So I've been having a hard time wrapping my head around expansion. Not expansion of the universe it's self, I get that, but how everywhere we look we see red light or "red shift" I can also understand the Doppler effect and the difference between red shift and blue shift.
It wasn't until I saw an explanation using a rubber band that I was able to fully grasp the awesomeness of the universe expanding. Here's how it goes, if you haven't heard it. Take a rubber band and cut it so now you have a long straight piece of rubber band. Now make marks equal lengths apart, let's say 1/2 apart(doesn't really matter) now if you stretch the rubber band out you'll notice that every mark you made is getting further away from each other! Bingo! It's that simple
I was having a problem because I kept wondering why is everything moving away from us? This helps explain that no matter where you are in the universe, everything is moving away from everything. Not just moving away from us because we are the center of the universe like my mommy told me I was