Copy of Ehrenfest's model (simple)
In the beginning N identical particles (or balls) randomly are disrtibuted over M containers (or urns).
Every step we select one ball with equal probability and move it to another (also random) urn.
With "Explanation" mode all the process is depicted slowly.
If N is high it's good to choose "BarChart" display method.
1. What is going on with initial distribution?
2. What is equilibrium distribution?
3. How relative fluctuations depend on N?