EDITORIAL.

In this preface we propose a synthetic survey of the main ideas which are in our aim at the origin of the "Physics and the City" Symposium (Bologna–Italy, 15–17 December 2005). These ideas are developed from different point of view in the following collected papers, also with different scientific languages, from the sociological or planning to the mathematical or physical ones. Very schematically we think that the present proceedings could prefigure the emergence of a new "science of the city", really multidisciplinary and with possible spin-off on every single science concerned. Moreover with a large range of possible applications to the actual social life, in order to contribute to a better quality of life. Surely we are at the beginning and the topology of this "science of the city" it is not still well defined, but as H. Poincaré said: Pour obtenir un résultat qui ait une valeur réelle, il ne suffit pas de mettre les choses en ordre; ce n'est pas seulement l'ordre, c'est l'ordre inattendu qui vaut quelque chose. [ABSTRACT FROM AUTHOR]