This shows the spontaneous separation of two fluids that don't like to mix. Press start, wait a little, and see how pure domains of each fluid form. The result is different each time.
This uses the Cahn-Hilliard equation: https://en.wikipedia.org/wiki/Cahn%E2%80%93Hilliard_equation which in turn uses the Laplace operator: https://en.wikipedia.org/wiki/Discrete_Laplace_operator
