Nonlinear Physics Lab



Dynamics at the surface of a layer of grains subjected to horizontal oscillation

In the following movies a layer of grain with a depth of 9 diameter is vibrated horizontally (see the experimental Device). The frequency of the oscillation is 3.33 Hz. The frame rate of the movies is 100fps.

For an acceleration equal to 0.36 g no motion relative to the container (located by a black marker)can be detected in the Lab frame (see movie). And indeed particles are almost at rest in the Box frame (see movie) .

For a slightly higher acceleration equal 0.41 g, particles seem still motionless relative to the container in the Lab frame (see movie). However a closer look in the Box frame reveals that particles move during a part a of the excitation cycle (see movie).

For an acceleration equal to 0.47 g, a well developed motion during the entire cycle is obvious in both the Lab frame (see movie) and the Box frame (see movie).