CAUSES AND SYMMETRIES IN NATURAL SCIENCES

Niveau: Supérieur, Doctorat, Bac+8
CAUSES AND SYMMETRIES IN NATURAL SCIENCES. THE CONTINUUM AND THE DISCRETE IN MATHEMATICAL MODELLING 1 . Francis Bailly Giuseppe Longo Physique, CNRS, Meudon LIENS, CNRS – ENS et CREA, Paris Introduction How do we make sense of physical phenomena? The answer is far from being univocal, particularly because the whole history of Physics has set, at the center of the intelligibility of phenomena, changing notions of cause, from Aristotle's rich classification, to which we will return, to Galileo's (too strong?) simplification and their modern understanding in terms of “structural relationships” or the replacement of these notions by structural relationships. It is then an issue of the stability of the structures in question, of their invariants and symmetries, ([Weyl, 1927 and 1952], [van Fraassen, 1994]). To the point of the attempt to completely dispel the notion of cause, following a great and still open debate, in favor, for instance, of probability correlations (in Quantum Physics, see, for example, [Anandan, 2002]). The situation is even more complex in Biology, where the “reduction” to one or another of the current physico-mathematical theories is far from being accomplished (see [Bailly, Longo, 2006]).

• physical phenomena


• time into


• thus constitute


• causal relationships


• symmetries


• quantum physics


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• symmetries proposed


• between property