Dispersion of white light and the colours of the visible spectrum
White light can be split up to form a Refers to the visible spectrum, the range of the electromagnetic spectrum visible to the human eye. It can be seen when white light is split by a prism, or by raindrops to form a rainbow. using a A block of glass or other transparent material that disperses light to form a spectrum..
This is a block of glass with a triangular cross section.
Light waves are Process by which a wave changes speed and sometimes direction upon entering a denser or less dense medium, eg a light ray changes direction when refracted by a lens. as they enter the glass because they are slowed down.
The spectrum is produced because different colours of light travel at different speeds in glass.
Red light is slowed down least by glass and is refracted least.
Violet light is slowed down most by glass and is refracted most.
As a result, the coloured light spreads out to form a spectrum of white light.
This is called dispersion.
Key points
- The spectrum of white light is produced because different colours of light travel at different speeds in glass.
- Red light is slowed down least by glass and is refracted least.
- Violet light is slowed down most by glass and is refracted most.
There is an easy way to remember the order of the colours of white light by using a sentence: Richard Of York Gave Battle In Vain
Red, Orange, Yellow, Green, Blue, Indigo, Violet.