Brian Cox Explains The True Size Of The Universe

In 1823, German astronomer Heinrich Olbers proposed the idea of a static universe. He suggested if the Universe is infinite and filled with stars all at different distances from Earth, then every single sight line should land on a star.  This means that if the universe is infinite and contains an infinite number of bright objects, the night sky will be bright! Since the night sky is dark, this tells us that one of our assumptions about the universe is incorrect.