Olber's paradox
Olber's paradox is an argument against the notion that the universe is static and infinite in size containing uniformly distributed luminous stars. This "paradox" is sometimes also known as the "dark night sky paradox".
If the universe is assumed that:
(i)the universe contain an infinite number of uniformly distributed luminous stars and (ii) the collective brightness from a set of stars at a given distance is independent of that distance;
Then it is possible to conclude that:
Every line of sight should terminate eventually on the surface of a star and every point in the sky should be as bright as the surface of a star. As the night sky is obsevered to be dark one or more of the assumptions must be incorrect. Many scientists now believe that the universe is expanding.