Instructions:
Drag the flashlight around to change its position and angle. Use the sliders to control the index of refraction in the two regions.
Explanation:
Snell's Law describes how the angle of refraction depends on the change in index of refraction between two materials. The angles of the raw follow the well known law $$n_1\sin\theta_1=n_2\sin\theta_2$$. This simulation shows the path a light ray would take based on the index of refraction of the two materials. Total internal reflection also occurs when the angle of incidence is too small.
Link to stand-alone sim: Here is a link to view the sim on its own, with no distractions.
