Definitions for "Heisenberg uncertainty principle"
The concept that systems of measurement allow for both position and momentum of a particle to be known only to a certain extent of accuracy; insignificant on larger scales, but very important on scales the size of atoms and smaller.
Principle that states there is a fundamental limit to how precisely both the position and velocity of a particle can be measured at the same time. See also: particle, Advanced Topics
A quantum-mechanical principle with the consequence that the position and momentum of an object cannot be precisely determined. The Heisenberg principle helps determine the size of electron clouds, and hence the size of atoms.