Imagine being a 13th century guy and just sitting down and saying hell yeah time to think about optics for awhile

At first I thought you were talking about this (which I love), but then I realized no, you're thinking of someone quite a bit earlier.

What I appreciate most about this exercise is that if you don't like the 13th century you can just go to the next one and the next one and...optics will still be there waiting for you!