5.1 The Nature of Waves
Light travels as waves. Waves can be described by their amplitude, wavelength and frequency. The speed of a wave can be calculated from its frequency and wavelength.
Waves are vibrations that transfer energy from place to place without matter (solid, liquid or gas) being transferred.
In longitudinal waves, the oscillations are along the same direction as the direction of travel and energy transfer. It is made up of compressions and rarefactions. Mechanical waves e.g. waves on spring or a sound wave, travel through a medium (substance)
In transverse waves, the oscillations(vibrations) are at right angles to the direction of travel and energy transfer. Electromagnetic waves e.g. light can travel through a vacuum as there are no particles moving in electromagnetic waves as they are oscillations in an electric or magnetic field.