Uncertainty & Tunnelling

Limits and loopholes

An interactive lesson with 7 steps, about 6 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Uncertainty principle: $\Delta x\,\Delta p \ge \hbar/2$. It's built into nature, not a measurement flaw.
• Quantum particles can tunnel through barriers they classically couldn’t cross.
• Tunnelling powers the Sun and enables electron microscopes and flash memory.

Steps

1. Pinning down a wave
2. Heisenberg’s uncertainty principle
3. Building a wave packet
4. Narrow slit
5. Tunnelling
6. Confined electron
7. Tunnelling in action