Where do electromagnetic waves come from?
Electromagnetic waves come from anything that emits electromagnetic radiation. Electromagnetic waves could be anything on the electromagnetic spectrum, eg. visible light, infra-red, gamma rays, x-rays, radio waves etc. Lets look at visible light for example – where does that come from? Look around – light bulbs. When an electric current passes through the filament in a light bulb, it heats up and emits light – which is an electromagnetic wave. What about gamma rays? Gamma rays can come from radioactive substances such as Uranium (which is used in making atomic bombs!). When a nucleus of uranium has too much energy (such as when it undergoes nuclear fission) it has to get rid of it to become more stable and in order to get rid of it, it emits gamma rays! There are many other sources of electromagnetic waves, Infra-red…your toaster! Radio Waves….the radio station transmitter.
