system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is Olber's Paradox?

One of the books I was reading (on astrophysics) used this term and I wasn't quite sure I understood I properly. So, I thought I'd look to the learned men and women of Reddit to help me understand this. ELI5 guys!
gpt
It suggests that the universe is dynamic and changing. In the past people thought the universe was basically static: it always existed, will always exist, and doesn't really change much.

But if the universe had always been here and always been in this state, that means the light from all stars everywhere would have reached earth by now. The entire sky would be filled with stars. The gaps between the oriignal stars would be filled in when the light from them reached us. 

Which means that if the universe was always there, the light would have reached us by now. So it would never be night. The sky would always be blue, because of the light always passing through it.

Since there is a night, it suggests that the universe is dynamic and expanding, and that the light from stars far enough away has not reached us, and never will.