Why Does the Sky Appear Dark at Night if the Universe Contains a Septillion Stars?
Imagine you are in the middle of a forest. Whatever direction you look at, sooner or later your line of sight will be blocked by a tree. In the same way, looking at the night sky, the deeper you zoom in, the more distant stars will be revealed. If stars are spread more or less uniformly throughout the universe, and the universe is infinitely big and infinitely old, then in whichever direction you look, you should end up seeing a…
