So I am piecing together a school project on the numerous misconceptions of the universe, which I plan to "provide proof against them" with information from various sources (one of the main ones will be A Brief History of Time by Stephen Hawking). In coming up with the myths, I am sure that I will miss some that are very important. So, what are the most mind blowing things that you have come across that have completely changed your thoughts on the universe?
The main one for me is proving that the universe is finite, by the conjecture that the night sky would be extremely bright, as one would eventually encounter a star on the way to the infinite edge of the universe.
What else is there?
(note that I have a basic(ish) understanding of QM, but I do not really want to take the project in such a way)