Quantum Tunneling in Nuclear Fusion

Quantum tunneling in nuclear fusion is a process where atomic particles, like protons, pass through an energy barrier that classical physics says they shouldn’t be able to cross. Normally, protons repel each other due to their positive charges, preventing fusion at low energies. However, quantum mechanics allows these particles to "tunnel" through the barrier if they have a tiny probability of doing so, enabling fusion to occur even when they don’t have enough energy to overcome the repulsion directly. This phenomenon is essential for stars, including our sun, where conditions allow fusion to happen efficiently despite lower temperatures.