Some remarks on percolation

Percolation theory is a powerful framework for studying strongly disordered systems. However, almost all the interesting physics of percolation happens in a very small range in parameter space, and often it may seem difficult to justify why a physical system should happen to be near this special point, the percolation threshold. In this paper we review some aspects of percolation theory from a different viewpoint than the usual one. In this formulation, it becomes natural why the percolation threshold plays an important role in many physical systems.