What is Brownian Motion? How to empirically simulate Brownian motion? What does this movement prove?

Brownian motion is called the random (chaotic) movement of the smallest particles of solid matter suspended in a liquid or gas. This movement is due to the thermal movement of liquid or gas molecules. The phenomenon was discovered by the British botanist Robert Brown (Brown) in 1827 while observing the movement of pollen particles in a liquid.

Brownian motion can be simulated by placing ink particles in a drop of water. You can observe Brownian motion on a glass slide under a microscope. Brownian motion proves the existence of such particles as molecules, in addition, it shows the essence of such a phenomenon as thermal energy.