# The uncertainty principle

The Heisenberg Uncertainty Principle states that a state of system cannot be prepared in which both the position and momentum of a particle can be defined simultaneously to arbitrary accuracy.

$\Delta x \Delta p \ge \frac{\hbar}{2}$

Key Points:

• It is physically impossible to measure simultaneously the exact position and exact momentum of a particle.
• The inescapable uncertainties do not arise from imperfections in practical measuring instruments
• The uncertainties arise from the quantum structure of matter

Back To Quantum Mechanics

Categories H3