What type of wave does not need a medium to transfer its energy?

1 Answer
Feb 17, 2016

Electrmagnetic waves don't need a material medium to propagate and so they will transfer energy through vacuum.

Explanation:

Electromagnetic waves are ripples in the electromagnetic field that it is not considered as a material medium (in comparison to air, for example, that is a material medium made up of sizeable entities, that is responsible for the propagation of sound) but a kind of a “sea” of possible interactions (basically it is a sea only for charges!).

EM waves are originated, say, in an antenna, they travel through vacuum and are collected by another antenna through an interesting process:

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You "give" energy to the electron in the first antenna and this energy is transferred, through vacuum, to the electron in the second antenna that, because of this energy, starts to move up and down as well!!!!

If you want you can check the idea behind the Poynting Vector representing the density flux of the energy carried by the EM wave.