Brownian motor Brownian motor Brownian motors are nano-scale or molecular devices by which thermally activated processes (chemical reactions) are controlled and used to generate directed motion in space and to do mechanical or electrical work. These tiny engines operate in an environment where viscosity dominates inertia, and where thermal noise makes moving in a specific direction as difficult as walking in a hurricane: the forces impelling these motors in the desired direction are minuscule in comparison with the random forces exerted by the environment. Because this type of motor is so strongly dependent on random thermal noise, Brownian motors are feasible only
Brownian motion mass of a mole of the gas by Avogadro's constant. The first part of Einstein's argument was to determine how far a Brownian particle travels in a given time interval. Classical mechanics is unable to determine this distance because of the enormous number of bombardments a Brownian particle will undergo, roughly of the order of 10 collisions per second. Thus Einstein was led to consider the collective motion of Brownian particles. He regarded the increment of particle positions in time formula_1 in a one dimensional ("x") space (with the coordinates chosen so that the origin lies at the initial position