gen-briefly-explain-quantum-tunneling-and-one-common-misconcepti-fcb4

Briefly explain quantum tunneling and one common misconception about it.

# Quantum Tunneling **What it is:** Quantum tunneling occurs when a particle passes through an energy barrier that it classically shouldn't have enough energy to overcome. This happens because quantum particles are described by wave functions that don't abruptly stop at barriers—instead, they decay exponentially into and through the barrier. If the barrier is thin enough, there's a nonzero probability the particle appears on the other side. **Common misconception:** Many people think particles "dig through" or "travel through" barriers like a ball rolling through a tunnel. In reality, tunneling is *instantaneous* in the sense that there's no classical trajectory through the barrier. The particle doesn't have a defined path inside the barrier—quantum mechanics only predicts probabilities of finding it on either side. It's a fundamentally non-classical phenomenon where the particle doesn't physically traverse the barrier in any conventional sense.