Galton's Bean Machine

Galton's bean machine is a probabilistic simulation where a disc is released on a triangular grid of pins. Each time the disc hits a pin it can either fall to the left or to the right. Where will the disc fall after 10 levels of pins?

After starting the animation you can see the trajectory of the disc moving down towards the baskets on the lower part of the machine. After falling into a basket a new trajectory is simulated.

The animation allows us to choose what's the probability of the disc falling to either side (simulating, for example, a tilted machine).

After several simulations (a few hundreds) one can see that the number of times the disc falls into each basket roughly follows a normal distribution.

Download the Galton Bean Machine in: