scoutit:  Astrophysicists have finally simulated an entire galaxy. It only took nine months of computing to do it, too! We were talking about how spiral galaxies form the other day, and simulations like this are key to checking our understanding of the processes behind the Milky Way and others. Essentially, they take all the applicable laws of physics and astronomy, dump them in a computer, let it build a galaxy and see if it matches what we see in real life.