The present experiment is concerned with one of many counter-intuitive properties of
granular materials: their tendency to separate according to size when subjected to motions like
shaking or stirring. If granules with a variety of sizes are placed together in a container and
vibrated vertically, the largest particles will move to the top. This behavior has come to be
known as the "Brazil nut effect" (hereafter BNE) [2]. The control of size segregation of this kind
is obviously of great importance in many industrial processes; if a pharmaceutical company uses
shaking to blend together a number of granular chemical components as a step in manufacturing
a drug or medication, the expectation is that a capsule made from the mixture will have all the
ingredients present in the proper proportions.