Refraction
Refraction is the change in direction of a wave when it passes from one medium into another medium.
When light passes from a less dense medium into a more dense medium, the wave speed of light decreases. As the wave speed decreases, the wavelength also decreases. This decreased wavelength leads to a change in direction of the wave when the angle of incidence is greater than 0 degrees.
This concept is best described through diagrams.
Diagrams and Definitions
The normal is the dotted line which cuts at a 90 degree angle where the light changes mediums.
The angle of incidence is the angle between the beam of light and the normal in the less dense material.
The angle of refraction is the angle between the beam of light and the normal in the more dense material.
The angle of incidence is always greater than the angle of refraction.
The critical angle is the minimum angle at which light is no longer internally refracted. Or, the greatest angle at which light can strike the new medium without being totally reflected.
Key Points!
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Refraction
Refraction is the change in direction of a wave when it passes from one medium into another medium.
When light passes from a less dense medium into a more dense medium, the wave speed of light decreases. As the wave speed decreases, the wavelength also decreases. This decreased wavelength leads to a change in direction of the wave when the angle of incidence is greater than 0 degrees.
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Definitions
The normal is the dotted line which cuts at a 90 degree angle where the light changes mediums.
The angle of incidence is the angle between the beam of light and the normal in the less dense material.
The angle of refraction is the angle between the beam of light and the normal in the more dense material.
The angle of incidence is always greater than the angle of refraction.
The critical angle is the minimum angle at which light is no longer internally refracted. Or, the greatest angle at which light can strike the new medium without being totally reflected.