Heisenberg's Uncertainty Principle

In quantum physics, the outcome of even an ideal measurement of a system is not deterministic, but instead is characterized by a probability distribution, and the larger the associated standard deviation is, the more "uncertain" we might say that that characteristic is for the system. The Heisenberg uncertainty principle, or HUP, gives a lower bound on the product of the standard deviations of position and momentum for a system, implying that it is impossible to have a particle that has an arbitrarily well-defined position and momentum simultaneously. More precisely, the product of the standard deviations , where is the reduced Planck constant. The principle generalizes to many other pairs of quantities besides position and momentum (for example, angular momentum about two different axes), and can be derived directly from the axioms of quantum mechanics.
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One of the fundamental consequences of wave-particle duality. It states that it is impossible to know the precise location of a particle and its exact velocity (momentum) simultaneously. The more precisely you know a particle's position, the less precisely you know the details of its motion. Likewise the exact total energy of a particle cannot be known at a precise time.The uncertainty principle, when linked to the quantities of energy and time within a given volume of space, is what states virtual particles can appear and disappear in a time too short to be detected.