More scientifically known as granular convection. the brazil nut effect is the phenomenon in which solid granules sort themselves according to particle size when shaken. In this brief video clip, Mr. VandenHeuvel discusses where this is a problem in industry, and he demonstrates it by shaking up a box of raisin nut bran, pouring a bowlful, and repeating the process a few times. In each consecutive pouring, fewer raisins appear. Watch this video to see how it's done, and then serve up some breakfast for your physical scientists!