How many stars are in the sky? There are actually only a couple thousand stars you can see with your eye on even on the clearest nights. It is estimated there are some 1011 stars in our own Milky Way and perhaps some 1010 galaxies within our horizon. That makes 1021 stars in the universe a good first guess.
JMP 57, 12: quantum mechanics for the universe
6 hours ago in Doc Madhattan