text: A further dynamic method to assemble such structures was introduced by Lee et al. Here, polymeric beads are placed together with a fluid of higher density inside a rotating lathe.
  When the lathe is static, the beads float on top of the liquid. With increasing rotational speed, the centripetal force then pushes the fluid outwards and the beads toward the central axis. Hence, the beads are essentially confined by a potential given by the rotational energywhere  is the mass of the beads,  the distance from the central axis, and  the rotational speed. Due to the  proportionality, the confining potential resembles that of a cylindrical harmonic oscillator.
  Depending on number of spheres and rotational speed, a variety of ordered structures that are comparable to the dense sphere packings were discovered.
  A comprehensive theory to this experiment was developed by Winkelmann et al. It is based on analytic energy calculations using a generic sphere model and predicts peritectoid structure transitions.