# Light

Source: https://projectgcse.co.uk/physics/waves/light

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The primary light colours are red blue and green. They can be mixed, as follows, to form secondary light colours:

- red + green = yellow
- red + blue = magenta
- blue + green = cyan

By using a prism, white light can be separated into all the different (dispersion) colours that make up white light. These are (starting with long wavelength):

- red, orange, yellow, green, blue, indigo, violet

Reflection:

- The angle of incident always equals the angle of reflection.
- These are measured against the normal which is an imaginary straight line at a right angle to the mirror.

Refraction:

- Refraction is the process that occurs when light travels from one material to another, it is either speed up or slowed down.
- This has an effect on the light and bends it.
- The denser the material, the slower the speed of light.