Polarized light

 

    
Light is the visible part of the electromagnetic spectrum. It is made up of two vibrating fields, electical and magnetic.  

 

The glare that comes off a road surface is due to polariseed light. Sun glasses can minimise the amount of light that reaches the eye by using special filters.

Natural sunlight and almost every other form of artificial illumination transmits light waves whose electric field vectors vibrate in all perpendicular planes with respect to the direction of propagation.

  

As the light bounces off the surface of the road, light in one plane is reflected.

Unpolarized light (natural sunlight, for example) is polarized to a certain degree when it is reflected from a surface such as water or a highway. In this case, light waves that have the electric field vectors parallel to the surface are reflected to a greater degree than those with different orientations

  
Light that is unpolarized has waves perpendicular to the direction of motion. Using polarizing filters we can select the orientation of waves that pass through the filter.  
Explain how the transparent filters on the right block light when turned as shown in the video.