Visible light

Visible light

1. Description

   • This is the small part of the electromagnetic spectrum that is detectable by the human eye.
   • All objects with enough heat to glow emit light waves. The sun is the main source of light.
   • White light is made up of a mixture of colours. This spectrum of colours making up white light can be viewed when light is dispersed such as in a rainbow. The colours, in order are red, orange, yellow, green, blue, indigo and violet.

2. Uses

   • Optical fibres are made from very pure glass and allow light waves carrying information to travel through them using the principle of total internal reflection.
   • Light waves are therefore used to carry vast amount of information at high speeds through optical fibre systems making the extremely important in the field of communications.
   • Lighthouses use light to communicate the potential hazards along a stretch of coastline. Morse code between ships during radio silence can be achieved using a flash light.