I'm having a little trouble with my textbook's explanation. This is regarding the energy - time variation of the uncertainty principle; very basic stuff, so I hope helping me out won't take too much. Let me quote exactly: "... the energy conservation can appear to be violated by an amount delta E, as long as it is only for a short time interval, delta t, consistent with the equation (delta E) * (delta t) >= (h / 4 pi )" I understand what is being said - and it makes sense. Otherwise we'd all be noticing these 'violations' of energy conservation. But I don't see how it is 'consistent' with the equation. Why must delta t be small? To me, it seems more 'consistent' with the equation that delta t is large, so that the equation becomes greater than h/4pi. Someone please help clarify. And thanks for your time.