I am generally an "artsy" person, though I am interested in science, too. I am curious about EM waves, particularly how they get started and what determines their amplitude and direction. I've read that an oscillating charge can generate a magnetic field, though I'm a bit confused about what is actually oscillating/fluctuating. For example, if I "shake" an electron, does the amplitude of the resulting EM wave depend upon how far it is displaced from its initial position via the shaking? Do the fluctuations of the E-field vector represent changes in charge? What exactly is periodically increasing and decreasing as per the crests and troughs of the waveform? Is it the charge at a given location? Also, when an EM wave starts, is it like a single ray or more like an infinite number of rays emanating from a sphere? Finally, why does EM field strength diminish with distance from its source, whereas amplitude and frequency of a beam of light do not vary with distance from the source?