Flowing Sand: A Physical Realization of Directed Percolation
Flowing Sand: A Physical Realization of Directed Percolation
We introduce and investigate a simple model to describe recent experiments by Douady and Daerr on flowing sand. The model reproduces experimentally observed compact avalanches, whose opening angle decreases linearly as a threshold is approached. On large scales the model exhibits a crossover from compact directed percolation to directed percolation; …