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Concept information

Preferred term

Brownian motion  

Definition

  • Brownian motion, or pedesis (from Ancient Greek: πήδησις /pɛ̌ːdɛːsis/ "leaping"), is the random motion of particles suspended in a medium (a liquid or a gas). This pattern of motion typically consists of random fluctuations in a particle's position inside a fluid sub-domain, followed by a relocation to another sub-domain. Each relocation is followed by more fluctuations within the new closed volume. This pattern describes a fluid at thermal equilibrium, defined by a given temperature. Within such a fluid, there exists no preferential direction of flow (as in transport phenomena). More specifically, the fluid's overall linear and angular momenta remain null over time. The kinetic energies of the molecular Brownian motions, together with those of molecular rotations and vibrations, sum up to the caloric component of a fluid's internal energy (the equipartition theorem). (Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/wiki/Brownian_motion)

Broader concept

Synonym(s)

  • Brownian movement

In other languages

URI

http://data.loterre.fr/ark:/67375/MDL-TGFTNSRJ-5

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