How do radio waves differ from visible light?

1 Answer
Apr 27, 2018

The frequencies and wavelengths are different as well as the way you produce the two.


Radio waves like the one you select to listen in your radio have frequencies in the MHz (mega-hertz, #10^6#) region and relatively long wavelengths while light in the visible have higher frequency (#~~10^15Hz#) and smaller wavelengths:


Also, to produce a radio wave you use an antenna that is a piece of conducting wire where you can put the electrons in motion up and down as in a block-spring motion. The electron oscillates up and down and being a charged particle (accelerated in the oscillation) it emits radiation...basically you connect the antenna to a power supply (plus some capacitor and inductor) and through the motion of the electron in the antenna you "transmit" the energy from the power supply into the atmosphere (or vacuum if you like) in form of a radio wave.

Light, and visible light in particular, is a bit more you need an electron inside an atom that on receiving energy "jumps" from an orbital to another and when comes back (it has to!) re-emits the energy it received previously as light. It is again an electron going up and down as in the antenna but a bit more microscopic!

Hope it helps!