Scaling properties of granular materials
  Given an assembly of viscoelastic spheres with certain material properties, we raise the question how the macroscopic properties of the assembly will change if all lengths of the system, i.e. radii, container size etc., are scaled by a constant. The result leads to a method to scale down experiments to lab-size. 
Thorsten Poeschel, Clara Saluena, and Thomas Schwager