What is a wave?

A wave is periodic motion
-ocean waves are examples
-sound waves are another example

A wave will have
SPEED: how fast it is going
FREQUENCY: how often the highs and the lows will occur
WAVELENGTH: how long it is before it repeats itself

The higher the frequency, the shorter the wavelength






The lower the frequency, the longer the wavelength

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Light and its many wavelengths

When light is passed through a perspex prism ( or a diamond!) it splits into its many wavelengths, giving us the colours of a rainbow

The wavelengths are very small in size, typically in the hundreds of NANOmetres (10^-9=0.000000001)

What colour you end up seeing, depends upon the ANGLE at which the light enters the object and leaves.

​The higher the "refractive index", the better the light splitting.
When light enters a glass or perspex boundary, it bends or refracts.
When it bounces off a surface, it reflects.

What waves can do

Reflect: bounce off a boundary
Refract: bend when entering a new medium
Diffract: spread out once they enter a very narrow opening
Absorbed: can be prevented from travelling further by certain materials
Transmitted: can be passed through materials

Light can also be scattered

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The Wave Equation