If a horizontal cylinder is approximately half-filled with two granular materials and rotated at a constant rate, the materials may mix or they may segregate, either radially, where a core rich in one material is seen, or axially, where alternating bands that are rich in one or the other of the granular materials appear along the length of the drum.
About this creation
Confused? Yeah, so was I (a little), and that was the subject of my Applied Maths Honours Project last year. So I decided to make a rotating apparatus out of LEGO to show the actual segregation.