  Over the last few years numerous papers concerning analog models for gravity
have been published. It was shown that the dynamical equation of several
systems (e.g. Bose-Einstein condensates with a sink or a vortex) have the same
wave equation as light in a curved-space (e.g. black holes). In the last few
months several papers were released which deal with simulations of the
universe.
  In this article the de-Sitter universe will be compared with a freely
expanding three-dimensional spherical Bose-Einstein condensate. Initially the
condensate is in a harmonic trap, which suddenly will be switched off. At the
same time a small perturbation will be injected in the center of the condensate
cloud.
  The motion of the perturbation in the expanding condensate will be discussed,
and after some transformations the similarity to an expanding universe will be
shown.
