Brownian motion

English

Etymology

Named after Scottish botanist Robert Brown (1773–1858), who investigated the movement of pollen suspended in water.

Noun

Brownian motion (countable and uncountable, plural Brownian motions)

1. (statistical mechanics) Random motion of particles suspended in a fluid, arising from those particles being struck by individual molecules of the fluid.
   • 2023, Robert M. Sapolsky, Determined: A Science of Life Without Free Will, New York: Penguin, →ISBN:

     To summarize, the world is filled with instances of indeterministic Brownian motion, with various biological phenomena having evolved to optimally exploit versions of this randomness. Are we talking free will here?

2. (idiomatic) A state of chaos or disarray.
   • 2003, Robert Wilson, Instruments of Darkness, Harvest Books, →ISBN, page 255:

     The sun was hot on my legs. I moved out of the doorway and stood in the room with my thoughts in Brownian motion.

   • 2007 November, Gil Schwartz, “Escape from the job monster”, in Men's Health, volume 22, number 9, →ISSN, page 122:

     That's pretty much what I'm doing here today—asking you, right now, to sit down, take a deep breath, and stop. Try to see a future beyond that Brownian motion of your daily affairs.

Synonyms

• Brownian movement

Related terms

• Brown noise

Translations

random motion of particles suspended in a fluid

• Arabic: حَرَكَة بَرَاوْنِيَّة f (ḥaraka barawniyya)
• Armenian: բրոունյան շարժում (brounyan šaržum)
• Bulgarian: Брауново движение n (Braunovo dviženie)
• Chinese:

  Mandarin: 布朗運動／布朗运动 (zh) (Bùlǎng yùndòng)

• Crimean Tatar: broun areketi
• Czech: Brownův pohyb m
• Danish: brownsk bevægelse
• Finnish: Brownin liike (fi)
• French: mouvement brownien (fr) m
• German: brownsche Bewegung f
• Hindi: ब्राउनी गति (brāunī gati)
• Italian: moto browniano m
• Japanese: ブラウン運動 (Buraun undō)
• Korean: 브라운 운동 (Beuraun undong)
• Portuguese: movimento browniano m
• Russian: бро́уновское движе́ние (ru) n (bróunovskoje dvižénije)
• Spanish: movimiento browniano m
• Swedish: brownsk rörelse c
• Ukrainian: бро́унівський рух m (bróunivsʹkyj rux)