Definition - What does Brownian Movement mean?
Brownian Movement, also known as Brownian Motion or Pedesis, is the phenomenon that states that molecules of liquid or gas tend to flow in an irregular motion. Because of this reason, when minute particles get suspended in the fluid or gas, they tend to move in any direction irrespective of the direction of flow of the fluid or gas. This happens because of the occurrence of random motion in the fluid or gas particles when they go through random collisions with the quick atoms of gas or liquid.
Petropedia explains Brownian Movement
Brownian Movement is named after botanist Robert Brown who in 1827, administered that a dirt particle on pollen grain in water was not able to derive its motion path while floating in water. He used his microscope and saw that a small water molecules had a zigzag motion which collided with a bigger dirt particle, making it to move in its own direction when suspended in the water. This effect considered no external factors, and thus it relates to the thermal motion of the fluid molecules. The velocity, at which a suspended particle floats in zigzag irregular motions, is proportional to the square root of the temperature.
The Weiner Process explains Brownian Motion through a mathematical model often called Particle Theory.