Theories, models, simulations: a computational challenge

In this talk I would like to illustrate with examples taken from Quantum Field Theory and Biophysics how an intelligent exploitation of the unprecedented power of today's computers could led not only to the solution of pivotal problems in the theory of Strong Interactions, but also to the emergence of new lines of interdisciplinary research, while at the same time pushing the limits of modeling to the realm of living systems. Prologue The somewhat schematic partition of the last century natural science into separated fields of research, which were essentially identified with mathematics, physics and biology, is nowadays becoming less and less rigid, leading to large areas of overlapping interests. The fundamental reason for the former de facto separation was the enormous amount of accumulated knowledge in each of the three areas, which resulted in an increasing, and at the end unsurmountable, degree of specialization for people working at the front-end of their research field. Two facts have been drastically changing the situation. One was the growing evidence that methods and ideas developed in one research area could be fruitfully exported to other, even distant, fields of investigation. The second, is a related one and has to do with the sharp increase of the available computing resources (in terms of CPU-time, memory and storing capacity), which is making algorithms and general computational strategies immediately ready for use to researchers working in different areas. In my opinion this last fact is of particular relevance in today's spectacular progress of science, because it has allowed to imagine and attack problems that were considered impossibly difficult only a few years ago. New, flexible and adaptive computational tools that can be of general help to many scientific disciplines are being implemented under the pressure of the challenges posed on the one hand by the developments of pure science and technology and on the other by the fast expanding needs of our modern societies (think to weather forecasting, stock market " surveillance " , power plant control systems, distributed information network management, etc.). Taking an example of this trend from a field which is nearer to the scientific interests of our community, it is interesting to remark that one of the most extraordinary and somewhat unexpected outcome of the long lasting interplay between Statistical Mechanics and the theory of Strong Interactions in its lattice formulation (lattice QCD-LQCD) was the decision taken within the community of …