Have you ever seen tiny dust particles floating in the air? If you look closely, you’ll notice that they seem to move around in unpredictable directions, never staying still. This seemingly random movement is called Brownian motion.
What is Brownian Motion?
Brownian motion refers to the random movement of microscopic particles suspended in a fluid (liquid or gas).
Brownian Motion was first observed by the botanist Robert Brown in 1827 , who noticed that pollen grains in water moved in haphazard manner when observed under a microscope. The cause of this movement was due to the collisions of fluid molecules with pollen grains, that collide randomly and in all directions.
Simulation of Brownian Motion
Below is a Brownian Motion simulation.
Brownian Motion Simulation:
In the figure below, the blue particles represent fluid particles (e.g. air, liquid), and the pink circle represents the suspended particle (e.g. smoke, pollen, etc.)
Brownian Motion Simulation
When smoke is suspended in air, it is seen to move haphazardly in all directions. This is due to the air particles (which are invisible) bombarding the smoke particle randomly and in all directions.