Dark matter distribution. Supercomputer simulation of the distribution of dark matter in the local universe. Dark matter is a form of matter that cannot be detected by telescopes as it emits no radiation. Its presence is inferred by its gravitational action on visible matter. It is thought that visible matter (such as galaxies) occupies halos of dark matter (bright dots). The halos are connected by filaments of cold, invisible dark matter (red). This simulation matches the observed distribution of galaxies well, suggesting current theories about the universe are accurate.