text: It was heisenburg.\n\nThe Heisenburg Uncertainly Principle is \n(change in position).(change in momentum) is always greater than half of plancks constant over pi.\n\nThis comes from the quantum phenomenon that you cannot know a particles position and momentum at the same time.  To observe something you have to see it with photons,but when the photons reflect from the particles you are observing they impart a change in momentum and change its position!