1. Refraction
Refraction

2. Refraction of Light
Refraction – the bending of a wave disturbance as it passes at an angle from one medium into another
Light bends whenever it changes media except when it strikes the boundary parallel to the normal
The angle between the normal and the incoming ray is called the angle of incidence (θi)
The angle between the normal and the outgoing ray is called the angle of refraction (θr)

3. Refraction of Light

4. Refraction of Light
Refraction symbolizes that the wave is changing speed
When light speeds up, it bends away from the normal
θi < θr
When light slows down, it bends toward the normal
θi > θr
Crossing a boundary typically causes reflection as well as refraction

5. The Law of Refraction
Index of refraction – the ratio of the speed of light in a vacuum to its speed in a given transparent medium
Index of refraction = (speed of light in a vacuum)/(speed of light in medium)
n=c/v
Can also be calculated using the wavelengths
We will assume air to essentially be a vacuum for index of refraction problems

6. The Law of Refraction

7. The Law of Refraction
Refraction causes objects to appear in different locations than they actually are
Wavelength affects the index of refraction
Each color of visible light refracts differently from the others
Snell’s Law determines the angle of refraction
ni(sinθi) = nr(sinθr)
(Index of refraction for the initial medium) * (sine of the angle of incidence) = (index of refraction for the second medium) *(the angle of refraction)

8. The Law of Refraction