Communicating with waves: visible light and infrared

Radio waves, microwaves, visible light and infrared can all be used for communication. You should know some typical examples of these, and associated hazards.

Visible light

Visible light is the light we can see. It allows us to communicate with one another through books, hand signals and video, for example. The use of visible light needs the transmitter and receiver to be in the line of sight. But…