2011-04-26

Life, Intelligence and the Second Law of Thermodynamics

[On how life locally creates order in a universe that is only supposed to increase in entropy over time]

The Second Law of Thermodynamics states that entropy in a closed system cannot decrease, and that this irreversible increase in entropy is somehow intimately interrelated with the arrow of time. However the unique, and perhaps the defining, characteristic of intelligence specifically and of life in general is the seeming ability to counter entropy [1] locally or temporarily by creating order in its own environment while it is alive. Furthermore, life posesses the unique ability to counter entropy on an ongoing basis -- “permanently” except perhaps at the limit [2] -- by reproducing or making multiple copies of itself: every offspring produced by an organism is also then able to counter entropy locally in its own sphere. Therefore if the hallmark of life is to locally counter entropy, then a branching, tree-like family pedigree structure is the hallmark of all intelligent life, and the continuation of intelligent species through reproduction is itself the guarantee of overcoming entropy beyond the lifetime of an organism [3][4].

Note that all this is also true of the organism's unconscious construction of its own ordered body: it is a system of high order and low entropy (and the development process produces waste heat through respiration etc.). As soon as the organism dies, it is by definition no longer alive, or its body no longer acts “intelligently” in creating order. Its ability to focus energy to maintain its own ordered structure is lost, and it will immediately begin to decay.

Also note that from the point of view of an organism, past work is at best a memory and so amounts to a sunk cost, and organisms are not typically aware of the waste heat lost in doing work to increase order, therefore they will typcially only trade off effort involved in doing work today with the apparent reward of increasing order as a direct result of that work. When the perceived reward outweighs the cost, the organism will tend to do the work to obtain the reward. Psychology and biochemical reward systems like dopamine have therefore typically evolved to reward organisms for making local decisions that seem rewarding while actually accomplishing a broader purpose, such as the propagation and continuation of the species.

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[1] Note that we are using a very loose definition of “countering entropy” here -- in fact, the second law of thermodynamics cannot be violated, even locally, so what is actually happening is that the organism is focusing energy to do work to “pile up order” in one local region. However doing work produces waste heat, which is effectively how the second law of thermodynamics is satisfied even in this case: the waste heat produces an overall increase in entropy. Nevertheless with a constant energy source external to the system (the sun), and an unbroken chain of life across the generations, individual workers can continue to increase order within the system: they effectively channel and focus the energy from the external source to locally increase structure and order in some sort of "meaningful" way.

[2] i.e. the heat death of the universe, the extinction of the species due to extinction-level events / resource exhaustion, etc.

[3] (Incidentally, this is a rather glaring indictment against the decidedly unintelligent behavior of every sufficiently developed nation, in letting the birthrate fall below replacement rate of 2.1 children per couple-lifetime -- since this trend, if continued to its only mathematically-possible end with no future change in birthrate, is extinction of the species and the final victory of the Second Law of Thermodynamics.)

[4] This is probably true in a fractal sense right up to the scale of entire universes, if the theory (proposed by Andrei Linde and others) that universes “bud off” in hierarchical tree-like structures to create new universes is to be believed.

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PS this is only orthogonally related, but I highly recommend the following article in the latest American Scientist magazine: The Man Behind the Curtain -- physics is not always the seamless subject that it pretends to be.

Also orthogonally related, but I love the following quote: "There is only one thing which is more unreasonable than the unreasonable effectiveness of mathematics in physics, and this is the unreasonable ineffectiveness of mathematics in biology. — Israel Gelfand" -- cited in the Wikipedia article for Unreasonable Effectiveness.


3 comments:

  1. Luke, I have had the same thoughts for quite a time. But I am not yet convinced that the second law of Thermodynamics will have victory in the end, but rather I believe that a "possible" end can occur with a balance between entropy and negentropy from intelligence. Entropy works without intelligence. Negentropy works ONLY with intelligence. I believe that in the same manner certain laws of physics came into existence at different times in the creation of the universe after the big bang, Intelligence is itself another law (albeit the most complex) to arise from the big bang. But I believe that the progress and evolution of intelligence is entirely non-linear unlike entropy and thus many possible ends of the universe exist. But I do believe the best of all possibilities is this balance between intelligence and entropy.
    I can see in my mind how intelligence (and it's consequence "organization") can virally expand to fill the universe and EVEN organize the waste heat (aka recycle the elements). But everything has a limit and that limit would be the perfect balance point between entropy and negentropy.
    HOWEVER, one thing I yet cannot see in my mind is how intelligence will adapt to an ever expanding space between the elemental particles of the universe. Either new laws of physics will emerge to destroy intelligence OR maybe enhance it. Is it wrong to have faith in that intelligence will adapt? Regardless, I am "keeping the faith"!
    I like your footnote comment #3. It is ironic that the reproduction rate is decreasing. But could we see a time in the future when we abandon the natural methods of reproduction and adopt new methods that are less impacting on the bodies and lives of the parents? Merge that together with the hope of expanding beyond our solar system and I forsee the reproduction rate increasing again.
    One last comment.... we are getting better at creating another form of intelligence (what we misnomer as "AI") that can spawn off new channels of intelligent life. But how do we recreate the drive that we humans have due to our dopamine and other similar reward systems in mechanized life?
    -cliff

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  2. Hi Cliff -- good thoughts -- I do think/"feel" that intelligence is something that our current laws of physics can't define, in the sense that it acts rather than is acted upon (i.e. intelligence does not just just unfold deterministically, domino-like, like all systems comprised only of dead matter and energy in some initial state).

    Also, my understanding is that although the universe is expanding, distances between atomic and subatomic particles are not expanding, or it would violate various fundamental laws (which raises a red flag about the theory of the expansion of the universe). Several things like this seem to make me think the Big Bang didn't happen anything like how physicists currently think it did.

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  3. Wrote the following email to somebody, which rephrases a lot of my original post, and adds a few things:

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    Bear with me here, and allow me a little philosophical creativity, but in a very metaphysical way, intelligence does indeed appear to create "perpetual motion" -- at least of some form -- by virtue of the fact that it is the nature of all intelligent life to reproduce. Intelligence seems able to focus energy to do work in a "meaningful" way (for some definition of meaning), creating a local blip of decreased entropy by increasing local meaning or structure in its environment during its lifespan, but each individual intelligent organism is, in the end, subject to the Second Law just like everything else, and the fruit of the labors of that organism towards achieving greater meaning or structure during its lifespan all eventually decay and disperse just like the body of the organism when it dies. However, by reproducing at greater than replacement rate, that intelligent organism can spread order (decrease entropy) perpetually: it can monotonically increase average total order of the environment, and do so "perpetually", at least for the duration of existence of the species, through the continued labors of its descendants. If it is indeed not the nature of all intelligent life to annihilate itself when sufficiently advanced (one of the responses to the Fermi paradox), and if it is arguable that a species could in theory reproduce, grow and spread perpetually, then there is no reason it couldn't be argued that the aggregate ongoing work performed by the species represents a violation of the Second Law, by virtue of meaning / structure created through continuance of the species and constant and unending, nonzero growth of the population.

    (Of course, all this is still subject to heat death of the universe arguments, and to be watertight you'd have to show that the creation of meaningful structure in an organism's environment was not a lossy process -- i.e. that the meaning embodied in the structures created by an intelligent organism somehow imbued more order than could have been achieved by an automaton doing random lossy work -- a deep rabbithole, especially when the current laws of physics do not extend to concepts of willful meaning, or to anything much for that matter beyond determinism with quantum randomness layered on top. But somehow we know, for example, what patterns are "beautiful" and what are not, even if both represent structures of equal complexity, so somehow one of them can embody higher meaning without embodying higher complexity.)

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