ELI5: Explain Like I'm 5

Brownian tree

Imagine you have a bowl filled with water and you put a tiny particle of dust in it. If you leave it alone for a while, you will notice that the dust particle moves around randomly. This movement is caused by the water molecules bouncing into the particle. This is called Brownian motion.

Now, imagine instead of one particle, there are many particles in the bowl, and they all start to stick together as they move around from the motion of the water molecules. After a while, they will form a clump, and this clump will keep growing as more and more particles stick to it.

This is essentially what happens in a Brownian tree. Instead of particles in a bowl of water, we imagine that we have a space where particles move around randomly. Every time a particle touches or comes into contact with a growing clump, it sticks to the clump, and the clump keeps growing.

The final shape that the clump takes as it grows is a tree-like structure, which is why it's called a Brownian tree. The branches of the tree are created by the random movement and sticking of the particles onto already existing branches.

Overall, a Brownian tree is a type of fractal pattern that arises from the random motion and sticking of particles onto a growing clump over time.