Paradox - (Image - Adam Cole / NPR) Sun Goes Down. Up Comes A Mystery by ROBERT KRULWICH Here’s a question you probably didn’t know was a question: Why is the sky dark at night? My daughter asked me this about 10 years ago. We were looking up at the night sky, and she said, “There’s lots of stars up there.” And I said, “Yes.” Then she said, “Are there stars everywhere?” And I said there were. Then she said, “Well, if there are stars everywhere, all of them shining, why don’t they fill the sky and make the sky shiny?” In her mind, the sky, instead of being dark, should look like this, brightness everywhere. MORE: http://www.npr.org/blogs/krulwich/2012/10/10/162630285/sun-goes-down-up-comes-a-mystery