Waves and Light: Wave Types

Different Types of Waves

There are two main types of waves: transverse waves and longitudinal waves.
Transverse waves are waves where the particle displacement is perpendicular to the direction of the wave propagation. These include light waves, radio waves, and other types of electromagnetic waves.
In longitudinal waves, the particle displacement is in the same direction as the wave propagation. Sound waves are a common example of this.

All waves possess certain basic properties: wavelength, frequency, speed, and amplitude.
The wavelength, usually denoted by the Greek letter lambda (λ), is the distance between consecutive peaks or troughs in a wave.
The frequency of a wave, denoted by the letter ‘f’, refers to how many wave cycles pass a given point per unit time. Frequency is usually measured in hertz (Hz).
The speed of a wave is related to its frequency and wavelength according to the equation v = fλ, where ‘v’ is the speed.
The amplitude of a wave corresponds to the ‘height’ of the wave; in other words, the maximum displacement or distance moved by a point on the wave from its undisturbed position.

Light is a form of electromagnetic radiation and is only a small part of the electromagnetic spectrum which ranges from radio waves to gamma rays.
Different regions of the electromagnetic spectrum correspond to different types of waves, each with their own set of unique properties and behaviours.
The visible light spectrum is the part of the electromagnetic spectrum that can be perceived by the human eye, and it varies in wavelength from about 400 nm (violet) to about 700 nm (red).

Light waves, like all electromagnetic waves, propagate in a vacuum at a constant speed, c, which is approximately 3 x 10^8 meters per second.
The speed of light can vary when light moves through different mediums. This change in speed gives rise to the refraction phenomenon which includes the bending of light as it passes from one medium to another.

The wave nature of light allows for a phenomenon known as polarisation, where the electric field vector of a light wave oscillates in a particular direction.
Transverse waves, such as light waves, can be polarised, while longitudinal waves cannot.
Polarised light has numerous applications, including in sunglasses, photography, and computer screens.