hermodynamic is  understood, in general, as a study of the interaction of heat with matter with the second law of thermodynamics predicting the disorder to which the universe might resign to in the form of heat death.

On the other hand, nature has been successful in creating more ordered, organised and complex structures by penetrating the barriers imposed by the second law of thermodynamics.

Nature has also been transferring information effectively from one generation to the next through the DNA. Ilya Prigogine, through a Nobel Prize winning theory, which literally transformed thermodynamics into a romantic comedy, resolved this paradox.

The story of thermodynamics, or in scientific parlance, the evolution of the concept of entropy originated with work of two giants Sadi Carnot and Rudolf Claussius. Focusing their attention on converting heat into work, Sadi Carnot came up with the design of Carnot’s engine and Claussius advanced the basic underlying concept termed as `entropy’. Originally entropy was thought of as a measure of randomness.

A clearer understanding of this phenomenon evolved through the pioneering work of Maxwell and Boltzmann who showed that entropy is a statistical property and is associated with the order-disorder transformations.

The man who completely revolutionised the concept of entropy is Claude E Shannon. He used the inverse of disorder for a better understanding of the organisation and information of a system.

This concept was used in his theory of communication concerned with the identification of message emanating from a source.

This theory, with its far-reaching consequences, resulted in conspicuous success like the transmission of colour signals, early radar warning signals and the like.

This evolution of the concept of entropy led to the foundation of thought that started recognising information as an active and constructive force giving form and character to matter and mind.

Decoding of the DNA brought to light the beauty with which nature can transfer information from one generation to the other. This widened the understanding of nature as a combination of matter, energy and information.

Based on these concepts Prigogine came out with his ideas on the “Order out of Chaos” through his theories on non-equilibrium thermodynamics and dissipative structures. Prigogine showed that there are chemical reactions in which the molecules adjust their behaviour not only to local circumstances but also to the larger parent organisation, the classic example being crystal growth.

Biological systems function far away from equilibrium by continuously exchanging energy and matter with the environment. At this non-equilibrium state the system gets self organised in creating more complex structures at low entropy levels.

His insight into complex systems led to the fusion of physical and biological sciences. The essence of non-equilibrium statistical mechanics stems from a point of view, which is purely dynamical in nature without any probabilistic assumptions.

This novel approach to the basics of thermodynamics has contributed extensively to fundamental approaches to theoretical and quantum physics.

His postulate on minimum entropy production has given leading clues for the better understanding of the riddles involving the stability of biological systems.

In short, our perception that non-equilibrium processes are only transitory and that equilibrium is the final result of evolution, has undergone a change due to the untiring efforts of Ilya Prigogine in formulating and sustaining this branch of science.

Prigogine was born on January 25, 1917, studied at Brussels, received the Nobel Prize for Chemistry in 1977, established a Centre for Statistical Mechanics and Complex Systems in Texas and passed away on May 28, 2003. He was a citizen of Belgium.

R. Sanjeevi, CLRI, Chennai
B.Viswanathan, IIT, Chennai

VIA: THE HINDU