Quote:No, that spell 'kills' golems also... The thing is that spell requires a certain level of HATE to function. Its so powerful, because it requires raw emotion to be put into it. Basically, its a life force/ki component that makes it physically draining as well as mentally draining, as many complicated spells are.
On the other hand, that might be the basis for the Avada Kedavra. A surge of magic without the standard safely limits alters reality for the subject to the point that all biological functions ceace. This might be why it is so dificult to defend against, because it is random in nature and also disrupts whatever you try to use to defend against it.
Most spells aren't more than negligiblely draining if at all... or else first year is impossible... I mean they cast spells in multiple classes for hours each day. Sometimes dozens of times in the same class.
The defense issue is because its a powerful spell... that is illegal to cast. I can't imagine the MoM allowing guys to stand around casting a forbidden spell in order to test defense spells against it. Even in controlled conditions, with the spells on dummies.
And Bob... GOOD scientists wait till they are 80% or more certain before calling it a theory. There was a study that concluded that 70% or more of studies were blatant BS and based on bad science (method wise and logic wise). Of course the study itself could be wrong.