FROM PILES OF GRAINS TO PILES OF VORTICES.

One of the most thrilling features of Physics is the possibility of establishing 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. [ABSTRACT FROM AUTHOR]