物理臨界角同全內反射

When the incident angle (入射角) is greater than the critical angle (臨界角), no refraction (折射) occurs. All the incident rays will be reflected (反射). Such phenomenon is called "total internal reflection"(全內反射).

Total internal reflection can only takes place when light goes from a dense medium to a less dense medium.

2012-12-08 19:28:39 補充：
Q:點樣知道臨界角係幾多？
The critical angle (臨界角) c is given by: sin(c) = 1/refractive index(折射率)

對呀!!!!!!!!!!!!!!!!!!!!!!!