Image: Indeterminacy principle

Description: The Gaussian wave function ψ{\displaystyle \psi } of an initially very localized free particle. The color (white, blue, green) indicates the phase of ψ{\displaystyle \psi }, its intensity indicates |ψ|2/|ψ|2{\displaystyle |\psi |^{2}/|\psi |^{2}}max . |ψ|2{\displaystyle |\psi |^{2}}max is always at the center. The indeterminacy principle is here about the initial state. The position is initially determined with high precision, but the momentum is not. The spreading of the wave packet in all directions shows that the initial momentum is not determined. One way to measure momentum is to measure positions at two different times. This is true both in classical and in quantum mechanics. Knowing the initial position, the dispersion of the second position, given by the wave packet, is also the dispersion of the initial momentum.
Title: Indeterminacy principle
Credit: Own work
Author: Thierry Dugnolle
Usage Terms: Creative Commons Zero, Public Domain Dedication
License: CC0
License Link: http://creativecommons.org/publicdomain/zero/1.0/deed.en
Attribution Required?: No