Night falls in the city but it is by no means truly dark.
Society's after hours activity generates enough of a glow to mute the twinkling canvass overhead . The light from the city is manmade, but it is no foregone conclusion that all the tiny points of light in the sky are nature's doing. The universe has its own constants. Natural selection smiled kindly to humanity on this insignificant bit of rock. Similar results are not ordained when compared over a much larger sample of what the universe has to offer.