By Prof Tiezzi, University of Siena, Italy

Prigogine.jpgLast Christmas I received greetings for the new year from Bruxelles. I was surprised to see the name: Ilya Prigogine. It is usually the scholar who writes to the Magister and non vice versa.

A few years earlier, Ilya invited me and Nadia to his home in Bruxelles. I remember the marvellous collection of “time machines”: the ancient Maya, the Chinese masterpieces, Inca pieces. Ilya’s wife Marina and his son Pascal are people of rare kindness. After dinner we talked about cosmology, irreversibility and the arrow of time with a French scientist.

Nobel price winner Ilya Prigogine, Viscount, professor of Physical Chemistry, came to Siena several times. We awarded him a Laurea Honoris Causa in Biological Sciences in the Aula Magna of Siena University. He noticed at the time that the University is one of the oldest in the world, founded in 1240.

For many years we exchanged Ph.D. students (or rather, students from Siena went to Bruxelles for a year). Now that he is no longer with us, I feel that we have lost not only a Magister but a brilliant young mind and a human being always friendly and kind. A friend, a very good friend.

I personally consider Ilya Prigogine the greatest scientist of the 20th century. He was awarded the Nobel Prize in chemistry in 1977 for his contributions to nonequilibrium thermodynamics, particularly the theory of dissipative structures. He was born in Moscow, Russia on January 25, 1917. He obtained both his undergraduate and graduate education in chemistry at the Université Libre de Bruxelles.

The main theme of his scientific work was the role of time in the physical sciences and biology. He has contributed significantly to the understanding of irreversible processes, particularly in systems far from equilibrium. The results of his work on dissipative structures have stimulated many scientists throughout the world and may have profound consequences for our understanding of biological and ecological systems.

In the Nobel Lecture (8 December, 1977) Prigogine wrote: “the development of the theory permits us to distinguish various levels of time: time as associated with classical or quantum dynamics, time associated with irreversibility through a Lyapounow function and time associated with ‘history’ through bifurcations. I believe that this diversification of the concept of time enables a better integration of theoretical physics and chemistry with disciplines dealing with other aspects of nature.”

As only a very intelligent person can do, he wrote an autobiography, which like his scientific career, was distinguished by a total absence of hypocritical respect. Here are some passages I found particularly significant:

“… Since my adolescence, I have read many philosophical texts, and I still remember the spell "L'évolution créatrice" cast on me. More specifically, I felt that some essential message was embedded, still to be made explicit, in Bergson's remark:

‘ The more deeply we study the nature of time, the better we understand that duration means invention, creation of forms, continuous elaboration of the absolutely new.’

Fortunate coincidences made the choice for my studies at the university. Indeed, they led me to an almost opposite direction, towards chemistry and physics. And so, in 1941, I was conferred my first doctoral degree. Very soon, two of my teachers were to exert an enduring influence on the orientation of my future work.

… It is difficult today to give an account of the hostility that such an approach was to meet. For example, I remember that towards the end of 1946, at the Brussels IUPAP meeting, after a presentation of the thermodynamics of irreversible processes, a specialist of great repute said to me, in substance: ‘I am surprised that you give more attention to irreversible phenomena, which are essentially transitory, than to the final result of their evolution, equilibrium.’

… The work of a theoretician is related in a direct way to his whole life. It takes, I believe, some amount of internal peace to find a path among all successive bifurcations. This peace I owe to my wife, Marina. I know the frailty of the present, but today, considering the future, I feel myself to be a happy man.”

Enzo Tiezzi, University of Siena, Italy

Prof Ilya Prigogine, Honorary President of the ECOSUD Conference Series and Honorary Editor of the Book Series “The Sustainable World”.