and capacities as we are to cows, bugs, or maybe even bacteria, and the effects might be tremendously destructive.

The funny part in this grim scenario is that the characters on Star Trek often did not follow the prime imperative.

2. We are not ready. If we cannot overcome our own self-destructive impulses and aggressive tendencies, and resolve the problems we have in relation to each other, let alone our inability to avoid environmental destruction due to the impact of our activities, we will self-destruct. Perhaps our primate heritage makes that inevitable, among other limiting factors. Thus, if you were an "alien", would it make sense to contact us if you knew this was our probable fate? What purpose would it serve? Kind of pointless, IMHO.

3. We have to get beyond issue #2, and self-mutate, or become trans humans at a much higher level of development, intelligence, consciousness, and understanding of the nature of the universe and it's origins and basis in order to leave the solar system for other star systems successfully. If we can. or do, which seems rather doubtful, all things considered, then perhaps we can begin to be on an "equal" or preliminary footing with other beings that may have had to go through this same process in order to be allowed contact with other intelligences, or to join the "cosmic club", as it were, without our being destroyed by premature contact, as noted above.

4. How do we know we are not already in some form of contact with "the others", on some level, determined by the higher intelligence, but that we just don't or can't recognize it, as it's so non-human or sophisticated that it calls the shots and manner of contact while it waits (or may even subtly intervene) for our evolution to take it's course, even if we begin to seriously prod ourselves to recursively evolve consciously at will and via technological and biogenetic means, as appears to be occurring presently. "They" may be either waiting for us to "grow up" or may even be influencing this direction of growth for unknown reasons.

5. The question of UFOs. I throw this in as I know Dvorsky dismisses it, yet, if one studies the history of the phenomena of ufos, there is good evidence something is definitely going on, and has been throughout history, particularly since WWII, and especially post-war. It's a fact, despite whatever Dvorsky may say. But it's extraordinarily elusive, and proof remains less than ...provable. Perhaps that's an evolutionary prod itself; a kind of plausible deniability and evolving form of ufo presence that makes us, like many other factors, like survival, to strive to know better what's going on and how to cope with all the self-made and external and subtle general threats to our ongoing existence that require us to either figure out how to overcome these obstacles or die trying, literally, as a species. This has religious and spiritual overtones, but perhaps we are in the "testing" phase of our existence, and contact by "the others" would distort and disturb that process in such a way that until or if we can evolve past the self-limiting factors of our evolutionary heritage, by direct action and modification, which itself seems to me to be a natural and perhaps required process to do so, we have no chance of getting off the home planet or even surviving as a species without such a self-created, self-started, independent (of the "others") recursive techno-genetic bootstrapping paradigm shift.

6. None of this is true. Everything I think I know is wrong. This is just idle speculation. We cannot judge the motivations, purposes, or intentions of a non-human, advanced species as we are humans, not "others". So take all this for what you think it's worth.

And contemplate the infinite.

Elf Sternberg said...

George, it occurred to me that there's one obvious solution to the Fermi Paradox, and it's suggested in you blog when you mention Nick Bostrom:

We are in a simulation. It simulates Terra. There's no need to simulate anything else. Therefore the great silence is due to our simulator's failure to have anyone else.

Bob Kowalski said...

See my rambling discussion of the Fermi Paradox at Bob Kowalski.

pfh said...

There's another possibility it seems, stemming from a possible error in the underlying assumption of physics.

Perhaps the universe is not a conceptual model at all, as initially found some use in representing it. Maybe it's a organizational construction process, and so has nothing but highly improbable outcomes.

That fits the problem in lots of ways, and matches the seemingly valid view of Elsasser on the question, and of some of the new views of how to study self-organization.

Dirk Bruere said...

The possibility never mentioned - that we are living in a simulation. That early in each galaxy's life superintelligence emerges, does all the H+ stuff eg Jupiter Brains, galactic engineering, converting the place into computronium etc. Everyone else who comes later gets to evolve and live in their own bit of computronium in simulation. If we play nice we get invited up for tea and biscuits. If not, we get deleted.

pfh said...

Well Dirk, For a universe represented as an information construct one couldn't rule that out, could you! ;-)

John Burger said...

The Drake equation is NONSENSE...always has been.

There are simply zero odds amino acids could pair to form the DNA molecule apart from an Intelligence.

The Fine Tuning data has been in for a while and it is only atheists who reject it for obvious reasons..they are the OJ Simpson jury. The answer that there is a God ...spells doom for them. Who votes to accept their destruction?

There is no signal from other planets are probes because they are NONE. But we are in an age when the facts dont actually mean anything anymore. If you dont like an invent an ad hoc rebuttal to it. Multiverse, simulation, we're not real. bla bla bla.
Humanity had it right from the beginning. God created the Universe--only dweebs are still sitting around trying to deny that.

Unknown said...

@ George: You mentioned that hypotheses such as "The ET's wouldn't be interested in a backward civilization like ours" are projections of the human psyche. Isn't the the idea of ever expanding civilizations also a projection of the human psyche, specifically the imperial mentalities of societies such as the Romans, the Mongols, and the British? Isn't the idea of "taming" (i.e. making obvious artificial modifications to) the universe a Modernist ambition that isn't remotely uniform across members of our own species?

Also, what would be the impetus for ET to come to us? The impulse "to explore strange new worlds and seek out new life and new civilizations" is particular to only one human subculture, and would be best accomplished by probes that hide themselves so as not to unduly affect the societies that they want to observe.

For the only civilized species that we know of, resource acquisition is a far more likely reason to spread one's civilization thither and yonder.

For ET's, owing to the daunting distances between stars, civilizations that couldn't sustain themselves by recycling resources within their own solar systems could probably not acquire resources from other solar systems fast enough to maintain themselves. Conversely, civilizations that could continue indefinitely by using the resources of one solar system would have no reason to journey to others. Crucially, absent faster-than-light travel, a given civilization could become self-sustaining within its own solar system far faster than it could gather resources from other solar systems.

Also, even if ET's were interstellar nomads who needed resources from our solar system, why would they mine them from Earth? Water, organic materials, and minerals are far more easily obtained from comets and asteroids than from Earth, since the latter has much stronger gravity.

Here's another point: Flight, sight, and bipedalism evolved more than once. The capacity to think about advanced mathematics evolved only once on this planet. Why should we assume that this prerequisite to space-faring civilization would inevitably evolve merely from the increases in information processing capacity and behavioral repertoires facilitated by increased brain-size?

Finally, what do we know about about the cultural factors that affect the behavior of typical space-faring ET civilizations? The answer of course, is nothing.

With all apologies to the people who discuss such matters, I don't see a paradox here. I see not only anthropocentric thinking, but thinking that reflects the intellectual legacy of Earthly empires. And I see this thinking applied to cultures--and creatures-- about which we know virtually nothing.

Our ignorance of the cosmos at large is not a paradox. And our speculations about ET civilizations are no more well-informed than medieval speculations about the monsters in the sea.

Charles said...

"Eggs in one basket" is perhaps the weakest filter argument.

Could it not be most possible for a civilization to colonize it's home star planets and then have an extinction level event on it's home planet, leaving the colonies still in tact?

To suggest that all civilizations wipe themselves out with some sort of advanced tech, discounts them populating their local system before doing so.

If even a fraction of civilizations ventured off their own home planet and colonized moons, etc in their own solar system and then "grey gooed" their homeworld, there should still be a vast quantity of ET's out there for us to see.