In a universe of infinite age and size, every line of sight should end in a star, so why is the night sky largely dark? Assuming a similar average density of stars throughout the universe, then the number of stars in a particular direction increases proportional to distance away. However, the intensity of light from distant stars diminishes proportional to the SQUARE of distance away. Therefore the total average light from any particular direction is inversely proportional to the distance of the nearest star, so some/most directions will appear dark.