The Heisenberg Uncertainty Principle states that the position and the momentum (velocity) of an object cannot be simultaneously measured to any degree of accuracy; accuracy in the measurement of one is lost at the expense of accuracy in the measurement of the other.(16) A homely macroscopic analogy illustrates this principle.
Take a photograph of an object in motion. The length of time the shutter is open (the reciprocal of the shutter speed) can be used in conjunction with the amount of blur in the image to estimate the speed of the object. The longer the shutter is open the longer the blur and the more accurately the speed can be measured. But the longer the blur is, the less accurately one is able to determine the position of the object. Conversely, the sharper the picture is, the more accurate knowledge of the position of the object will be, but the more uncertain knowledge of its velocity will be.