The behavior of materials under high speed impact is hardly known, despite a lot of applications in industry and defense.

The following movie shows how glass beads (16mm diameter) breaks when stricken by a steel bar at high velocity (Split Hopkinson Bar device). The video is recorded using a high speed camera, recording 50000 frames per seconds.  One can easily see how particle breaks depending on their position (the second one splitters, whereas the other ones have breakage only at the contact point). Note the propagation of the first breakage wave at the beginning of the video.