Energy propagation in dense granular media Katja Lindenberg, Department of Chemistry and Biochemistry, University of California San Diego QUESTIONS: How does a pulse propagate in a granular medium? How does the physical design of the medium affect propagation? e.g. vs vs Initial condition Shapes of granules Mass and size distribution Dimensionality vs We have developed a binary collision approximation that permits ANALYTIC SOLUTION and consequently FULL PREDICTIVE POWER in many cases. Typical agreement with numerical simulations