The Milky Way is estimated to be ~100,000 light years across. We're not quite on the edge but we're closer to the edge than the center. So to colonize the galax

The Milky Way is estimated to be ~100,000 light years across. We're not quite on the edge but we're closer to the edge than the center. So to colonize the galaxy you have to assume we'd need to travel almost 100,000 LY. If you assume moving at 1% of the speed of light, you come up with a lower bound of 10M years.