"Waves" in spherical emission... Hi all, I just thought of this and wondered why it had never occurred to me before. In any source emitting EM radiation (a lightbulb for example), it does so all around it, so a sphere of EM radiation propagates out from the source. However how in the world do we know consider this EM radiation as sinusoidal waves? Wouldn't waves be interfering with eachother, causing a whole mess, and you'd never actually get a nice sinusoidal waveform would you? I hope you see what I'm saying here, cause its confusing the buggery out of me Its almost as if one has to consider the EM field propagating outward in the spherical manner, and the EM wave traveling through it as compressions and rarefractions like sound. One can't really make EM waves analagous to water waves can they, as water wave occur in a 2D plane so to speak...the surface of the water. If you then have a 3D "plane", waves don't travel like this. In fact a 3D "plane" for water would be simply sound underwater, thus does not this seem to support EM radiation being like sound in a sphere expanding at c? Whenever we are shown waves in books etc, its a sinusoidal wave, however how one gets a sinusoidal ray from a sphere of EM, I've got no idea. Photons looks oh so amazingly appealing right now! If anyone could spread some light on this it'd be much appreciated, Kcodon PS just clarifying, do EM waves self propagate, i.e. they aren't ripples in an EM field...they make their own EM field so to speak. Correct or not?