Should we be shocked and dumbfounded by the absence of an intergalactic alien civilization? Or is the lack of evidence for aliens precisely what we would expect? Can the rarity of the origin of life tell us anything about the probability of developing a prosperous future in space? Or is there a great filter in our future that will wipe us out? Is the absence of evidence the same thing as evidence of absence? Do we really know what makes a planet potentially life-permitting and how do we differentiate potentially from actually life-permitting? Is evolution a process that always moves towards bigger, better and more expansive? Or is this a false characterization of evolution that really just builds new onto old and is limited by historical constraints and other issues?
Can we really assume that alien civilizations will have the intimate peculiarities of human psychology? Is the reason why we do not see any intergalactic civilizations that they have converted themselves to pure energy or dark matter or migrated into black holes? Is a static situation of no change really a good characterization of the concepts of equilibrium? Can we build a sphere around our sun to make productive use of its output, or will this kill most organisms on the earth? Is it really incredibly reckless to send out messages into space when there is so much passive leakage of television and radio signals?
In previous installments of this articles series, we have covered many interesting and thought-provoking issues such as biological weapons, anti-psychiatry, embryo selection and IQ, cryogenics, destructive teleportation, uploading your mind to computer hardware, superintelligent artificial intelligence, atomically precise manufacturing, 3D printing, philosophy of science, the specter of statistical significance and various doomsday scenarios. In this seventh part, we take a closer look at the ninth chapter about space colonization of Here Be Dragons by mathematical statistician Olle Häggström.
Section XLI: The Fermi Paradox
Häggström spends a large portion of this section on thinking why aliens have not visited us or why we see no evidence of their existence. He begins by bringing up the Fermi paradox (pp. 203-205), which is the claim that we experience a great silence (i.e. lack of evidence for alien civilizations), despite the fact that rudimentary mathematical arguments might lead us to suppose that there should be alien civilizations in many locations in the universe. He mentions proposed explanations for why this is, from the rarity of abiogenesis and the danger from asteroid impacts to self-destruction and fear of exploration. He also decides to bring up the idea that “perhaps they exist but have all chosen to transform themselves into pure energy (or dark matter) in forms that we are unable to recognize”. This is, of course, completely batshit, since humans already consists of energy as matter is a form of energy (Nobel Media, 2014) and there is no evidence that humans can transform themselves into dark matter and certainly no reason to believe that transforming a human into dark matter (even if possible) would result in anything different that destruction of that person. There is really no such thing as “pure” energy, since that would assume that humans currently consists of energy and some non-energy contaminant. One wonders what Häggström thinks this contaminant is.
The Fermi paradox is the core assumption in almost all subsequent arguments, so it is crucial to think critically about how much this makes sense. Should this survive, most of the arguments that appear later in the book would topple. It is probably the case that life cannot exist in a universe that is not old enough. This is because the temperature has to be low enough for atoms to form and developed enough to form specific types of stars that produce heavier elements and planets. This rules out billions of years in the past and could mean that we should not be surprised to find a great silence, since the circumstances where life is even physically possible has recently (on cosmological scale) come around the corner.
Section XLII: The Great Filter I (problems relating to statistics and physics)
In the next section, Häggström introduces his favorite framework to think about these issues that is called the Great Filter. The basic idea is that you estimate the number of intergalactic civilizations by multiplying the number of life-permitting planets (N) with the probability of going from life-permitting planet to an equivalent of current human civilization (p) with the probability of going from an equivalent current human civilization to an intergalactic civilization (q). Since Häggström says that “our observations tell us that the actual number of planets that have made it is 0”, he thinks that Npq . Since N is very large (~1022 is the figure he mentions), the product pq has to be small for the expression to work and so either p, q or both are small. This is the great filter: somewhere there has to be a bottleneck that greatly restricts the possibility for life to advance towards intergalactic state: either it is in our past (we are probably alone in the universe), or in our future (which means that we are probably not going to expand into an intergalactic state).
However, the Great Filter argument is fatally flawed in a large number of ways:
(1) It treats the absence of evidence as evidence of absence. This is not correct as the distances in space are so vast that light can take many billions of years to travel within the observable universe (not to mention what lies in other parts of the universe we currently do not observe). This means that there could be many intergalactic civilizations of small to moderate size, but that the light from their activities has not reached us yet and will not reach us for many billions of years. It might also have already reached us in the past when we were not looking or it is currently visible but we cannot correctly interpret the signs of it from so far away and so on. Häggström thinks this will only changes the result by approximately an order of magnitude (p. 209), but this is clearly wrong considering the large size of the universe and the many locations that we observed with a delay of billions of years (Baraniuk, 2016).
(2) It makes the same fallacy as the Fermi paradox. It may be the case that it is just recently that the observable universe has even started to allow the possibility of life, which debunks the supposed great mystery of the great silence.
(3) The concept of life-permitting planet is not independent of other factors in the equation. What makes a planet life-permitting are some of the same factors that influence the probability of going from origin of life to a state equivalent to current human civilization. For instance, life-permitting stellar characteristics allow photosynthesis, the potential for life-permitting chemistries decides if the evolutionary paths towards the equivalent human civilization is likely or even possible and so on. This falls under the general umbrella of historical constraints that will be discussed in greater detail below. Thus, simply multiplying them together is mathematically invalid.
(4) It confuses the a priori probability of a specific set of events with the a fortiori probability of a class of events. This is because p is treated as the product of specific events, such as the origin of self-replicating RNAs, multicellularity, animals, large brains etc. But this is like multiplying together the probability of all mutations from the origin of life to humans and concluding that the product is low, so therefore it must not have happened. The relevant probability is not the probability of the specific series of mutations, but rather the probability that any series of mutations could have produced our species, or something similar (Isaak, 2005). Similarity, there is no reason to suppose that any of these events have to occur to reach the functional equivalent of human-level civilization. It is possible that some other chain of evolutionary events could have happened that yielded the same functional outcome. This fallacious argument underestimates the probability of p substantially. Häggström makes precisely this error where he claims that estimating p is precisely “a matter of judging whether any of the breakthroughs in the development of life […] constitutes a serious enough bottleneck (i.e. an event unlikely enough) to account for the great filter” and list the development of life on earth as factors. Häggström commits this fallacy again when he discusses the low probability of the origin of life (p. 215).
(5) Thinking about p or q typically assumes that the factors that go into p (or q for that matter) are independent. But the origin of e. g. large brains (made of cells in a multi-cellular organism) is not independent from the origin of life, cells, and previous evolutionary steps constrain what kind of future steps can be taken. So while the same functional outcome could have been produced by different evolutionary lineages (see 4), a given point on a specific evolutionary lineage is not independent of prior points.
(6) Ignores the difference between potentially life-permitting and actually life-permitting. N was the number of planets that were potentially life-permitting and p was the probability that a potentially life-permitting planet gives rise to a human-level civilization (or equivalent). However, the first factor Häggström mentions is the origin of life. Thus, he completely ignores the difference between potentially life-permitting and actually life-permitting. A planet can be potentially life-permitting without being actually life-permitting. This might be an intrinsic effect or an effect of the uncertainty of what it means to be actually life-permitting. Again, this shows the lack of independence between N and p.
Section XLIII: The Great Filter II (problems relating to biology, culture and psychology)
(7) Make dubious arguments about evolution. Häggström claims that life has a natural tendency to expand and fill all areas and functional roles that exists (both ecological and cultural) and therefore embraces a naive view of evolution that supposes that life “carries with them a propensity for further expansiveness, either in their genes or (in the more recent human case more likely culturally) in their memes.” But this is not how evolution works. Evolution is merely the differential survival of randomly varying replicators. Organisms become more adapted to their environment, regardless of this requires expansion, contraction or equilibrium. Other factors are involved as well such as historical constraints, the lack of the required genetic variation, and random chance (Hansen, 2005; Understanding Evolution, 2016). Evolution builds new onto old, not with an overarching genetic goal of “further expansiveness”.
For instance, if pigs had wings, this would promote the “further expansiveness” goal since pigs could now fly around and reach much larger resources, escape predators and so on. Yet this has not happened. This is probably because the required genetic variation was never available to be selected for to begin with and because of the historical constraints of four-legged animals. Wings are, after all, modified limbs, and so it is not possible for an animal to have four limbs plus limb-modified wings. This is a trivial example, but it illustrates the fallacy of thinking of evolution as producing things that are bigger, stronger or more expansive (Gould, 1997).
Another problem, of course, is that the kind of life that can survive hot and acidic environments in the ocean are not the kind of life that has any realistic possibility of becoming space explorers that can build colonies or advanced robotics. Becoming adapted to some environments robs you of the possibility of being adapted to others, either because the species if exploring some other parts of genetic space or because of historical constraints. For instance, it is hard to evolve a human brain from a banana than to evolve a human brain from a previous primate species. By the way, the former is actually possible, you just reverse the genetic changes from the banana to the most recent common ancestor of bananas and humans, then the genetic changes that occurred in the lineage that went to humans. The arguments delivered by Häggström show a greater understanding of biological evolution than the average creationist, but just barely.
(8) Appealing to cultural evolution blatantly imports human psychology and tacks that on to potentially alien civilizations when there is no evidence whatsoever that they must have a psychology that is comparable to humans. Like superintelligent AI, this is typically also human male psychology, which although understandable since most thinkers in the field are male, is a clear bias. Häggström also ignores the fact that historical research do not show an uninterrupted progress towards more complexity and expansiveness, but rather periods of development and periods of collapse in between. Indeed, all cultures that have ever lived but do currently not exist have been decimated. This is in stark contrast with the ideas put forward by Häggström when he claims that it is enough for one exception to cultures refraining from space colonization for them to “fill every inhabitable corner of the galaxy” (p. 210).
The exponential expansion that Häggström seems to appeal to is very recent and potentially very fleeting. This kind of implicit importing of human peculiarities is obvious when he speaks of civilizations “changing its mind” (p. 210) about space colonization, clearly assuming that planets with advanced life will organize itself into human-like democratic rule, clearly an unjustified assumption since he have no reason to suppose that evolution produces human-like creatures in other parts of the universe let alone the specific intricacies of their psychology or political organization, even if we, for the moment, grant the existence of life that are on an equivalent level to humans. Häggström again fallaciously invokes specific aspects of human psychology when he discusses potential fears a civilization might have that another civilization is colonizing the universe and becoming a threat, leading to preemptive colonization (p. 221) or that a civilization wants to optimize energy usage and gains as well as to avoid energy waste (p. 222).
Section XLIV: Migrate into black holes?
Häggström feels the persuasiveness of the view that if p is large, q is small and the future looks bleak to humanity, but correctly notes that this is just an average that tells us nothing about the spread or the specifics for the human civilization on earth (p. 212). He then raises the possibility that humans can flourish without intergalactic space colonization by proposing the possibility that the “typical long-term fate of civilizations is to migrate into black holes”. A completely ridiculous idea, of course, since black holes will destroy humans if they try to enter due to their strong gravity. This is not just conjecture, because black holes have been observed to destroy and swallow stars and other cosmic material (NASA Science, 2016). He appeals to some future physics to back up this idea, but the correspondence principle tells us that future physics has to agree with contemporary physics in areas where they both apply (such as destruction by black holes). If Häggström doubts this, he should provide evidence for his suggestion. If he does not, we can reject it as absurd.
Section XLV: The Bullerby Distraction
For a moment, Häggström considers scenarios that do not involve an unrealistic exponential growth based on pseudoscientific distortions of evolution. He calls this the Bullerby scenario, which involves humans alter their society to an existence that does not involve space colonization, but rather clean energy and agriculture that does not destroy the planet and they live happily ever after. In particular, he describes this situation as “peaceful” and “quiet”. However, he immediately rejects this, again by appealing to mischaracterizations of evolution and culture.
However, the problem with this distraction goes further than this. What Häggström probably had in mind was an equilibrium scenario. However, he chose a scenario where there is virtually no change, but this is only one form of equilibrium. All that is required for an equilibrium to exist is that the processes in one direction is balanced by processes in the other, but this does not mean that there has to be no change (IUPAC, 1997). Two parts of a city connected by a bridge can be in equilibrium with respect to the number of cars in each part despite the bridge being heavily trafficked. Likewise, there can be equilibrium scenarios without space colonization where the growth and decline are roughly balanced, or occur in cycles or oscillations.
By mischaracterizing equilibrium as virtually no change (i.e. “peaceful” and “quiet”), he has excluded a large number of plausible and evidence-based scenarios of human flourishing because he did not survey the alternatives to his “neverending growth paradigm” (p. 212) in economy and scientific knowledge. Here he neglects to mention that most published research findings are false (Ioannidis, 2005) and that economic growth in some parts of the world has often come to the expense of other human populations in other parts of the world (e. g. colonialism and slavery) or future human populations (e. g. climate emissions) or other aspects of the planet (e. g. coral bleaching and species extinctions). Häggström cannot understand how equilibrium conditions can come about without “a totalitarian global government” (p. 212), but his lack of imagination is not evidence.
Section XLVI: The demand to be disproved in principle
A lot of proponents of superintelligence, cryonics, destructive teleportation and many other issues discussed in this book have a bizarre approach to refutation. This is because they demand that critics show that their beliefs are impossible in principle. If this is not show, the true believers assert that their position has not been conclusively refuted, and throughout the discussion of a particular issue, this moves from “not conclusively disproved” to “wide-open question”, “plausible” or even “probable”.
This is, of course, a dishonest approach. The burden of evidence is on the proponents, not the skeptics, and if the proponents cannot present any solid evidence for their position, it is enough for skeptics to show that the idea is very improbable.
Section XLVII: Dyson sphere is unlikely to work
Häggström moves on to discuss some of the technological advances he thinks could be useful to ensure human space colonization. One such advances is the Dyson sphere, where a civilization attempts to make maximum use of its star by surrounding it by a sphere that collects most or all of the energy from the sun and use it for beneficial things (p. 219). However, there are serious problems with the idea of a Dyson sphere that Häggström does not seem aware of, or at least not mention. He seems content to mention some difficulties with getting the raw material (by mining Mercury) or moving it (p. 219). First, he replaces one hard problem with another twice: space colonization is an extremely difficult problem that Häggström wants to solve with a Dyson sphere, but this is also a very hard problem that he wants to solve with self-replicating robots collecting material, transporting it and building it, which of course, is also a difficult problem. This is just a hopeless approach and he has no evidence that he has made the problem substantially easier.
Häggström seems completely unaware that a Dyson sphere might be way to hot for electronics (so you will not be able to extract energy from the sun or store it in batteries) or even the material used to construct the sphere, require a ton of material, is very unstable to perturbations and might crash into the sun and require a lot of energy to spin and so on.
However, there is an even bigger problem that will surely make a Dyson sphere unfeasible and indeed completely batshit. This is because building a Dyson sphere is a substantial existential risk that will be explored in the next section.
Section XLVIII: Dyson sphere as an existential risk
So why is a Dyson sphere an existential risk? Recall that a Dyson sphere is a sphere that captures either all or most of the outgoing radiation from the sun. Let us, for the sake of argument, say that this means 90% or more of the outgoing radiation. This does not mean that the Dyson sphere and associated systems are efficient enough to utilize all of it, merely that the energy is being diverted from the surface of the earth to the Dyson sphere. So at most, only 10% of the light now reaches the earth. This might be irrelevant for humans, since you could (if the system actually works), use that energy to create lights. It might not even be a problem for the production of food, since you might use lamps to grow crop.
However, other organisms are not as lucky. Phytoplankton in the ocean that rely on the sun for photosynthesis will likely undergo a massive extinction unlike anything that has ever been seen. This might seem inconsequential at first sight, but phytoplankton produce at least half of the oxygen in the atmosphere (Boyce, Lewis and Worm, 2010), so a massive die-off of phytoplankton will cause an oxygen crash in the atmosphere. This will lead to the death of most plants and animals currently in existence, since they rely on oxygen for life. Contrary to popular opinion, plants do require oxygen to live since it is needed for aerobic metabolism in mitochondria (BBC, 2014). This will likely also lead to an accumulation of carbon dioxide and thus enhanced global warming, which together with oxygen depletion will lead to a climate crisis and massive ecosystem collapse.
Thus, the building of a Dyson sphere might be considered a worse existential risk than current climate change and probably comparable to a mass extinction, or worse. The reason it might be worse is that the available solar energy did not permanently decline by ~90% or more. Häggström attempts to sidestep some of these issues (even though he does not mention it by name) by suggesting that “energy slip out of their system at longer wavelengths and lower negentropy” (p. 222 footnote 477), but primary producers have evolved to use the wavelengths that are the primary output from the star, and substantially longer wavelengths cannot be utilized by them. For instance, plants make use of red and blue light from the visible part of the electromagnetic spectrum, but cannot survive on, say, radio waves or any other radiation with much longer wavelengths. The time span for constructing a Dyson sphere would probably be too short to evolve a new system, since it would not just be a matter of evolving a new pigment, but that the electron transport chain would have to be adjusted because the incoming energy will raise the energy level of electrons much lower than before, and it might not even be able to use water as an electron donor (Shen, 2015). Even if this somehow works, the product would not be oxygen since the electron donor is no longer water. Instead, the byproduct might be something else, which could be potentially harmful.
This problem probably exist for any other planet that carry advanced life. If Häggström can boldly assume that other civilizations out there in the universe have specific intricacies of human psychology, I can carefully propose that there will be primary producers on that planet that rely on solar energy. If not, being near a sun would not be required for a planet to be potentially life-permitting, at least not as a source of energy.
Section LXIX: Dystonian SETI
Häggström briefly discuss the SETI project that tries to analyze signals from space and figure out if any one it could be evidence of an alien civilization (p. 221). He advocates a slightly different approach called Dystonian SETI, which involves looking for the signs of advanced technology in space, such as foreign Dyson spheres (p. 222). This is, of course, misbegotten, since a Dyson sphere might erase most of life on that planet due to the killing of of global primary producers, so this idea makes precious little sense. No rational civilization would build a Dyson sphere, and if they did, it would probably lead to a very large mass extinction, so it is not given that such a civilization would survive the build. The civilization you might detect signs from might be dead since billion of years as a result of their own undoing.
Here, Häggström appeals to the intricacies of human psychology as well, suggesting that alien civilizations might want to “do as much as they can of whatever it is they’re doing” or “may not want to let much of their star’s energy output go to waste”. But we have no reason to suppose that alien psychology looks anything like that of humans, because human psychology originates from a combination of the twists and turns of our particular evolutionary lineage as well as the specifics of the civilization we have built. Although there is reason to suppose that their world have some similarities to ours e. g. primary producers that use their star as energy, optical detectors if they move in transparent medium and so on, just arbitrarily importing human psychology into the mix is deeply unwarranted. He also suggests that a Dyson sphere can be detected by infrared radiation because it will heat up after being put in operation. However, infrared radiation is emitted from anything that has a temperature (NASA, 2007). He is then left with trying to find “the right sort of infrared spectrum” (p. 222), but never tells us what this is.
So detecting a Dyson sphere is likely unreasonable. What other possibilities does Häggström propose? One such possibility is detecting “anomalous arrangements of stars” (p. 222) because an advanced civilization might want to move stars because they are in a “suboptimal position” (p. 222). This is, of course, an ignorant claim because the relative position of planets to the star depends largely on the gravity of the star. If you move the star, you move the gravity field of the star and thus all other planets as well. So it makes precious little sense to attempt to move a star. Häggström makes a triple error when he claims that “it is hardly inconceivable that they, for some reason or other, will find the natural locations of stars in their neighborhood suboptimal”. He makes an unabashed import of the intricacies of human psychology when he appeals to star location optimization, he makes unreasonable demands for critics when he states that his position is not impossible in theory and appeals to his own lack of imagination when he talks about what is conceivable or not, rather than evidence.
Section LXX: METI
Unlike SETI that just passively listens for signs of extraterrestrial, METI involves sending customized messages in specific directions into space. Häggström thinks this is “inexcusably reckless” (p. 223) with the potential to be “terribly dangerous” (p. 223). He goes so far as to suggest that we should simply not do it (p. 225), and even calls for a ban on radio astronomy (p. 225).
This, of course, is just pseudoscientific (and indeed anti-scientific) hostility to technology that we have seen before in this book. This is because our planet passively leaks radiation all the time (from both human and physical sources) and METI poses hardly any additional risk. This is the same erroneous thinking that leads people to be concerned about the supposed negative health effects of 1 parts per billion glyphosate in red wine, but now about the 13% ethanol content that we know is harmful and even known to cause cancer. It is just an ignorant and incompetent risk assessment. You simply cannot dismiss a scientific research project by inventing extreme and far-fetched alleged “risks” that are considerably less than risks we already accepts. By the way, this anti-technology approach can be applied to mathematics as well, as it has provided the basis for many destructive techniques (such as nuclear weapons) and can be used as a modelling tool for criminals and totalitarian dictators to enhance their activities. One wonders if Häggström therefore would want to ban math.
Astonishingly, Häggström seems aware of this problem (p. 224), but dismisses this by insinuating that there is no point with METI if there is no increased risk. However, this confuses risks with benefits. There is nothing unreasonable with an action having more benefits than another action, yet no substantially increased risk. Vaccines, for instance, are generally less risky than the disease and generally has more benefits than the disease. Although METI probably offers no non-negligible increase in risk, it does have benefits: the message can be customized compared with passive leakage and the direction can also be carefully chosen.
However, the problems for Häggström does not end here. This is because our planet is under the risk of being detected simply by existing. A planet such as the earth can be detected by a potentially alien civilization by the dimming of our sun as the earth passes between the sun and the observer (Stromberg, 2014). This is, in fact, one of the principle ways that we humans detect exoplanets. So if we apply the reasoning provided by Häggström, namely that we have no reason to suppose that emission of radiation will not be an existential risk to humanity, then we must do everything in our power to avoid detection. This means that, according to Häggström’s line of reasoning, we must construct giant emitters of electromagnetic radiation that mimics solar radiation so that we can eliminate the dimming. Since it is a 3D situation, these emitters has to be constructed all across the planet to factor in angles and the spinning of the earth around its axis and the orbit around the sun itself. If this seems ludicrous and laughable in its absurdity, it is because it a dumb idea. But from the existential risk perspective, it does not matter if the risk of this scenario is extremely tiny, because the potential negative outcome are so large that the utility calculation would favor this action. Since this is an absurd idea, it must mean that the existential risk approach is terribly misguided and erroneous, and this will be argued in additional detail in a later installment of this series.
The core message is this: if Häggström is not calling for the destruction of television or radio, he has no business in calling for the ban of METI or radio astronomy. Even if Häggström appeals to the differences in magnitude of these actions, the existential risk argument where the massive consequences outweigh the tiny risk would indicate that a small change in the risk is rounding error compared with the massive negative consequences. So it appears as if Häggström has gotten himself hopelessly entangled in his own web of irrational risk assessment.
References and further reading:
Baraniuk, C. (2016). It Took Centuries But We Now Know The Size Of The Universe. BBC News. Accessed: 2016-09-12.
BBC. (2015). Respiration in plants. Accessed: 2016-09-12.
Boyce, D. G., Lewis, M. R., & Worm, B. (2010). Global phytoplankton decline over the past century. Nature, 466(7306), 591-596.
Gould S. J. (1997). Full House: The Spread of Excellence from Plato to Darwin. New York: Harmony.
Hansen, T. F. (2015). Evolutionary Constraints. Oxford Bibliography. Accessed: 2016-09-12.
Ioannidis J. P. A. (2005). Why Most Published Research Findings Are False. PLoS Med 2(8): e124.
Isaak. M (2005). Probability of Abiogenesis. TalkOrigins Archive. Accessed: 2016-09-12.
IUPAC. (1997). Chemical Equilibrium. IUPAC Gold Book. Accessed: 2016-09-12.
NASA. (2007). Infrared. Accessed: 2016-09-12.
NASA Science. (2016). Black Holes. NASA. Accessed: 2016-09-12.
Nobel Media. (2014). Energy from Matter. Nobelprize.org. Accessed: 2016-09-12.
Shen, J. (2015). The Structure of Photosystem II and the Mechanism of Water Oxidation in Photosynthesis. Annual Review of Plant Biology, 66(1), 23-48.
Stromberg, J. (2014). How Do Astronomers Actually Find Exoplanets?. Smithsonian. Accessed: 2016-09-12.
Understanding Evolution. (2016). Genetic Drift. Accessed: 2016-09-12.