Each learning path is one chapter: a guided route through a topic, one small course at a time. Pick a class to see its chapters in order.
You see your face in a spoon, and a straw in a glass of water looks broken. Light does both of these things, and it follows simple rules. In this chapter we find the rules of reflection and refraction. We use them to understand mirrors and lenses, to draw where an image forms, and to calculate its place and size with a formula. Python helps us draw and calculate.