The Sun Wouldn’t Shine Without Quantum Physics
“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 overwhelming majority of today’s stars in the Universe would never have ignited, including our own. Rather than a world and a sky alight with the nuclear fires burning across the cosmos, our Universe would be desolate and frozen, with the vast majority of stars and solar systems unlit by anything other than a cold, rare, distant starlight.
It’s the power of quantum mechanics that allows the Sun to shine. In a fundamental way, if God didn’t play dice with the Universe, we’d never win the Powerball three times in a row. Yet with this randomness, we win all the time, to the continuous tune of hundreds of Yottawatts of power, and here we are.”
In the core of our Sun, where temperatures cross the threshold of 4 million K (and rise all the way up to 15 million K), nuclear fusion occurs, driving the energy output of our Sun. Yet if you looked at what was going on at a particle level, that first step towards fusion is where two protons collide to form a deuteron. Only, there are two immediate problems: a deuteron is made out of a proton and neutron, not two protons, and that the two protons don’t even have enough energy to overcome the electrostatic repulsion between them! Thankfully, the Universe is quantum in nature, meaning weak interactions do occur, changing a quark’s flavor type, and particle positions are defined by quantum wavefunctions, which can overlap.