  One of the most thrilling features of Physics is the possibility to establish
analogies between apparently distant areas. Here we explain the parallel
between a pile of grains interacting mechanically with each other, and a "pile"
of superconducting vortices. In both cases the macroscopic slope of the pile is
maintained by a very nonlinear avalanche process. Furthermore, both types of
piles logarithmically relax in time due to "agitational" or thermal effects,
aiming at a state of equilibrium.
