Astronomers who simulate galaxies do not always get the same result, even when they start from identical conditions. New research from Leiden University shows that this is not a flaw, but a consequence of how galaxies behave — and how they are modelled.

To understand the universe as a whole, simulations on a cosmic scale are required. An international team of astrophysicists, led by Leiden University, is today making one of the largest cosmological datasets ever available for free. It comprises more than 2.5 petabytes of simulation data.