Hi! Been enjoying the show for some time - hopefully, I'll be able to join live, for the first time, for the 400th episode...which should fall on the 18th, a holiday for the US that at least we public servants get paid time off.
I have a question, though: why, on #398, did you guys include sodium vapor lamps, fluorescent lamps, and neon signs in the "emitting" group, but not in the "ionizing" group? All three are ionizing sources, where the light we see is due to very narrow, discrete emission lines characteristic of the elements being excited by the plasma. Fundamentally no different from auroras and streaking meteors, where those natural phenomena get their energy from the kinetic energy of the CME or the meteor, while the artificial sources are jump-started by a few kilovolts of electricity.