We just observed how a convex lens bundles the light rays from the sun into a single bright spot. This means that a convex lens refracts light in a very special way, as this graphic will illustrate. It shows a lens from the side, and light rays coming . . .

This is a collection of three animations describing the microscope and its history, detailing how it is setup and how a microscope is put together.

In this interactive animation, you can rotate a laser beam and change the angle at which it hits a plane mirror. Move the laser around and observe what happens: as you change the direction of the incoming (or incident) beam, the direction of the refle . . .

In this online learning tool, you can study how light rays are reflected from different types of mirrors: plane mirrors, spherical concave mirrors, and spherical convex mirrors. You will also learn how images are formed by mirrors, and what type of mi . . .

We have seen in the last video how we can shift the focal point if we add a second lens to the original convex lens that is the model for our eye. This interactive animation lets you explore how to correct the vision problems of near sightedness and f . . .

This is an audio file detailing how light rays get kinks. The audio is as follows: "Have you ever observed what happens when you stick a pencil in a glass of water, and then look at it from different directions? This picture shows you that the pencil . . .

Here you have another principal ray diagram, just like the one we constructed on the previous page, only this one is interactive. You can click on the object and drag it, and observe what happens to the image. Notice that, as we saw on the previous pa . . .

On this slide, you see a schematic of a principal ray diagram. By identifying two sets of similar triangles, we will be able to derive the thin lens equation. Let's first define the variables: i is the image distance, and o the object distance; f is t . . .

This interactive animation allows you to explore Snell's law by shining a laser from air into a different medium, which can be either water or glass. Move the laser to change the angle of incidence, and observe how the refracted beam changes direction . . .

Not all mirrors are flat, of course. Now we want to consider two special cases of mirrors, both of which are pieces of a shiny sphere. Convex spherical mirrors are the outside of a reflecting sphere (or a part of it), and concave spherical mirrors are . . .