Tag Archives: Fermi Paradox

A Less Bleak Lesson from the Silent Universe

Mars Veg brain

The astronomers Adam Frank and Woodruff Sullivan have an interesting paper out where they’ve essentially flipped the Drake Equation on its head. If that equation is meant to give us some handle on the probability that there are aliens out there, Frank and Sullivan have used the plethora of exoplanets discovered since the launch of the Kepler space telescope to calculate the chance that, so far, we alone have been the only advanced civilization in the 13.7 billion year history of the universe. I won’t bore you with actual numbers, but they estimate the chance that we’re the first and only is 1 in 10 billion trillion. I shouldn’t have to tell you that is a really, really small number.

Frank and Sullivan’s paper emerges as a consequence of the fact that we now have very clear answers to at least some of the values of the Drake equation. We now know not only how many stars are out there, but also how many of those stars are likely to have planets, and how many of those planets are likely within their star’s habitable zone. It is the fact that this number of potentially habitable planets is, to channel Donald Trump, so huge, which leads to the conclusion that (when plugged into Frank and Sullivan’s rejiggered Drake equation where the requirements that alien civilization exists presently and are within communication distance from us are dropped) the only way we have been the first and only technological civilization would be if we were the beneficiaries of the most extraordinary luck.

We’re not quite at the point, however, where we can make a definitive guess as to just how lucky, or how normal, our civilization is in history the cosmos. To do that we’ll need to find out what the probability is that life will develop on planets that have liquid water, and how difficult the leap is from single celled life to multicellularity. As I’ve written about before these questions are the subject of sharp differences and debate between bio-physicists and evolutionary biologists with some of the former, notably Jeremy England, seeing the laws of physics in a sense priming the universe for life and complexity and the latter seeing evolution as much more contingent and intelligence of our sort a lucky accident.

The historical question, namely, how likely is complex life likely to give rise to a technological species will remain unanswerable as long as the universe continues to be silent or until we discover the artifacts of some dead civilization. Frank and Sullivan’s answer to the silence is that the vast majority of alien civilizations have died, and those that might exist are beyond any distance in which we could observe or communicate with them. Theirs is the ultimate cautionary tale.

Then again,  perhaps we’re on the very verge of finding other technological civilizations that either exist now or existed in the very recent past once we start to look in the proper way. That, I think, is the lesson we should take from last year’s observation by the Kepler space telescope of some very strange phenomenon circling a star between the constellations of Cygnus the Swan and Lyra. Initially caught by citizen scientists reviewing Kepler data, what stuck astronomers such as Tabetha Boyajian  was the fact whatever it is they are looking at is distributed so widely, and follows such an unusual orbit, that it has lead some to speculate that there is a remote possibility that this object might be some sort of Dyson Sphere.

It seems most likely that some natural explanation will be found for the Kepler data, and yet, whatever happens, we are witnessing the birth of what Frank and Sullivan call cosmic archeology. The use of use of existing tools, and eventually the creation of tools for that purpose, to look for the imprint of technological civilizations elsewhere in the cosmos.

We do have pretty good evidence of at least one thing: if there are, or have been, technological civilizations out there none is using the majority of its galaxy’s energy. As Jim Wright at Penn State who conceived of the recent scanning 100,000 galaxies that had been observed by NASA’s Wise satellite for the infrared fingerprints of a galactic civilization  discovered. Wright observed:

Our results mean that, out of the 100,000 galaxies that WISE could see in sufficient detail, none of them is widely populated by an alien civilization using most of the starlight in its galaxy for its own purposes. That’s interesting because these galaxies are billions of years old, which should have been plenty of time for them to have been filled with alien civilizations, if they exist. Either they don’t exist, or they don’t yet use enough energy for us to recognize them.

Yet perhaps we should conclude something different about the human future from this absence of galactic scale civilizations than the sad recognition that our species is highly unlikely to have one.  Instead, maybe what we’re learning is that the kind of extrapolation of the industrial revolution into an infinite future that has been prevalent in science-fiction and futurism for well over a century is itself deeply flawed. We might actually have very little idea of what the future will actually be like.

Then again, maybe the silence gives us some clues. Rather than present us with evidence for our species probable extinction, perhaps what we’re witnessing is the propensity of civilizations to reach technological limits before they have grown to the extent that they are observable across great interstellar distances by other technological civilizations. To quote myself from a past post:

This physics of civilizational limits comes from Tom Murphy of the University of California, San Diego who writes the blog Do The Math. Murphy’s argument, as profiled by the BBC, has some of the following points:

  • Assuming rising energy use and economic growth remain coupled, as they have in the past, confronts us with the absurdity of exponentials. At a 2.3 percent growth rate within 2,500 hundred years we would require all the energy from all the stars in the Milky Way galaxy to function.
  • At 3 percent growth, within four hundred years we will have boiled away the earth’s oceans, not because of global warming, but from the excess heat that is the normal product of energy production. (Even clean fusion leaves us burning away the world’s oceans for the same reason)
  • Renewables push out this reckoning, but not indefinitely. At a 3 percent growth rate,even if the solar efficiency was 100% we would need to capture all of the sunlight hitting the earth within three hundred years.

There are thus reasonable grounds for assuming no technological civilization ever reaches a galactic scale whether because it has destroyed itself, or, for all we know just as likely, that all such civilizations run into development constraints far closer to our own than someone like Ray Kurzweil would have you believe.

Energy constraints might even result in the cyclical return of intelligence from silicon back to carbon based forms. At least that’s one unique version of the future as imagined by the astrobiologists Caleb Scharf in a recent piece for Aeon. Silicon intelligence has some advantages over carbon-based, as Lee Sedo can tell you, but you can’t beat life when it come to efficiency. As Scarf points out:

Estimates of what you’d need in terms of computing power to approach the oomph of a human brain (measured by speed and complexity of operations) come with an energy efficiency budget that needs to be about a billion times better than that wall.

To put that in a different context, our brains use energy at a rate of about 20 watts. If you wanted to upload yourself intact into a machine using current computing technology, you’d need a power supply roughly the same as that generated by the Three Gorges Dam hydroelectric plant in China, the biggest in the world. To take our species, all 7.3 billion living minds, to machine form would require an energy flow of at least 140,000 petawatts. That’s about 800 times the total solar power hitting the top of Earth’s atmosphere. Clearly human transcendence might be a way off.

A problem that neither Murphy nor Scharf really deal with is one of integration over a vast scale. A not insignificant group of techno-optimists sees the human technological artifice not just an advanced form of industry-based civilization but as an emerging universal mind in embryo. Personally, I think it more likely that we are moving in the exact opposite direction, towards a balkanization of this global brain, but there might be reasons to think that even if what we’re seeing is the birth pangs of something out of Stanisław Lem’s Solaris or Teilhard de Chardin, that such intelligence wouldn’t occupy a space all that much larger than the earth.   

As the physicists Gregory Laughlin recently pointed out in the magazine Nautilus, the speed of light would seem to impose limits on how big any integrated intelligent being can become:

If our brains grew enormously to say, the size of our solar system, and featured speed-of-light signaling, the same number of message crossings would require more than the entire current age of the universe, leaving no time for evolution to work its course. If a brain were as big as our galaxy, the problem would become even more severe. From the moment of its formation, there has been time for only 10,000 or so messages to travel from one side of our galaxy to the other. We can argue, then, that, it is difficult to imagine any life-like entities with complexity rivaling the human brain that occupy scales larger than the stellar size scale. Were they to exist, they wouldn’t yet have had sufficient time to actually do anything.

Since the industrial revolution our ideas about both the human future and the nature of any alien civilization have taken the shape of being more of the same. Yet the evidence so far seems to point to a much different fate. We need to start thinking through the implications of the silence beyond just assuming we are either prodigies,or that, in something much less than the long run, we’re doomed.

 

Life: Inevitable or Accident?

The-Tree-Of-Life Gustav Klimt                                                             https://www.artsy.net/artist/gustav-klimt

Here’s the question: does the existence of life in the universe reflect something deep and fundamental or is it merely an accident and epiphenomenon?

There’s an interesting new theory coming out of the field of biophysics that claims the cosmos is indeed built for life, and not just merely in the sense found in the so-called “anthropic principle” which states that just by being here we can assume that all of nature’s fundamental values must be friendly for complex organisms such as ourselves that are able to ask such questions. The new theory makes the claim that not just life, but life of ever growing complexity and intelligence is not just likely, but the inevitable result of the laws of nature.

The proponent of the new theory is a young physicist at MIT named Jeremy England. I can’t claim I quite grasp all the intricate details of England’s theory, though he does an excellent job of explaining it here, but perhaps the best way of capturing it succinctly is by thinking of the laws of physics as a landscape, and a leaning one at that.

The second law of thermodynamics leans in the direction of increased entropy: systems naturally move in the direction of losing rather than gaining order over time, which is why we break eggs to make omelettes and not the other way round. The second law would seem to be a bad thing for living organisms, but oddly enough, ends up being a blessing not just for life, but for any self-organizing system so long as that system has a means of radiating this entropy away from itself.

For England, the second law provides the environment and direction in which life evolves. In those places where energy outputs from outside are available and can be dissipated because they have some boundary, such as a pool of water, self-organizing systems naturally come to be dominated by those forms that are particularly good at absorbing energy from their surrounding environment and dissipating less organized forms of energy in the form of heat (entropy) back into it.

This landscape in which life evolves, England postulates, may tilt as well in the direction of complexity and intelligence due to the fact that in a system that frequently changes in terms of oscillations of energy, those forms able to anticipate the direction of such oscillations gain the possibility of aligning themselves with them and thus become able to accomplish even more work through resonance.

England is in no sense out to replace Darwin’s natural selection as the mechanism through which evolution is best understood, though, should he be proved right, he would end up greatly amending it. If his theory ultimately proves successful, and it is admittedly very early days, England’s theory will have answered one of the fundamental questions that has dogged evolution since its beginnings. For while Darwin’s theory provides us with all the explanation we need for how complex organisms such as ourselves could have emerged out of seemingly random processes- that is through natural selection- it has never quite explained how you go from the inorganic to the organic and get evolution working in the first place. England’s work is blurring the line between the organic and the most complicated self-organizing forms of the inorganic, making the line separating cells from snowflakes and storms a little less distinct.

Whatever its ultimate fate, however, England’s theory faces major hurdles, not least because it seems to have a bias towards increasing complexity, and in its most radical form, points towards the inevitability that life will evolve in the direction of increased intelligence, ideas which many evolutionary thinkers vehemently disavow.

Some evolutionary theorists may see effort such as England’s not as a paradigm shift waiting in the wings, but as an example of a misconception regarding the relationship between increasing complexity and evolution that now appears to have been adopted by actual scientists rather than a merely misguided public. A misconception that, couched in scientific language, will further muddy the minds of the public leaving them with a conception of evolution that belongs much more to the 19th century than to the 21st. It is a misconception whose most vocal living opponent after the death of the irreplaceable Stephen J Gould has been the paleontologist, evolutionary biologist, and senior editor of the journal Nature, Henry Gee, who has set out to disabuse us of it in his book The Accidental Species.

Gee’s goal is to remind us of what he holds to be the fundamental truth behind the theory of evolution- evolution has one singular purpose from which everything else follows in lockstep- reproduction. His objective is to do away, once and for all, with what he feels is a common misconception that evolution is leading towards complexity and progress and that the highest peak of this complexity and progress is us- human beings.

If improved prospects for reproduction can be bought through the increased complexity of an organism then that is what will happen, but it needn’t be the case. Gee points out that many species, notably some worms and many parasites, have achieved improved reproductive prospects by decreasing their complexity.Therefore the idea that complexity (as in an increase in the specialization and number of parts an organism has)  is a merely matter of evolution plus time doesn’t hold up to close scrutiny. Judged through the eyes of evolution, losing features and becoming more simple is not necessarily a vice. All that counts is an organism’s ability to make more copies, or for animals that reproduce through sex, blended copies of itself.

Evolution in this view isn’t beautiful but coldly functional and messy- a matter of mere reproductive success. Gee reminds us of Darwin’s idea of evolution’s product as a “tangled bank”- a weird menagerie of creatures each having their own particular historical evolutionary trajectory. The anal retentive Victorian era philosophers who tried to build upon his ideas couldn’t accept such a mess and:

…missed the essential metaphor of Darwin’s tangled bank, however, and saw natural selection as a sort of motor that would drive transformation from one preordained station on the ladder of life to the next one.” (37)

Gee also sets out to show how deeply limited our abilities are when it comes to understanding the past through the fossil record. Very, very, few of the species that have ever existed left evidence of their lives in the form of fossils, which are formed only under very special conditions, and where the process of fossilization greatly favors the preservation of some species over others. The past is thus incredibly opaque making it impossible to impose an overarching narrative upon it- such as increasing complexity- as we move from the past towards the present.

Gee, though an ardent defender of evolution and opponent of creationist pseudoscience, finds the gaps in the fossil record so pronounced that he thinks we can create almost any story we want from it and end up projecting our contemporary biases onto the speechless stones. This is the case even when the remains we are dealing with are of much more recent origin and especially when their subject is the origin of us.

We’ve tended, for instance, to link tool use and intelligence, even in those cases such as Homo Habilis, when the records and artifacts point to a different story. We’ve tended not to see other human species such as the so-called Hobbit man as ways we might have actually evolved had circumstances not played out in precisely the way they had. We have not, in Gee’s estimation, been working our way towards the inevitable goal of our current intelligence and planetary dominance, but have stumbled into it by accident.

Although Gee is in no sense writing in anticipation of a theory such as England’s his line of thinking does seem to pose obstacles that the latter’s hypothesis will have to address. If it is indeed the case that, as England has stated it, complex life arises inevitably from the physics of the universe, so that in his estimation:

You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant.

Then England will have to address why it took so incredibly long – 4 billion years out of the earth’s 4.5 billion year history for actual plants to make their debut, not to mention similar spans for other complex eukarya such as animals like ourselves.

Whether something like England’s inevitable complexity or Gee’s, not just blind, but drunk and random, evolutionary walk is ultimately the right way to understand evolution has implications far beyond evolutionary theory. Indeed, it might have deep implications for the status and distribution of life in the universe and even inform the way we understand the current development of new forms of artificial intelligence.

What we have discovered over the last decade is that bodies of water appear to be both much more widespread and can be found in environments far beyond those previously considered. Hence NASA’s recent announcement that we are likely to find microbial life in the next 10 – 30 years both in our solar system and beyond. What this means is that England’s heat baths are likely ubiquitous, and if he’s correct, life likely can be found anywhere there is water- meaning nearly everywhere. There may even be complex lifelike forms that did not evolve through what we would consider normal natural selection at all.

If Gee is right the universe might be ripe for life, but the vast, vast majority of that life will be microbial and no amount of time will change that fate on most life inhabited worlds. If England in his minor key is correct the universe should at least be filled with complex multicellular life forms such as ourselves. Yet it is the possibility that England is right in his major key, that consciousness, civilization, and computation might flow naturally from the need of organisms to resonate with their fluctuating environments that, biased as we are, we likely find most exciting. Such a view leaves us with the prospect of many, many more forms of intelligence and technological civilizations like ourselves spread throughout the cosmos.

The fact that the universe so far has proven silent and devoid of any signs of technological civilization might give us pause when it comes to endorsing England’s optimism over Gee’s pessimism, unless, that is, there is some sort of limit or wall when it comes to our own perceived technological trajectory that can address the questions that emerge from the ideas of both. To that story, next time…