I just re-connected with this modest plain-looking JPG file which is a plot of the universe's scale factor over time and thought I'd share it
this post in this other thread gives some context---links to the text of the article where this figure appeared, and to the other figures---so there's more explanation if you want.
but here is the figure itself "The Size and Destiny of the Universe"
It is at the Caltech "Level 5" site.
Even though this picture is very simple and plain-looking, I really like it. It is like a favorite poster. First encountered it in 2003 and didn't see it for a long time, then re-encountered because of a question asked by a new member named Mwsund