Assuming humanity can unify on Earth, and develop von newman probes *and* either master fusion, or create a dyson swarm type thing? Either combination of the two technologies being developed would make colonizing, or developing almost any planet in the galaxy a viable idea. We would be able to spread across the galaxy in only a few million years, maybe in the hundreds of thousands if we put our backs into it. We may blot out all the stars in the galaxy.