Quantum Physics and the Heisenberg Uncertainty Principle

Part of Quantum Physics For Dummies Cheat Sheet

In quantum physics, you encounter the Heisenberg uncertainty principle, which says that the better you know the position of a particle, the less you know the momentum, and vice versa. In the x direction, for example, that looks like this:


where Dx is the measurement uncertainty in the particle’s x position, Dpx is its measurement uncertainty in its momentum in the x direction, and


This relation holds for all three dimensions: