According to the second law of thermodynamics, in an isolated system (i.e. which does not exchange matter and energy with its environment), the total entropy increases progressively, while the free energy decreases until the system reaches the equilibrium state, when its entropy acquires its maximum value. In thermodynamic equilibrium state, the system is homogeneous and idle. If we also suppose, as Clausius did, that the whole universe is an isolated system of gigantic dimensions, then, according to the second law, the progressive degradation of the energy, i.e. the maximization of entropy inevitably leads to the “heat death” of the universe. In classical thermodynamics the arrow of time, i.e. the decay, the disorder and the death, is introduced. Classical thermodynamics referred to isolated and closed-linear systems.
However, how can we explain the “weird” behavior of the open systems? These systems are located far from the equilibrium state and continuously exchange matter and energy with their environment. They do not tend to a state of minimum free energy and maximum entropy, but, on the contrary, they use some energy inputs and fluctuations not only in order to maintain their structural stability but also in order to evolve towards new dynamical states. The open thermodynamic systems are the rules, not the exception. Those systems contain not only the living organisms and the human societies, but also the greatest part of the “simpler” physicochemical systems. Prigogine proved that on conditions away from thermodynamic equilibrium state, the matter acquires new unexpected properties, organizes itself and produces complex structures from random fluctuations. He will name these structures dissipative structures. Basically, we are talking about systems which consume energy. The dissipative structures are states which reflect their interaction with the environment, with which they interchange energy, sustained through an endless dynamic flow. The simplest forms of dissipative structures are some rather simple physicochemical systems in which minimum disturbances and fluctuations in microscopic scale lead to the emergence of new unexpected macroscopic structures. The living systems are open systems, organization complexes that are far from the equilibrium state and Prigozine, as it is said, classifies them in the “dissipative structures.”
Prigozine mentions that these random (unpredictable) processes show that the open systems and therefore the greatest part of our universe are not mechanistic but random. He uses the idea of randomness in a more different manner than the other scientists do. For example, for Jacques Monod, author of the book “Chance and Necessity”, chance means a world governed blindly and implies a universe, which according to human terms, is meaningless, namely it is very close to the illogical world of existential philosophy.
However, for Prigozine, chance is a synonym for non-determinism, for spontaneity, for innovation and creativity. Prigozine’s universe is not far from being a living organism, just because it has got space for the random behavior. This allows the dissipative structures – which can be anything – from a chemical solution to a cloud, a brain or a human – to recreate themselves according to unpredictable models. These new models are usually caused by small changes or disturbances. These small changes or disturbances create an unpredictable type of behavior which challenges a mechanical interpretation of entropy, as well as a conventional interpretation of the arrow of time.
This way, the dissipative structures introduce continuous creativity in nature. This means that nature is not something stable, inert molecules that are governed only by impulses and attractions, but something energetic and alive. In those open systems, the matter is not isolated, but on the contrary it is rewarding, and correlative self – changing, with respect to the activities of the rest matter. In those “out of balance” systems, the minimum change can “destabilize” the system and bring about a result that has not been foreseen by the logic of linear equations. Examples of dissipative structures The key to the answer to the time paradox is located in the study of systems that are far from the equilibrium state. In systems like that self – organizing processes as well as dissipative structures are possible to come out. In order to understand this meaning, at first we shall refer to a system which is located close to the equilibrium state, e.g. a pendulum with frictions. If we remove it from the equilibrium state, after a certain period of time it will return to the above state. However, in systems which are not far from the equilibrium state, there are bonds which do not allow them to return to the equilibrium state. Prigοgine mentions the ecosystem on the surface of the earth as an example of the above phenomenon. As the ecosystem gets the influence of the solar radiation, it is removed from the equilibrium state and it is lead to the creation of complex structures. “The important thing”, Prigοgine mentions, “has to do with the fact that away from the equilibrium state, when the system is disturbed, there is no guarantee that it will return again in its former condition. On the contrary, the system starts exploring new structures, new types of organization in space – time, which I named dispersing structure.