Optics- day 13

Total Internal Reflection

•	when light travels from one medium to another, some of the light is reflected and some is refracted

•	light bends away from the normal when it goes from water (higher density) to air (lower density, in this case the angle of refraction is larger than the angle of incidence

•	the angle of refraction continues to increase as the angle of incidence increases

•	the angle of refraction will eventually become 90 , the angle of incidence at this point is called the critical angle (this is a physical property of that medium, water has a critical angle of 48.8 )

•	if you increase the angle of incidence past the critical angle, the refracted ray will no longer exit the medium, it will reflect back, this is called total internal reflection