Optics Problem #2 - - Snell's law with n1<n2 .. total internal reflection

A light beam source is incident on a substance of unknown index of refraction. You can click-drag both the position and the ray angle of the beam. Assume the black area on the left is air and has a 1.0 index of refraction (the blue area on the right has an "unknown" index of refraction). You can click on one of the beam lines, and drag the mouse along the line to measure the angle - angle measurements are displayed in the yellow message box. Refresh the image if necessary.