15 Pancake Rotation
Place a few balls in a round container. If you move the container around a vertical axis, the balls can move codirectionally with the movement of the container, or they can move in the opposite direction. Explain this phenomenon and investigate how the direction of movement depends on relevant parameters.
  •  Vorführexperimente, Videos
  • PANCAKE EFFEKT erstmals gelöst [Compact Physics]

    Demonstration and basic explanation of the phenomenon (german).

  •  Wissenschaftliche Artikel
  • Geometric frustration induces the transition between rotation and counterrotation in swirled granular media

    Experiments and numerical simulations of swirled granular media and identification of the minimal ingredients for the particles and their interactions necessary to induce counterrotation.

  • Swirling granular matter: From rotation to reptation

    Experiments and numerical simulations of granular material under swirling motion of the container.

  • Swirling granular solidlike clusters

    Experiments and three-dimensional numerical simulations are presented to elucidate the dynamics of granular material in a cylindrical dish driven by a horizontal, periodic motion. (Following publication to "Swirling granular matter: From rotation to reptation")

  • The rotation-reptation transition under broken rotational symmetry

    Experimentally investigation of the transitions between rotational to reptational mode (and "snake mode") under the influence of geometrical distortions which break the rotational symmetry of the container. The driving mechanism for the rotational motion of the clusters is also discussed.