Olbers' Paradox

Olbers' Paradox questions why the night sky is dark despite the universe being vast and filled with countless stars. If the universe were infinite, static, and filled uniformly with stars, every line of sight should end on a star’s surface, making the sky uniformly bright. However, the night sky remains dark, suggesting the universe is neither infinite nor static, and that it’s expanding and evolving. These factors mean distant light is redshifted or has not yet reached us, explaining why the sky is mostly dark at night.