Given the task definition and input, reply with output. In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

In 2001, researchers at Lawrence Berkeley Labs discovered it in an aluminum matrix doped with molten lead. A mathematical description of this Wiener process typically begins with the Langevin equation and the Stokes flow for a sphere. Jean Perrin provided evidence for the most famous formulation of this process, for which, in the limit of small times, the rms displacement is proportional to the time squared. In the large time limit, it is a diffusive process which can be described by the Fokker-Planck equation and it has a diffusive constant proportional to the temperature. Observed by its namesake in pollen grains suspended in water, and explained by Einstein using the kinetic theory of gases, FTP name this random motion of small particles in a fluid.
Science