the higher index of refraction and strikes a boundary beyond which the index
of refraction is lower (and if the angle of incidence is greater than the critical
angle). So, if a beam of light striking an air/water boundary experiences total
internal reflection, it must have originated (and remain) in the water.
- The angle of incidence is 50°, which is greater than the critical angle.
However, total internal reflection does not occur because the beam is in the
air, the medium of lower refractive index. So, the light will experience some
reflection (bouncing off the water) and some refraction (bending into the
water). The angle of reflection will be the same as the angle of incidence
(50°), and the angle of refraction will be smaller than 50° because a beam of
light always bends toward the normal when it enters a medium with a greater
index of refraction.