Quantum Measurement

Explore how measurement affects quantum systems

The Heisenberg Uncertainty Principle states that position and momentum cannot both be precisely known simultaneously: Δx·Δp ≥ ℏ/2. This is not a measurement limitation but a fundamental property of quantum states. Narrowing a slit (precise position) causes wider diffraction (uncertain momentum). The double-slit experiment shows that measuring which-path information destroys the interference pattern — measurement irreversibly disturbs the quantum state.