"Quantum leap" is one of the most misunderstood terms in the modern idiom. People use it to mean an enormous, almost impossible passage from one point to another, and then others complain that, because quantum theory is actually used to describe the universe at the most minuscule scales, a quantum leap is actually a very tiny step. I was one of those people, until yesterday.
I finally finished reading The Elegant Universe by Brian Greene. This marathon explanation of the workings of String Theory took me a few years to digest, mainly because I was mostly reading it in bed–and there is no cure for insomnia like a good dose of supersymmetry!
Despite regularly feeling as though I'd never wrap my brain around the concept of branes, I must have managed to absorb some fundamentals, because it occurred to me in the middle of Chapter 13 that a "quantum leap", like a four-dimensional sphere, bridges both a very short distance and a very large distance, depending on how you look at it. So the idiom as it is widely understood is actually correct, and the pedants (me included) are not wrong, but not completely right either.
Last night when I closed the cover of the book for the last time and turned out the bedside light, I dreamed of Calabi-Yau spaces. Now I've ticked that book off the list of classic texts I must read before I die, I'm not sure what's next: perhaps it's time for me to tackle Marcel Proust at last. Can anyone recommend a good English edition of Swann's Way?