I'm reading an astronomy textbook, and I'm not sure about some things. The textbook says the EM waves are caused by accelerating charges. I don't understand how this is. I'm not sure, but my memory and intuition tells me that only charges moving in a sinuosidal (can never spell it) manner. Also regarding synchrotron emission, since the magnetic field does no work on the charge and the KE of the particle does not decrease, where does the energy in the radiation come from? And one more question. From what exactly does the radiation from a blackbody originate? Thanks.