تعريف brownian motion في الإنجليزية الإنجليزية القاموس.
Random motion of particles suspended in a fluid, arising from those particles being struck by individual molecules of the fluid
Any of various physical phenomena in which some quantity is constantly undergoing small, random fluctuations. It was named for Robert Brown, who was investigating the fertilization process of flowers in 1827 when he noticed a "rapid oscillatory motion" of pollen grains suspended in water. He later discovered that similar motions could be seen in smoke or dust particles suspended in air and other fluids. The idea that molecules of a fluid are constantly in motion is a key part of the kinetic theory of gases, developed by James Clerk Maxwell, Ludwig Boltzmann, and Rudolf Clausius (1822-1888) to explain heat phenomena