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 ...

Electromagnetic waves can be separated into seven distinct groups in the spectrum. Each group contains a range of frequencies. For example, visible light contains all the 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 ...

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 ...