No, he's bringing it up because he's never heard of "millihertz". Neither have I. And I'm willing to bet that damn few people here have *ever* heard of it. As discussed above, period is the term used for long-duration waves. (That is, frequencies below 1 Hz) Maybe it's commonplace in the Netherlands? I don't know for sure, but I consider it unlikely. For certain it's not common here though.
I think you have less experience than you give yourself credit for. If you were more experienced, then surely you would have used this term before and been corrected by someone else already. As for this particular incident, I think you were searching for a way to describe your experiment in English, and simply chose the standard unit prefix for 1/1000 without stopping to consider whether this was appropriate or not. And given that English is not your native language, I don't think anyone was terribly bothered by this - at least not at first.
But when you start trying to argue that it is in fact common to express things in terms of "millihertz", *that's* when people begin to take offense, because (at least in our experience) it is absolutely *not* common. So now, instead of it being a simple issue of a language barrier, now you're trying to teach us how to speak our own language. (That usually pisses people off, by the way.) Tocket's statements about how the English measurement system is "dumb" only added fuel to the fire...
Furthermore, your statement that your "message is only meant to be conveyed to those who grasp the concept of mHz at first glance" is considerably insulting. There are many people here who have more than enough experience to "grasp the concept". It is *you* who do not grasp the concept that the term you used is inappropriate when discussing waves of this nature.
In short, we don't need lessons in English from a non-native English speaker. Also, you are not the only one here who knows how to use an oscilloscope. Try to remember that before you talk down to the forums in the future.
Adam
PS: I should point out that despite the controversy over the terms you used, I nonetheless appreciate the time you spent performing the experiment and publishing the results. It's good information to have.