Question

what is brown motion?

Answer 1

Pretty much the motion created in any complex system because, although it may be stationary overall, it is made up of a seething mess of particles which individually move around , even if on average the gas or liquid doesn't. If you were to track one particle in this collection of randomly moving particles, it would seem to jitter all about. This jittering is called 'Brownian motion'. You only really notice it if you put a marker (e.g.: a dye) into the gas/liquid and hence see the motion of the individual particle.

http://en.wikipedia.org/wiki/Brownian_motion

Answer 2

do u mean 'brownian motion'