pedesis
/pəˈdiːsɪs/
noun
- The random movement of microscopic particles suspended in a fluid, caused by collisions with molecules of the fluid; also called Brownian motion.
- In biology class, we watched the pedesis of tiny particles in a drop of milk.
- Pedesis can be observed under a microscope when looking at pollen grains in water.
- The concept of pedesis helped scientists understand the nature of atoms.