ABSTRACT
In June 1827 Robert Brown (1773-1858) started to study pollen grains and found out that they fluctuate in an arbitrary manner [Lin08]. Actually, he was not the first one to notice this phenomenon of randomly appearingmovements of tiny particles, but due to his precise work he was the first one to demonstrate that these movements are neither caused by animalcules, nor by measurement imperfections like vibrations, turbulences or exterior influences from heat or electromagnetism [Lin08]. Brown then studied this phenomenon on inorganic materials like stones, glasses and even a piece of the sphinx and observed these fluctuations in all of those [Lin08]. This ubiquity led to the idea of a rather general underlying process. Albert Einstein (1879-1955) published the first satisfying theory on this topic in 1905, in which he used stochastical approaches to model a frequent bombardment on the pollen grains by molecules [Ein05]. The theory on statistical thermodynamics gathers probabilistic methods to describe the interaction of particles in macroscopic systems. Studies on quantummechanics proved a very important physical limitation. Not only are stochastic methodologies handy for the description of the sheer incredible amount of particles, a deterministic description of particles is actually not possible. Heisenberg (1901-1976) proved that particles cannot be perfectly characterized. If e.g. the location is measured more precisely, the uncertainty in the impulse is worsening. This is known as the uncertainty principle.
