Brownian motion

[ brou-nee-uhn moh-shuhn ]

nounPhysics.
  1. the irregular motion of small particles suspended in a liquid or a gas, caused by the bombardment of the particles by molecules of the medium: first observed by Scottish botanist Robert Brown in 1827.

Origin of Brownian motion

1
1870–75; Brown + -ian
  • Also called Brown·i·an move·ment [brou-nee-uhn moov -muhnt]. /ˈbraʊ ni ən ˈmuv mənt/.

Words Nearby Brownian motion

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Scientific definitions for Brownian motion

Brownian motion

[ brounē-ən ]


  1. The random movement of microscopic particles suspended in a liquid or gas, caused by collisions between these particles and the molecules of the liquid or gas. This movement is named for its identifier, Scottish botanist Robert Brown (1773-1858). See also kinetic theory.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for Brownian motion

Brownian motion

The erratic motion, visible through a microscope, of small grains suspended in a fluid. The motion results from collisions between the grains and atoms or molecules in the fluid.

Notes for Brownian motion

Brownian motion was first explained by the twentieth-century physicist Albert Einstein, who considered it direct proof of the existence of atoms.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.