\Let's start off by saying that electromagnetic waves actually do not need a medium.
For example let's talk about sound waves? Do you remember the old saying: If a tree fell in the forest and nobody was around does it still make a sound? Well that answer is yes it does still make a three-dimensional pressure wave in the air which IF any human ear was to be placed in that local proximity would be heard and interpreted as a sound. As for electromagnetic waves they have the property that they can travel through a vacuum of space-time. (there are currently some theories which Concurr, that an electric pulse does not create a magnetic field and vis visa. I have not yet fully been able to actually read these theories in any great details, so my opinion should and Does Not hold any weight on this subject.) Yet, something worth mentioning...
As an electromagnetic wave will traverse indefinitely into the far future following light light propagation of space-time events a null geodesic indefinitely into the future there's a part of Maxwell's equations that actually travel indefinitely into the past which we seem not to use.
This happens in physics and in engineering and anyone who needs to use Maxwell's equations, it's kind of like we just throw out half of the equation. this could be vital in future physics what do you think?
Could we use and manipulate Maxwell's equations to possible send signals no matter if its radio waves, OR A MORE LOWER ENERGY-EFFICIENT BLUETOOTH WAVE, or any E.M. wave with any useful information in general?
From my calculations yes this can be achieved very easily. But im still waiting for myself to call me with THE WINNING POWER BALL NUMBERS... IT HASN'T HAPPENED YET!