||Mon 2015-08-10 13:09|
|Yeah, I was thinking of HPMOR. After some frantic re-googling, there's some more detail on language specifically in http://hpmor.com/chapter/22.|
Specifically, Harry finds some spells which are easy to cast but Hermione doesn't already know (from a joke book), and describes them to her. If he gives her the instructions, but she doesn't know at all what the spell is for, it doesn't work. If he gives her the wrong instructions, nothing happens at all. If he gives her the instructions very slightly distorted, she gets a spell which partly works. If he gives her the instructions correctly, and an inaccurate description of what it does, it works perfectly the way it's supposed to.
What I think is interesting, is that that description is pretty close to how it works in the books. (I don't think the books stick to it perfectly.) But I doubt JKR thought it through like that: that's just how you'd EXPECT magic to work. Enough to predict the outcome, even if it depends on woolly concepts like what someone "expects" to happen. But not enough to formulate a law of physics about it.
(continued in response to main post)