Some nice discussion above. Adding a little bit, it just occured to me that I have been creating an EM wave with a frequency of 1 day per cycle for the last few years!
My printer has a power supply plugged into a power strip. I turn it off at night and on in the morning. Thus the ouptut of the power supply goes from 0 V to 12 VDC and back once per day. OK, it is a square wave, not a sine wave. But all that means is that there are a lot of harmonics.
That square wave propagates from the power supply to the more-or-less well matched load, the printer, on a coaxial cable.
Now, getting it to radiate at that low frequency would be a problem. I would require a dipole about 1/2 light-day long. That is about 100 times the distance from the earth to the sun. Think I will pass on that challenge.
So, Maxwell's equations work fine at low frequency, and even at zero frequency (electro- and magneto-statics). But Maxwell's eqautions fail spectacularly for...LOW POWER!!!
How can that be? Please feel free to take a guess. When someone asks for the answer I will give it, unless of course someone posts the right answer first. (If you have seen my Maxwell presenation, you know the answer, so please don't post it in that case.)
Hint...the failure gets worse at higher frequencies.