(Forbes) It’s the power of quantum mechanics that allows the Sun to shine. If it weren’t for the quantum nature of every particle in the Universe, and the fact that their positions are described by wavefunctions with an inherent quantum uncertainty to their position, this overlap that enables nuclear fusion to occur would never have happened. The Sun is the source of the overwhelming majority of light, heat, and energy on Earth’s surface, and is powered by nuclear fusion.
But without the quantum rules that govern the Universe at a fundamental level, fusion wouldn’t be possible at all. Only 5% of the stars produced get as hot or hotter as our Sun does in its interior. And yet, nuclear fusion happens, the Sun and all the stars emit these tremendous amounts of power, and hydrogen gets converted into helium. The secret is that, at a fundamental level, these atomic nuclei don’t behave as particles alone, but rather as waves, too. Each proton is a quantum particle, containing a probability function that describes its location, enabling the two wavefunctions of interacting particles to overlap ever so slightly, even when the repulsive electric force would otherwise keep them entirely apart.