We humans can’t help but be equal parts fascinated and repelled by the concept of the alien. We live in a universe so large we can’t even begin to grok how big it is: a universe chock full of suns (did you know that if it weren’t for interstellar dust and the fact that our universe is expanding at such a rapid rate, our sky would be so full of stars we wouldn’t even be able to see space? That it would be blazingly, blindingly bright, day and night? Sort of an extension of Asimov’s famous story, “Nightfall.” Imagine how different our concept of our universe might be then!), many of which appear likely to be chock full of planets.
SF writer Fred Saberhagen, who died recently after a two-year battle with cancer, came up with some of the most imaginative concepts in the literature. Best known, perhaps, is his Berserker series. In his books, self-replicating machine intelligences travel throughout the galaxy, hunting out and destroying biological life wherever they find it.
The series is an one of the earliest and most definitive appearances of the Singularity in science fact or fiction: the notion that an artificial intelligence(s) would eventually develop free will, outpace us intellectually, and render humans either dead or irrelevant. Robert Charles Wilson toys with many different aspects of the Singularity, simulated life, and consciousness; e.g., in Darwinia and Spin. Wil McCarthy’s Bloom is another excellent examination of the concept, using nanotech/ programmable matter to create a Singular super-intelligence. Madeleine L’Engle’s A Wrinkle in Time has one of the most malevolent alien/computer intelligences ever imagined.
Many other SF authors have made use of this notion. But it is SF writer and computer scientist Vernor Vinge in particular who is known for bringing the concept of the Singularity into modern discussions of technological progress. His excellent science fiction novel, A Fire Upon the Deep, and many of his other works, pivot on this concept. (By the way, I’m mentioning all these books because they are really good—go read them!) It is difficult to write an SF novel involving space, nanotech, or computer technology these days, without coming within shouting distance of the Singularity in one form or another. (This is partly, I believe, because we are in the heliopause of the Singularity already.)
Some SF writers, who aren’t interested in writing about the Singularity, are irritated by this fact, but I think grappling with this concept is resulting in some of the best hard SF in recent memory (see above examples). Check out Charles Stross’s Accelerando and Chris Moriarty’s Spin Control, for instance (I can’t stop recommending good SF books! Help!)
The concept of the Singularity has a clear association with the question of whether a superior alien intelligence originating elsewhere in the universe—if there are such beings—might come around someday, and harbor ill intent toward us. After all, we have daily evidence of our own perfidy toward each other; it’s hard to have confidence that a technologically superior race would show mercy toward us.
Some scientists believe that Fermi’s paradox (if there is intelligent life out there, it should have found us by now) proves that (Roswell and Area 51 notwithstanding) we are alone in the universe. Here is an interesting discussion that sets Fermi’s paradox on its ear: if there is intelligence out there somewhere, why haven’t they destroyed us yet? Whether a superior, potentially hostile intelligence originates within our computer systems, or from a different solar system, it remains the veil beyond which, try as we might, we are unable—utterly lack the capacity—to see.
What does this have to do with the Second Law of Thermodynamics, you ask? It has everything to do with it. Because 2nd thermo underlies the behavior of all organic and digital systems.
Simply put, 2nd-thermo says, Things fall apart. Clocks wind down. Organisms age, die, and decay. Suns cool. Though this is a gross oversimplification, 2nd-thermo can be thought of as the Grim Reaper of physics (calumny! poor, maligned 2nd-thermo!).
You might have heard it referred to as the law of increasing entropy. According to 2nd-thermo, heat can’t move on its own from a cold place to a hot place. In a closed system, heat gradually dissipates throughout till everything is at the same temperature. At that point, no further work can be done. The system is unable to change further, and is essentially “dead.” 2nd-thermo is the physical law that predicts the well-known heat death of the universe (not to worry overmuch, as that future appears to be about 10150 years away or so. To put this in perspective, the universe is only about 1010 years old. We have a long way to go before everything winds down that far. Life as we know it, of course, would be gone long beforehand).
It is a popular misconception that life somehow defies 2nd-thermo. The argument goes that since life is self-organizing and tends to increase in complexity, then entropy must be decreasing (i.e., the amount of complexity and net level of organization within the system is increasing). But this is a fallacy: living organisms are not closed systems. They exist in a larger system: the biosphere. And the biosphere exists in an even larger system: our solar system. The sun feeds energy into our biosphere, and life converts that energy to work, shedding heat. Cells are little heat engines. The refrigerator is an example of a simple heat engine that uses energy to expand a compressed liquid or gas, which rapidly cools as it expands, and sheds heat into the room at large.
When we burn carbon-based fuels, we are converting energy produced by earlier biological or chemical processes that used the sun’s heat and light, energy stored in the Earth’s crust for many millions of years. We produce work by combining that carbon with oxygen, to get heat and CO2.
2nd-thermo states that no work can be done that uses 100% of the energy used to produce the work; i.e., that some of that energy must be dissipated as heat. That is why there is no such thing as a perpetual motion engine. 2nd-thermo is Robert Heinlein’s TANSTAAFL made manifest in the workings of the universe. There is always a cost.
All life, and all other working systems in this universe, rely on entropy gradients to exist. Or more precisely, negative-entropy gradients. If you have a higher-energy state sitting next to a lower-energy state, you can use that energy difference to drive a heat engine. And that heat engine can perform work, effect change, increase complexity: increase the information content of a system. That is what life, intelligence, and consciousness are all about, and why 2nd-thermo matters.
2nd-thermo thus has strong implications for information theory, because the amount of useful information contained in a system is equivalent to its complexity. (There’s a bunch of cool stuff about conservation of information, black holes, and Heisenberg’s Uncertainty Principle that you can delve into at this point that I won’t go into here. Maybe another time.) An organized system can only exist if it can harness energy to organize information in some way. Biological organisms are simply a particular, carbon-based form of information: DNA is simply a set of instructions—algorithms—for creating a living being.
(Note, it does not take conscious intelligence for this kind of information organization to occur. Stars [unless they are conscious, which I suppose is not beyond the realm of possibility] are an excellent example of a system that contains a whopping negative entropy gradient, and thus a huge amount of information. Whether such information has any meaning unless a conscious being somewhere can interpret it is a whole separate matter, of the tree-falling-in-the-forest sort. Let’s not go there—this post is long enough as it is.)
And returning to the beginning of this post, with the question of stars and planets and the ingredients needed for life elsewhere in the universe, consider this. In a very basic sense the primary ingredient needed for life is simply a strong enough negative-entropy gradient in a given locale. Simply because a world doesn’t have water or isn’t at the right temperature to support life as we know it does NOT mean life as we don’t know it can’t form. (Lots of negatives in that sentence…are you still with me?) So if you ever read articles saying life can’t exist on a given world because “it’s outside the Goldilocks zone for that star,” be sure to insert a mental “as we know it” after the word “life.” ‘Cuz you just never know.
In fact, since stars have such enormous negative-entropy gradients, it certainly makes you wonder if someday we will discover electromagnetic life forms within them. With enough of a gradient, over time, systems tend to organize, and eventually life might develop. Perhaps also intelligence and self-awareness. Thus leading to a Singularity: galaxy-spanning super-conscious entity or entities that eventually take over the universe. Unless the heat death of the universe catches up with them first.