Why is the Sky Dark at Night?

The

Minute Physics

folks have created another great video, this time explaining why the sky is dark at night. Although at first glance it seems like an easy question to answer, throw in

Olbers' Paradox

(the light from an infinite amount of stars should make the night sky completely bright) and it really is quite a complicated matter. In fact, it takes the Minute Physics teams nearly

four

minutes to explain it all!