Saturday, June 20, 2009

Notes from The Ages of Gaia by James Lovelock

First, let's start with a word of wisdom:

"The young usually find the constraints of convention too heavy to escape, except as part of a cult. The middle-aged have no time to spare from the conservative business of living. Only the old can happily make fools of themselves."
James Lovelock, The Ages of Gaia, Introductory.

The second point concerns entropy and the fact that has become more and more obvious to me recently, that for any achievement, from the construction of a building to that of an idea, waste is unavoidable and this waste represents the entropy that needs to be rejected for the achievement to be meaningful, to be out of the ordinary and randomness:
"You, as you read these words, are creating entropy by consuming oxygen and the fats and sugars stored in your body. As you breathe, you excrete waste products high in entropy into the air, such as carbon dioxide, and your warm body emits to your surroundings infrared radiation high in entropy. If your excretion of entropy is as large or larger than your internal generation of entropy, you will continue to live and remain a miraculous, improbable, but still legal avoidance of the second law of the Universe. «Excretion of entropy» is just a fancy way of expressing the dirty words excrements and pollution. [...] We animals pollute the air with carbon dioxide, and the vegetation pollutes it with oxygen. The pollution of one is the meat of another. Gaia [Planet Earth] is more subtle and, at least until humans appeared, polluted the region of the Solar System with no more than the gentle warmth of infrared radiation."
James Lovelock, The Ages of Gaia, What is Gaia?

I will write, tomorrow, "Entropy" on the side of my garbage cans.

We keep going with an issue concerning the stability of a system and its level of complexity. Is the more complex a system, the more stable? This is, from what I have heard still a controversial issue. In his book, James Lovelock agrees with the theoretical ecologist, Robert May: the more complex a system, the more fragile and unstable and inversely. This goes maybe against the naive assumption that if a system has a greater diversity, it has a greater chance to handle external perturbation. But May's mathematics prove the contrary: "increasing complexity makes for dynamical fragility rather than robustness". Thus, "the complex natural ecosystems currently under siege in the tropics and subtropics are less able to withstand our battering than are the relatively simple temperate and boreal systems." (R. May, in Theoretical Ecology, cited in The Ages of Gaia, Exploring Daisyworld)

In the chapter Middle Ages, James Lovelock mentions an extraordinary theory that Earth biosphere would be responsible in part to...the plate tectonics:
"The geologist Don Anderson has speculated that the deposition of limestone on the ocean floor [via, for instance, the dying and sinking of Coccolithophores and the burying of their calcium shells] is a key factor in the motion of the Earth's crust. He proposed that sometime far back in the Earth's history, sufficient limestone was deposited to alter the chemical composition of the crustal rocks of the ocean floor near the continental margins. As a result an event, called the basalt-eclogite phase transition by geologists, took place. This transition so altered the physical properties of the crustal rocks that it became possible for the great machinery of plate movement to begin turning."
James Lovelock, The Ages of Gaia, The Middle Ages.

This theory would explain why plate tectonics are not a universal properties of the planets. I have no idea, however, if this idea has been dropped or is still alive. More reading will be needed. But fascinating idea nonetheless.

I will finish on an improved definition of Gaia's theory, that also gives some explanation on the origin of the interaction between the biosphere and its environment. James Lovelock, himself, has corrected a previous definition of Gaia's theory and has re-defined it in his book as follows:
"Living organisms and their material environment are tightly coupled. The coupled system is a superorganism, and as it evolves there emerges a new property, the ability to self-regulate climate and chemistry."
James Lovelock, The Ages of Gaia, Gaia since 1988.

In this definition, the co-evolution of the biosphere and its environment is the key to explain why the self-regulation of the system is a likely property. I know that there is a lot of criticisms against Gaia, even with this improved definition. Although I am also a bit skeptical, I am wondering why there is no such criticism relative to the thermal regulation of mammals. In this case as well, it should be hard to believe that cells can organize at such a higher level that the whole system succeeds in regulating its temperature. If such feast is possible for an organism, given the geological time over which evolution is working, why not for the Earth's system as well?

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