Heisenberg Uncertainty Principle

The Heisenberg Uncertainty Principle is a fundamental states that for any given quantum particle with position <math>x</math> and momentum <math>p</math>, then the product of the standard deviations of the measurements of <math>x</math> and <math>p</math> must be of the order of Planck's constant (<math>\hbar</math>), which is a non-zero, positive-valued, real number.

Mathematically it is represented with this equation: <math>\left(\Delta x \Delta p\geq\frac{\hbar}{2}\right)</math>.

In English, this means - for example - that if we measure the position of the particle perfectly then there has to be a non-zero error in our measurement of momentum (and similarly the reverse) and so we can never know the exact position and momentum of a particle at any instant.