QUANTUM LEAP: (in physics) “an abrupt transition of a system described by quantum mechanics from one of its discrete states to another, as the fall of an electron in an atom to an orbit of lower energy;” (vernacular) “any sudden and significant change, advance, or increase” —Random House Dictionary
Last month, Lexicide deconstructed “ground zero,” so while we’re in a nuclear state of mind, let’s turn our electron microscopes on quantum leap. When sub-atomic particles change states, the change is sudden and the stages in between state #1 and state #2 are imperceptible. One nanosecond, they’re one place; the next, they’re someplace else. Subatomic particles don’t walk — apparently, they take the transporter. I don’t understand it any better than you (and I’m not talking to you folks over at CalTech or the Large Hadron Collider), but I do understand when eggheads speak of quantum leaps, that’s what they mean.
I also understand that quantum leaps are by definition very, very, very tiny. Yes, they are sudden. Yes, they are significant (and puzzling), but they are rarely colossal in scale. Not so in the vernacular usage. If you speak of a quantum leap in skill, growth or numbers, it must be a dramatic change. I suppose on an atomic level, a change from one state to the next ranks as dramatic. However, the key characteristic of a quantum leap is not scale, but suddenness. More and more I hear phrases like: “In five to ten years, this company will have made a quantum leap in terms of sales.” If it takes ten years, it is not a quantum leap. To sum up: sudden change=quantum leap; sudden and dramatic change=quantum leap; dramatic, yet gradual, change=dramatic change.
So I’m issuing an out-of-character plea: do not subject this handy phrase to a dramatic (but not sudden) shift in meaning. Quantum leap is too cool a term to leave only to PhDs. However, it’s also too useful an analogy to abandon to BS.
— Otto E. Mezzo