>>/12358/
Whoops, forgot the name field... Old habits die hard, as they say.
 >>/12209/
> I guess I could say that if no one else believed it, why would they tell otherwise? If Rainbow Dash couldn't replicate it, they probably would go ahead and might even decide that themselves regardless of their own eyes. 
Being charitable here as I was with the rock farm: how many ponies actually saw Rainbow Dash directly causing the sonic rainboom, and how many saw just the sonic rainboom? The way the sonic rainboom is framed in every part of the show where it's been brought up so far, it is presented as something a pegasus directly causes, but at least theoretically it could either be something which can also occur as a freak accident of nature or is BELIEVED to sometimes occur as a freak accident of nature (I could possibly see some snooty unicorn scientists proposing this purely out of disdain for theories of earth pony and pegasi magical abilities, at least those beyond the ones that are indisputable (and arguably none of earth pony magic is indisputable!)). So, again being extra charitable and stretching my suspension of disbelief to the limit, MAYBE the spectators and even the bullies were for the most part convinced/convinced themselves that it was all a big coincidence. It's flimsy but that's all I got - if I treat this as a reality that I've been presented with rather than a show that's been artificially constructed, then I'd simply say that there's clear a deficit of information somewhere, that there's some big missing pieces that create, in their absence, this apparent contradiction. That's I guess the second way I could be charitable, simply assuming the world is real in the same way we assume our world is real and going from there. In fairness, there are irl plotholes (such as the incongruities between general relativity and quantum mechanics, or the uncertainty principle)
> My sometimes militaristic mind can't help but think in the ways that this could be weaponized.
It's sort of the question of weaponizing superheroes in a way, since (iirc) only Rainbow Dash is ever able to perform a rainboom. The Super Mario series raises a similar question: are the Toad Guards effectively a ceremonial military (given their perfect track record of failure in even slightly hindering the Koopa armed forces) and the Mario brothers essentially the two-man army of the entire (rather large!) Mushroom Kingdom? There's a couple of exceptions possibly but seemingly Princess Peach's defense policy rests entirely on relying upon two superheroes. Luckily, in spite of Equestria's occasional reliance on the elements of harmony, it never gets quite as silly as aspects of the Mario series do, we can clearly extrapolate that the Equestrian military exists and does effectively deal with some threats even if we see very little of it. 
> I wonder how many other cultural inferences I can make with that though?
We have a bit of a precedent for it from Winter Wrap-Up, where Ponyville traditions bar the use of magic (which I believe I theorized at the time later had an exception added for Pegasi, since weather manipulation seems rather obviously to be Pegasus magic at least to me) - if we just make that principle slightly more extreme, and assume that Ponyville was founded on those principles for a reason, it would make sense to me that Pinkie's family might well be purists of this kind of philosophy. In fact, I could even see this potentially justifying the rock farm: Earth pony magic primarily deals with plants and animals seemingly, so farming rocks could potentially be a way of subsisting without even the use of Earth pony magic, a totally nonmagical way of life. As to what the reasons or rationale for this way of life would be, I have absolutely no idea, and I don't even feel that I have enough of a basis to speculate really.