It states
The apparent paradox that if stars were distributed uniformly throughout an infinite universe, the sky would be as bright at night as in the daytime, owing to the fact that whilst the apparent brightness of individual stars decreases with the square of the distance, the number of stars increases in the same proportion.
The paradox is resolved by the observation that distant stars are of finite age, and recede from the observer as the universe expands.
Further reading: Scott Chase