Things start off slow in the simulation, but the civilization’s rate of spread really picks up once the power of exponential growth kicks in. But that’s only part of the story; the expansion rate is heavily influenced by the increased density of stars near the galactic center and a patient policy, in which the settlers wait for the stars to come to them, a result of the galaxy spinning on its axis. The whole process, in which the entire inner galaxy is settled, takes one billion years. That sounds like a long time, but it’s only somewhere between 7% and 9% the total age of the Milky Way galaxy. Another neat aspect of the video is that it shows a civilization transitioning from Kardashev II status—in which it harnesses the power of entire star systems—to a full-blown Kardashev III civilization, which has tapped into the energy output of the entire galaxy (more about the Kardashev scale here).