Simulations created on supercomputers yield completely new insights in science. Consequently, CSCS operates cutting-edge computer systems as an essential service facility for Swiss researchers. These computers aid scientsts with diverse issues and requirements - from the pure calculation of complex problems to analysis of complex data. The pool of national high-performance computers is available to its users as a so-called user lab: all researchers in Switzerland can use the supercomputer infrastructure. Disciplines such as physics, materials science and cosmology traditionally use high-performance computers like those operated by CSCS. Cosmologists, for instance, are unable to reproduce the Big Bang in the lab and endeavour to reconstruct the origin and development of the cosmos with the aid of simulations instead. Understanding the development of the universe is of crucial importance as basic principles of physics with far-reaching implications can be confirmed or refuted as a result.