Brownian motion

[brou-nee-uhn moh-shuhn]

noun

Physics.

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.

Brownian motion

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).

2. See also kinetic theory

Brownian motion

1. 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.

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

Word History and Origins

Origin of Brownian motion¹

1870–75; Brown + -ian

Example Sentences

Since the motion of the skyrmion is due to temperature-dependent Brownian motion, which is disorderly in nature, this is an interesting case of getting an orderly result through disordered motion.

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Though debate continued for decades, the correct answer came from botanist Robert Brown, for whom Brownian motion was named.

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The boozy, Brownian motion of the party carried me past 30-somethings in superhero leotards and feather boas, cat ears and vampire capes.

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The ‘miracle year’ of 1905, when he published papers on Brownian motion and the photoelectric effect as well as on special relativity, made Einstein a star of physics.

Read more on Nature

He calculated exactly how a microscopic, but visible, particle should behave if it was bumping into unseen atoms—a phenomenon called Brownian motion.

Read more on Scientific American