The refractive index of a medium is a measure of how much light is slowed down when it passes through that medium. The refractive index of air is 1.000, which means that light waves travel at the same speed in air as they do in a vacuum. The refractive index of glass is about 1.5, which means that light waves travel about 1.5 times slower in glass than they do in air.
When a light wave moves from air into a denser medium, such as glass or water, it slows down. This causes the light wave to bend towards the normal, or the perpendicular line to the surface of the denser medium. The angle of refraction is the angle between the incident light wave and the refracted light wave.
The angle of refraction can be calculated using Snell's law, which is:
`n1 sin θ1 = n2 sin θ2`
Where:
- `n1` and `n2` are the refractive indices of the two media.
- `θ1` is the angle of incidence, or the angle between the incident light wave and the normal.
- `θ2` is the angle of refraction, or the angle between the refracted light wave and the normal.
The path of light changes when it enters into another medium because of the change in speed of the light wave. The amount of bending depends on the difference in the refractive indices of the two media.
