Embark on a journey through the fascinating world of Brownian motion. This random yet patterned phenomenon, first observed by botanist Robert Brown, has profound implications in fields as diverse as physics, finance, and biology. Prepare to delve into its intriguing complexities.
Brownian Motion
Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules.
- It is also known as pedesis, which comes from the Greek word for “leaping.”
- Even though a particle may be large compared to the size of atoms and molecules in the surrounding medium, it can be moved by the impact with many tiny, fast-moving masses.
Brownian Motion Versus Motility
It can be difficult to distinguish between movements due to Brownian motion and movement due to other effects.
- True motility appears often as a path, or else the motion is twisting or turning in a specific direction (e.g., a sample in a semisolid medium).
What Is Brownian Motion?
Because the movements of atoms and molecules in a liquid and gas is random, over time, larger particles will disperse evenly throughout the medium.
- Any factor that affects the movement of particles in a fluid impacts the rate of Brownian motion
- For example, increased temperature, increased number of particles, small particle size, and low viscosity increase the rates of motion
Brownian Motion Examples
Most examples of Brownian motion are transport processes that are affected by larger currents, yet also exhibit pedesis. Examples include: pollen grains on still water, diffusion of pollutants in the air, diffusion of calcium through bones, and movement of “holes” of electrical charge in semiconductors.
