Filtered Light

Light is an electromagnetic wave that moves in all directions. An electromagnetic wave consists of an electric and magnetic field that moves at the speed of light – or close to it – from its source, for example the sun. Using a polarisation filter, the waves are removed so only one beam of light remains. In the experiment, the light passes between two polarisation filters set at 90-degree angles in relation to each other. The light goes out completely if it is not reflected off any object. When the light reflects, a spectrum of colours emerges. The polarisation filter works by only allowing certain waves of light through, if they are at specific angles. The physical term is called “polarisation of light”, hence the name.

Where can you see this?

If you take a photograph through a window using a polarisation filter, you can either photograph what is on the other side of the window, or the reflection by moving the angle of the camera.