About 30 years ago Wheeler introduced the motto “law without law” to indicate the possibility to build part of the physics, even in absence of a detailed treatment in terms of the fundamental theories, only following “regularity principles” and few “relevant aspects”. As examples, Wheeler cited the Boltzmann Gibbs distribution of the canonical ensemble, the universality of the critical exponents and the statistical feature of heavy nuclei. At the end of his paper Wheeler writes “Oh, how beautiful and simple it all is! How could we ever have missed it so long!” We discuss how the simplicity is only a posteriori, and actually consequence of rather nontrivial results of probability theory, mainly ergodicity and limit theorems.
Pubblicato Mercoledì, 19 Luglio, 2017 - 16:16 | ultima modifica Mercoledì, 19 Luglio, 2017 - 16:16