"It seems to boil down to simply forcing too much energy through too small a conduit. Picture a dam with a tiny hole bored through it. The water may trickle through slowly and steadily, but trying to squeeze more water through more swiftly or with greater force will eventually destroy the dam." Nightingale shrugs. "I'm not a medical man - I have a brilliant doctor friend researching the matter much more thoroughly - but that is my understanding, at least."