Brownian motion

American  

[brou-nee-uhn moh-shuhn] / ˈbraʊ ni ən ˈmoʊ ʃən /

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.

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Brownian motion Scientific  

/ brou′nē-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).

2. See also kinetic theory

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Brownian motion Cultural  

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.

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Discover More

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

Etymology

Origin of Brownian motion

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.

From Science Daily • Feb. 13, 2024

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

From Seattle Times • Jul. 21, 2023

Figure 30.2 The position of a pollen grain in water, measured every few seconds under a microscope, exhibits Brownian motion.

From Textbooks • Aug. 12, 2015

Fans followed with smaller versions of the instrument, moving about haphazardly rather than in formation, an activity meant to celebrate the concept of Brownian motion, the random movement of particles.

From New York Times • Sep. 17, 2011

Clumps and clusters of birds in flight were questing back and forth, black dots against the blue sky, moving in some kind of desperate Brownian motion.

From "American Gods" by Neil Gaiman