The nature of self-organized criticality (SOC) is pin-pointed with a simple mechanical model: a pinball machine. Its phase space is fully parameterized by two integer variables, one describing the state of an on-going game, the other describing the state of the machine. This is the simplest...

The coarsening process of soap froths is described statistically in two dimensions by a “random neighbour model”. This non-linear dynamical model contains no free parameters. It describes normal growth with distributions that agree with experimental results.

We model the self-organizing dynamics of two-dimensional magnetic domain patterns with magnetic bubble traps. Avalanches of topological rearrangements and domain destruction are simulated numerically. Asymptotic forms for distributions of avalanche sizes and lifetimes are found analytically....