KARIEL vASELENAK: WAVES OF SPATIAL DIFFUSION D=2 PASTURE GRAZING TUBERCULOSIS GHETTO SUBSIDY CONTROL EXPANS ION FIGURE 4: Number of Acceptances for Three Phenomena Over Time at Various Distances use the model given by Morrill for this purpose. The general wave formula, as iven by morrill is e t! where as= the amplitude or vertical displacement, Ao= the initial amplitude b= the coefficient of frictio d= distance and When this equation is applied to the study of spatial diffusion, the amplitude at would represent the number of adopters at time t, which is a function of Ao, the number of adopters at time to, distance, time, and a coefficient of friction. morrill hints at the existence of th s coefficient of friction by suggesting that early