1) Black holes succor! So we live in a spiral galaxy, right? That means it's a flat disk, with spiral arms, a bulge of stars in the middle, and right at the center sits a black hole -- all big galaxies appear to have one. The monster in our middle tips the cosmic scales at over 4 million times the mass of the Sun. That sounds like a lot, but remember there are about 200 billion stars in the Milky Way, so in reality the black hole is 0.002% of the mass of the galaxy, more or less.
Near the black hole, you'd think the environment is not exactly nurturing. The gravity of the hole is enormous, of course. Stars can orbit it in stable paths that last for billions of years, but big objects like gas clouds can be shredded; the black hole pulls on one side more strongly ...
