A simulation is run exploring the random motion of particles and its role in diffusion. At the start of the program, there are 20 blue spheres on one side of the membrane and 10 red spheres on the other side. After a period of time, the distribution of spheres reaches an equal number independent of each other, so that there are 10 blue spheres and 5 red spheres on either side of the membrane. What evidence suggests that diffusion results in a dynamic equilibrium across the membrane?.