The recent report on the findings of climatic research into the causes and probable evolution of climate change – a more accurate term than “global warming” – prompted me to consider a possible answer to Enrico Fermi’s classic question “Where is everybody?” Multiple generations of science fiction writers have projected a future in which the Milky Way Galaxy fairly teems with life, rather like Times Square on New Year’s Eve or the tavern in the first Star Wars movie – so much so that the late Prof. Stephen Hawking has publicly counseled SETI investigators to – not literally STFU – but certainly to exercise due caution in broadcasting the existence of intelligent life on earth to every corner of the Galaxy. (Not that we have a choice by now: earth’s electromagnetic emissions by now comprise a bubble 200-plus light-years in diameter.) We do not know, says Prof. Hawking, what sharks may inhabit the interstellar waters. (My analogy, not his.) So far, we have been safe. Except for the never-reproduced “Wow Signal”, for which a serious possible explanation has now been proposed, SETI researchers have so far not found any intelligent signal, using any kind electromagnetic energy, that so much as hints at an intelligent origin. The following is pure speculation on my part, albeit – so I would argue – intelligent and informed speculation, as to this eerie silence. Anyway, I submit the following for your consideration …
The evolution of an intelligent species – actually, any species – usually takes multiple millions, even billions, of years. I say “often” and not “always” because the speed with which a species evolves can be measured in days, perhaps even hours, if the evolving organism is simple enough. Consider a flu virus comprising only several dozen base pairs. Add the adjective “intelligent” to the noun “species” and then we really are talking hundreds of millions, most likely billions, of years. It took about 4 billion years for the intelligent species homo sapiens sapiens to make an appearance on Planet Earth.
However … in terms of “boots on the ground” real time, evolution proceeds by fractions of a millimeter, temporally speaking. The proto-hominid is concerned with finding enough wood to keep her / his family warm tonight, and perhaps for a couple nights in the future. S/He is likewise concerned with finding an area with abundant resources for hunting and gathering for perhaps a week or so in the future. Even when settled agricultural communities evolved, the primary emphasis was on this year’s harvest, and perhaps … maybe … next year’s. What is the point of all this? Only that the fraction-of-a-millimeter-at-a-time nature of evolution militates against anything that could reasonably be considered long-term planning. From the standpoint of survival and the propagation of one’s genes into the future, this is a good thing. A hunter-gatherer of, say, 100,000 years ago who paused to consider the long-term ecological effects of rampant deforestation, the poisoning of the atmosphere by wood smoke, the depletion of the oceans, etc., would probably be devoured by animals – or other hunter-gatherers – before s/he had a chance to reproduce, in which case I would not be around to write this "Skeptic's" column and you would not be around to read it. At least in terms of earth-like intelligent life, it would appear that individual human beings, and human communities, are not “hard-wired” to reflexively consider The Big Picture. From a “boots on the ground” perspective, evolution has simply not equipped us to think in those terms. We can certainly learn to do so. But it does not come naturally. It is like learning to use your left hand if you are right-handed. Furthermore, this difficulty is reflected in our political institutions and our educational systems. Ditto economics. It is no accident that late capitalism does not encourage long-term planning – defined as time-frames measured in generations at least or centuries. As for millennia, i.e., the time-scale when climate change becomes glaringly, life-and-death critical … well … fugg-id-aboud-it!
Granted, I am referring now to terrestrial life, and to cognates thereof, i.e., to life that evolved on temperate, water-abundant earth-like planets, perhaps on a “super-earth”, orbiting a stable, main-sequence sun-like yellow-dwarf or red-dwarf star like our sun within that sun’s habitable zone. If the evolution of intelligent life on such earth-cognates was anything like the evolution of intelligent life on earth, then the environmental challenges we face on earth today would – so I would speculate – have their equivalents on those extraterrestrial worlds. So, from the standpoint of SETI, there is good news, but there also may be – remember, I am speculating here – bad news. The good news is that it is reasonable to conclude that, in the Milky Way Galaxy, there are around 2 billion earth-like planets (“earth cognates” in my terminology), but perhaps as many as 17 billion or even 100 billion. The bad news is that, for the reasons I have outlined above, the challenges posed for the evolution of intelligent life may be as difficult for beings inhabiting those planets as they are for us. (And remember: this is assuming the existence of intelligent life to begin with, i.e., discounting the “rare-earth hypothesis”, which is by no means a crackpot opinion.) Assuming that the laws of chemistry, physics, and celestial mechanics are the same everywhere, it is reasonable to conclude that our own environmental challenges on earth would have their equivalents on those alien worlds. So the key question in assessing the likelihood of the existence of intelligent life elsewhere in our Galaxy is: are there evolutionary regimes that result in brains whose “hard-wiring” is more congenial to long-term – as defined above – planning? I mean planning in time-frames commensurate with large-scale changes in the home planet's environment.
Forms of socio-political organization also enter the mix. Serious question: to what extent, if any, is an emphasis on individuality, individual rights, individual liberty – basically, the presuppositions of an “Enlightenment-centric” socio-political culture – compatible with long-term planning for the survival of the species when challenged by incipient catastrophies like climate change? Maybe dealing with these challenges requires that intelligent species develop, if they have not done so earlier, forms of social organization similar to, e.g., the “formics” in the Ender's Game / Speaker for the Dead cycle of novels, or the Borg Collective of Star Trek, or the Caretakers who used – but did not build – the wormhole subway in Carl Sagan’s incomparable science-fiction novel Contact. Or, less benevolently, the Dark Ones of Babylon 5 or the malignant alien collective that launched the planet-devouring self-replicating Von Neumann machines in Greg Bear's The Forge of God and Anvil of Stars. Without in any way advocating for such a collectivist polity, a lucidly honest historical assessment would certainly indicate that trying to induce human beings to unite for collective action to confront a common danger is pretty much like herding cats … and feral cats, at that … unless the end-in-view is the apocalyptic and uncompromising destruction of some human enemy. Think “Manhattan Project.” That kind of cooperation we are damned good at! Climate change / global warming? Well ... maybe not so much.
Back in the '60s, the astronomer Frank Drake formulated the by-now-classical Drake equation, which attempts to quantify the number of intelligent species in the Milky Way Galaxy by factoring in quantitative estimates of the various coefficients that combine to produce intelligence in various planets' species. I like to think of the Drake equation as analogous to the design of a digital circuit, with various "gates" -- AND gates, OR gates, NAND gates, XOR gates, etc., etc., -- that determine whether a given species achieves intelligence and a technological civilization capable of communicating with other intelligent species inhabiting planets and evolving their own civilizations. Many of the factors in the classical Drake equation are obvious, e.g., the rate of planet formation in a star's habitable zone (however one might define that), the fraction of planets that actually evolve life, the fraction that evolve intelligent life, etc., etc. The historical trend strongly suggests that we have greatly underestimated the number and type of relevant coefficients in the Drake equation. For example, I would suggest that one such overlooked coefficient -- one that I have never seen acknowledged in the literature -- is the fraction of planets whose axis of rotation is stabilized by the presence of a large moon and the influence of other, probably gas-giant, planets in the same star-system. (An example of where the absence of these factors is critical is Mars. Mars only has two little pebbles for moons, Deimos and Phobos, and so Mars' axis of rotation has, over the millennia, precessed perhaps 90 degrees, and the climatic variations would virtually preclude the evolution of intelligent life. By contrast, earth has a very large moon and is farther away from Jupiter, with the result that earth's axis of rotation is stable enough to ensure a stable climate congenial to the evolution of intelligence.) Bottom line: it is reasonable to conclude that the proportion of intelligent species capable of taking the long view, of planning for the future in terms, not of years or even of generations, but at least of centuries would have a critical bearing on whether a given "candidate" species achieved intelligence and survived long enough to develop space travel and a sophisticated communication technology. This is perhaps one missing coefficient in the classical Drake equation: the percentage of species that have evolved intelligence sufficient to engage in long-range planning.
But our response -- or lack thereof -- to climate change strongly suggests that we may in perhaps a century, maybe less, encounter a break point where our endemic inability to take future centuries, even future millennia, into proper account may render us a footnote in some hypothetical Sagan-esque Galactic survey. We have to overcome the short-sightedness selected into us by the imperatives of evolution. So far, there have been five mass extinction events in earth's history. We may well be in the middle of the sixth. Granted, some of these were unavoidable, e.g., the end-Permian catastrophe 250 million years ago. Others, if they occurred today, might be preventable, given long-term planning, e.g., the Chicxulub event 65 million years ago. But all would require a capacity for long-range planning for which we humans have thus far shown little aptitude or inclination.
So perhaps now we have the answer to Dr. Fermi's question of "Where is everyone?". Perhaps the eerie silence we detect with our radio telescopes is mute testimony to the scarcity of intelligent species that evolved an intelligence, and the accompanying social and political organizations, sufficient to deal with multiple-millennia-long threats to those species' existence. Maybe the Universe is silent because, thanks to the in-built limitations inherent in evolution, intelligent species' own short-sightedness caught up with them.
James R. Cowles
"Wow" signal ... North American Astrophysical Observatory ... Public domain
SETI logo ... SETI Institute ... Creative Commons Attribution-Share Alike 4.0 International
Radio telescopes ... Bure Peak Observatory ... Public domain
Drake equation ... Mohammad Alrohmany ... Creative Commons Attribution-Share Alike 3.0 Unported
Human evolution ... Wellcome Images ... Creative Commons Attribution 4.0 International
Global warming map ... Environmemtal Protection Agency ... Public domain
Desert and tree ... Max Pixel ... Public domain
Two planets ... Pixabay ... Public domain