[Update: JMG's 2007 blog post on the same subject. - 2007/07/31]
[Pulling out my Crayolas for some free-form think-piecin'. These being uninformed opinions, they can easily be discounted, in which case the rest of this essay is useless for those with other opinions.]
Whither the aliens?
Given the unthinkable vastness of the universe and the countless bodies contained therein, and given my personal resistance to any ideas of Earth exceptionalism, it is my considered opinion that it is likely that there is "life out there."
And - given the unimaginable age of the universe, and given that we have achieved some pathetic semblance of space flight, one could reasonably be puzzled that other civilizations have not yet continued with this technology and shown up on our doorstep*.
See Fermi paradox. So, whither the aliens?
If we look at the contemporary activity and conditions here on planet Earth, perhaps we can surmise an answer to this strange condition. I mean, here we have an effectively infinite universe that has evolved for an unimaginably vast period of time, and two technological civilizations have not yet bumped into each other? (I am making the reasonable logical conclusion that if we have not met anyone, then no one has met anyone. My aversion to exceptionalism, again.) Perhaps there is an inherent ceiling on technological development?
If there is a ceiling, it is certainly not one limited by imagination or skill. In my 54 years on this planet, I have been continually stunned by what human beings have been able to achieve. In my decades of computer programming and home computer use (from the TRS-80 to today's commodity desktops, laptops, etc.), I now have on my desk more computing power and storage than any of our large clients had in their climate-controlled "computer rooms," with banks of computers, disk drives, and magnetic tape machines, all rivaling in size the largest refrigerators. What we have learned about ourselves biologically, and what we are understanding about the very matter of the universe, is truly breathtaking - a depth of investigation so daunting that lifetimes are spent comprehending just a shard of what we've achieved.
So daunting that lifetimes are spent comprehending just a shard of what we've achieved.
There's a clue.
Joseph Tainter's The Collapse of Complex Societies (New Studies in Archaeology) discusses the necessity for leisure and wealth to free human beings up for specialized education and activities. (YouTube.com has a 7 part lecture given by Mr. Tainter on his subject.) Since I'm using crayons here, I'm going to boil that requirement down to cheap and abundant energy.
The pursuit of science and other such esoterica is highly dependant on an abundance of resources in order to free up not only enough labor in the day to study, but to free up entire lifetimes for the kind of dedicated and intensive investigation for the achievements we have seen. Further, high-tech infrastructures rapidly deteriorate without the continuing production of properly educated engineers.
It's all in the book.
And then there is the fuel. Even the most utopian of our Star Four-Letter-Word fantasies acknowledge the need for power resources. Most acknowledge this with their nods to "mining planets" - rare is the digestible sci-fi that entertains the idea of an infinite supply. Even allowing for the dubious idea that the energy spent running to-and-fro these orbs is offset by the yields (though $20 million a kilo for Unobtanium sounds kinda do-able,) these epics allow that they are taking depletable resources, and are dependant on discovering more planets and asteroids, etc. Indeed, many of these operas have this imperative as a strong driver in their plot lines.
So, given the contemporary activity and conditions here on planet Earth, I don't think that we have the "seed" energy to get off of this planet and start mining other resources, even assuming that that activity would be cost-effective.
One could argue that we mighta, sorta, coulda - we ran into an incredible gift awhile back. Hundreds of millions of years of stored solar energy is quite a battery, and one could argue that if we had marshaled that bounty into a dedicated effort to begin our Space Empire, we just might have had enough "seed" energy after all. Maybe. But political and sociological realities are, after all, realities - and I am of the opinion that such factors would cripple any civilization's extraterrestrial aspirations. Again, no exceptionalism.
I am proposing the idea that there may be a built-in limitation to what an intelligent planet can achieve - a built-in prohibition against cosmic cosmopolitanism. The twin observations - one, that the infinity of the universe should have coughed up alien contact by now, and it hasn't - and two, our pathetic prospects for space travel - point to this possibility.
This is highly dependant on another assumption that I am making here - the rejection of exceptionalism. I am taking this idea into a dubious area, but here it is.
Is there an as-yet-not-understood quality of life-evolving planets that inherently limits the amount of energy available to its population? Thinking holistically, I would take into account not only the volume of resources that might accumulate before a society "notices" and makes use of it, but also the sociological characteristics of a naturally evolved society that might make squandering that resource inevitable as well.
For example, one could imagine that there might be a large disparity in the amount of interred carbon from planet-to-planet (although that in itself might be too big of an allowance - it is quite possible that the evolutionary "distance" between the appearance of carbon-sinking life and "intelligent" life is sufficiently ubiquitous to fix this amount.) Could there be an inverse-supply relationship between the quantity and the squandering?
For example (and leaving climate disruption out for the moment,) if we had even more oil to play with than what we did (we're close to have burned through half of what is economically feasible to extract, in less than 200 years,) would we have woken up in time to say, "Whoa! We better get started on our Space Empire project before we use up too much of this stuff!" Or would we have socio-politically continued to squander our way past that window anyway (if there ever really was one?)
I'm thinking squander.
Let's talk about climate disruption for the moment. It's pretty clear that there is a ceiling on how much carbon can be willy-nilly released into an atmosphere before dramatic changes occur that would probably unseat any complex society. So maybe the fixed amount of "oil to play with" is also governed by this factor as well. Maybe a civilization could have ten times the extractable carbon we have now, and would hit the wall anyway, as it were. You think airplanes are dirty? Try a booster rocket on for size.
I'm of the camp that feels that there is no tolerance for paradoxes in the universe. This is why I've always found time-travel laughable. Paradoxes are merely pointers to something we don't yet understand. The Fermi paradox is no exception.
There is a reason there are no aliens. We just don't understand why. Yet.
(I would be remiss not to note that I am also puzzled by the conspicuous silence from the SETI folks, and nothing I've written here addresses that. Must. Think. More.)
*Indeed, the odds would be that they had shown up early and often, as in Arthur C. Clarke's semi-utopian story threads. I do not think that this has happened - it is my opinion that the "Chariots of the Gods" theories are bunk, at least for the purposes of this discussion, which rests on the idea that we have not made contact with extraterrestrials.