RDT---
Last first again. The "radio laws" are merely an organized observation of the phenomenon, which can be used to communicate about them, and even to attempt to predict new ones. If you are talking to someone who speaks English, then start interweaving other languages, it would likely result in misunderstanding or, at best, confusion.
So if you are talking to someone about electronics, it's best to stick to standard electronics terminology, si?
If someone discovers some new technology, and needs to invent new terminology, then the new terms need to be fully defined to the point of satisfactory comprehension. Otherwise he's speaking a non-language, and how is that going to help him communicate what he wants to say?
If you strike a tuning fork, and place one of a harmonic near it, the second will vibrate at it's own resonant frequency. They will mix, and give you four frequencies until they die out. But if you use a frequency analyser, you will only see the four frequencies. There would be no further harmonics generated, because there is nothing further to resonate, in that frequency range. (I've never heard anything about air, itself, resonating; but it might, at a molecular level or something.
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Since perfection is hard to accomplish, a person could argue that no sine wave is perfect, and therefore there must be some minuscule harmonics generated even with the best of them. But that gets into the "halfwar to the wall" kind of stuff, which is outside the realm of measurement, and thus beyond any applicable practicality.
Sparks, can generate all frequencies, so they can usually be picked up on all receivers. They are not limited to any particular harmonics. For example, what frequency would it be that was generating a multiple of itself? There is no primary frequency, which is required to properly define a harmonic of it. A spark is just "random" conduction across a gap. So is lightning.
And I said it would smooth it out, I just didn't say how much! A tuned circuit is a filter. It only resonates at the frequency it's tuned to. And the idea is usually to design them to resonate in a sine wave form. How much "hash" might get through them is a function of how they are designed and built.
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