The Concept of Entropy and the Principle of Increasing Entropy

As stated before, the thermodynamic function known as 'entropy' (S) is a measure of the degree of energy dissipation. The spontaneous tendency of energy to degrade and be dissipated in the environment is evident in the phenomena of everyday life. A ball bouncing tends to smaller and smaller bounces and dissipation of heat. A jug that falls to the ground breaks (dissipation) into many pieces and the inverse process which could be seen running a film of the fall backwards never happens in nature. Perfume leaves a bottle and dissipates into the room; we never see an empty bottle spontaneously fill. There is thus a spontaneous dissipation process which results in a degradation of energy toward lowest quality forms (heat). Transformations tend to occur spontaneously in the direction of increasing entropy or maximum dissipation. The idea of the passage of time, of the direction of the transformation, is inherent to the concept of entropy.

With the concept of entropy Clausius (1865) reworded the second law of thermodynamics in a wider and more universal framework: Die Entropie der Welt strebt einem Maximum zu (The entropy of the world tends toward a maximum). Maximum entropy, which corresponds to the state ofequilibrium ofa system, is a state in which the energy is completely degraded and can no longer produce work.

Entropy is therefore a concept that shows us the direction of events. Barry Commoner notes that sand castles (order) do not appear spontaneously but can only disappear (disorder); a wooden hut in time becomes a pile of beams and boards: the inverse process does not occur. The direction is thus from order to disorder and entropy indicates this inexorable process, the process which has the maximum probability of occurring. In this way the concepts of disorder and probability are linked in the concept of entropy. 'Entropy is in fact a measure of disorder and probability'. In order to understand this better, it is useful to describe a model experiment: the mixing of gases.

Suppose we have two gases, one red and one yellow, in two containers separated by a wall. If we remove the wall we see that the two gases mix until there is a uniform distribution: an orange mixture. If they were originally mixed we would not expect to see them spontaneously separate into red and yellow. The 'orange' state is that of maximum disorder, the situation of greatest entropy because it was reached spontaneously from a situation of initial order. Entropy is a measure of the degree of disorder of the system. The disordered state occurred because it had the highest statistical probability. The probability of there being 13 hearts in a hand of bridge is 1 in 635 013 559 600. In other words, such a hand is almost impossible; a mixed hand, with a few cards of each suit, is the most probable. The law ofincreasing entropy is therefore a law of probability, of statistical tendency toward disorder. The most likely state is realized, namely the state of greatest entropy or disorder. When the gases mix, the most probable phenomenon occurs: degeneration into disorder. Nobel Prize winner for physics, Richard Feynman, comments that irreversibility is caused by the general accidents of life. It is not against the laws of physics that the molecules rebound so as to separate; it is simply improbable and would not happen in a million years. Things are irreversible only in the sense that going in one direction is probable whereas going in the other, while it is possible and in agreement with the laws of physics, would never happen in a million years.

The universality of the law of entropy increase was stressed by Clausius in the sense that energy is degraded from one end of the universe to the other and that it becomes less and less available in time, until 'Warmetod', or the 'thermal death' of the universe.

Thermodynamics has taught us two fascinating lessons: that energy cannot be created or destroyed but is conserved, and that entropy is always increasing, striking the hours of the cosmic clock and reminding us that both for man and for energy-matter time exists and the future is distinct from the past by virtue of a higher value of S.

In this way thermodynamics' second principle addresses the pathways we should avoid in order to keep life on Earth. It shows the universal, inescapable tendency toward disorder (or the general trend toward an entropy maximum), which is also a loss of information and of usable energy availability. This tendency to the Clausius' 'thermal death', takes to the thermodynamic equilibrium, namely the death of biological systems and ecosystems, through the destruction of diversities.

There are two ways to achieve such a condition:

1. when, through energy exchanges as heat fluxes, there are no more differences in temperature and nothing more can be done, because any exchange of usable energy is allowed; and

2. when a system, becoming isolated, consumes its resources, reaching a great increase in its internal entropy and, at the end, to self-destruction.

For this reason living systems try to avoid the condition of thermodynamic equilibrium, keeping themselves as far as possible from that state, self-organizing due to material and energetic fluxes received from outside and from systems with different conditions of temperature and energy.

This concept has been further applied to different issues in order to achieve, for instance, a general description of human behaviors through a thermodynamic viewpoint. Economics and our society cannot be unaware of thermodynamics' second principle. As a consequence globalization, the destruction of both biological and cultural diversities, homogenization, and the unique thought take inescapably to the thermal death (or to the 'entropic euthanasia', as we called it).

In the same way a country, a nation, a system that makes a political dogma of its isolation, of its refusing of cultural contamination (better: of cross-fertilizations), of its castling on fundamentalist positions, of self-conservation, will go to the same end. An excessive defense of one's diversity and a complete loss of diversity are two faces of the same thermodynamic foolishness.

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