By Henrik Jensen (London, UK).
We will briefly recall the description of behaviour near a critical equilibrium phase transition, i.e., when the correlation length diverges to infinity leading to universal behaviour captured by exponents determined by the symmetry and dimensionality of the system but otherwise fixed and constant in the vicinity of the critical region. Comparing data on precipitation and brain activity with simulations of the Forest Fire Model (FFM), we will discuss communalities across these very diverse systems in terms of visits to a region of onset of the order parameter and maximal fluctuations. Focusing on the FFM, we will discuss how the relation between the diverging range of correlations and measured event distributions is more subtle than one might have expected.
