Why does nuclear fusion require extremely high temperatures despite nuclei being positively charged?

💡 The Answer

• Atomic nuclei repel each other due to their positive charges, creating the Coulomb barrier.
• Fusion requires overcoming this barrier by combining high kinetic energy and quantum tunneling.
• Temperatures in the millions of Kelvin provide the necessary kinetic energy.
• In stars, gravity provides confinement; on Earth, magnetic or inertial confinement is used.