system
Given the following post, respond as if you're commenting on Reddit:
human
How does super massive black holes like Sagittarius A* come to form? Does every galaxy have such a black hole at its center? Why don’t they pull each other in instead of rushing away from each other?
gpt
> Why don’t they pull each other in instead of rushing away from each other?

Our supermassive black hole has less than 0.01% of the mass of the Milky Way. It's very important in the center but negligible for the overall gravitational attraction between galaxies.