# What is the visible spectrum?

Jun 24, 2015

It is the part of the electromagnetic spectrum that can be detected by our eyes. We usually call it light .

#### Explanation:

Electromagnetic waves are a type of wave transmitted in electric and magnetic fields. A spectrum is a range of wavelengths.

The electromagnetic spectrum consists of a wide range of wavelengths, from radio waves hundreds of metres long to gamma rays that are tiny fractions of a metre long (approx. ${10}^{- 12} m$).

As the spectrum is so broad it is considered as a series of different regions (seven in total) that are grouped according to their wavelengths, waves in each region have similar wavelengths. Each region is like a "sub-spectrum". One of those regions is the visible spectrum , or visible light.

All visible light can be detected by our retinas, this is the defining characteristic of this region. The different wavelengths in the spectrum correspond to different colours, red light has the longest wavelength and violet light has the shortest wavelength.