Brownian motion

Brown·ian motion

noun \ˈbrau̇-nē-ən-\

Definition of BROWNIAN MOTION

: a random movement of microscopic particles suspended in liquids or gases resulting from the impact of molecules of the surrounding medium —called also Brownian movement

Origin of BROWNIAN MOTION

Robert Brown †1858 Scottish botanist

First Known Use: 1871

Rhymes with BROWNIAN MOTION

Antarctic Ocean, Atlantic Ocean, harmonic motion, Pacific Ocean, social promotion

Brown·ian motion

noun \ˌbrau̇-nē-ən-\   (Medical Dictionary)

Medical Definition of BROWNIAN MOTION

: a random movement of microscopic particles suspended in liquids or gases resulting from the impact of molecules of the fluid surrounding the particles—called also Brownian movement

Biographical Note for BROWNIAN MOTION

Brown \ˈbrau̇n\ (audio pronunciation) Robert (1773–1858), British botanist. Brown was one of the leading botanists of his day. In 1801 he accompanied a surveying expedition to and around Australia, acting as the company's naturalist. In 1805 he returned to Great Britain with about 3,900 species of plants, and in 1810 he published a great work on the flora of Australia. In the field of botany he is also known for his substantial contributions to plant morphology, embryology, and geography, for improving plant classification and making a fundamental distinction between gymnosperms and angiosperms, for establishing and defining new families and genera, and for describing and naming the nucleus of a plant cell. He published his observations on Brownian motion in 1831.

Brownian motion

noun    (Concise Encyclopedia)

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 microscopic particles within 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 (1822–88) to explain heat phenomena.