# Where does Light go if it is in a glass prism and why?

I know that photons/light bends or bounces when it hits glass so if it was in a glass prism where would it go. I know that light/photons hit the glass at different angles and if it hits at almost a straight angle it will escape but why does it escape if it hits at almost a straight angle? I don't really understand Snell's law. Could you look at my profile before answering flagging or leaving a comment please.

## 1 Answer

I know that photons/light bends or bounces when it hits glass so if it was in a glass prism where would it go.

Source: Light entering prism

It goes through the prism and two things happen. The white light gets split into the rainbow of colors and it also gets bent (refracted), because each of the colors is a different wavelength than the others. The colors between red and blue get refracted as well, not as much as red but more refracted than blue.

The light can be reflected or refracted or both, as in the picture below.

I don't really understand Snell's law.

The best way to think of Snell's law is to imagine you have to run from a point A to a point C, but on the way you must touch a pole at point B, which is midway between A and C but 50 metres below the straight line connecting A and C. That's the way light works, it gets from A to B and B to C in the shortest time. You should be able to see that on the picture above.

If it went any other way, it would take more time, so the angle it hits B (coming from A), must equal the angle going to C.

I bet you can't think of a quicker way to go this route than the way light goes.