All forms of electromagnetic radiation, whether they're called waves or rays, are generated by particles in motion. In a radio signal, for example, negatively charged electrons quickly move back ...

For example, radio waves are transmitted by walls - this explains why these signals can be detected by radios inside a person’s house. However, visible light rays are absorbed by walls ...

Electromagnetic waves travel at 300,000,000 metres per second ... Each group contains a range of frequencies. For example, visible light contains the limited range of frequencies that can be ...

Terahertz electromagnetic waves occupy a middle ground between electronics waves, like microwave and radio waves, and photonics waves, such as infrared and UV waves. For example, mobile phones use ...