Invasion percolation

Invasion percolation is the process of a imaginary liquid spreading through a medium, like a sponge. This liquid spreads from one place to the next, like how water or oil would flow. It's like a game where you imagine that the sponge is a map and the liquid is a substance that's spilling into the map in different ways. You want to see what paths the liquid takes as it spreads. As it spreads, the liquid makes paths by squeezing its way through the spaces of the sponge and connecting one area to the next.