Waves, Vibrations and Polarisation

Waves and Vibrations:

 

Waves that pass through a substance are vibrations that pass through the substance. Sound waves and seismic waves are examples of waves that pass through a substance and are often called mechanical waves. When waves progress through a substance, the particles of the substance vibrate in the same way. Electromagnetic waves are vibrating electric and magnetic fields that progress through space without the need for a substance. The vibrating electric field generates a vibrating magnetic field, which generates a vibrating electric field further away. Electromagnetic waves includes radio waves, visible light, ultraviolet radiation and many more (as shown in the diagram below)

 

 

Transverse waves: Waves in which the direction of vibration is perpendicular to the direction in which the wave travels. Examples: Electromagnetic waves and secondary seismic waves.

 

 

Longitudinal waves: Waves in which the direction of vibration of the particles is parallel to (along) the direction in which the wave travels. Examples: sound waves, primary seismic waves and compression waves.

Polarisation:



The process of transforming unpolarised light into polarised light is known as polarisation. It is possible to transform unpolarised light into polarised light. Polarised light waves are light waves in which the vibrations occur in a single plane.