Olbers Paradox
In an infinite universe filled with stars, everyline of sight should eventually meet the surface of a star.
The dimming of starlight with distance should be exactly cancelled by the increase in the number of stars you see as you look farther out, so that the night sky should appear as bright as the surface of the sun.
Day and night should blend into one!
Solved by Edgar Allan Poe in 1848:
Stars must not have had enough time to fill the universe with light. The universe has not existed forever. This led to the Big Bang Theory.
The Milky Way:
Notice how bright it is where stars are densest.