This paper describes a unique way to disperse an impulse in granular material. A number of chrome steel balls are arranged in a chain formation with monotonically decreasing size. The incoming impulse is received by the largest ball at one end and propagates through the chain. Due to translation symmetry breaking, the classical solitary wave known to develop in a chain of particles of the same size quickly lose its signature, disperses itself throughout the balls in the chain, and finally manifests itself as a collection of smaller impulses. This paper presents experimental confirmation of this mechanism and a comparison with recent theoretical predictions of impulse dispersion in a chain of hard inelastic spheres. Some discrepancies with theory are interpreted in terms of energy transfer to rotational degrees of freedom.
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